From 050d51ba63309ec2d9e34a0790dbbfe40d194dc1 Mon Sep 17 00:00:00 2001
From: Kaz Wesley <kaz@lambdaverse.org>
Date: Thu, 9 Feb 2023 19:33:44 +0000
Subject: [PATCH 01/16] eager shader compilation

---
 lib/rust/ensogl/core/src/display/scene.rs     |  12 +-
 .../src/display/shape/primitive/system.rs     |   2 +-
 .../core/src/display/symbol/gpu/shader.rs     |   4 +-
 lib/rust/ensogl/core/src/display/world.rs     |  20 ++-
 .../core/src/system/gpu/shader/compiler.rs    | 122 ++++++++++--------
 5 files changed, 97 insertions(+), 63 deletions(-)

diff --git a/lib/rust/ensogl/core/src/display/scene.rs b/lib/rust/ensogl/core/src/display/scene.rs
index 91cf84d9a8af..c8d543d8e96f 100644
--- a/lib/rust/ensogl/core/src/display/scene.rs
+++ b/lib/rust/ensogl/core/src/display/scene.rs
@@ -719,6 +719,7 @@ pub struct SceneData {
     display_mode: Rc<Cell<glsl::codes::DisplayModes>>,
     extensions: Extensions,
     disable_context_menu: Rc<EventListenerHandle>,
+    persistent_shaders: Rc<Vec<shader::Code>>,
 }
 
 impl SceneData {
@@ -727,6 +728,7 @@ impl SceneData {
         stats: &Stats,
         on_mut: OnMut,
         display_mode: &Rc<Cell<glsl::codes::DisplayModes>>,
+        persistent_shaders: Vec<shader::Code>,
     ) -> Self {
         debug!("Initializing.");
         let display_mode = display_mode.clone_ref();
@@ -766,6 +768,7 @@ impl SceneData {
         let context_lost_handler = default();
         let pointer_position_changed = default();
         let shader_compiler = default();
+        let persistent_shaders = Rc::new(persistent_shaders);
         Self {
             display_object,
             display_mode,
@@ -791,6 +794,7 @@ impl SceneData {
             shader_compiler,
             extensions,
             disable_context_menu,
+            persistent_shaders,
         }
         .init()
     }
@@ -808,6 +812,11 @@ impl SceneData {
         *self.context.borrow_mut() = context.cloned();
         self.dirty.shape.set();
         self.renderer.set_context(context);
+        if let Some(context) = context {
+            for code in self.persistent_shaders.iter().cloned() {
+                context.shader_compiler.submit_background_job(code);
+            }
+        }
     }
 
     pub fn shape(&self) -> &frp::Sampler<Shape> {
@@ -1018,8 +1027,9 @@ impl Scene {
         stats: &Stats,
         on_mut: OnMut,
         display_mode: &Rc<Cell<glsl::codes::DisplayModes>>,
+        persistent_shaders: Vec<shader::Code>,
     ) -> Self {
-        let no_mut_access = SceneData::new(stats, on_mut, display_mode);
+        let no_mut_access = SceneData::new(stats, on_mut, display_mode, persistent_shaders);
         let this = Self { no_mut_access };
         this
     }
diff --git a/lib/rust/ensogl/core/src/display/shape/primitive/system.rs b/lib/rust/ensogl/core/src/display/shape/primitive/system.rs
index 47205d84f0a7..f189a397a012 100644
--- a/lib/rust/ensogl/core/src/display/shape/primitive/system.rs
+++ b/lib/rust/ensogl/core/src/display/shape/primitive/system.rs
@@ -445,7 +445,7 @@ impl ShapeSystemModel {
         if let Some(shader) = crate::display::world::PRECOMPILED_SHADERS
             .with_borrow(|map| map.get(*self.definition_path).cloned())
         {
-            let code = crate::display::shader::builder::CodeTemplate::new("", shader.fragment, "");
+            let code = crate::display::shader::builder::CodeTemplate::new("", &shader.fragment, "");
             self.material.borrow_mut().set_code(code);
         } else {
             if !display::world::with_context(|t| t.run_mode.get().is_shader_extraction()) {
diff --git a/lib/rust/ensogl/core/src/display/symbol/gpu/shader.rs b/lib/rust/ensogl/core/src/display/symbol/gpu/shader.rs
index 04440ceb97c8..676e2c565933 100644
--- a/lib/rust/ensogl/core/src/display/symbol/gpu/shader.rs
+++ b/lib/rust/ensogl/core/src/display/symbol/gpu/shader.rs
@@ -62,7 +62,7 @@ pub struct ShaderData {
     geometry_material   : Material,
     surface_material    : Material,
     program             : Rc<RefCell<Option<shader::Program>>>,
-    shader_compiler_job : Option<shader_compiler::JobHandler>,
+    shader_compiler_job : Option<shader_compiler::JobHandle>,
     dirty               : Dirty,
     stats               : Stats,
     profiler            : Option<profiler::Debug>,
@@ -196,7 +196,7 @@ impl {
     }
 
     fn cancel_previous_shader_compiler_job_and_use_new_one
-    (&mut self, handler: shader_compiler::JobHandler) {
+    (&mut self, handler: shader_compiler::JobHandle) {
         // Dropping the previous handler.
         self.shader_compiler_job = Some(handler);
     }
diff --git a/lib/rust/ensogl/core/src/display/world.rs b/lib/rust/ensogl/core/src/display/world.rs
index ffd097946a64..89532ff14e76 100644
--- a/lib/rust/ensogl/core/src/display/world.rs
+++ b/lib/rust/ensogl/core/src/display/world.rs
@@ -116,12 +116,9 @@ thread_local! {
 
 /// A precompiled shader definition. It contains the main function body for the vertex and fragment
 /// shaders.
-#[derive(Clone, Debug)]
+#[derive(Clone, Debug, Deref)]
 #[allow(missing_docs)]
-pub struct PrecompiledShader {
-    pub vertex:   String,
-    pub fragment: String,
-}
+pub struct PrecompiledShader(shader::Code);
 
 thread_local! {
     /// List of all precompiled shaders. They are registered here before main entry point is run by
@@ -168,7 +165,7 @@ fn extract_shaders_from_js(value: JsValue) -> Result<(), JsValue> {
         let fragment_field = web::Reflect::get(&value, &"fragment".into())?;
         let vertex: String = vertex_field.dyn_into::<web::JsString>()?.into();
         let fragment: String = fragment_field.dyn_into::<web::JsString>()?.into();
-        let precompiled_shader = PrecompiledShader { vertex, fragment };
+        let precompiled_shader = PrecompiledShader(shader::Code { vertex, fragment });
         debug!("Registering precompiled shaders for '{key}'.");
         PRECOMPILED_SHADERS.with_borrow_mut(move |map| {
             map.insert(key, precompiled_shader);
@@ -192,6 +189,13 @@ fn gather_shaders() -> HashMap<&'static str, shader::Code> {
     map
 }
 
+/// Returns the source code for shaders that should be compiled as soon as a context is available.
+fn get_persistent_shaders() -> Vec<shader::Code> {
+    PRECOMPILED_SHADERS.with_borrow(|shaders| {
+        shaders.values().cloned().map(|PrecompiledShader(shader)| shader).collect()
+    })
+}
+
 
 
 // ================
@@ -272,6 +276,7 @@ impl<'t> From<&'t World> for &'t Scene {
 }
 
 
+
 // ===========
 // === FRP ===
 // ===========
@@ -283,6 +288,7 @@ crate::define_endpoints_2! {
 }
 
 
+
 // =========================
 // === WorldDataWithLoop ===
 // =========================
@@ -411,7 +417,7 @@ impl WorldData {
         let scene_dirty = dirty::SharedBool::new(());
         let on_change = f!(scene_dirty.set());
         let display_mode = Rc::<Cell<glsl::codes::DisplayModes>>::default();
-        let default_scene = Scene::new(&stats, on_change, &display_mode);
+        let default_scene = Scene::new(&stats, on_change, &display_mode, get_persistent_shaders());
         let uniforms = Uniforms::new(&default_scene.variables);
         let debug_hotkeys_handle = default();
         let garbage_collector = default();
diff --git a/lib/rust/ensogl/core/src/system/gpu/shader/compiler.rs b/lib/rust/ensogl/core/src/system/gpu/shader/compiler.rs
index acc0c6cd36d2..e104c98b480f 100644
--- a/lib/rust/ensogl/core/src/system/gpu/shader/compiler.rs
+++ b/lib/rust/ensogl/core/src/system/gpu/shader/compiler.rs
@@ -76,16 +76,17 @@ const MAX_PARALLEL_COMPILE_JOBS: usize = 2;
 // ===========
 
 /// Compiler job. After the job is created it can be either transformed to another job, or, in case
-/// that was the final job, the [`handler`] callback will be called. See the documentation of the
+/// that was the final job, the [`on_ready`] callback will be called. See the documentation of the
 /// [`Compiler`] to learn more.
 #[derive(Derivative, Deref)]
 #[derivative(Debug)]
 pub struct Job<T> {
     #[derivative(Debug = "ignore")]
-    on_ready:  Box<dyn FnOnce(shader::Program)>,
+    on_ready:  Option<Box<dyn FnOnce(shader::Program)>>,
     #[deref]
     input:     T,
-    handler:   WeakJobHandler,
+    /// A cancellation handle. If none is present, the job cannot be cancelled.
+    handle:    Option<WeakJobHandle>,
     /// A key used to cache the compiled program that this job is making progress on. When the job
     /// is finished or failed, the program or failure status is stored in the cache under this key.
     cache_key: ShaderCacheKey,
@@ -95,42 +96,50 @@ pub struct Job<T> {
 impl<T> Job<T> {
     fn map_input<S>(self, f: impl FnOnce(T) -> S) -> Job<S> {
         let on_ready = self.on_ready;
-        let handler = self.handler;
+        let handle = self.handle;
         let input = f(self.input);
         let profiler = self.profiler;
         let cache_key = self.cache_key;
-        Job { on_ready, input, handler, profiler, cache_key }
+        Job { on_ready, input, handle, profiler, cache_key }
+    }
+
+    /// Return whether the job has been cancelled (by its handle being dropped).
+    fn is_cancelled(&self) -> bool {
+        match self.handle.as_ref() {
+            Some(handle) if !handle.exists() => true,
+            _ => false,
+        }
     }
 }
 
-/// A handler to a job. After the handler is dropped, the job is invalidated and will no longer be
+/// A handle to a job. After the handle is dropped, the job is invalidated and will no longer be
 /// scheduled for evaluation.
 #[derive(Debug, Clone, CloneRef)]
-pub struct JobHandler {
+pub struct JobHandle {
     rc: Rc<()>,
 }
 
-/// A weak version of [`JobHandler`].
+/// A weak version of [`JobHandle`].
 #[derive(Debug, Clone, CloneRef)]
-pub struct WeakJobHandler {
+pub struct WeakJobHandle {
     weak: Weak<()>,
 }
 
-impl JobHandler {
+impl JobHandle {
     /// Constructor.
     fn new() -> Self {
         Self { rc: default() }
     }
 
-    /// Get weak reference to this handler.
-    pub fn downgrade(&self) -> WeakJobHandler {
+    /// Get weak reference to this handle.
+    pub fn downgrade(&self) -> WeakJobHandle {
         let weak = Rc::downgrade(&self.rc);
-        WeakJobHandler { weak }
+        WeakJobHandle { weak }
     }
 }
 
-impl WeakJobHandler {
-    /// Check whether the handler was dropped.
+impl WeakJobHandle {
+    /// Check whether the handle was dropped.
     pub fn exists(&self) -> bool {
         self.weak.strong_count() > 0
     }
@@ -182,7 +191,7 @@ pub struct Jobs {
 
 /// Compiles and links GL shader programs, asynchronously. The compiler works in the following way:
 /// 1. A new shader code is submitted with the [`submit`] method. A new job is created in the
-///    [`Jobs::compile`] queue and the job handler is returned to the user.
+///    [`Jobs::compile`] queue and the job handle is returned to the user.
 ///
 /// 2. The following pseudo-algorithm is performed:
 /// ```text
@@ -222,14 +231,25 @@ impl Compiler {
         Self { cell: RefCell::new(CompilerData::new(context)) }
     }
 
-    /// Submit shader for compilation.
+    /// Submit shader for compilation. The job will be cancelled if the returned handle is dropped.
+    #[must_use]
     pub fn submit<F: 'static + Fn(shader::Program)>(
         &self,
         input: shader::Code,
         profiler: profiler::Debug,
         on_ready: F,
-    ) -> JobHandler {
-        self.cell.borrow_mut().submit(input, profiler, on_ready)
+    ) -> JobHandle {
+        let strong_handle = JobHandle::new();
+        let handle = strong_handle.downgrade();
+        let on_ready = Box::new(on_ready);
+        self.cell.borrow_mut().submit(input, profiler, Some(on_ready), Some(handle));
+        strong_handle
+    }
+
+    /// Submit a shader for compilation, without awaiting its completion.
+    pub fn submit_background_job(&self, input: shader::Code) {
+        let profiler = profiler::create_debug!("submit_background_job");
+        self.cell.borrow_mut().submit(input, profiler, None, None);
     }
 
     /// Returns `true` if the compiler has no jobs in progress or queued.
@@ -258,15 +278,13 @@ impl CompilerData {
         Self { dirty, context, jobs, cache, performance }
     }
 
-    fn submit<F: 'static + FnOnce(shader::Program)>(
+    fn submit(
         &mut self,
         input: shader::Code,
         profiler: profiler::Debug,
-        on_ready: F,
-    ) -> JobHandler {
-        let strong_handler = JobHandler::new();
-        let handler = strong_handler.downgrade();
-        let on_ready = Box::new(on_ready);
+        on_ready: Option<Box<dyn FnOnce(shader::Program)>>,
+        handle: Option<WeakJobHandle>,
+    ) {
         let cache_key = ShaderCache::code_key(&input);
 
         match self.cache.get_program(cache_key) {
@@ -274,7 +292,7 @@ impl CompilerData {
                 debug!("Awaiting shader compilation {cache_key:?}.");
                 // This shader is currently being processed by another job. Create a new job that
                 // will wait for that job to finish.
-                let job = Job { input: (), handler, on_ready, profiler, cache_key };
+                let job = Job { input: (), handle, on_ready, profiler, cache_key };
                 self.cache.add_to_waiting_list(job);
                 self.dirty = true;
             }
@@ -283,7 +301,7 @@ impl CompilerData {
                 // This shader has been successfully compiled in the past. Spawn a cache lookup job,
                 // so that `on_ready` callback is will be called from within the job runner during
                 // next processing round.
-                let job = Job { input: (), handler, on_ready, profiler, cache_key };
+                let job = Job { input: (), handle, on_ready, profiler, cache_key };
                 self.jobs.read_cache.push(job);
                 self.dirty = true;
             }
@@ -297,13 +315,11 @@ impl CompilerData {
             None => {
                 debug!("Submitting shader for compilation {cache_key:?}.");
                 self.cache.program_submitted(cache_key);
-                let job = Job { input, handler, on_ready, profiler, cache_key };
+                let job = Job { input, handle, on_ready, profiler, cache_key };
                 self.jobs.compile.push(job);
                 self.dirty = true;
             }
         };
-
-        strong_handler
     }
 
     #[profile(Debug)]
@@ -416,10 +432,10 @@ impl CompilerData {
             })?;
             profiler.pause();
             let input = shader::Sources { vertex, fragment };
-            let handler = job.handler;
+            let handle = job.handle;
             let on_ready = job.on_ready;
             let cache_key = job.cache_key;
-            let link_job = Job { input, handler, on_ready, profiler, cache_key };
+            let link_job = Job { input, handle, on_ready, profiler, cache_key };
             this.jobs.link.push(link_job);
             Ok(())
         })
@@ -437,17 +453,17 @@ impl CompilerData {
             this.context.link_program(&program);
             profiler.pause();
             let input = shader::Program::new(shader, program);
-            let handler = job.handler;
+            let handle = job.handle;
             let on_ready = job.on_ready;
             let cache_key = job.cache_key;
             match this.context.extensions.khr_parallel_shader_compile {
                 Some(khr) => {
                     let input = KhrProgram { khr, program: input };
-                    let job = Job { input, handler, cache_key, on_ready, profiler };
+                    let job = Job { input, handle, cache_key, on_ready, profiler };
                     this.jobs.khr_completion_check.push(job)
                 }
                 None => {
-                    let job = Job { input, handler, cache_key, on_ready, profiler };
+                    let job = Job { input, handle, cache_key, on_ready, profiler };
                     this.jobs.link_check.push(job)
                 }
             }
@@ -479,7 +495,9 @@ impl CompilerData {
             // processed. `Validated` is the only expected cache entry state at this point.
             match this.cache.get_program(job.cache_key) {
                 Some(ProgramCacheEntry::Validated(program)) => {
-                    (job.on_ready)(program.clone());
+                    if let Some(on_ready) = job.on_ready {
+                        (on_ready)(program.clone());
+                    }
                     Ok(())
                 }
                 _ => panic!("Shader cache read was submitted for non-completed entry."),
@@ -497,17 +515,17 @@ impl CompilerData {
         while let Some(mut job) = jobs(self).pop() {
             let cache_key = job.cache_key;
 
-            if !job.handler.exists() {
+            if job.is_cancelled() {
                 // A compilation job has been cancelled, but there still might be other jobs waiting
                 // for it to complete and write data to the cache. Take one of those waiting jobs
                 // and resume the compilation process with its callback.
                 if let Some(waiting_job) = self.cache.take_next_waiting_job(cache_key) {
-                    job.handler = waiting_job.handler;
+                    job.handle = waiting_job.handle;
                     job.on_ready = waiting_job.on_ready;
                 } else {
                     // No waiting jobs, cancel the compilation process.
                     self.cache.program_canceled(cache_key);
-                    trace!("Job handler dropped, skipping.");
+                    trace!("Job handle dropped, skipping.");
                     continue;
                 }
             }
@@ -581,16 +599,12 @@ impl ShaderCache {
     /// cancelled will be removed from the waiting list to avoid processing them in the future.
     fn take_next_waiting_job(&mut self, key: ShaderCacheKey) -> Option<Job<()>> {
         let jobs = self.waiting_jobs.get_mut(&key)?;
-        if let Some(first_active) = jobs.iter().position(|job| job.handler.exists()) {
-            // Remove all leading cancelled jobs from the list and take the active in single pass.
-            // This ensures the minimum number of necessary memory moves and preserves the order of
-            // submitted jobs.
-            jobs.drain(0..=first_active).next_back()
-        } else {
-            // All jobs in the waiting list were cancelled.
-            self.waiting_jobs.clear();
-            None
+        while let Some(job) = jobs.pop() {
+            if !job.is_cancelled() {
+                return Some(job);
+            }
         }
+        None
     }
 
     fn program_submitted(&mut self, key: ShaderCacheKey) {
@@ -611,7 +625,7 @@ impl ShaderCache {
         &mut self,
         key: ShaderCacheKey,
         program: shader::Program,
-        on_ready: impl FnOnce(shader::Program),
+        on_ready: Option<impl FnOnce(shader::Program)>,
     ) {
         self.programs.insert(key, ProgramCacheEntry::Validated(program.clone()));
 
@@ -619,11 +633,15 @@ impl ShaderCache {
         // entry is updated, in case the job callback schedules another compilation of the same
         // shader program. We want those submissions to recognize cache status as validated and
         // dispatch a read from cache.
-        on_ready(program.clone());
+        if let Some(on_ready) = on_ready {
+            on_ready(program.clone());
+        }
         if let Some(jobs) = self.waiting_jobs.remove(&key) {
             for job in jobs {
-                if job.handler.exists() {
-                    (job.on_ready)(program.clone());
+                if !job.is_cancelled() {
+                    if let Some(on_ready) = job.on_ready {
+                        (on_ready)(program.clone());
+                    }
                 }
             }
         }

From 04b0164a63fa3d2e68559fc242650e29d3b7d23f Mon Sep 17 00:00:00 2001
From: Kaz Wesley <kaz@lambdaverse.org>
Date: Fri, 10 Feb 2023 01:39:34 +0000
Subject: [PATCH 02/16] support compiling unpaired shaders

---
 lib/rust/ensogl/core/src/display/scene.rs     |   6 +-
 .../src/display/shape/primitive/system.rs     |   2 +-
 .../core/src/system/gpu/context/extension.rs  |  14 +-
 lib/rust/ensogl/core/src/system/gpu/shader.rs |  30 +-
 .../core/src/system/gpu/shader/compiler.rs    | 271 +++++++++++-------
 5 files changed, 221 insertions(+), 102 deletions(-)

diff --git a/lib/rust/ensogl/core/src/display/scene.rs b/lib/rust/ensogl/core/src/display/scene.rs
index c8d543d8e96f..c236178f8595 100644
--- a/lib/rust/ensogl/core/src/display/scene.rs
+++ b/lib/rust/ensogl/core/src/display/scene.rs
@@ -813,7 +813,11 @@ impl SceneData {
         self.dirty.shape.set();
         self.renderer.set_context(context);
         if let Some(context) = context {
-            for code in self.persistent_shaders.iter().cloned() {
+            for code in self.persistent_shaders.iter() {
+                let code = shader::Sources {
+                    fragment: Some(code.fragment.clone()),
+                    vertex: None,
+                };
                 context.shader_compiler.submit_background_job(code);
             }
         }
diff --git a/lib/rust/ensogl/core/src/display/shape/primitive/system.rs b/lib/rust/ensogl/core/src/display/shape/primitive/system.rs
index f189a397a012..6b3f79a781a6 100644
--- a/lib/rust/ensogl/core/src/display/shape/primitive/system.rs
+++ b/lib/rust/ensogl/core/src/display/shape/primitive/system.rs
@@ -445,7 +445,7 @@ impl ShapeSystemModel {
         if let Some(shader) = crate::display::world::PRECOMPILED_SHADERS
             .with_borrow(|map| map.get(*self.definition_path).cloned())
         {
-            let code = crate::display::shader::builder::CodeTemplate::new("", &shader.fragment, "");
+            let code = crate::display::shader::builder::CodeTemplate::from_main(&shader.fragment);
             self.material.borrow_mut().set_code(code);
         } else {
             if !display::world::with_context(|t| t.run_mode.get().is_shader_extraction()) {
diff --git a/lib/rust/ensogl/core/src/system/gpu/context/extension.rs b/lib/rust/ensogl/core/src/system/gpu/context/extension.rs
index 99afed4981c7..35a3f9ed75e3 100644
--- a/lib/rust/ensogl/core/src/system/gpu/context/extension.rs
+++ b/lib/rust/ensogl/core/src/system/gpu/context/extension.rs
@@ -4,7 +4,7 @@ use crate::prelude::*;
 
 use crate::system::gpu::data::GlEnum;
 
-use web_sys::WebGl2RenderingContext;
+use web_sys::{WebGl2RenderingContext, WebGlShader};
 use web_sys::WebGlProgram;
 
 
@@ -68,11 +68,21 @@ impl KhrParallelShaderCompile {
 
     /// Asynchronously check if the job is ready. Returns [`None`] if it was impossible to get this
     /// information. This can happen during context loss or driver failure.
-    pub fn is_ready(
+    pub fn is_program_ready(
         &self,
         context: &WebGl2RenderingContext,
         program: &WebGlProgram,
     ) -> Option<bool> {
         context.get_program_parameter(program, *self.completion_status_khr).as_bool()
     }
+
+    /// Asynchronously check if the job is ready. Returns [`None`] if it was impossible to get this
+    /// information. This can happen during context loss or driver failure.
+    pub fn is_shader_ready(
+        &self,
+        context: &WebGl2RenderingContext,
+        program: &WebGlShader,
+    ) -> Option<bool> {
+        context.get_shader_parameter(program, *self.completion_status_khr).as_bool()
+    }
 }
diff --git a/lib/rust/ensogl/core/src/system/gpu/shader.rs b/lib/rust/ensogl/core/src/system/gpu/shader.rs
index 76a937702c17..357a3e1f8290 100644
--- a/lib/rust/ensogl/core/src/system/gpu/shader.rs
+++ b/lib/rust/ensogl/core/src/system/gpu/shader.rs
@@ -60,7 +60,7 @@ impl ToGlEnum for Type {
 
 /// Abstractions for shader sources (vertex and fragment one).
 #[allow(missing_docs)]
-#[derive(Clone, Copy, Debug, Eq, PartialEq)]
+#[derive(Clone, Copy, Debug, Eq, PartialEq, Hash)]
 pub struct Sources<Vertex, Fragment> {
     pub vertex:   Vertex,
     pub fragment: Fragment,
@@ -72,6 +72,34 @@ pub type Code = Sources<String, String>;
 /// Shader sources as compiled shaders that are not linked yet.
 pub type CompiledCode = Sources<Shader<Vertex>, Shader<Fragment>>;
 
+impl<V, F> Sources<V, F> {
+    /// Apply a [`Into::into`] to the [`vertex`] and [`fragment`] elements and return the result.
+    pub fn into<V1, F1>(self) -> Sources<V1, F1> where V: Into<V1>, F: Into<F1> {
+        let Sources { vertex, fragment } = self;
+        let vertex = vertex.into();
+        let fragment = fragment.into();
+        Sources { vertex, fragment }
+    }
+
+    /// Return references to the [`vertex`] and [`fragment`] elements.
+    pub fn as_ref(&self) -> Sources<&V, &F> {
+        let Sources { vertex, fragment } = self;
+        let vertex = &vertex;
+        let fragment = &fragment;
+        Sources { vertex, fragment }
+    }
+}
+
+impl<VF> Sources<VF, VF> {
+    /// Apply a function to the [`vertex`] and [`fragment`] elements and return the result.
+    pub fn map<VF1, F>(self, f: F) -> Sources<VF1, VF1> where F: Fn(VF) -> VF1 {
+        let Sources { vertex, fragment } = self;
+        let vertex = f(vertex);
+        let fragment = f(fragment);
+        Sources { vertex, fragment }
+    }
+}
+
 
 
 // ==============
diff --git a/lib/rust/ensogl/core/src/system/gpu/shader/compiler.rs b/lib/rust/ensogl/core/src/system/gpu/shader/compiler.rs
index e104c98b480f..fde5906f6faf 100644
--- a/lib/rust/ensogl/core/src/system/gpu/shader/compiler.rs
+++ b/lib/rust/ensogl/core/src/system/gpu/shader/compiler.rs
@@ -67,7 +67,8 @@ const FRAME_TIME_THRESHOLD: Duration = (1000.0 / FPS_THRESHOLD).ms();
 /// a crude form of backpressure by blocking until all pending jobs complete. We are not sure if it
 /// is a feature or a bug. To learn more about our findings so far, see:
 /// https://github.com/enso-org/enso/pull/3378#issuecomment-1090958946
-const MAX_PARALLEL_COMPILE_JOBS: usize = 2;
+//const MAX_PARALLEL_COMPILE_JOBS: usize = 2;
+const MAX_PARALLEL_COMPILE_JOBS: usize = 1000;
 
 
 
@@ -147,16 +148,16 @@ impl WeakJobHandle {
 
 
 
-// ==================
-// === KhrProgram ===
-// ==================
+// ===============
+// === WithKhr ===
+// ===============
 
 /// A program together with the [`KhrParallelShaderCompile`] extension. Used as one of the
 /// [`Compiler`] jobs to provide nice API.
 #[derive(Debug)]
-struct KhrProgram {
+struct WithKhr<T> {
     khr:     KhrParallelShaderCompile,
-    program: shader::Program,
+    program: T,
 }
 
 
@@ -182,11 +183,12 @@ pub enum Progress {
 /// Compiler job queues. See the documentation of [`Compiler`] to learn more.
 #[derive(Debug, Default)]
 pub struct Jobs {
-    compile:              Vec<Job<shader::Code>>,
-    link:                 Vec<Job<shader::CompiledCode>>,
-    read_cache:           Vec<Job<()>>,
-    khr_completion_check: Vec<Job<KhrProgram>>,
-    link_check:           Vec<Job<shader::Program>>,
+    compile:       Vec<Job<shader::Sources<Option<String>, Option<String>>>>,
+    compile_poll:  Vec<Job<WithKhr<web_sys::WebGlShader>>>,
+    compile_check: Vec<Job<web_sys::WebGlShader>>,
+    link:          Vec<Job<shader::CompiledCode>>,
+    link_poll:     Vec<Job<WithKhr<shader::Program>>>,
+    link_check:    Vec<Job<shader::Program>>,
 }
 
 /// Compiles and links GL shader programs, asynchronously. The compiler works in the following way:
@@ -223,6 +225,7 @@ struct CompilerData {
     jobs:        Jobs,
     cache:       ShaderCache,
     performance: web::Performance,
+    callbacks:   Vec<DeferredCallback>,
 }
 
 impl Compiler {
@@ -233,7 +236,7 @@ impl Compiler {
 
     /// Submit shader for compilation. The job will be cancelled if the returned handle is dropped.
     #[must_use]
-    pub fn submit<F: 'static + Fn(shader::Program)>(
+    pub fn submit<F: 'static + FnOnce(shader::Program)>(
         &self,
         input: shader::Code,
         profiler: profiler::Debug,
@@ -241,13 +244,13 @@ impl Compiler {
     ) -> JobHandle {
         let strong_handle = JobHandle::new();
         let handle = strong_handle.downgrade();
-        let on_ready = Box::new(on_ready);
-        self.cell.borrow_mut().submit(input, profiler, Some(on_ready), Some(handle));
+        let on_ready: Box<dyn FnOnce(shader::Program)> = Box::new(on_ready);
+        self.cell.borrow_mut().submit(input.into(), profiler, on_ready.into(), handle.into());
         strong_handle
     }
 
     /// Submit a shader for compilation, without awaiting its completion.
-    pub fn submit_background_job(&self, input: shader::Code) {
+    pub fn submit_background_job(&self, input: shader::Sources<Option<String>, Option<String>>) {
         let profiler = profiler::create_debug!("submit_background_job");
         self.cell.borrow_mut().submit(input, profiler, None, None);
     }
@@ -275,18 +278,18 @@ impl CompilerData {
         let jobs = default();
         let cache = default();
         let performance = web::window.performance_or_panic();
-        Self { dirty, context, jobs, cache, performance }
+        let callbacks = default();
+        Self { dirty, context, jobs, cache, performance, callbacks }
     }
 
     fn submit(
         &mut self,
-        input: shader::Code,
+        input: shader::Sources<Option<String>, Option<String>>,
         profiler: profiler::Debug,
         on_ready: Option<Box<dyn FnOnce(shader::Program)>>,
         handle: Option<WeakJobHandle>,
     ) {
         let cache_key = ShaderCache::code_key(&input);
-
         match self.cache.get_program(cache_key) {
             Some(ProgramCacheEntry::Submitted) => {
                 debug!("Awaiting shader compilation {cache_key:?}.");
@@ -296,17 +299,17 @@ impl CompilerData {
                 self.cache.add_to_waiting_list(job);
                 self.dirty = true;
             }
-            Some(ProgramCacheEntry::Validated(_)) => {
+            Some(ProgramCacheEntry::Validated(program)) => {
                 debug!("Reusing cached shader {cache_key:?}.");
-                // This shader has been successfully compiled in the past. Spawn a cache lookup job,
-                // so that `on_ready` callback is will be called from within the job runner during
-                // next processing round.
-                let job = Job { input: (), handle, on_ready, profiler, cache_key };
-                self.jobs.read_cache.push(job);
-                self.dirty = true;
+                // This shader has been successfully compiled in the past. Queue the `on_ready`
+                // callback to be called from within the job runner during next processing round.
+                if let Some(callback) = on_ready {
+                    let program = program.clone();
+                    self.callbacks.push(DeferredCallback { callback, program })
+                }
             }
             Some(ProgramCacheEntry::Failed) => {
-                debug!("Submitted a shader that previously failed to compile {cache_key:?}.");
+                warn!("Submitted a shader that previously failed to compile {cache_key:?}.");
                 // This shader failed to compile in the past. Don't spawn any job, as the `on_ready`
                 // callback is never supposed to be called anyway when the compilation fails.
 
@@ -325,7 +328,9 @@ impl CompilerData {
     #[profile(Debug)]
     fn run(&mut self, time: animation::TimeInfo) -> bool {
         let mut any_new_shaders_ready = false;
-        self.run_khr_completion_check_jobs();
+        any_new_shaders_ready = self.run_callbacks() || any_new_shaders_ready;
+        self.poll_shaders_ready();
+        self.poll_programs_ready();
         while self.dirty {
             match self.run_step() {
                 Ok(progress) => {
@@ -356,8 +361,7 @@ impl CompilerData {
     }
 
     /// Runs the next compiler job if there is any left and if it will not cause too many jobs being
-    /// run in parallel. The result [`bool`] indicates if the call to this function did any
-    /// progress.
+    /// run in parallel. The result indicates if the call to this function made any progress.
     fn run_step(&mut self) -> Result<Option<Progress>, Error> {
         let ok_progress = |_| Ok(Some(Progress::StepProgress));
         let no_progress = Ok(None);
@@ -370,10 +374,7 @@ impl CompilerData {
                 self.run_next_link_check_job()?;
                 Ok(Some(Progress::NewShaderReady))
             }
-            _ if !jobs.read_cache.is_empty() => {
-                self.run_next_read_cache_job()?;
-                Ok(Some(Progress::NewShaderReady))
-            }
+            _ if !jobs.compile_check.is_empty() => ok_progress(self.run_next_compile_check_job()?),
             _ => {
                 if max_jobs {
                     if !jobs.compile.is_empty() {
@@ -381,7 +382,7 @@ impl CompilerData {
                         let msg2 = "Skipping spawning new ones.";
                         trace!("{msg1} {msg2}");
                     }
-                } else if jobs.khr_completion_check.is_empty() {
+                } else if jobs.compile_poll.is_empty() && jobs.link_poll.is_empty() {
                     trace!("All shaders compiled.");
                     self.dirty = false;
                 }
@@ -395,52 +396,97 @@ impl CompilerData {
     /// it is costly and can prevent the parallelism altogether. To learn more, see:
     /// https://developer.mozilla.org/en-US/docs/Web/API/WebGL_API/WebGL_best_practices#dont_check_shader_compile_status_unless_linking_fails
     fn current_parallel_job_count(&self) -> usize {
-        self.jobs.link.len() + self.jobs.khr_completion_check.len() + self.jobs.link_check.len()
+        [
+            self.jobs.compile.len(),
+            self.jobs.compile_poll.len(),
+            self.jobs.compile_check.len(),
+            self.jobs.link.len(),
+            self.jobs.link_poll.len(),
+            self.jobs.link_check.len(),
+        ]
+        .iter()
+        .sum()
     }
 
     #[profile(Debug)]
-    fn run_khr_completion_check_jobs(&mut self) {
-        trace!("Running KHR parallel shader compilation check job.");
-        let jobs = &mut self.jobs.khr_completion_check;
-        let ready_jobs =
-            jobs.drain_filter(|job| match job.khr.is_ready(&self.context, &job.program) {
-                Some(val) => val,
-                None => {
-                    if !self.context.is_context_lost() {
-                        reportable_warn!(
-                            "context.getProgramParameter returned non-bool value for KHR Parallel \
-                            Shader Compile status check. This should never happen, however, it \
-                            should not cause visual artifacts. Reverting to non-parallel mode."
-                        );
-                    }
-                    true
-                }
-            });
+    fn poll_programs_ready(&mut self) {
+        let ready_jobs = self.jobs.link_poll.drain_filter(|job| {
+            job.khr.is_program_ready(&self.context, &job.program).unwrap_or(true)
+        });
         self.jobs.link_check.extend(ready_jobs.map(|job| job.map_input(|t| t.program)));
     }
 
+    #[profile(Debug)]
+    fn poll_shaders_ready(&mut self) {
+        let ready_jobs = self.jobs.compile_poll.drain_filter(|job| {
+            job.khr.is_shader_ready(&self.context, &job.program).unwrap_or(true)
+        });
+        self.jobs.compile_check.extend(ready_jobs.map(|job| job.map_input(|t| t.program)));
+    }
+
     #[allow(unused_parens)]
     fn run_next_compile_job(&mut self) -> Result<(), Error> {
         self.with_next_job("shader compilation", (|t| &mut t.jobs.compile), |this, job| {
             let profiler = job.profiler;
             profiler.resume();
-            let vertex = this.cache.get_or_insert_vertex_shader(job.cache_key, || {
-                CompilerData::compile_shader(&this.context, Vertex, job.input.vertex)
-            })?;
-            let fragment = this.cache.get_or_insert_fragment_shader(job.cache_key, || {
-                CompilerData::compile_shader(&this.context, Fragment, job.input.fragment)
-            })?;
+            let vertex = job.input.vertex.and_then(|code| {
+                this.cache.get_or_insert_vertex_shader(job.cache_key, || {
+                    CompilerData::compile_shader(&this.context, Vertex, code)
+                })
+            });
+            let fragment = job.input.fragment.and_then(|code| {
+                this.cache.get_or_insert_fragment_shader(job.cache_key, || {
+                    CompilerData::compile_shader(&this.context, Fragment, code)
+                })
+            });
             profiler.pause();
-            let input = shader::Sources { vertex, fragment };
-            let handle = job.handle;
-            let on_ready = job.on_ready;
-            let cache_key = job.cache_key;
-            let link_job = Job { input, handle, on_ready, profiler, cache_key };
-            this.jobs.link.push(link_job);
+            let vertex = match vertex {
+                Some(vertex) => Some(vertex?),
+                None => None,
+            };
+            let fragment = match fragment {
+                Some(fragment) => Some(fragment?),
+                None => None,
+            };
+            match (vertex, fragment) {
+                (Some(vertex), Some(fragment)) => {
+                    let input = shader::Sources { vertex, fragment };
+                    let handle = job.handle;
+                    let on_ready = job.on_ready;
+                    let cache_key = job.cache_key;
+                    let link_job = Job { input, handle, on_ready, profiler, cache_key };
+                    this.jobs.link.push(link_job);
+                }
+                (Some(vertex), None) => {
+                    let input = vertex.native;
+                    let handle = job.handle;
+                    let on_ready = job.on_ready;
+                    let cache_key = job.cache_key;
+                    let job = Job { input, handle, cache_key, on_ready, profiler };
+                    this.queue_shader_check_job(job);
+                }
+                (None, Some(fragment)) => {
+                    let input = fragment.native;
+                    let handle = job.handle;
+                    let on_ready = job.on_ready;
+                    let cache_key = job.cache_key;
+                    let job = Job { input, handle, cache_key, on_ready, profiler };
+                    this.queue_shader_check_job(job);
+                }
+                _ => (),
+            }
             Ok(())
         })
     }
 
+    fn queue_shader_check_job(&mut self, job: Job<web_sys::WebGlShader>) {
+        match self.context.extensions.khr_parallel_shader_compile {
+            Some(khr) =>
+                self.jobs.compile_poll.push(job.map_input(|program| WithKhr { khr, program })),
+            None => self.jobs.compile_check.push(job),
+        }
+    }
+
     #[allow(unused_parens)]
     fn run_next_link_job(&mut self) -> Result<(), Error> {
         self.with_next_job("shader linking", (|t| &mut t.jobs.link), |this, job| {
@@ -458,9 +504,9 @@ impl CompilerData {
             let cache_key = job.cache_key;
             match this.context.extensions.khr_parallel_shader_compile {
                 Some(khr) => {
-                    let input = KhrProgram { khr, program: input };
+                    let input = WithKhr { khr, program: input };
                     let job = Job { input, handle, cache_key, on_ready, profiler };
-                    this.jobs.khr_completion_check.push(job)
+                    this.jobs.link_poll.push(job)
                 }
                 None => {
                     let job = Job { input, handle, cache_key, on_ready, profiler };
@@ -473,7 +519,7 @@ impl CompilerData {
 
     #[allow(unused_parens)]
     fn run_next_link_check_job(&mut self) -> Result<(), Error> {
-        self.with_next_job("shader validation", (|t| &mut t.jobs.link_check), |this, job| {
+        self.with_next_job("program validation", (|t| &mut t.jobs.link_check), |this, job| {
             let program = job.input;
             let param = WebGl2RenderingContext::LINK_STATUS;
             job.profiler.resume();
@@ -489,21 +535,27 @@ impl CompilerData {
     }
 
     #[allow(unused_parens)]
-    fn run_next_read_cache_job(&mut self) -> Result<(), Error> {
-        self.with_next_job("shader cache read", (|t| &mut t.jobs.read_cache), |this, job| {
-            // This job is only scheduled after this cache entry was determined to be successfully
-            // processed. `Validated` is the only expected cache entry state at this point.
-            match this.cache.get_program(job.cache_key) {
-                Some(ProgramCacheEntry::Validated(program)) => {
-                    if let Some(on_ready) = job.on_ready {
-                        (on_ready)(program.clone());
-                    }
-                    Ok(())
-                }
-                _ => panic!("Shader cache read was submitted for non-completed entry."),
+    fn run_next_compile_check_job(&mut self) -> Result<(), Error> {
+        self.with_next_job("shader validation", (|t| &mut t.jobs.compile_check), |this, job| {
+            let shader = job.input;
+            let param = WebGl2RenderingContext::COMPILE_STATUS;
+            job.profiler.resume();
+            let status = this.context.get_shader_parameter(&shader, param);
+            job.profiler.finish();
+            if !status.as_bool().unwrap_or(false) {
+                error!("Failed to compile shader: {:?}", status);
+                return Err(Error::ShaderCompilingError(shader));
             }
-        })?;
-        Ok(())
+            Ok(())
+        })
+    }
+
+    fn run_callbacks(&mut self) -> bool {
+        let any_new_shaders_ready = !self.callbacks.is_empty();
+        for DeferredCallback { callback, program } in self.callbacks.drain(..) {
+            (callback)(program);
+        }
+        any_new_shaders_ready
     }
 
     fn with_next_job<T>(
@@ -554,6 +606,18 @@ impl CompilerData {
 }
 
 
+// === DeferredCallback ===
+
+/// A callback waiting to be invoked.
+#[derive(Derivative)]
+#[derivative(Debug)]
+struct DeferredCallback {
+    #[derivative(Debug = "ignore")]
+    callback: Box<dyn FnOnce(shader::Program)>,
+    program:  shader::Program,
+}
+
+
 
 // ===================
 // === ShaderCache ===
@@ -582,8 +646,8 @@ enum ProgramCacheEntry {
 
 impl ShaderCache {
     /// Generate new shader cache key
-    fn code_key(code: &shader::Code) -> ShaderCacheKey {
-        (ShaderHash::new(&code.vertex), ShaderHash::new(&code.fragment))
+    fn code_key(code: &shader::Sources<Option<String>, Option<String>>) -> ShaderCacheKey {
+        code.as_ref().map(|shader| shader.as_ref().map(ShaderHash::new))
     }
 
     fn get_program(&self, key: ShaderCacheKey) -> Option<&ProgramCacheEntry> {
@@ -651,22 +715,23 @@ impl ShaderCache {
         &mut self,
         key: ShaderCacheKey,
         compile: impl FnOnce() -> Result<Shader<Vertex>, Error>,
-    ) -> Result<Shader<Vertex>, Error> {
-        Ok(self.vertex_shaders.get_or_insert_with_result(key.0, compile)?.clone())
+    ) -> Option<Result<Shader<Vertex>, Error>> {
+        key.vertex.map(|key| self.vertex_shaders.get_or_insert_with_result(key, compile).cloned())
     }
 
     fn get_or_insert_fragment_shader(
         &mut self,
         key: ShaderCacheKey,
         compile: impl FnOnce() -> Result<Shader<Fragment>, Error>,
-    ) -> Result<Shader<Fragment>, Error> {
-        Ok(self.fragment_shaders.get_or_insert_with_result(key.1, compile)?.clone())
+    ) -> Option<Result<Shader<Fragment>, Error>> {
+        key.fragment
+            .map(|key| self.fragment_shaders.get_or_insert_with_result(key, compile).cloned())
     }
 }
 
 /// Shader cache entry key. Allows retrieving linked programs or individual compiled vertex and
 /// fragment shaders from [`ShaderCache`].
-type ShaderCacheKey = (ShaderHash, ShaderHash);
+type ShaderCacheKey = shader::Sources<Option<ShaderHash>, Option<ShaderHash>>;
 
 /// A shader source hash value used for cache storage.
 /// We do not want to store and compare very long shader source strings in the hashmap. Instead, we
@@ -680,7 +745,7 @@ struct ShaderHash(u64);
 
 
 impl ShaderHash {
-    fn new(code: &str) -> Self {
+    fn new(code: impl Hash) -> Self {
         let mut hasher = DefaultHasher::new();
         code.hash(&mut hasher);
         Self(hasher.finish())
@@ -698,6 +763,7 @@ impl ShaderHash {
 #[allow(missing_docs)]
 pub enum Error {
     ShaderCreationError,
+    ShaderCompilingError(web_sys::WebGlShader),
     ProgramCreationError,
     ProgramLinkingError(shader::CompiledCode),
 }
@@ -706,17 +772,26 @@ impl Error {
     /// Report the error. This function uses GPU blocking API and thus will cause a significant
     /// performance hit.  Use it only when necessary.
     pub fn blocking_report(self, context: &WebGl2RenderingContext) -> String {
+        let unwrap_error = |name: &str, err: Option<String>| {
+            let header = format!("----- {name} Shader -----");
+            err.map(|t| format!("\n\n{header}\n\n{t}")).unwrap_or_else(|| "".into())
+        };
         match self {
             Self::ShaderCreationError => "WebGL was unable to create a new shader.".into(),
             Self::ProgramCreationError => "WebGl was unable to create a new program shader.".into(),
-            Self::ProgramLinkingError(shader) => {
-                let unwrap_error = |name: &str, err: Option<String>| {
-                    let header = format!("----- {name} Shader -----");
-                    err.map(|t| format!("\n\n{header}\n\n{t}")).unwrap_or_else(|| "".into())
+            Self::ShaderCompilingError(shader) => {
+                let shader = Shader::<()> {
+                    native: shader,
+                    code:   Default::default(),
+                    tp:     Default::default(),
                 };
-
-                let vertex = &shader.vertex;
-                let fragment = &shader.fragment;
+                let log = context.blocking_format_error_log(&shader);
+                let error = unwrap_error("Shader", log);
+                format!("Unable to compile shader.\n{error}")
+            }
+            Self::ProgramLinkingError(program) => {
+                let vertex = &program.vertex;
+                let fragment = &program.fragment;
                 let vertex_log = context.blocking_format_error_log(vertex);
                 let fragment_log = context.blocking_format_error_log(fragment);
                 let vertex_error = unwrap_error("Vertex", vertex_log);
@@ -741,7 +816,9 @@ impl Error {
 
                 let dbg_msg = format!("{}\n{}", run_msg("vertex"), run_msg("fragment"));
 
-                format!("Unable to compile shader.\n{dbg_msg}\n{vertex_error}{fragment_error}")
+                format!(
+                    "Unable to compile shader program.\n{dbg_msg}\n{vertex_error}{fragment_error}"
+                )
             }
         }
     }

From 9cb79bca54bc5abd2e3818ed8b4b66f10d35386a Mon Sep 17 00:00:00 2001
From: Kaz Wesley <kaz@lambdaverse.org>
Date: Fri, 10 Feb 2023 18:17:18 +0000
Subject: [PATCH 03/16] clean up

---
 lib/rust/ensogl/core/src/system/gpu/shader/compiler.rs | 8 ++------
 1 file changed, 2 insertions(+), 6 deletions(-)

diff --git a/lib/rust/ensogl/core/src/system/gpu/shader/compiler.rs b/lib/rust/ensogl/core/src/system/gpu/shader/compiler.rs
index fde5906f6faf..cf85d11b46c3 100644
--- a/lib/rust/ensogl/core/src/system/gpu/shader/compiler.rs
+++ b/lib/rust/ensogl/core/src/system/gpu/shader/compiler.rs
@@ -67,8 +67,7 @@ const FRAME_TIME_THRESHOLD: Duration = (1000.0 / FPS_THRESHOLD).ms();
 /// a crude form of backpressure by blocking until all pending jobs complete. We are not sure if it
 /// is a feature or a bug. To learn more about our findings so far, see:
 /// https://github.com/enso-org/enso/pull/3378#issuecomment-1090958946
-//const MAX_PARALLEL_COMPILE_JOBS: usize = 2;
-const MAX_PARALLEL_COMPILE_JOBS: usize = 1000;
+const MAX_PARALLEL_COMPILE_JOBS: usize = 32;
 
 
 
@@ -106,10 +105,7 @@ impl<T> Job<T> {
 
     /// Return whether the job has been cancelled (by its handle being dropped).
     fn is_cancelled(&self) -> bool {
-        match self.handle.as_ref() {
-            Some(handle) if !handle.exists() => true,
-            _ => false,
-        }
+        self.handle.as_ref().map(|| !handle.exists()).unwrap_or_default()
     }
 }
 

From 3f364a3655a24b286a8cf1def75cc54bb1e4f8ac Mon Sep 17 00:00:00 2001
From: Kaz Wesley <kaz@lambdaverse.org>
Date: Fri, 10 Feb 2023 18:19:18 +0000
Subject: [PATCH 04/16] fix

---
 lib/rust/ensogl/core/src/system/gpu/shader/compiler.rs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/rust/ensogl/core/src/system/gpu/shader/compiler.rs b/lib/rust/ensogl/core/src/system/gpu/shader/compiler.rs
index cf85d11b46c3..a23dab26c48a 100644
--- a/lib/rust/ensogl/core/src/system/gpu/shader/compiler.rs
+++ b/lib/rust/ensogl/core/src/system/gpu/shader/compiler.rs
@@ -105,7 +105,7 @@ impl<T> Job<T> {
 
     /// Return whether the job has been cancelled (by its handle being dropped).
     fn is_cancelled(&self) -> bool {
-        self.handle.as_ref().map(|| !handle.exists()).unwrap_or_default()
+        self.handle.as_ref().map(|handle| !handle.exists()).unwrap_or_default()
     }
 }
 

From 6648441f3ed48fe51f5a505138726ad86e325302 Mon Sep 17 00:00:00 2001
From: Kaz Wesley <kaz@lambdaverse.org>
Date: Mon, 13 Feb 2023 22:33:09 +0000
Subject: [PATCH 05/16] fix log-level changing bug

---
 lib/rust/logging/macros/build.rs | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/lib/rust/logging/macros/build.rs b/lib/rust/logging/macros/build.rs
index ac34acf59f5e..67031e82e547 100644
--- a/lib/rust/logging/macros/build.rs
+++ b/lib/rust/logging/macros/build.rs
@@ -15,8 +15,8 @@
 
 
 fn main() {
-    declare_env_dependence("ENSO_MAX_LOGGING_LEVEL");
-    declare_env_dependence("ENSO_UNCOLLAPSED_LOGGING_LEVEL");
+    declare_env_dependence("ENSO_MAX_LOG_LEVEL");
+    declare_env_dependence("ENSO_UNCOLLAPSED_LOG_LEVEL");
 }
 
 /// Make cargo aware that the result of compiling this crate depends on an environment variable.

From a20e168452529c188b36096ce5f1a4c34d3e32cb Mon Sep 17 00:00:00 2001
From: Kaz Wesley <kaz@lambdaverse.org>
Date: Fri, 10 Feb 2023 20:53:52 +0000
Subject: [PATCH 06/16] cleanup

---
 lib/rust/ensogl/core/src/gui/component.rs | 6 ------
 1 file changed, 6 deletions(-)

diff --git a/lib/rust/ensogl/core/src/gui/component.rs b/lib/rust/ensogl/core/src/gui/component.rs
index 5aff02adce3f..d2bc5bfb2a4a 100644
--- a/lib/rust/ensogl/core/src/gui/component.rs
+++ b/lib/rust/ensogl/core/src/gui/component.rs
@@ -168,8 +168,6 @@ impl<S: Shape> ShapeViewModel<S> {
                 self.add_to_scene_layer(scene, &layer)
             }
         } else {
-            // Bug in clippy: https://github.com/rust-lang/rust-clippy/issues/9763
-            #[allow(clippy::explicit_auto_deref)]
             let (shape, _) = scene.layers.DETACHED.instantiate(&*self.data.borrow());
             self.shape.swap(&shape);
         }
@@ -189,8 +187,6 @@ impl<S: Shape> ShapeViewModel<S> {
 }
 
 impl<S: Shape> ShapeViewModel<S> {
-    // Clippy error: https://github.com/rust-lang/rust-clippy/issues/9763
-    #[allow(clippy::explicit_auto_deref)]
     fn add_to_scene_layer(&self, scene: &Scene, layer: &scene::Layer) {
         let (shape, instance) = layer.instantiate(&*self.data.borrow());
         scene.pointer_target_registry.insert(instance.global_instance_id, self.events.clone_ref());
@@ -200,8 +196,6 @@ impl<S: Shape> ShapeViewModel<S> {
 }
 
 impl<S: Shape> ShapeViewModel<S> {
-    // Clippy error: https://github.com/rust-lang/rust-clippy/issues/9763
-    #[allow(clippy::explicit_auto_deref)]
     fn unregister_existing_mouse_targets(&self) {
         for global_instance_id in mem::take(&mut *self.pointer_targets.borrow_mut()) {
             scene().pointer_target_registry.remove(global_instance_id);

From 40c674d7d19ad0040e38204adaa045a54481a547 Mon Sep 17 00:00:00 2001
From: Kaz Wesley <kaz@lambdaverse.org>
Date: Mon, 13 Feb 2023 20:46:52 +0000
Subject: [PATCH 07/16] cleanup

---
 .../src/display/shape/primitive/system.rs     |  4 ++--
 .../ensogl/core/src/display/symbol/gpu.rs     | 12 +++++------
 .../core/src/display/symbol/gpu/shader.rs     | 21 ++++++++++---------
 lib/rust/ensogl/core/src/gui/component.rs     | 12 +++++------
 4 files changed, 24 insertions(+), 25 deletions(-)

diff --git a/lib/rust/ensogl/core/src/display/shape/primitive/system.rs b/lib/rust/ensogl/core/src/display/shape/primitive/system.rs
index 6b3f79a781a6..6e1c0a29d145 100644
--- a/lib/rust/ensogl/core/src/display/shape/primitive/system.rs
+++ b/lib/rust/ensogl/core/src/display/shape/primitive/system.rs
@@ -632,7 +632,7 @@ macro_rules! _shape_old {
             // =============
 
             /// The type of the shape. It also contains the parameters of the shape. The parameters
-            /// are stored in this type in order to simplify bounds for utlities managing shape
+            /// are stored in this type in order to simplify bounds for utilities managing shape
             /// systems. For example, if we would like to handle any shape with given parameters,
             /// we will be processing [`ShapeSystem<S>`] and we can add bounds to [`S`] to reflect
             /// what parameters it should contain.
@@ -788,7 +788,7 @@ macro_rules! _shape {
             // =============
 
             /// The type of the shape. It also contains the parameters of the shape. The parameters
-            /// are stored in this type in order to simplify bounds for utlities managing shape
+            /// are stored in this type in order to simplify bounds for utilities managing shape
             /// systems. For example, if we would like to handle any shape with given parameters,
             /// we will be processing [`ShapeSystem<S>`] and we can add bounds to [`S`] to reflect
             /// what parameters it should contain.
diff --git a/lib/rust/ensogl/core/src/display/symbol/gpu.rs b/lib/rust/ensogl/core/src/display/symbol/gpu.rs
index 06c8babf7a3f..9582a6dd8473 100644
--- a/lib/rust/ensogl/core/src/display/symbol/gpu.rs
+++ b/lib/rust/ensogl/core/src/display/symbol/gpu.rs
@@ -409,15 +409,13 @@ impl Symbol {
         &self,
         global_variables: &UniformScope,
     ) -> Vec<shader::VarBinding> {
-        let mut vars = self.shader.collect_variables();
-        for binding in &mut vars {
-            let scope = self.lookup_variable(&binding.name, global_variables);
+        self.shader.collect_variables().map(|(name, decl)| {
+            let scope = self.lookup_variable(&name, global_variables);
             if scope.is_none() {
-                warn!("Unable to bind variable '{}' to geometry buffer.", binding.name);
+                warn!("Unable to bind variable '{name}' to geometry buffer.");
             }
-            binding.scope = scope;
-        }
-        vars
+            shader::VarBinding::new(name, decl, scope)
+        }).collect()
     }
 
     /// Runs the provided function in a context of active program and active VAO. After the function
diff --git a/lib/rust/ensogl/core/src/display/symbol/gpu/shader.rs b/lib/rust/ensogl/core/src/display/symbol/gpu/shader.rs
index 676e2c565933..ffcd065a6533 100644
--- a/lib/rust/ensogl/core/src/display/symbol/gpu/shader.rs
+++ b/lib/rust/ensogl/core/src/display/symbol/gpu/shader.rs
@@ -122,9 +122,10 @@ impl {
     /// Get the shader code in GLSL 310 format. The shader parameters will not be bound to any
     /// particular mesh and thus this code can be used for optimization purposes only.
     pub fn abstract_shader_code_in_glsl_310(&self) -> crate::system::gpu::shader::Code {
-        let bindings = self.collect_variables().into_iter().map(|mut binding| {
-            binding.scope = Some(ScopeType::Mesh(crate::display::symbol::geometry::primitive::mesh::ScopeType::Instance));
-            binding
+        let bindings = self.collect_variables().map(|(name, decl)| {
+            let instance = crate::display::symbol::geometry::primitive::mesh::ScopeType::Instance;
+            let scope = Some(ScopeType::Mesh(instance));
+            VarBinding::new(name, decl, scope)
         }).collect_vec();
         self.gen_gpu_code(glsl::Version::V310, &bindings)
     }
@@ -202,13 +203,13 @@ impl {
     }
 
     /// Traverses the shader definition and collects all attribute names.
-    pub fn collect_variables(&self) -> Vec<VarBinding> {
-        let mut out = vec![];
-        let vars = self.geometry_material.inputs().iter().chain(self.surface_material.inputs());
-        for (name,decl) in vars {
-            out.push(VarBinding::new(name.clone(), decl.clone(), None));
-        }
-        out
+    pub fn collect_variables(&self) -> impl Iterator<Item=(String, VarDecl)> {
+        let geometry_inputs = self.geometry_material.inputs().iter();
+        let surface_inputs = self.surface_material.inputs().iter();
+        geometry_inputs.chain(surface_inputs)
+            .map(|(s, d)| (s.clone(), d.clone()))
+            .collect_vec()
+            .into_iter()
     }
 }}
 
diff --git a/lib/rust/ensogl/core/src/gui/component.rs b/lib/rust/ensogl/core/src/gui/component.rs
index d2bc5bfb2a4a..5abfd5583ebf 100644
--- a/lib/rust/ensogl/core/src/gui/component.rs
+++ b/lib/rust/ensogl/core/src/gui/component.rs
@@ -228,8 +228,8 @@ impl<S: Shape> display::Object for ShapeView<S> {
 struct WidgetData<Model: 'static, Frp: 'static> {
     app:            Application,
     display_object: display::object::Instance,
-    frp:            std::mem::ManuallyDrop<Frp>,
-    model:          std::mem::ManuallyDrop<Rc<Model>>,
+    frp:            mem::ManuallyDrop<Frp>,
+    model:          mem::ManuallyDrop<Rc<Model>>,
 }
 
 impl<Model: 'static, Frp: 'static> WidgetData<Model, Frp> {
@@ -242,8 +242,8 @@ impl<Model: 'static, Frp: 'static> WidgetData<Model, Frp> {
         Self {
             app: app.clone_ref(),
             display_object,
-            frp: std::mem::ManuallyDrop::new(frp),
-            model: std::mem::ManuallyDrop::new(model),
+            frp: mem::ManuallyDrop::new(frp),
+            model: mem::ManuallyDrop::new(model),
         }
     }
 }
@@ -255,8 +255,8 @@ impl<Model: 'static, Frp: 'static> Drop for WidgetData<Model, Frp> {
         // This is clearly the case, because the structure will be soon dropped anyway.
         #[allow(unsafe_code)]
         unsafe {
-            let frp = std::mem::ManuallyDrop::take(&mut self.frp);
-            let model = std::mem::ManuallyDrop::take(&mut self.model);
+            let frp = mem::ManuallyDrop::take(&mut self.frp);
+            let model = mem::ManuallyDrop::take(&mut self.model);
             self.app.display.collect_garbage(frp);
             self.app.display.collect_garbage(model);
         }

From b56fcb028c6a5ca0413b04e9c05c17185515ea12 Mon Sep 17 00:00:00 2001
From: Kaz Wesley <kaz@lambdaverse.org>
Date: Mon, 13 Feb 2023 22:33:29 +0000
Subject: [PATCH 08/16] cleanup

---
 app/gui/src/model/undo_redo.rs                     | 2 +-
 lib/rust/ensogl/core/src/system/gpu/data/buffer.rs | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/app/gui/src/model/undo_redo.rs b/app/gui/src/model/undo_redo.rs
index f4d1b408c4af..f4be92bd37dc 100644
--- a/app/gui/src/model/undo_redo.rs
+++ b/app/gui/src/model/undo_redo.rs
@@ -132,7 +132,7 @@ impl Drop for Transaction {
                 urm.push_to(Stack::Undo, self.frame.borrow().clone());
                 urm.clear(Stack::Redo);
             } else {
-                info!(
+                debug!(
                     "Dropping the ignored transaction '{}' without pushing a frame to repository.",
                     self.name()
                 )
diff --git a/lib/rust/ensogl/core/src/system/gpu/data/buffer.rs b/lib/rust/ensogl/core/src/system/gpu/data/buffer.rs
index a0a8d2b83d46..5318d0dbcd93 100644
--- a/lib/rust/ensogl/core/src/system/gpu/data/buffer.rs
+++ b/lib/rust/ensogl/core/src/system/gpu/data/buffer.rs
@@ -280,7 +280,7 @@ impl<T: Storable> BufferData<T> {
     /// Upload the provided data range to the GPU buffer. In case the local buffer was resized,
     /// it will be re-created on the GPU.
     fn upload_data(&mut self, opt_range: &Option<RangeInclusive<usize>>) {
-        info_span!("Uploading buffer data.").in_scope(|| {
+        debug_span!("Uploading buffer data.").in_scope(|| {
             self.stats.inc_data_upload_count();
             match opt_range {
                 None => self.replace_gpu_buffer(),

From cbfb37510089e9e211ea75e8b6abc4220c58b031 Mon Sep 17 00:00:00 2001
From: Kaz Wesley <kaz@lambdaverse.org>
Date: Fri, 10 Feb 2023 20:53:12 +0000
Subject: [PATCH 09/16] set up shader-program inputs correctly

---
 lib/rust/ensogl/core/src/display/scene.rs     | 16 +++++++------
 .../ensogl/core/src/display/symbol/gpu.rs     |  2 +-
 lib/rust/ensogl/core/src/display/world.rs     | 23 ++++++++++++++-----
 3 files changed, 27 insertions(+), 14 deletions(-)

diff --git a/lib/rust/ensogl/core/src/display/scene.rs b/lib/rust/ensogl/core/src/display/scene.rs
index c236178f8595..7990c702e092 100644
--- a/lib/rust/ensogl/core/src/display/scene.rs
+++ b/lib/rust/ensogl/core/src/display/scene.rs
@@ -719,7 +719,7 @@ pub struct SceneData {
     display_mode: Rc<Cell<glsl::codes::DisplayModes>>,
     extensions: Extensions,
     disable_context_menu: Rc<EventListenerHandle>,
-    persistent_shaders: Rc<Vec<shader::Code>>,
+    persistent_shaders: Rc<RefCell<Vec<shader::Code>>>,
 }
 
 impl SceneData {
@@ -728,7 +728,6 @@ impl SceneData {
         stats: &Stats,
         on_mut: OnMut,
         display_mode: &Rc<Cell<glsl::codes::DisplayModes>>,
-        persistent_shaders: Vec<shader::Code>,
     ) -> Self {
         debug!("Initializing.");
         let display_mode = display_mode.clone_ref();
@@ -768,7 +767,7 @@ impl SceneData {
         let context_lost_handler = default();
         let pointer_position_changed = default();
         let shader_compiler = default();
-        let persistent_shaders = Rc::new(persistent_shaders);
+        let persistent_shaders = default();
         Self {
             display_object,
             display_mode,
@@ -813,10 +812,10 @@ impl SceneData {
         self.dirty.shape.set();
         self.renderer.set_context(context);
         if let Some(context) = context {
-            for code in self.persistent_shaders.iter() {
+            for code in self.persistent_shaders.borrow().iter() {
                 let code = shader::Sources {
                     fragment: Some(code.fragment.clone()),
-                    vertex: None,
+                    vertex: Some(code.vertex.clone()),
                 };
                 context.shader_compiler.submit_background_job(code);
             }
@@ -950,6 +949,10 @@ impl SceneData {
         let world_space = camera.inversed_view_projection_matrix() * clip_space;
         (inv_object_matrix * world_space).xy()
     }
+
+    pub fn set_persistent_shaders(&self, shaders: Vec<shader::Code>) {
+        *self.persistent_shaders.borrow_mut() = shaders;
+    }
 }
 
 
@@ -1031,9 +1034,8 @@ impl Scene {
         stats: &Stats,
         on_mut: OnMut,
         display_mode: &Rc<Cell<glsl::codes::DisplayModes>>,
-        persistent_shaders: Vec<shader::Code>,
     ) -> Self {
-        let no_mut_access = SceneData::new(stats, on_mut, display_mode, persistent_shaders);
+        let no_mut_access = SceneData::new(stats, on_mut, display_mode);
         let this = Self { no_mut_access };
         this
     }
diff --git a/lib/rust/ensogl/core/src/display/symbol/gpu.rs b/lib/rust/ensogl/core/src/display/symbol/gpu.rs
index 9582a6dd8473..e08d269572ce 100644
--- a/lib/rust/ensogl/core/src/display/symbol/gpu.rs
+++ b/lib/rust/ensogl/core/src/display/symbol/gpu.rs
@@ -405,7 +405,7 @@ impl Symbol {
     }
 
     /// For each variable from the shader definition, looks up its position in geometry scopes.
-    fn discover_variable_bindings(
+    pub fn discover_variable_bindings(
         &self,
         global_variables: &UniformScope,
     ) -> Vec<shader::VarBinding> {
diff --git a/lib/rust/ensogl/core/src/display/world.rs b/lib/rust/ensogl/core/src/display/world.rs
index 89532ff14e76..93069dfc9769 100644
--- a/lib/rust/ensogl/core/src/display/world.rs
+++ b/lib/rust/ensogl/core/src/display/world.rs
@@ -190,10 +190,19 @@ fn gather_shaders() -> HashMap<&'static str, shader::Code> {
 }
 
 /// Returns the source code for shaders that should be compiled as soon as a context is available.
-fn get_persistent_shaders() -> Vec<shader::Code> {
-    PRECOMPILED_SHADERS.with_borrow(|shaders| {
-        shaders.values().cloned().map(|PrecompiledShader(shader)| shader).collect()
-    })
+fn get_persistent_shaders(variables: &UniformScope) -> Vec<shader::Code> {
+    let mut shaders = vec![];
+    SHAPES_DEFINITIONS.with_borrow(|shapes| {
+        for shape_cons in shapes {
+            let symbol = &shape_cons().sprite().symbol;
+            let bindings = symbol.discover_variable_bindings(variables);
+            let shader = symbol.shader();
+            let version = crate::system::gpu::shader::glsl::Version::V300;
+            let code = shader.gen_gpu_code(version, &bindings);
+            shaders.push(code);
+        }
+    });
+    shaders
 }
 
 
@@ -417,8 +426,10 @@ impl WorldData {
         let scene_dirty = dirty::SharedBool::new(());
         let on_change = f!(scene_dirty.set());
         let display_mode = Rc::<Cell<glsl::codes::DisplayModes>>::default();
-        let default_scene = Scene::new(&stats, on_change, &display_mode, get_persistent_shaders());
-        let uniforms = Uniforms::new(&default_scene.variables);
+        let default_scene = Scene::new(&stats, on_change, &display_mode);
+        let variables = &default_scene.variables;
+        let uniforms = Uniforms::new(variables);
+        default_scene.set_persistent_shaders(get_persistent_shaders(variables));
         let debug_hotkeys_handle = default();
         let garbage_collector = default();
         let stats_draw_handle = on.prev_frame_stats.add(f!([stats_monitor] (stats: &StatsData) {

From 177f105e03b03ebc1f54a680180e8801f2dc2ab7 Mon Sep 17 00:00:00 2001
From: Kaz Wesley <kaz@lambdaverse.org>
Date: Tue, 14 Feb 2023 20:27:01 +0000
Subject: [PATCH 10/16] program inputs

---
 lib/rust/ensogl/core/src/display/scene.rs     |  9 +++
 .../ensogl/core/src/display/scene/layer.rs    | 13 ++--
 .../src/display/shape/primitive/system.rs     | 72 +++++++++++++++++--
 lib/rust/ensogl/core/src/display/world.rs     | 34 +++++++--
 lib/rust/ensogl/core/src/lib.rs               |  1 +
 .../core/src/system/gpu/shader/compiler.rs    | 28 +++-----
 6 files changed, 120 insertions(+), 37 deletions(-)

diff --git a/lib/rust/ensogl/core/src/display/scene.rs b/lib/rust/ensogl/core/src/display/scene.rs
index 7990c702e092..7b02746ba0d5 100644
--- a/lib/rust/ensogl/core/src/display/scene.rs
+++ b/lib/rust/ensogl/core/src/display/scene.rs
@@ -812,6 +812,11 @@ impl SceneData {
         self.dirty.shape.set();
         self.renderer.set_context(context);
         if let Some(context) = context {
+            /*
+            if self.persistent_shaders.borrow().is_empty() {
+                *self.persistent_shaders.borrow_mut() = world::get_persistent_shaders();
+            }
+             */
             for code in self.persistent_shaders.borrow().iter() {
                 let code = shader::Sources {
                     fragment: Some(code.fragment.clone()),
@@ -953,6 +958,10 @@ impl SceneData {
     pub fn set_persistent_shaders(&self, shaders: Vec<shader::Code>) {
         *self.persistent_shaders.borrow_mut() = shaders;
     }
+
+    pub fn debug_layer_contents(&self) {
+        warn!("{:?}", &self.layers);
+    }
 }
 
 
diff --git a/lib/rust/ensogl/core/src/display/scene/layer.rs b/lib/rust/ensogl/core/src/display/scene/layer.rs
index b4a427ebd847..b054a732e4a8 100644
--- a/lib/rust/ensogl/core/src/display/scene/layer.rs
+++ b/lib/rust/ensogl/core/src/display/scene/layer.rs
@@ -19,7 +19,6 @@ use crate::display::symbol::SymbolId;
 use enso_data_structures::dependency_graph::DependencyGraph;
 use enso_shapely::shared;
 use smallvec::alloc::collections::BTreeSet;
-use std::any::TypeId;
 
 
 
@@ -1143,8 +1142,8 @@ shared! { ShapeSystemRegistry
 /// the same type on the same layer. Read the docs of [`ShapeProxy`] to learn more.
 #[derive(Default,Debug)]
 pub struct ShapeSystemRegistryData {
-    shape_system_map : HashMap<(TypeId, ShapeSystemFlavor),ShapeSystemRegistryEntry>,
-    shape_system_flavors: HashMap<TypeId, Vec<ShapeSystemFlavor>>,
+    shape_system_map : HashMap<(ShapeSystemId, ShapeSystemFlavor),ShapeSystemRegistryEntry>,
+    shape_system_flavors: HashMap<ShapeSystemId, Vec<ShapeSystemFlavor>>,
 }
 
 impl {
@@ -1184,7 +1183,7 @@ impl {
 
         // Intentional short-circuit - avoid computing `total_system_instances` when we know there
         // are still more instances in the currently processed entry.
-        let no_more_instances = entry_is_empty && self.total_system_instances(*system_id) == 0;
+        let no_more_instances = entry_is_empty && self.total_system_instances(system_id) == 0;
 
         (no_more_instances, system_id, PhantomData)
     }
@@ -1198,7 +1197,7 @@ impl ShapeSystemRegistryData {
     where
         S: Shape,
     {
-        let id = TypeId::of::<S>();
+        let id = ShapeSystemId::of::<S>();
         self.shape_system_map.get_mut(&(id, flavor)).and_then(|t| {
             let shape_system = t.shape_system.downcast_mut::<ShapeSystem<S>>();
             let instance_count = &mut t.instance_count;
@@ -1217,7 +1216,7 @@ impl ShapeSystemRegistryData {
     where
         S: Shape,
     {
-        let id = TypeId::of::<S>();
+        let id = ShapeSystemId::of::<S>();
         let flavor = S::flavor(data);
         let system = ShapeSystem::<S>::new(data);
         let any = Box::new(system);
@@ -1229,7 +1228,7 @@ impl ShapeSystemRegistryData {
     }
 
     /// Get total number of shape instances from shape systems of given type and all flavors.
-    fn total_system_instances(&self, system_id: TypeId) -> usize {
+    fn total_system_instances(&self, system_id: ShapeSystemId) -> usize {
         let Some(flavors) = self.shape_system_flavors.get(&system_id) else { return 0 };
         flavors.iter().map(|f| self.shape_system_map[&(system_id, *f)].instance_count).sum()
     }
diff --git a/lib/rust/ensogl/core/src/display/shape/primitive/system.rs b/lib/rust/ensogl/core/src/display/shape/primitive/system.rs
index 6e1c0a29d145..c5ac019d6d61 100644
--- a/lib/rust/ensogl/core/src/display/shape/primitive/system.rs
+++ b/lib/rust/ensogl/core/src/display/shape/primitive/system.rs
@@ -60,6 +60,7 @@
 //! shape system will be detached from the parent display object (and not attached to another one),
 //! it will also be moved to the `DETACHED` layer.
 
+use std::fmt::Formatter;
 use crate::prelude::*;
 use crate::system::gpu::types::*;
 
@@ -82,9 +83,67 @@ use super::def;
 // === ShapeSystemId ===
 // =====================
 
-newtype_prim_no_default_no_display! {
-    /// The ID of a user generated shape system.
-    ShapeSystemId(std::any::TypeId);
+/// The ID of a user generated shape system.
+#[derive(Copy, Clone, CloneRef, Eq, Hash, Ord, PartialOrd, PartialEq, Debug)]
+pub struct ShapeSystemId {
+    definition_path: DistinctStr,
+}
+
+impl ShapeSystemId {
+    #[inline(always)]
+    pub fn of<S: Shape>() -> Self {
+        let definition_path = DistinctStr::new_unchecked(S::definition_path());
+        Self { definition_path }
+    }
+}
+
+
+////////
+
+#[derive(Copy, Clone, Eq, Ord)]
+pub struct DistinctStr(&'static str);
+
+impl DistinctStr {
+    /// Cast the input to a [`DistinctStr`].
+    #[inline(always)]
+    const fn new_unchecked(s: &'static str) -> Self {
+        Self(s)
+    }
+}
+
+impl PartialEq for DistinctStr {
+    #[inline(always)]
+    fn eq(&self, other: &Self) -> bool {
+        self.0.as_ptr() == other.0.as_ptr()
+    }
+}
+
+impl PartialOrd for DistinctStr {
+    #[inline(always)]
+    fn partial_cmp(&self, other: &Self) -> Option<std::cmp::Ordering> {
+        self.0.as_ptr().partial_cmp(&other.0.as_ptr())
+    }
+}
+
+impl Hash for DistinctStr {
+    #[inline(always)]
+    fn hash<H: Hasher>(&self, state: &mut H) {
+        self.0.as_ptr().hash(state)
+    }
+}
+
+impl Debug for DistinctStr {
+    #[inline(always)]
+    fn fmt(&self, f: &mut Formatter<'_>) -> fmt::Result {
+        write!(f, "{:?}", self.0)
+    }
+}
+
+impl CloneRef for DistinctStr {
+    #[inline(always)]
+    fn clone_ref(&self) -> Self {
+        *self
+    }
 }
 
 
@@ -249,8 +308,8 @@ pub struct ShapeSystemStandardData<S: Shape> {
 
 impl<S: Shape> ShapeSystem<S> {
     /// The ID of this shape system.
-    pub const fn id() -> ShapeSystemId {
-        ShapeSystemId::new(std::any::TypeId::of::<S>())
+    pub fn id() -> ShapeSystemId {
+        ShapeSystemId::of::<S>()
     }
 
     /// Reference to the underlying sprite system.
@@ -874,7 +933,8 @@ macro_rules! _shape {
             #[before_main]
             pub fn register_shape() {
                 $crate::display::world::SHAPES_DEFINITIONS.with(|shapes| {
-                    shapes.borrow_mut().push(Box::new(|| Box::new(View::new())));
+                    let path = Shape::definition_path();
+                    shapes.borrow_mut().push((path, Box::new(|| Box::new(View::new()))));
                 });
             }
 
diff --git a/lib/rust/ensogl/core/src/display/world.rs b/lib/rust/ensogl/core/src/display/world.rs
index 93069dfc9769..fc0f5f575602 100644
--- a/lib/rust/ensogl/core/src/display/world.rs
+++ b/lib/rust/ensogl/core/src/display/world.rs
@@ -101,7 +101,7 @@ pub struct CachedShapeDefinition {
 thread_local! {
     /// All shapes defined with the `shape!` macro. They will be populated on the beginning of
     /// program execution, before the `main` function is called.
-    pub static SHAPES_DEFINITIONS: RefCell<Vec<ShapeCons>> = default();
+    pub static SHAPES_DEFINITIONS: RefCell<Vec<(&'static str, ShapeCons)>> = default();
 
     /// All shapes defined with the `cached_shape!` macro. They will be populated on the beginning
     /// of program execution, before the `main` function is called.
@@ -178,7 +178,7 @@ fn gather_shaders() -> HashMap<&'static str, shader::Code> {
     with_context(|t| t.run_mode.set(RunMode::ShaderExtraction));
     let mut map = HashMap::new();
     SHAPES_DEFINITIONS.with(|shapes| {
-        for shape_cons in shapes.borrow().iter() {
+        for (_, shape_cons) in shapes.borrow().iter() {
             let shape = shape_cons();
             let path = shape.definition_path();
             let code = shape.abstract_shader_code_in_glsl_310();
@@ -190,8 +190,30 @@ fn gather_shaders() -> HashMap<&'static str, shader::Code> {
 }
 
 /// Returns the source code for shaders that should be compiled as soon as a context is available.
-fn get_persistent_shaders(variables: &UniformScope) -> Vec<shader::Code> {
+pub fn get_persistent_shaders() -> Vec<shader::Code> { // variables: &UniformScope
     let mut shaders = vec![];
+    //PRECOMPILED_SHADERS.with_borrow(|shaders| info!("PRECOMPILED_SHADERS: {shaders:?}"));
+    SHAPES_DEFINITIONS.with_borrow(|shapes| {
+        with_context(|t| {
+            //let layer = &t.layers.root;
+            for (path, shape_cons) in shapes {
+                let do_it = match path {
+                    //_ if path.starts_with("app/gui/view/component-browser") => true,
+                    _ => true,
+                };
+                if do_it {
+                    let shape = shape_cons();
+                }
+                //scene().add_child(&*shape);
+                //layer.add(&*shape);
+                //mem::forget(shape);
+                //let shape: Box<dyn display::Object> = shape_cons();
+                //layer.remove(&*shape);
+                //mem::forget(shape);
+            }
+        });
+    });
+    /*
     SHAPES_DEFINITIONS.with_borrow(|shapes| {
         for shape_cons in shapes {
             let symbol = &shape_cons().sprite().symbol;
@@ -202,6 +224,7 @@ fn get_persistent_shaders(variables: &UniformScope) -> Vec<shader::Code> {
             shaders.push(code);
         }
     });
+     */
     shaders
 }
 
@@ -419,6 +442,7 @@ pub struct WorldData {
 impl WorldData {
     /// Create and initialize new world instance.
     pub fn new(frp: &api::private::Output) -> Self {
+        get_persistent_shaders();
         let frp = frp.clone_ref();
         let stats = Stats::new(web::window.performance_or_panic());
         let stats_monitor = debug::monitor::Monitor::new();
@@ -429,7 +453,6 @@ impl WorldData {
         let default_scene = Scene::new(&stats, on_change, &display_mode);
         let variables = &default_scene.variables;
         let uniforms = Uniforms::new(variables);
-        default_scene.set_persistent_shaders(get_persistent_shaders(variables));
         let debug_hotkeys_handle = default();
         let garbage_collector = default();
         let stats_draw_handle = on.prev_frame_stats.add(f!([stats_monitor] (stats: &StatsData) {
@@ -475,6 +498,7 @@ impl WorldData {
         let display_mode = self.display_mode.clone_ref();
         let display_mode_uniform = self.uniforms.display_mode.clone_ref();
         let emit_measurements_handle = self.emit_measurements_handle.clone_ref();
+        let scene = self.default_scene.clone_ref();
         let closure: Closure<dyn Fn(JsValue)> = Closure::new(move |val: JsValue| {
             let event = val.unchecked_into::<web::KeyboardEvent>();
             let digit_prefix = "Digit";
@@ -497,6 +521,8 @@ impl WorldData {
                 } else if key == "KeyQ" {
                     enso_debug_api::save_profile(&profiler::internal::get_log());
                     enso_debug_api::LifecycleController::new().map(|api| api.quit());
+                } else if key == "KeyL" {
+                    scene.debug_layer_contents();
                 } else if key.starts_with(digit_prefix) {
                     let code_value = key.trim_start_matches(digit_prefix).parse().unwrap_or(0);
                     if let Some(mode) = glsl::codes::DisplayModes::from_value(code_value) {
diff --git a/lib/rust/ensogl/core/src/lib.rs b/lib/rust/ensogl/core/src/lib.rs
index f53d9a8116fa..a59da12729d3 100644
--- a/lib/rust/ensogl/core/src/lib.rs
+++ b/lib/rust/ensogl/core/src/lib.rs
@@ -25,6 +25,7 @@
 #![feature(auto_traits)]
 #![feature(int_roundings)]
 #![feature(let_chains)]
+#![feature(trait_upcasting)]
 // === Standard Linter Configuration ===
 #![deny(non_ascii_idents)]
 #![warn(unsafe_code)]
diff --git a/lib/rust/ensogl/core/src/system/gpu/shader/compiler.rs b/lib/rust/ensogl/core/src/system/gpu/shader/compiler.rs
index a23dab26c48a..ee1457de29dc 100644
--- a/lib/rust/ensogl/core/src/system/gpu/shader/compiler.rs
+++ b/lib/rust/ensogl/core/src/system/gpu/shader/compiler.rs
@@ -67,7 +67,7 @@ const FRAME_TIME_THRESHOLD: Duration = (1000.0 / FPS_THRESHOLD).ms();
 /// a crude form of backpressure by blocking until all pending jobs complete. We are not sure if it
 /// is a feature or a bug. To learn more about our findings so far, see:
 /// https://github.com/enso-org/enso/pull/3378#issuecomment-1090958946
-const MAX_PARALLEL_COMPILE_JOBS: usize = 32;
+const MAX_PARALLEL_COMPILE_JOBS: usize = 2000;
 
 
 
@@ -238,6 +238,7 @@ impl Compiler {
         profiler: profiler::Debug,
         on_ready: F,
     ) -> JobHandle {
+        //info!("submit: {}", &input.fragment);
         let strong_handle = JobHandle::new();
         let handle = strong_handle.downgrade();
         let on_ready: Box<dyn FnOnce(shader::Program)> = Box::new(on_ready);
@@ -301,7 +302,8 @@ impl CompilerData {
                 // callback to be called from within the job runner during next processing round.
                 if let Some(callback) = on_ready {
                     let program = program.clone();
-                    self.callbacks.push(DeferredCallback { callback, program })
+                    self.callbacks.push(DeferredCallback { callback, program });
+                    self.dirty = true;
                 }
             }
             Some(ProgramCacheEntry::Failed) => {
@@ -436,36 +438,22 @@ impl CompilerData {
                 })
             });
             profiler.pause();
-            let vertex = match vertex {
-                Some(vertex) => Some(vertex?),
-                None => None,
-            };
-            let fragment = match fragment {
-                Some(fragment) => Some(fragment?),
-                None => None,
-            };
-            match (vertex, fragment) {
+            let handle = job.handle;
+            let on_ready = job.on_ready;
+            let cache_key = job.cache_key;
+            match (vertex.transpose()?, fragment.transpose()?) {
                 (Some(vertex), Some(fragment)) => {
                     let input = shader::Sources { vertex, fragment };
-                    let handle = job.handle;
-                    let on_ready = job.on_ready;
-                    let cache_key = job.cache_key;
                     let link_job = Job { input, handle, on_ready, profiler, cache_key };
                     this.jobs.link.push(link_job);
                 }
                 (Some(vertex), None) => {
                     let input = vertex.native;
-                    let handle = job.handle;
-                    let on_ready = job.on_ready;
-                    let cache_key = job.cache_key;
                     let job = Job { input, handle, cache_key, on_ready, profiler };
                     this.queue_shader_check_job(job);
                 }
                 (None, Some(fragment)) => {
                     let input = fragment.native;
-                    let handle = job.handle;
-                    let on_ready = job.on_ready;
-                    let cache_key = job.cache_key;
                     let job = Job { input, handle, cache_key, on_ready, profiler };
                     this.queue_shader_check_job(job);
                 }

From 4332f686b9d3c5cbd4fc872ece88c2a00186298b Mon Sep 17 00:00:00 2001
From: Kaz Wesley <kaz@lambdaverse.org>
Date: Tue, 14 Feb 2023 21:00:24 +0000
Subject: [PATCH 11/16] fix & cleanup

---
 lib/rust/ensogl/core/src/display/scene.rs     | 25 ------
 .../src/display/shape/primitive/system.rs     | 65 ++++------------
 .../ensogl/core/src/display/symbol/gpu.rs     | 19 +++--
 lib/rust/ensogl/core/src/display/world.rs     | 76 +++++++++----------
 lib/rust/ensogl/core/src/lib.rs               |  1 -
 .../core/src/system/gpu/context/extension.rs  |  3 +-
 lib/rust/ensogl/core/src/system/gpu/shader.rs | 10 ++-
 .../core/src/system/gpu/shader/compiler.rs    | 46 +++++------
 8 files changed, 87 insertions(+), 158 deletions(-)

diff --git a/lib/rust/ensogl/core/src/display/scene.rs b/lib/rust/ensogl/core/src/display/scene.rs
index 7b02746ba0d5..91cf84d9a8af 100644
--- a/lib/rust/ensogl/core/src/display/scene.rs
+++ b/lib/rust/ensogl/core/src/display/scene.rs
@@ -719,7 +719,6 @@ pub struct SceneData {
     display_mode: Rc<Cell<glsl::codes::DisplayModes>>,
     extensions: Extensions,
     disable_context_menu: Rc<EventListenerHandle>,
-    persistent_shaders: Rc<RefCell<Vec<shader::Code>>>,
 }
 
 impl SceneData {
@@ -767,7 +766,6 @@ impl SceneData {
         let context_lost_handler = default();
         let pointer_position_changed = default();
         let shader_compiler = default();
-        let persistent_shaders = default();
         Self {
             display_object,
             display_mode,
@@ -793,7 +791,6 @@ impl SceneData {
             shader_compiler,
             extensions,
             disable_context_menu,
-            persistent_shaders,
         }
         .init()
     }
@@ -811,20 +808,6 @@ impl SceneData {
         *self.context.borrow_mut() = context.cloned();
         self.dirty.shape.set();
         self.renderer.set_context(context);
-        if let Some(context) = context {
-            /*
-            if self.persistent_shaders.borrow().is_empty() {
-                *self.persistent_shaders.borrow_mut() = world::get_persistent_shaders();
-            }
-             */
-            for code in self.persistent_shaders.borrow().iter() {
-                let code = shader::Sources {
-                    fragment: Some(code.fragment.clone()),
-                    vertex: Some(code.vertex.clone()),
-                };
-                context.shader_compiler.submit_background_job(code);
-            }
-        }
     }
 
     pub fn shape(&self) -> &frp::Sampler<Shape> {
@@ -954,14 +937,6 @@ impl SceneData {
         let world_space = camera.inversed_view_projection_matrix() * clip_space;
         (inv_object_matrix * world_space).xy()
     }
-
-    pub fn set_persistent_shaders(&self, shaders: Vec<shader::Code>) {
-        *self.persistent_shaders.borrow_mut() = shaders;
-    }
-
-    pub fn debug_layer_contents(&self) {
-        warn!("{:?}", &self.layers);
-    }
 }
 
 
diff --git a/lib/rust/ensogl/core/src/display/shape/primitive/system.rs b/lib/rust/ensogl/core/src/display/shape/primitive/system.rs
index c5ac019d6d61..a0e9e1fa3ea4 100644
--- a/lib/rust/ensogl/core/src/display/shape/primitive/system.rs
+++ b/lib/rust/ensogl/core/src/display/shape/primitive/system.rs
@@ -60,7 +60,6 @@
 //! shape system will be detached from the parent display object (and not attached to another one),
 //! it will also be moved to the `DETACHED` layer.
 
-use std::fmt::Formatter;
 use crate::prelude::*;
 use crate::system::gpu::types::*;
 
@@ -84,63 +83,21 @@ use super::def;
 // =====================
 
 /// The ID of a user generated shape system.
-#[derive(Copy, Clone, CloneRef, Eq, Hash, Ord, PartialOrd, PartialEq, Debug)]
+#[derive(Copy, Clone, Eq, Hash, Ord, PartialOrd, PartialEq, Debug)]
 pub struct ShapeSystemId {
-    definition_path: DistinctStr,
+    type_id: std::any::TypeId,
 }
 
 impl ShapeSystemId {
+    /// Return an identifier unique to the given [`Shape`] type.
     #[inline(always)]
     pub fn of<S: Shape>() -> Self {
-        let definition_path = DistinctStr::new_unchecked(S::definition_path());
-        Self { definition_path }
+        let type_id = std::any::TypeId::of::<S>();
+        Self { type_id }
     }
 }
 
-
-////////
-
-#[derive(Copy, Clone, Eq, Ord)]
-pub struct DistinctStr(&'static str);
-
-impl DistinctStr {
-    /// Cast the input to a [`DistinctStr`].
-    #[inline(always)]
-    const fn new_unchecked(s: &'static str) -> Self {
-        Self(s)
-    }
-}
-
-impl PartialEq for DistinctStr {
-    #[inline(always)]
-    fn eq(&self, other: &Self) -> bool {
-        self.0.as_ptr() == other.0.as_ptr()
-    }
-}
-
-impl PartialOrd for DistinctStr {
-    #[inline(always)]
-    fn partial_cmp(&self, other: &Self) -> Option<std::cmp::Ordering> {
-        self.0.as_ptr().partial_cmp(&other.0.as_ptr())
-    }
-}
-
-impl Hash for DistinctStr {
-    #[inline(always)]
-    fn hash<H: Hasher>(&self, state: &mut H) {
-        self.0.as_ptr().hash(state)
-    }
-}
-
-impl Debug for DistinctStr {
-    #[inline(always)]
-    fn fmt(&self, f: &mut Formatter<'_>) -> fmt::Result {
-        write!(f, "{:?}", self.0)
-    }
-}
-
-impl CloneRef for DistinctStr {
-    #[inline(always)]
+impl CloneRef for ShapeSystemId {
     fn clone_ref(&self) -> Self {
         *self
     }
@@ -933,8 +890,14 @@ macro_rules! _shape {
             #[before_main]
             pub fn register_shape() {
                 $crate::display::world::SHAPES_DEFINITIONS.with(|shapes| {
-                    let path = Shape::definition_path();
-                    shapes.borrow_mut().push((path, Box::new(|| Box::new(View::new()))));
+                    let definition_path = Shape::definition_path();
+                    let cons = Box::new(|| {
+                        let view: Box<dyn $crate::gui::component::AnyShapeView> =
+                            Box::new(View::new());
+                        view
+                    });
+                    let def = $crate::display::world::ShapeDefinition { definition_path, cons };
+                    shapes.borrow_mut().push(def);
                 });
             }
 
diff --git a/lib/rust/ensogl/core/src/display/symbol/gpu.rs b/lib/rust/ensogl/core/src/display/symbol/gpu.rs
index e08d269572ce..7c68954af2af 100644
--- a/lib/rust/ensogl/core/src/display/symbol/gpu.rs
+++ b/lib/rust/ensogl/core/src/display/symbol/gpu.rs
@@ -405,17 +405,20 @@ impl Symbol {
     }
 
     /// For each variable from the shader definition, looks up its position in geometry scopes.
-    pub fn discover_variable_bindings(
+    fn discover_variable_bindings(
         &self,
         global_variables: &UniformScope,
     ) -> Vec<shader::VarBinding> {
-        self.shader.collect_variables().map(|(name, decl)| {
-            let scope = self.lookup_variable(&name, global_variables);
-            if scope.is_none() {
-                warn!("Unable to bind variable '{name}' to geometry buffer.");
-            }
-            shader::VarBinding::new(name, decl, scope)
-        }).collect()
+        self.shader
+            .collect_variables()
+            .map(|(name, decl)| {
+                let scope = self.lookup_variable(&name, global_variables);
+                if scope.is_none() {
+                    warn!("Unable to bind variable '{name}' to geometry buffer.");
+                }
+                shader::VarBinding::new(name, decl, scope)
+            })
+            .collect()
     }
 
     /// Runs the provided function in a context of active program and active VAO. After the function
diff --git a/lib/rust/ensogl/core/src/display/world.rs b/lib/rust/ensogl/core/src/display/world.rs
index fc0f5f575602..03b9e6b7f3b2 100644
--- a/lib/rust/ensogl/core/src/display/world.rs
+++ b/lib/rust/ensogl/core/src/display/world.rs
@@ -87,6 +87,17 @@ fn init_context() {
 /// A constructor of view of some specific shape.
 pub type ShapeCons = Box<dyn Fn() -> Box<dyn crate::gui::component::AnyShapeView>>;
 
+/// The definition of shapes created with the `shape!` macro.
+#[derive(Derivative)]
+#[derivative(Debug)]
+pub struct ShapeDefinition {
+    /// Location in the source code that the shape was defined.
+    pub definition_path: &'static str,
+    /// A constructor of single shape view.
+    #[derivative(Debug = "ignore")]
+    pub cons:            ShapeCons,
+}
+
 /// The definition of shapes created with the `cached_shape!` macro.
 #[derive(Derivative)]
 #[derivative(Debug)]
@@ -101,7 +112,7 @@ pub struct CachedShapeDefinition {
 thread_local! {
     /// All shapes defined with the `shape!` macro. They will be populated on the beginning of
     /// program execution, before the `main` function is called.
-    pub static SHAPES_DEFINITIONS: RefCell<Vec<(&'static str, ShapeCons)>> = default();
+    pub static SHAPES_DEFINITIONS: RefCell<Vec<ShapeDefinition>> = default();
 
     /// All shapes defined with the `cached_shape!` macro. They will be populated on the beginning
     /// of program execution, before the `main` function is called.
@@ -178,8 +189,8 @@ fn gather_shaders() -> HashMap<&'static str, shader::Code> {
     with_context(|t| t.run_mode.set(RunMode::ShaderExtraction));
     let mut map = HashMap::new();
     SHAPES_DEFINITIONS.with(|shapes| {
-        for (_, shape_cons) in shapes.borrow().iter() {
-            let shape = shape_cons();
+        for shape in shapes.borrow().iter() {
+            let shape = (shape.cons)();
             let path = shape.definition_path();
             let code = shape.abstract_shader_code_in_glsl_310();
             map.insert(path, code);
@@ -189,43 +200,28 @@ fn gather_shaders() -> HashMap<&'static str, shader::Code> {
     map
 }
 
-/// Returns the source code for shaders that should be compiled as soon as a context is available.
-pub fn get_persistent_shaders() -> Vec<shader::Code> { // variables: &UniformScope
-    let mut shaders = vec![];
-    //PRECOMPILED_SHADERS.with_borrow(|shaders| info!("PRECOMPILED_SHADERS: {shaders:?}"));
+
+
+// ===================================
+// === Eager shaders instantiation ===
+// ===================================
+
+/// Begin compilation of all shaders that will be needed for the default scene.
+#[profile(Task)]
+pub fn instantiate_shaders() {
     SHAPES_DEFINITIONS.with_borrow(|shapes| {
-        with_context(|t| {
-            //let layer = &t.layers.root;
-            for (path, shape_cons) in shapes {
-                let do_it = match path {
-                    //_ if path.starts_with("app/gui/view/component-browser") => true,
-                    _ => true,
-                };
-                if do_it {
-                    let shape = shape_cons();
-                }
-                //scene().add_child(&*shape);
-                //layer.add(&*shape);
-                //mem::forget(shape);
-                //let shape: Box<dyn display::Object> = shape_cons();
-                //layer.remove(&*shape);
-                //mem::forget(shape);
+        for shape in shapes {
+            let path = &shape.definition_path;
+            let preload = match path {
+                _ if path.starts_with("app/gui/view/debug_scene/") => false,
+                _ if path.starts_with("lib/rust/ensogl/example/") => false,
+                _ => true,
+            };
+            if preload {
+                let _shape = (shape.cons)();
             }
-        });
-    });
-    /*
-    SHAPES_DEFINITIONS.with_borrow(|shapes| {
-        for shape_cons in shapes {
-            let symbol = &shape_cons().sprite().symbol;
-            let bindings = symbol.discover_variable_bindings(variables);
-            let shader = symbol.shader();
-            let version = crate::system::gpu::shader::glsl::Version::V300;
-            let code = shader.gen_gpu_code(version, &bindings);
-            shaders.push(code);
         }
     });
-     */
-    shaders
 }
 
 
@@ -442,7 +438,6 @@ pub struct WorldData {
 impl WorldData {
     /// Create and initialize new world instance.
     pub fn new(frp: &api::private::Output) -> Self {
-        get_persistent_shaders();
         let frp = frp.clone_ref();
         let stats = Stats::new(web::window.performance_or_panic());
         let stats_monitor = debug::monitor::Monitor::new();
@@ -451,8 +446,7 @@ impl WorldData {
         let on_change = f!(scene_dirty.set());
         let display_mode = Rc::<Cell<glsl::codes::DisplayModes>>::default();
         let default_scene = Scene::new(&stats, on_change, &display_mode);
-        let variables = &default_scene.variables;
-        let uniforms = Uniforms::new(variables);
+        let uniforms = Uniforms::new(&default_scene.variables);
         let debug_hotkeys_handle = default();
         let garbage_collector = default();
         let stats_draw_handle = on.prev_frame_stats.add(f!([stats_monitor] (stats: &StatsData) {
@@ -486,6 +480,7 @@ impl WorldData {
         self.init_environment();
         self.init_composer();
         self.init_debug_hotkeys();
+        instantiate_shaders();
         self
     }
 
@@ -498,7 +493,6 @@ impl WorldData {
         let display_mode = self.display_mode.clone_ref();
         let display_mode_uniform = self.uniforms.display_mode.clone_ref();
         let emit_measurements_handle = self.emit_measurements_handle.clone_ref();
-        let scene = self.default_scene.clone_ref();
         let closure: Closure<dyn Fn(JsValue)> = Closure::new(move |val: JsValue| {
             let event = val.unchecked_into::<web::KeyboardEvent>();
             let digit_prefix = "Digit";
@@ -521,8 +515,6 @@ impl WorldData {
                 } else if key == "KeyQ" {
                     enso_debug_api::save_profile(&profiler::internal::get_log());
                     enso_debug_api::LifecycleController::new().map(|api| api.quit());
-                } else if key == "KeyL" {
-                    scene.debug_layer_contents();
                 } else if key.starts_with(digit_prefix) {
                     let code_value = key.trim_start_matches(digit_prefix).parse().unwrap_or(0);
                     if let Some(mode) = glsl::codes::DisplayModes::from_value(code_value) {
diff --git a/lib/rust/ensogl/core/src/lib.rs b/lib/rust/ensogl/core/src/lib.rs
index a59da12729d3..f53d9a8116fa 100644
--- a/lib/rust/ensogl/core/src/lib.rs
+++ b/lib/rust/ensogl/core/src/lib.rs
@@ -25,7 +25,6 @@
 #![feature(auto_traits)]
 #![feature(int_roundings)]
 #![feature(let_chains)]
-#![feature(trait_upcasting)]
 // === Standard Linter Configuration ===
 #![deny(non_ascii_idents)]
 #![warn(unsafe_code)]
diff --git a/lib/rust/ensogl/core/src/system/gpu/context/extension.rs b/lib/rust/ensogl/core/src/system/gpu/context/extension.rs
index 35a3f9ed75e3..87f733caab78 100644
--- a/lib/rust/ensogl/core/src/system/gpu/context/extension.rs
+++ b/lib/rust/ensogl/core/src/system/gpu/context/extension.rs
@@ -4,8 +4,9 @@ use crate::prelude::*;
 
 use crate::system::gpu::data::GlEnum;
 
-use web_sys::{WebGl2RenderingContext, WebGlShader};
+use web_sys::WebGl2RenderingContext;
 use web_sys::WebGlProgram;
+use web_sys::WebGlShader;
 
 
 
diff --git a/lib/rust/ensogl/core/src/system/gpu/shader.rs b/lib/rust/ensogl/core/src/system/gpu/shader.rs
index 357a3e1f8290..4d05c1b63fc0 100644
--- a/lib/rust/ensogl/core/src/system/gpu/shader.rs
+++ b/lib/rust/ensogl/core/src/system/gpu/shader.rs
@@ -73,8 +73,11 @@ pub type Code = Sources<String, String>;
 pub type CompiledCode = Sources<Shader<Vertex>, Shader<Fragment>>;
 
 impl<V, F> Sources<V, F> {
-    /// Apply a [`Into::into`] to the [`vertex`] and [`fragment`] elements and return the result.
-    pub fn into<V1, F1>(self) -> Sources<V1, F1> where V: Into<V1>, F: Into<F1> {
+    /// Apply [`Into::into`] to the [`vertex`] and [`fragment`] elements and return the result.
+    pub fn into<V1, F1>(self) -> Sources<V1, F1>
+    where
+        V: Into<V1>,
+        F: Into<F1>, {
         let Sources { vertex, fragment } = self;
         let vertex = vertex.into();
         let fragment = fragment.into();
@@ -92,7 +95,8 @@ impl<V, F> Sources<V, F> {
 
 impl<VF> Sources<VF, VF> {
     /// Apply a function to the [`vertex`] and [`fragment`] elements and return the result.
-    pub fn map<VF1, F>(self, f: F) -> Sources<VF1, VF1> where F: Fn(VF) -> VF1 {
+    pub fn map<VF1, F>(self, f: F) -> Sources<VF1, VF1>
+    where F: Fn(VF) -> VF1 {
         let Sources { vertex, fragment } = self;
         let vertex = f(vertex);
         let fragment = f(fragment);
diff --git a/lib/rust/ensogl/core/src/system/gpu/shader/compiler.rs b/lib/rust/ensogl/core/src/system/gpu/shader/compiler.rs
index ee1457de29dc..94fde29afc63 100644
--- a/lib/rust/ensogl/core/src/system/gpu/shader/compiler.rs
+++ b/lib/rust/ensogl/core/src/system/gpu/shader/compiler.rs
@@ -67,7 +67,7 @@ const FRAME_TIME_THRESHOLD: Duration = (1000.0 / FPS_THRESHOLD).ms();
 /// a crude form of backpressure by blocking until all pending jobs complete. We are not sure if it
 /// is a feature or a bug. To learn more about our findings so far, see:
 /// https://github.com/enso-org/enso/pull/3378#issuecomment-1090958946
-const MAX_PARALLEL_COMPILE_JOBS: usize = 2000;
+const MAX_PARALLEL_COMPILE_JOBS: usize = 16;
 
 
 
@@ -238,7 +238,6 @@ impl Compiler {
         profiler: profiler::Debug,
         on_ready: F,
     ) -> JobHandle {
-        //info!("submit: {}", &input.fragment);
         let strong_handle = JobHandle::new();
         let handle = strong_handle.downgrade();
         let on_ready: Box<dyn FnOnce(shader::Program)> = Box::new(on_ready);
@@ -288,13 +287,13 @@ impl CompilerData {
     ) {
         let cache_key = ShaderCache::code_key(&input);
         match self.cache.get_program(cache_key) {
-            Some(ProgramCacheEntry::Submitted) => {
+            Some(ProgramCacheEntry::Submitted { waiters }) => {
                 debug!("Awaiting shader compilation {cache_key:?}.");
                 // This shader is currently being processed by another job. Create a new job that
                 // will wait for that job to finish.
                 let job = Job { input: (), handle, on_ready, profiler, cache_key };
-                self.cache.add_to_waiting_list(job);
-                self.dirty = true;
+                waiters.push(job);
+                debug_assert!(self.dirty);
             }
             Some(ProgramCacheEntry::Validated(program)) => {
                 debug!("Reusing cached shader {cache_key:?}.");
@@ -394,8 +393,8 @@ impl CompilerData {
     /// it is costly and can prevent the parallelism altogether. To learn more, see:
     /// https://developer.mozilla.org/en-US/docs/Web/API/WebGL_API/WebGL_best_practices#dont_check_shader_compile_status_unless_linking_fails
     fn current_parallel_job_count(&self) -> usize {
+        // [`compile`] is the only excluded queue, because those jobs are waiting to start.
         [
-            self.jobs.compile.len(),
             self.jobs.compile_poll.len(),
             self.jobs.compile_check.len(),
             self.jobs.link.len(),
@@ -561,7 +560,7 @@ impl CompilerData {
                 } else {
                     // No waiting jobs, cancel the compilation process.
                     self.cache.program_canceled(cache_key);
-                    trace!("Job handle dropped, skipping.");
+                    info!("Job handle dropped, skipping.");
                     continue;
                 }
             }
@@ -615,13 +614,12 @@ struct ShaderCache {
     vertex_shaders:   HashMap<ShaderHash, Shader<Vertex>>,
     fragment_shaders: HashMap<ShaderHash, Shader<Fragment>>,
     programs:         HashMap<ShaderCacheKey, ProgramCacheEntry>,
-    waiting_jobs:     HashMap<ShaderCacheKey, Vec<Job<()>>>,
 }
 
-#[derive(Debug, Clone)]
+#[derive(Debug)]
 enum ProgramCacheEntry {
     /// Shader program is already submitted for compilation.
-    Submitted,
+    Submitted { waiters: Vec<Job<()>> },
     /// Shader program was already compiled and linked successfully.
     Validated(shader::Program),
     /// Compilation of this shader program already failed.
@@ -634,38 +632,33 @@ impl ShaderCache {
         code.as_ref().map(|shader| shader.as_ref().map(ShaderHash::new))
     }
 
-    fn get_program(&self, key: ShaderCacheKey) -> Option<&ProgramCacheEntry> {
-        self.programs.get(&key)
-    }
-
-    fn add_to_waiting_list(&mut self, job: Job<()>) {
-        self.waiting_jobs.entry(job.cache_key).or_default().push(job);
+    fn get_program(&mut self, key: ShaderCacheKey) -> Option<&mut ProgramCacheEntry> {
+        self.programs.get_mut(&key)
     }
 
     /// Get single job that is awaiting for the completed compilation under specific cache entry.
     /// Only returns jobs that were not cancelled yet. All jobs that were scanned and found to be
     /// cancelled will be removed from the waiting list to avoid processing them in the future.
     fn take_next_waiting_job(&mut self, key: ShaderCacheKey) -> Option<Job<()>> {
-        let jobs = self.waiting_jobs.get_mut(&key)?;
-        while let Some(job) = jobs.pop() {
-            if !job.is_cancelled() {
-                return Some(job);
+        if let Some(ProgramCacheEntry::Submitted { waiters }) = self.get_program(key) {
+            while let Some(job) = waiters.pop() {
+                if !job.is_cancelled() {
+                    return Some(job);
+                }
             }
         }
         None
     }
 
     fn program_submitted(&mut self, key: ShaderCacheKey) {
-        self.programs.insert(key, ProgramCacheEntry::Submitted);
+        self.programs.insert(key, ProgramCacheEntry::Submitted { waiters: default() });
     }
 
     fn program_failed(&mut self, key: ShaderCacheKey) {
-        self.waiting_jobs.remove(&key);
         self.programs.insert(key, ProgramCacheEntry::Failed);
     }
 
     fn program_canceled(&mut self, key: ShaderCacheKey) {
-        self.waiting_jobs.remove(&key);
         self.programs.remove(&key);
     }
 
@@ -675,8 +668,7 @@ impl ShaderCache {
         program: shader::Program,
         on_ready: Option<impl FnOnce(shader::Program)>,
     ) {
-        self.programs.insert(key, ProgramCacheEntry::Validated(program.clone()));
-
+        let entry = self.programs.insert(key, ProgramCacheEntry::Validated(program.clone()));
         // Complete all jobs that were scheduled for this program. This must be done after the cache
         // entry is updated, in case the job callback schedules another compilation of the same
         // shader program. We want those submissions to recognize cache status as validated and
@@ -684,8 +676,8 @@ impl ShaderCache {
         if let Some(on_ready) = on_ready {
             on_ready(program.clone());
         }
-        if let Some(jobs) = self.waiting_jobs.remove(&key) {
-            for job in jobs {
+        if let Some(ProgramCacheEntry::Submitted { waiters }) = entry {
+            for job in waiters {
                 if !job.is_cancelled() {
                     if let Some(on_ready) = job.on_ready {
                         (on_ready)(program.clone());

From efcd01de6d5cd1f399c532d6e43bdbbd36cff78c Mon Sep 17 00:00:00 2001
From: Kaz Wesley <kaz@lambdaverse.org>
Date: Mon, 20 Feb 2023 17:05:41 +0000
Subject: [PATCH 12/16] Apply review.

---
 Cargo.toml                                    |  2 +-
 app/gui/Cargo.toml                            |  2 +-
 app/gui/docs/CONTRIBUTING.md                  |  2 +-
 build/intellij-run-config-gen/src/main.rs     |  2 +-
 .../src/display/shape/primitive/system.rs     |  8 +------
 .../core/src/display/symbol/gpu/shader.rs     |  2 +-
 lib/rust/ensogl/core/src/display/world.rs     | 23 +++++++++++--------
 .../ensogl/{example => examples}/Cargo.toml   |  0
 .../animation/Cargo.toml                      |  0
 .../animation/src/lib.rs                      |  0
 .../auto-layout/Cargo.toml                    |  0
 .../auto-layout/src/lib.rs                    |  0
 .../cached-shape/Cargo.toml                   |  0
 .../cached-shape/src/lib.rs                   |  0
 .../complex-shape-system/Cargo.toml           |  0
 .../complex-shape-system/src/lib.rs           |  0
 .../custom-shape-system/Cargo.toml            |  0
 .../custom-shape-system/src/lib.rs            |  0
 .../dom-symbols/Cargo.toml                    |  0
 .../dom-symbols/src/lib.rs                    |  0
 .../drop-down/Cargo.toml                      |  0
 .../drop-down/src/lib.rs                      |  0
 .../drop-manager/Cargo.toml                   |  0
 .../drop-manager/src/lib.rs                   |  0
 .../easing-animator/Cargo.toml                |  0
 .../easing-animator/src/lib.rs                |  0
 .../focus-management/Cargo.toml               |  0
 .../focus-management/src/lib.rs               |  0
 .../grid-view/Cargo.toml                      |  0
 .../grid-view/src/lib.rs                      |  0
 .../list-view/Cargo.toml                      |  0
 .../list-view/src/lib.rs                      |  0
 .../mouse-events/Cargo.toml                   |  0
 .../mouse-events/src/lib.rs                   |  0
 .../profiling-run-graph/Cargo.toml            |  0
 .../profiling-run-graph/src/lib.rs            |  0
 .../render-profile-flamegraph/Cargo.toml      |  0
 .../render-profile-flamegraph/src/lib.rs      |  0
 .../scroll-area/Cargo.toml                    |  0
 .../scroll-area/src/lib.rs                    |  0
 .../{example => examples}/slider/Cargo.toml   |  0
 .../{example => examples}/slider/src/lib.rs   |  0
 .../sprite-system-benchmark/Cargo.toml        |  0
 .../sprite-system-benchmark/src/lib.rs        |  0
 .../sprite-system/Cargo.toml                  |  0
 .../sprite-system/src/lib.rs                  |  0
 .../ensogl/{example => examples}/src/lib.rs   |  0
 .../text-area/Cargo.toml                      |  0
 .../text-area/src/lib.rs                      |  0
 49 files changed, 19 insertions(+), 22 deletions(-)
 rename lib/rust/ensogl/{example => examples}/Cargo.toml (100%)
 rename lib/rust/ensogl/{example => examples}/animation/Cargo.toml (100%)
 rename lib/rust/ensogl/{example => examples}/animation/src/lib.rs (100%)
 rename lib/rust/ensogl/{example => examples}/auto-layout/Cargo.toml (100%)
 rename lib/rust/ensogl/{example => examples}/auto-layout/src/lib.rs (100%)
 rename lib/rust/ensogl/{example => examples}/cached-shape/Cargo.toml (100%)
 rename lib/rust/ensogl/{example => examples}/cached-shape/src/lib.rs (100%)
 rename lib/rust/ensogl/{example => examples}/complex-shape-system/Cargo.toml (100%)
 rename lib/rust/ensogl/{example => examples}/complex-shape-system/src/lib.rs (100%)
 rename lib/rust/ensogl/{example => examples}/custom-shape-system/Cargo.toml (100%)
 rename lib/rust/ensogl/{example => examples}/custom-shape-system/src/lib.rs (100%)
 rename lib/rust/ensogl/{example => examples}/dom-symbols/Cargo.toml (100%)
 rename lib/rust/ensogl/{example => examples}/dom-symbols/src/lib.rs (100%)
 rename lib/rust/ensogl/{example => examples}/drop-down/Cargo.toml (100%)
 rename lib/rust/ensogl/{example => examples}/drop-down/src/lib.rs (100%)
 rename lib/rust/ensogl/{example => examples}/drop-manager/Cargo.toml (100%)
 rename lib/rust/ensogl/{example => examples}/drop-manager/src/lib.rs (100%)
 rename lib/rust/ensogl/{example => examples}/easing-animator/Cargo.toml (100%)
 rename lib/rust/ensogl/{example => examples}/easing-animator/src/lib.rs (100%)
 rename lib/rust/ensogl/{example => examples}/focus-management/Cargo.toml (100%)
 rename lib/rust/ensogl/{example => examples}/focus-management/src/lib.rs (100%)
 rename lib/rust/ensogl/{example => examples}/grid-view/Cargo.toml (100%)
 rename lib/rust/ensogl/{example => examples}/grid-view/src/lib.rs (100%)
 rename lib/rust/ensogl/{example => examples}/list-view/Cargo.toml (100%)
 rename lib/rust/ensogl/{example => examples}/list-view/src/lib.rs (100%)
 rename lib/rust/ensogl/{example => examples}/mouse-events/Cargo.toml (100%)
 rename lib/rust/ensogl/{example => examples}/mouse-events/src/lib.rs (100%)
 rename lib/rust/ensogl/{example => examples}/profiling-run-graph/Cargo.toml (100%)
 rename lib/rust/ensogl/{example => examples}/profiling-run-graph/src/lib.rs (100%)
 rename lib/rust/ensogl/{example => examples}/render-profile-flamegraph/Cargo.toml (100%)
 rename lib/rust/ensogl/{example => examples}/render-profile-flamegraph/src/lib.rs (100%)
 rename lib/rust/ensogl/{example => examples}/scroll-area/Cargo.toml (100%)
 rename lib/rust/ensogl/{example => examples}/scroll-area/src/lib.rs (100%)
 rename lib/rust/ensogl/{example => examples}/slider/Cargo.toml (100%)
 rename lib/rust/ensogl/{example => examples}/slider/src/lib.rs (100%)
 rename lib/rust/ensogl/{example => examples}/sprite-system-benchmark/Cargo.toml (100%)
 rename lib/rust/ensogl/{example => examples}/sprite-system-benchmark/src/lib.rs (100%)
 rename lib/rust/ensogl/{example => examples}/sprite-system/Cargo.toml (100%)
 rename lib/rust/ensogl/{example => examples}/sprite-system/src/lib.rs (100%)
 rename lib/rust/ensogl/{example => examples}/src/lib.rs (100%)
 rename lib/rust/ensogl/{example => examples}/text-area/Cargo.toml (100%)
 rename lib/rust/ensogl/{example => examples}/text-area/src/lib.rs (100%)

diff --git a/Cargo.toml b/Cargo.toml
index edd028090a0c..19626d1583fb 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -1,7 +1,7 @@
 [workspace]
 resolver = "2"
 # Listing only the "root" crates of each app/library. All path dependencies are included in the workspace automatically.
-# If you want to add sub crate (like `app/gui/config` or `lib/rust/ensogl/example`), just add it as a path dependency
+# If you want to add sub crate (like `app/gui/config` or `lib/rust/ensogl/examples`), just add it as a path dependency
 # where plausible.
 members = [
   "app/gui",
diff --git a/app/gui/Cargo.toml b/app/gui/Cargo.toml
index 1361dab8cd06..124f1657f23d 100644
--- a/app/gui/Cargo.toml
+++ b/app/gui/Cargo.toml
@@ -25,7 +25,7 @@ enso-text = { path = "../../lib/rust/text" }
 enso-web = { path = "../../lib/rust/web" }
 enso-suggestion-database = { path = "suggestion-database" }
 ensogl = { path = "../../lib/rust/ensogl" }
-ensogl-examples = { path = "../../lib/rust/ensogl/example" }
+ensogl-examples = { path = "../../lib/rust/ensogl/examples" }
 ensogl-component = { path = "../../lib/rust/ensogl/component" }
 ensogl-text-msdf = { path = "../../lib/rust/ensogl/component/text/src/font/msdf" }
 ensogl-hardcoded-theme = { path = "../../lib/rust/ensogl/app/theme/hardcoded" }
diff --git a/app/gui/docs/CONTRIBUTING.md b/app/gui/docs/CONTRIBUTING.md
index 068d7266298c..d4f04fcaef47 100644
--- a/app/gui/docs/CONTRIBUTING.md
+++ b/app/gui/docs/CONTRIBUTING.md
@@ -210,7 +210,7 @@ below:
 - **Selective mode** In order to compile only part of the project, and thus
   drastically shorten the incremental compile time, you are advised to use the
   selective compilation mode by passing the `--crate-path` option to the `build`
-  or `watch` command, e.g. `./run ide watch --crate-path ensogl/example` to
+  or `watch` command, e.g. `./run ide watch --crate-path ensogl/examples` to
   compile only the renderer-related example scenes. Please note, that in order
   to run a scene in a web-browser, the scene has to be compiled and has to
   expose a public function with a name starting with `entry_point_`. Thus, if
diff --git a/build/intellij-run-config-gen/src/main.rs b/build/intellij-run-config-gen/src/main.rs
index ba174311698f..f642189b1b4e 100644
--- a/build/intellij-run-config-gen/src/main.rs
+++ b/build/intellij-run-config-gen/src/main.rs
@@ -83,7 +83,7 @@ const DIR_BLACK_LIST: &[&str] = &["target", "dist"];
 const FOLDER_TO_HEADER_MAP: &[(&str, &str, usize)] = &[
     ("build/", "🚧 Build", 10),
     ("tools/", "🔨 Tools", 9),
-    ("lib/rust/ensogl/example/", "🧸 Example", 4),
+    ("lib/rust/ensogl/examples/", "🧸 Example", 4),
     ("lib/rust/ensogl/", "🎨 EnsoGl", 6),
     ("lib/rust/ensogl", "🎨 EnsoGl", 0),
     ("lib/rust/parser/", "👓 Parser", 7),
diff --git a/lib/rust/ensogl/core/src/display/shape/primitive/system.rs b/lib/rust/ensogl/core/src/display/shape/primitive/system.rs
index a0e9e1fa3ea4..35216f877a5a 100644
--- a/lib/rust/ensogl/core/src/display/shape/primitive/system.rs
+++ b/lib/rust/ensogl/core/src/display/shape/primitive/system.rs
@@ -83,7 +83,7 @@ use super::def;
 // =====================
 
 /// The ID of a user generated shape system.
-#[derive(Copy, Clone, Eq, Hash, Ord, PartialOrd, PartialEq, Debug)]
+#[derive(Copy, Clone, CloneRef, Eq, Hash, Ord, PartialOrd, PartialEq, Debug)]
 pub struct ShapeSystemId {
     type_id: std::any::TypeId,
 }
@@ -97,12 +97,6 @@ impl ShapeSystemId {
     }
 }
 
-impl CloneRef for ShapeSystemId {
-    fn clone_ref(&self) -> Self {
-        *self
-    }
-}
-
 
 
 // =============
diff --git a/lib/rust/ensogl/core/src/display/symbol/gpu/shader.rs b/lib/rust/ensogl/core/src/display/symbol/gpu/shader.rs
index ffcd065a6533..dfe4564a7401 100644
--- a/lib/rust/ensogl/core/src/display/symbol/gpu/shader.rs
+++ b/lib/rust/ensogl/core/src/display/symbol/gpu/shader.rs
@@ -207,7 +207,7 @@ impl {
         let geometry_inputs = self.geometry_material.inputs().iter();
         let surface_inputs = self.surface_material.inputs().iter();
         geometry_inputs.chain(surface_inputs)
-            .map(|(s, d)| (s.clone(), d.clone()))
+            .map(|(name, declaration)| (name.clone(), declaration.clone()))
             .collect_vec()
             .into_iter()
     }
diff --git a/lib/rust/ensogl/core/src/display/world.rs b/lib/rust/ensogl/core/src/display/world.rs
index 03b9e6b7f3b2..e7e76e743d51 100644
--- a/lib/rust/ensogl/core/src/display/world.rs
+++ b/lib/rust/ensogl/core/src/display/world.rs
@@ -98,6 +98,14 @@ pub struct ShapeDefinition {
     pub cons:            ShapeCons,
 }
 
+impl ShapeDefinition {
+    /// Return `true` if it is possible that this shape is used by the main application.
+    fn is_main_application_shape(&self) -> bool {
+        // Shapes defined in `examples` directories are not used in the main application.
+        !self.definition_path.contains("/examples/")
+    }
+}
+
 /// The definition of shapes created with the `cached_shape!` macro.
 #[derive(Derivative)]
 #[derivative(Debug)]
@@ -210,16 +218,11 @@ fn gather_shaders() -> HashMap<&'static str, shader::Code> {
 #[profile(Task)]
 pub fn instantiate_shaders() {
     SHAPES_DEFINITIONS.with_borrow(|shapes| {
-        for shape in shapes {
-            let path = &shape.definition_path;
-            let preload = match path {
-                _ if path.starts_with("app/gui/view/debug_scene/") => false,
-                _ if path.starts_with("lib/rust/ensogl/example/") => false,
-                _ => true,
-            };
-            if preload {
-                let _shape = (shape.cons)();
-            }
+        for shape in shapes.iter().filter(|shape| shape.is_main_application_shape()) {
+            // Instantiate shape so that its shader program will be submitted to the shader
+            // compiler. The runtime compiles the shaders in background threads, and starting early
+            // ensures they will be ready when we want to render them.
+            let _shape = (shape.cons)();
         }
     });
 }
diff --git a/lib/rust/ensogl/example/Cargo.toml b/lib/rust/ensogl/examples/Cargo.toml
similarity index 100%
rename from lib/rust/ensogl/example/Cargo.toml
rename to lib/rust/ensogl/examples/Cargo.toml
diff --git a/lib/rust/ensogl/example/animation/Cargo.toml b/lib/rust/ensogl/examples/animation/Cargo.toml
similarity index 100%
rename from lib/rust/ensogl/example/animation/Cargo.toml
rename to lib/rust/ensogl/examples/animation/Cargo.toml
diff --git a/lib/rust/ensogl/example/animation/src/lib.rs b/lib/rust/ensogl/examples/animation/src/lib.rs
similarity index 100%
rename from lib/rust/ensogl/example/animation/src/lib.rs
rename to lib/rust/ensogl/examples/animation/src/lib.rs
diff --git a/lib/rust/ensogl/example/auto-layout/Cargo.toml b/lib/rust/ensogl/examples/auto-layout/Cargo.toml
similarity index 100%
rename from lib/rust/ensogl/example/auto-layout/Cargo.toml
rename to lib/rust/ensogl/examples/auto-layout/Cargo.toml
diff --git a/lib/rust/ensogl/example/auto-layout/src/lib.rs b/lib/rust/ensogl/examples/auto-layout/src/lib.rs
similarity index 100%
rename from lib/rust/ensogl/example/auto-layout/src/lib.rs
rename to lib/rust/ensogl/examples/auto-layout/src/lib.rs
diff --git a/lib/rust/ensogl/example/cached-shape/Cargo.toml b/lib/rust/ensogl/examples/cached-shape/Cargo.toml
similarity index 100%
rename from lib/rust/ensogl/example/cached-shape/Cargo.toml
rename to lib/rust/ensogl/examples/cached-shape/Cargo.toml
diff --git a/lib/rust/ensogl/example/cached-shape/src/lib.rs b/lib/rust/ensogl/examples/cached-shape/src/lib.rs
similarity index 100%
rename from lib/rust/ensogl/example/cached-shape/src/lib.rs
rename to lib/rust/ensogl/examples/cached-shape/src/lib.rs
diff --git a/lib/rust/ensogl/example/complex-shape-system/Cargo.toml b/lib/rust/ensogl/examples/complex-shape-system/Cargo.toml
similarity index 100%
rename from lib/rust/ensogl/example/complex-shape-system/Cargo.toml
rename to lib/rust/ensogl/examples/complex-shape-system/Cargo.toml
diff --git a/lib/rust/ensogl/example/complex-shape-system/src/lib.rs b/lib/rust/ensogl/examples/complex-shape-system/src/lib.rs
similarity index 100%
rename from lib/rust/ensogl/example/complex-shape-system/src/lib.rs
rename to lib/rust/ensogl/examples/complex-shape-system/src/lib.rs
diff --git a/lib/rust/ensogl/example/custom-shape-system/Cargo.toml b/lib/rust/ensogl/examples/custom-shape-system/Cargo.toml
similarity index 100%
rename from lib/rust/ensogl/example/custom-shape-system/Cargo.toml
rename to lib/rust/ensogl/examples/custom-shape-system/Cargo.toml
diff --git a/lib/rust/ensogl/example/custom-shape-system/src/lib.rs b/lib/rust/ensogl/examples/custom-shape-system/src/lib.rs
similarity index 100%
rename from lib/rust/ensogl/example/custom-shape-system/src/lib.rs
rename to lib/rust/ensogl/examples/custom-shape-system/src/lib.rs
diff --git a/lib/rust/ensogl/example/dom-symbols/Cargo.toml b/lib/rust/ensogl/examples/dom-symbols/Cargo.toml
similarity index 100%
rename from lib/rust/ensogl/example/dom-symbols/Cargo.toml
rename to lib/rust/ensogl/examples/dom-symbols/Cargo.toml
diff --git a/lib/rust/ensogl/example/dom-symbols/src/lib.rs b/lib/rust/ensogl/examples/dom-symbols/src/lib.rs
similarity index 100%
rename from lib/rust/ensogl/example/dom-symbols/src/lib.rs
rename to lib/rust/ensogl/examples/dom-symbols/src/lib.rs
diff --git a/lib/rust/ensogl/example/drop-down/Cargo.toml b/lib/rust/ensogl/examples/drop-down/Cargo.toml
similarity index 100%
rename from lib/rust/ensogl/example/drop-down/Cargo.toml
rename to lib/rust/ensogl/examples/drop-down/Cargo.toml
diff --git a/lib/rust/ensogl/example/drop-down/src/lib.rs b/lib/rust/ensogl/examples/drop-down/src/lib.rs
similarity index 100%
rename from lib/rust/ensogl/example/drop-down/src/lib.rs
rename to lib/rust/ensogl/examples/drop-down/src/lib.rs
diff --git a/lib/rust/ensogl/example/drop-manager/Cargo.toml b/lib/rust/ensogl/examples/drop-manager/Cargo.toml
similarity index 100%
rename from lib/rust/ensogl/example/drop-manager/Cargo.toml
rename to lib/rust/ensogl/examples/drop-manager/Cargo.toml
diff --git a/lib/rust/ensogl/example/drop-manager/src/lib.rs b/lib/rust/ensogl/examples/drop-manager/src/lib.rs
similarity index 100%
rename from lib/rust/ensogl/example/drop-manager/src/lib.rs
rename to lib/rust/ensogl/examples/drop-manager/src/lib.rs
diff --git a/lib/rust/ensogl/example/easing-animator/Cargo.toml b/lib/rust/ensogl/examples/easing-animator/Cargo.toml
similarity index 100%
rename from lib/rust/ensogl/example/easing-animator/Cargo.toml
rename to lib/rust/ensogl/examples/easing-animator/Cargo.toml
diff --git a/lib/rust/ensogl/example/easing-animator/src/lib.rs b/lib/rust/ensogl/examples/easing-animator/src/lib.rs
similarity index 100%
rename from lib/rust/ensogl/example/easing-animator/src/lib.rs
rename to lib/rust/ensogl/examples/easing-animator/src/lib.rs
diff --git a/lib/rust/ensogl/example/focus-management/Cargo.toml b/lib/rust/ensogl/examples/focus-management/Cargo.toml
similarity index 100%
rename from lib/rust/ensogl/example/focus-management/Cargo.toml
rename to lib/rust/ensogl/examples/focus-management/Cargo.toml
diff --git a/lib/rust/ensogl/example/focus-management/src/lib.rs b/lib/rust/ensogl/examples/focus-management/src/lib.rs
similarity index 100%
rename from lib/rust/ensogl/example/focus-management/src/lib.rs
rename to lib/rust/ensogl/examples/focus-management/src/lib.rs
diff --git a/lib/rust/ensogl/example/grid-view/Cargo.toml b/lib/rust/ensogl/examples/grid-view/Cargo.toml
similarity index 100%
rename from lib/rust/ensogl/example/grid-view/Cargo.toml
rename to lib/rust/ensogl/examples/grid-view/Cargo.toml
diff --git a/lib/rust/ensogl/example/grid-view/src/lib.rs b/lib/rust/ensogl/examples/grid-view/src/lib.rs
similarity index 100%
rename from lib/rust/ensogl/example/grid-view/src/lib.rs
rename to lib/rust/ensogl/examples/grid-view/src/lib.rs
diff --git a/lib/rust/ensogl/example/list-view/Cargo.toml b/lib/rust/ensogl/examples/list-view/Cargo.toml
similarity index 100%
rename from lib/rust/ensogl/example/list-view/Cargo.toml
rename to lib/rust/ensogl/examples/list-view/Cargo.toml
diff --git a/lib/rust/ensogl/example/list-view/src/lib.rs b/lib/rust/ensogl/examples/list-view/src/lib.rs
similarity index 100%
rename from lib/rust/ensogl/example/list-view/src/lib.rs
rename to lib/rust/ensogl/examples/list-view/src/lib.rs
diff --git a/lib/rust/ensogl/example/mouse-events/Cargo.toml b/lib/rust/ensogl/examples/mouse-events/Cargo.toml
similarity index 100%
rename from lib/rust/ensogl/example/mouse-events/Cargo.toml
rename to lib/rust/ensogl/examples/mouse-events/Cargo.toml
diff --git a/lib/rust/ensogl/example/mouse-events/src/lib.rs b/lib/rust/ensogl/examples/mouse-events/src/lib.rs
similarity index 100%
rename from lib/rust/ensogl/example/mouse-events/src/lib.rs
rename to lib/rust/ensogl/examples/mouse-events/src/lib.rs
diff --git a/lib/rust/ensogl/example/profiling-run-graph/Cargo.toml b/lib/rust/ensogl/examples/profiling-run-graph/Cargo.toml
similarity index 100%
rename from lib/rust/ensogl/example/profiling-run-graph/Cargo.toml
rename to lib/rust/ensogl/examples/profiling-run-graph/Cargo.toml
diff --git a/lib/rust/ensogl/example/profiling-run-graph/src/lib.rs b/lib/rust/ensogl/examples/profiling-run-graph/src/lib.rs
similarity index 100%
rename from lib/rust/ensogl/example/profiling-run-graph/src/lib.rs
rename to lib/rust/ensogl/examples/profiling-run-graph/src/lib.rs
diff --git a/lib/rust/ensogl/example/render-profile-flamegraph/Cargo.toml b/lib/rust/ensogl/examples/render-profile-flamegraph/Cargo.toml
similarity index 100%
rename from lib/rust/ensogl/example/render-profile-flamegraph/Cargo.toml
rename to lib/rust/ensogl/examples/render-profile-flamegraph/Cargo.toml
diff --git a/lib/rust/ensogl/example/render-profile-flamegraph/src/lib.rs b/lib/rust/ensogl/examples/render-profile-flamegraph/src/lib.rs
similarity index 100%
rename from lib/rust/ensogl/example/render-profile-flamegraph/src/lib.rs
rename to lib/rust/ensogl/examples/render-profile-flamegraph/src/lib.rs
diff --git a/lib/rust/ensogl/example/scroll-area/Cargo.toml b/lib/rust/ensogl/examples/scroll-area/Cargo.toml
similarity index 100%
rename from lib/rust/ensogl/example/scroll-area/Cargo.toml
rename to lib/rust/ensogl/examples/scroll-area/Cargo.toml
diff --git a/lib/rust/ensogl/example/scroll-area/src/lib.rs b/lib/rust/ensogl/examples/scroll-area/src/lib.rs
similarity index 100%
rename from lib/rust/ensogl/example/scroll-area/src/lib.rs
rename to lib/rust/ensogl/examples/scroll-area/src/lib.rs
diff --git a/lib/rust/ensogl/example/slider/Cargo.toml b/lib/rust/ensogl/examples/slider/Cargo.toml
similarity index 100%
rename from lib/rust/ensogl/example/slider/Cargo.toml
rename to lib/rust/ensogl/examples/slider/Cargo.toml
diff --git a/lib/rust/ensogl/example/slider/src/lib.rs b/lib/rust/ensogl/examples/slider/src/lib.rs
similarity index 100%
rename from lib/rust/ensogl/example/slider/src/lib.rs
rename to lib/rust/ensogl/examples/slider/src/lib.rs
diff --git a/lib/rust/ensogl/example/sprite-system-benchmark/Cargo.toml b/lib/rust/ensogl/examples/sprite-system-benchmark/Cargo.toml
similarity index 100%
rename from lib/rust/ensogl/example/sprite-system-benchmark/Cargo.toml
rename to lib/rust/ensogl/examples/sprite-system-benchmark/Cargo.toml
diff --git a/lib/rust/ensogl/example/sprite-system-benchmark/src/lib.rs b/lib/rust/ensogl/examples/sprite-system-benchmark/src/lib.rs
similarity index 100%
rename from lib/rust/ensogl/example/sprite-system-benchmark/src/lib.rs
rename to lib/rust/ensogl/examples/sprite-system-benchmark/src/lib.rs
diff --git a/lib/rust/ensogl/example/sprite-system/Cargo.toml b/lib/rust/ensogl/examples/sprite-system/Cargo.toml
similarity index 100%
rename from lib/rust/ensogl/example/sprite-system/Cargo.toml
rename to lib/rust/ensogl/examples/sprite-system/Cargo.toml
diff --git a/lib/rust/ensogl/example/sprite-system/src/lib.rs b/lib/rust/ensogl/examples/sprite-system/src/lib.rs
similarity index 100%
rename from lib/rust/ensogl/example/sprite-system/src/lib.rs
rename to lib/rust/ensogl/examples/sprite-system/src/lib.rs
diff --git a/lib/rust/ensogl/example/src/lib.rs b/lib/rust/ensogl/examples/src/lib.rs
similarity index 100%
rename from lib/rust/ensogl/example/src/lib.rs
rename to lib/rust/ensogl/examples/src/lib.rs
diff --git a/lib/rust/ensogl/example/text-area/Cargo.toml b/lib/rust/ensogl/examples/text-area/Cargo.toml
similarity index 100%
rename from lib/rust/ensogl/example/text-area/Cargo.toml
rename to lib/rust/ensogl/examples/text-area/Cargo.toml
diff --git a/lib/rust/ensogl/example/text-area/src/lib.rs b/lib/rust/ensogl/examples/text-area/src/lib.rs
similarity index 100%
rename from lib/rust/ensogl/example/text-area/src/lib.rs
rename to lib/rust/ensogl/examples/text-area/src/lib.rs

From da7bb1b46480733b310c71cc06b774d85f8ee5d7 Mon Sep 17 00:00:00 2001
From: Kaz Wesley <kaz@lambdaverse.org>
Date: Mon, 20 Feb 2023 17:50:12 +0000
Subject: [PATCH 13/16] Apply review.

---
 .../clippy-debug-scene-component-list-panel-view-wasm-linux.xml | 2 +-
 .../clippy-debug-scene-component-list-panel-view-wasm-macos.xml | 2 +-
 ...lippy-debug-scene-component-list-panel-view-wasm-windows.xml | 2 +-
 .../clippy-debug-scene-component-list-panel-view-wasm.xml       | 2 +-
 .idea/runConfigurations/clippy-debug-scene-icons-wasm-linux.xml | 2 +-
 .idea/runConfigurations/clippy-debug-scene-icons-wasm-macos.xml | 2 +-
 .../runConfigurations/clippy-debug-scene-icons-wasm-windows.xml | 2 +-
 .idea/runConfigurations/clippy-debug-scene-icons-wasm.xml       | 2 +-
 .../clippy-debug-scene-interface-wasm-linux.xml                 | 2 +-
 .../clippy-debug-scene-interface-wasm-macos.xml                 | 2 +-
 .../clippy-debug-scene-interface-wasm-windows.xml               | 2 +-
 .idea/runConfigurations/clippy-debug-scene-interface-wasm.xml   | 2 +-
 .../clippy-debug-scene-text-grid-visualization-wasm-linux.xml   | 2 +-
 .../clippy-debug-scene-text-grid-visualization-wasm-macos.xml   | 2 +-
 .../clippy-debug-scene-text-grid-visualization-wasm-windows.xml | 2 +-
 .../clippy-debug-scene-text-grid-visualization-wasm.xml         | 2 +-
 .../clippy-debug-scene-visualization-wasm-linux.xml             | 2 +-
 .../clippy-debug-scene-visualization-wasm-macos.xml             | 2 +-
 .../clippy-debug-scene-visualization-wasm-windows.xml           | 2 +-
 .../runConfigurations/clippy-debug-scene-visualization-wasm.xml | 2 +-
 .idea/runConfigurations/clippy-enso-debug-scene-wasm-linux.xml  | 2 +-
 .idea/runConfigurations/clippy-enso-debug-scene-wasm-macos.xml  | 2 +-
 .../runConfigurations/clippy-enso-debug-scene-wasm-windows.xml  | 2 +-
 .idea/runConfigurations/clippy-enso-debug-scene-wasm.xml        | 2 +-
 .../doc-test-debug-scene-component-list-panel-view-native.xml   | 2 +-
 .idea/runConfigurations/doc-test-debug-scene-icons-native.xml   | 2 +-
 .../runConfigurations/doc-test-debug-scene-interface-native.xml | 2 +-
 .../doc-test-debug-scene-text-grid-visualization-native.xml     | 2 +-
 .../doc-test-debug-scene-visualization-native.xml               | 2 +-
 .idea/runConfigurations/doc-test-enso-debug-scene-native.xml    | 2 +-
 .../test-debug-scene-component-list-panel-view-native.xml       | 2 +-
 .idea/runConfigurations/test-debug-scene-icons-native.xml       | 2 +-
 .idea/runConfigurations/test-debug-scene-interface-native.xml   | 2 +-
 .../test-debug-scene-text-grid-visualization-native.xml         | 2 +-
 .../runConfigurations/test-debug-scene-visualization-native.xml | 2 +-
 .idea/runConfigurations/test-enso-debug-scene-native.xml        | 2 +-
 app/gui/Cargo.toml                                              | 2 +-
 app/gui/view/{debug_scene => examples}/Cargo.toml               | 0
 .../component-list-panel-view/Cargo.toml                        | 0
 .../component-list-panel-view/src/lib.rs                        | 0
 app/gui/view/{debug_scene => examples}/documentation/Cargo.toml | 0
 app/gui/view/{debug_scene => examples}/documentation/src/lib.rs | 0
 app/gui/view/{debug_scene => examples}/icons/Cargo.toml         | 0
 app/gui/view/{debug_scene => examples}/icons/src/lib.rs         | 0
 app/gui/view/{debug_scene => examples}/interface/Cargo.toml     | 0
 app/gui/view/{debug_scene => examples}/interface/src/lib.rs     | 0
 app/gui/view/{debug_scene => examples}/src/lib.rs               | 0
 .../text-grid-visualization/Cargo.toml                          | 0
 .../text-grid-visualization/src/lib.rs                          | 0
 app/gui/view/{debug_scene => examples}/visualization/Cargo.toml | 0
 app/gui/view/{debug_scene => examples}/visualization/src/lib.rs | 0
 51 files changed, 37 insertions(+), 37 deletions(-)
 rename app/gui/view/{debug_scene => examples}/Cargo.toml (100%)
 rename app/gui/view/{debug_scene => examples}/component-list-panel-view/Cargo.toml (100%)
 rename app/gui/view/{debug_scene => examples}/component-list-panel-view/src/lib.rs (100%)
 rename app/gui/view/{debug_scene => examples}/documentation/Cargo.toml (100%)
 rename app/gui/view/{debug_scene => examples}/documentation/src/lib.rs (100%)
 rename app/gui/view/{debug_scene => examples}/icons/Cargo.toml (100%)
 rename app/gui/view/{debug_scene => examples}/icons/src/lib.rs (100%)
 rename app/gui/view/{debug_scene => examples}/interface/Cargo.toml (100%)
 rename app/gui/view/{debug_scene => examples}/interface/src/lib.rs (100%)
 rename app/gui/view/{debug_scene => examples}/src/lib.rs (100%)
 rename app/gui/view/{debug_scene => examples}/text-grid-visualization/Cargo.toml (100%)
 rename app/gui/view/{debug_scene => examples}/text-grid-visualization/src/lib.rs (100%)
 rename app/gui/view/{debug_scene => examples}/visualization/Cargo.toml (100%)
 rename app/gui/view/{debug_scene => examples}/visualization/src/lib.rs (100%)

diff --git a/.idea/runConfigurations/clippy-debug-scene-component-list-panel-view-wasm-linux.xml b/.idea/runConfigurations/clippy-debug-scene-component-list-panel-view-wasm-linux.xml
index 0bec8612bd87..7d80334bfd6c 100644
--- a/.idea/runConfigurations/clippy-debug-scene-component-list-panel-view-wasm-linux.xml
+++ b/.idea/runConfigurations/clippy-debug-scene-component-list-panel-view-wasm-linux.xml
@@ -5,7 +5,7 @@
     name="clippy/debug-scene-component-list-panel-view [wasm, linux]"
     type="CargoCommandRunConfiguration" 
     factoryName="Cargo Command"
-    folderName="🚥 GUI            view/debug_scene/component-list-panel-view"
+    folderName="🚥 GUI            view/examples/component-list-panel-view"
   >
     <option name="command" value="clippy --all-targets --target wasm32-unknown-unknown --target x86_64-unknown-linux-gnu --target-dir dist/intellij_wasm_linux --package debug-scene-component-list-panel-view" />
     <option name="workingDirectory" value="file://$PROJECT_DIR$" />
diff --git a/.idea/runConfigurations/clippy-debug-scene-component-list-panel-view-wasm-macos.xml b/.idea/runConfigurations/clippy-debug-scene-component-list-panel-view-wasm-macos.xml
index fffd236bc5ae..70fd649ad61e 100644
--- a/.idea/runConfigurations/clippy-debug-scene-component-list-panel-view-wasm-macos.xml
+++ b/.idea/runConfigurations/clippy-debug-scene-component-list-panel-view-wasm-macos.xml
@@ -5,7 +5,7 @@
     name="clippy/debug-scene-component-list-panel-view [wasm, macos]"
     type="CargoCommandRunConfiguration" 
     factoryName="Cargo Command"
-    folderName="🚥 GUI            view/debug_scene/component-list-panel-view"
+    folderName="🚥 GUI            view/examples/component-list-panel-view"
   >
     <option name="command" value="clippy --all-targets --target wasm32-unknown-unknown --target aarch64-apple-darwin --target-dir dist/intellij_wasm_macos --package debug-scene-component-list-panel-view" />
     <option name="workingDirectory" value="file://$PROJECT_DIR$" />
diff --git a/.idea/runConfigurations/clippy-debug-scene-component-list-panel-view-wasm-windows.xml b/.idea/runConfigurations/clippy-debug-scene-component-list-panel-view-wasm-windows.xml
index 7647ed1e5fcf..bc3a11d930f2 100644
--- a/.idea/runConfigurations/clippy-debug-scene-component-list-panel-view-wasm-windows.xml
+++ b/.idea/runConfigurations/clippy-debug-scene-component-list-panel-view-wasm-windows.xml
@@ -5,7 +5,7 @@
     name="clippy/debug-scene-component-list-panel-view [wasm, windows]"
     type="CargoCommandRunConfiguration" 
     factoryName="Cargo Command"
-    folderName="🚥 GUI            view/debug_scene/component-list-panel-view"
+    folderName="🚥 GUI            view/examples/component-list-panel-view"
   >
     <option name="command" value="clippy --all-targets --target wasm32-unknown-unknown --target x86_64-pc-windows-msvc --target-dir dist/intellij_wasm_windows --package debug-scene-component-list-panel-view" />
     <option name="workingDirectory" value="file://$PROJECT_DIR$" />
diff --git a/.idea/runConfigurations/clippy-debug-scene-component-list-panel-view-wasm.xml b/.idea/runConfigurations/clippy-debug-scene-component-list-panel-view-wasm.xml
index 18962ce9b030..efc9f96f5052 100644
--- a/.idea/runConfigurations/clippy-debug-scene-component-list-panel-view-wasm.xml
+++ b/.idea/runConfigurations/clippy-debug-scene-component-list-panel-view-wasm.xml
@@ -5,7 +5,7 @@
     name="clippy/debug-scene-component-list-panel-view [wasm]"
     type="CargoCommandRunConfiguration" 
     factoryName="Cargo Command"
-    folderName="🚥 GUI            view/debug_scene/component-list-panel-view"
+    folderName="🚥 GUI            view/examples/component-list-panel-view"
   >
     <option name="command" value="clippy --all-targets --target wasm32-unknown-unknown --target-dir dist/intellij_wasm --package debug-scene-component-list-panel-view" />
     <option name="workingDirectory" value="file://$PROJECT_DIR$" />
diff --git a/.idea/runConfigurations/clippy-debug-scene-icons-wasm-linux.xml b/.idea/runConfigurations/clippy-debug-scene-icons-wasm-linux.xml
index 7591018f99af..83585e355095 100644
--- a/.idea/runConfigurations/clippy-debug-scene-icons-wasm-linux.xml
+++ b/.idea/runConfigurations/clippy-debug-scene-icons-wasm-linux.xml
@@ -5,7 +5,7 @@
     name="clippy/debug-scene-icons [wasm, linux]"
     type="CargoCommandRunConfiguration" 
     factoryName="Cargo Command"
-    folderName="🚥 GUI            view/debug_scene/icons"
+    folderName="🚥 GUI            view/examples/icons"
   >
     <option name="command" value="clippy --all-targets --target wasm32-unknown-unknown --target x86_64-unknown-linux-gnu --target-dir dist/intellij_wasm_linux --package debug-scene-icons" />
     <option name="workingDirectory" value="file://$PROJECT_DIR$" />
diff --git a/.idea/runConfigurations/clippy-debug-scene-icons-wasm-macos.xml b/.idea/runConfigurations/clippy-debug-scene-icons-wasm-macos.xml
index 4cb8dd1ce758..d38c9dbf7d69 100644
--- a/.idea/runConfigurations/clippy-debug-scene-icons-wasm-macos.xml
+++ b/.idea/runConfigurations/clippy-debug-scene-icons-wasm-macos.xml
@@ -5,7 +5,7 @@
     name="clippy/debug-scene-icons [wasm, macos]"
     type="CargoCommandRunConfiguration" 
     factoryName="Cargo Command"
-    folderName="🚥 GUI            view/debug_scene/icons"
+    folderName="🚥 GUI            view/examples/icons"
   >
     <option name="command" value="clippy --all-targets --target wasm32-unknown-unknown --target aarch64-apple-darwin --target-dir dist/intellij_wasm_macos --package debug-scene-icons" />
     <option name="workingDirectory" value="file://$PROJECT_DIR$" />
diff --git a/.idea/runConfigurations/clippy-debug-scene-icons-wasm-windows.xml b/.idea/runConfigurations/clippy-debug-scene-icons-wasm-windows.xml
index 81f5a717198a..3101e13ae4f6 100644
--- a/.idea/runConfigurations/clippy-debug-scene-icons-wasm-windows.xml
+++ b/.idea/runConfigurations/clippy-debug-scene-icons-wasm-windows.xml
@@ -5,7 +5,7 @@
     name="clippy/debug-scene-icons [wasm, windows]"
     type="CargoCommandRunConfiguration" 
     factoryName="Cargo Command"
-    folderName="🚥 GUI            view/debug_scene/icons"
+    folderName="🚥 GUI            view/examples/icons"
   >
     <option name="command" value="clippy --all-targets --target wasm32-unknown-unknown --target x86_64-pc-windows-msvc --target-dir dist/intellij_wasm_windows --package debug-scene-icons" />
     <option name="workingDirectory" value="file://$PROJECT_DIR$" />
diff --git a/.idea/runConfigurations/clippy-debug-scene-icons-wasm.xml b/.idea/runConfigurations/clippy-debug-scene-icons-wasm.xml
index 80c4d47e115d..c33a5652007f 100644
--- a/.idea/runConfigurations/clippy-debug-scene-icons-wasm.xml
+++ b/.idea/runConfigurations/clippy-debug-scene-icons-wasm.xml
@@ -5,7 +5,7 @@
     name="clippy/debug-scene-icons [wasm]"
     type="CargoCommandRunConfiguration" 
     factoryName="Cargo Command"
-    folderName="🚥 GUI            view/debug_scene/icons"
+    folderName="🚥 GUI            view/examples/icons"
   >
     <option name="command" value="clippy --all-targets --target wasm32-unknown-unknown --target-dir dist/intellij_wasm --package debug-scene-icons" />
     <option name="workingDirectory" value="file://$PROJECT_DIR$" />
diff --git a/.idea/runConfigurations/clippy-debug-scene-interface-wasm-linux.xml b/.idea/runConfigurations/clippy-debug-scene-interface-wasm-linux.xml
index 3fda64b7c772..53020837f386 100644
--- a/.idea/runConfigurations/clippy-debug-scene-interface-wasm-linux.xml
+++ b/.idea/runConfigurations/clippy-debug-scene-interface-wasm-linux.xml
@@ -5,7 +5,7 @@
     name="clippy/debug-scene-interface [wasm, linux]"
     type="CargoCommandRunConfiguration" 
     factoryName="Cargo Command"
-    folderName="🚥 GUI            view/debug_scene/interface"
+    folderName="🚥 GUI            view/examples/interface"
   >
     <option name="command" value="clippy --all-targets --target wasm32-unknown-unknown --target x86_64-unknown-linux-gnu --target-dir dist/intellij_wasm_linux --package debug-scene-interface" />
     <option name="workingDirectory" value="file://$PROJECT_DIR$" />
diff --git a/.idea/runConfigurations/clippy-debug-scene-interface-wasm-macos.xml b/.idea/runConfigurations/clippy-debug-scene-interface-wasm-macos.xml
index 0957659d6b76..5ea31d67d5de 100644
--- a/.idea/runConfigurations/clippy-debug-scene-interface-wasm-macos.xml
+++ b/.idea/runConfigurations/clippy-debug-scene-interface-wasm-macos.xml
@@ -5,7 +5,7 @@
     name="clippy/debug-scene-interface [wasm, macos]"
     type="CargoCommandRunConfiguration" 
     factoryName="Cargo Command"
-    folderName="🚥 GUI            view/debug_scene/interface"
+    folderName="🚥 GUI            view/examples/interface"
   >
     <option name="command" value="clippy --all-targets --target wasm32-unknown-unknown --target aarch64-apple-darwin --target-dir dist/intellij_wasm_macos --package debug-scene-interface" />
     <option name="workingDirectory" value="file://$PROJECT_DIR$" />
diff --git a/.idea/runConfigurations/clippy-debug-scene-interface-wasm-windows.xml b/.idea/runConfigurations/clippy-debug-scene-interface-wasm-windows.xml
index 58b55ac0b0d8..8d0243196d57 100644
--- a/.idea/runConfigurations/clippy-debug-scene-interface-wasm-windows.xml
+++ b/.idea/runConfigurations/clippy-debug-scene-interface-wasm-windows.xml
@@ -5,7 +5,7 @@
     name="clippy/debug-scene-interface [wasm, windows]"
     type="CargoCommandRunConfiguration" 
     factoryName="Cargo Command"
-    folderName="🚥 GUI            view/debug_scene/interface"
+    folderName="🚥 GUI            view/examples/interface"
   >
     <option name="command" value="clippy --all-targets --target wasm32-unknown-unknown --target x86_64-pc-windows-msvc --target-dir dist/intellij_wasm_windows --package debug-scene-interface" />
     <option name="workingDirectory" value="file://$PROJECT_DIR$" />
diff --git a/.idea/runConfigurations/clippy-debug-scene-interface-wasm.xml b/.idea/runConfigurations/clippy-debug-scene-interface-wasm.xml
index 2de12565f1d6..1db0ca8d2f35 100644
--- a/.idea/runConfigurations/clippy-debug-scene-interface-wasm.xml
+++ b/.idea/runConfigurations/clippy-debug-scene-interface-wasm.xml
@@ -5,7 +5,7 @@
     name="clippy/debug-scene-interface [wasm]"
     type="CargoCommandRunConfiguration" 
     factoryName="Cargo Command"
-    folderName="🚥 GUI            view/debug_scene/interface"
+    folderName="🚥 GUI            view/examples/interface"
   >
     <option name="command" value="clippy --all-targets --target wasm32-unknown-unknown --target-dir dist/intellij_wasm --package debug-scene-interface" />
     <option name="workingDirectory" value="file://$PROJECT_DIR$" />
diff --git a/.idea/runConfigurations/clippy-debug-scene-text-grid-visualization-wasm-linux.xml b/.idea/runConfigurations/clippy-debug-scene-text-grid-visualization-wasm-linux.xml
index 17d6e3b55f8b..48ca407fd15c 100644
--- a/.idea/runConfigurations/clippy-debug-scene-text-grid-visualization-wasm-linux.xml
+++ b/.idea/runConfigurations/clippy-debug-scene-text-grid-visualization-wasm-linux.xml
@@ -5,7 +5,7 @@
     name="clippy/debug-scene-text-grid-visualization [wasm, linux]"
     type="CargoCommandRunConfiguration" 
     factoryName="Cargo Command"
-    folderName="🚥 GUI            view/debug_scene/text-grid-visualization"
+    folderName="🚥 GUI            view/examples/text-grid-visualization"
   >
     <option name="command" value="clippy --all-targets --target wasm32-unknown-unknown --target x86_64-unknown-linux-gnu --target-dir dist/intellij_wasm_linux --package debug-scene-text-grid-visualization" />
     <option name="workingDirectory" value="file://$PROJECT_DIR$" />
diff --git a/.idea/runConfigurations/clippy-debug-scene-text-grid-visualization-wasm-macos.xml b/.idea/runConfigurations/clippy-debug-scene-text-grid-visualization-wasm-macos.xml
index 701bebdc3339..66b2cd6c342e 100644
--- a/.idea/runConfigurations/clippy-debug-scene-text-grid-visualization-wasm-macos.xml
+++ b/.idea/runConfigurations/clippy-debug-scene-text-grid-visualization-wasm-macos.xml
@@ -5,7 +5,7 @@
     name="clippy/debug-scene-text-grid-visualization [wasm, macos]"
     type="CargoCommandRunConfiguration" 
     factoryName="Cargo Command"
-    folderName="🚥 GUI            view/debug_scene/text-grid-visualization"
+    folderName="🚥 GUI            view/examples/text-grid-visualization"
   >
     <option name="command" value="clippy --all-targets --target wasm32-unknown-unknown --target aarch64-apple-darwin --target-dir dist/intellij_wasm_macos --package debug-scene-text-grid-visualization" />
     <option name="workingDirectory" value="file://$PROJECT_DIR$" />
diff --git a/.idea/runConfigurations/clippy-debug-scene-text-grid-visualization-wasm-windows.xml b/.idea/runConfigurations/clippy-debug-scene-text-grid-visualization-wasm-windows.xml
index cec1f76063fb..c490b76bd4f4 100644
--- a/.idea/runConfigurations/clippy-debug-scene-text-grid-visualization-wasm-windows.xml
+++ b/.idea/runConfigurations/clippy-debug-scene-text-grid-visualization-wasm-windows.xml
@@ -5,7 +5,7 @@
     name="clippy/debug-scene-text-grid-visualization [wasm, windows]"
     type="CargoCommandRunConfiguration" 
     factoryName="Cargo Command"
-    folderName="🚥 GUI            view/debug_scene/text-grid-visualization"
+    folderName="🚥 GUI            view/examples/text-grid-visualization"
   >
     <option name="command" value="clippy --all-targets --target wasm32-unknown-unknown --target x86_64-pc-windows-msvc --target-dir dist/intellij_wasm_windows --package debug-scene-text-grid-visualization" />
     <option name="workingDirectory" value="file://$PROJECT_DIR$" />
diff --git a/.idea/runConfigurations/clippy-debug-scene-text-grid-visualization-wasm.xml b/.idea/runConfigurations/clippy-debug-scene-text-grid-visualization-wasm.xml
index fee11326b395..eb0cfca20390 100644
--- a/.idea/runConfigurations/clippy-debug-scene-text-grid-visualization-wasm.xml
+++ b/.idea/runConfigurations/clippy-debug-scene-text-grid-visualization-wasm.xml
@@ -5,7 +5,7 @@
     name="clippy/debug-scene-text-grid-visualization [wasm]"
     type="CargoCommandRunConfiguration" 
     factoryName="Cargo Command"
-    folderName="🚥 GUI            view/debug_scene/text-grid-visualization"
+    folderName="🚥 GUI            view/examples/text-grid-visualization"
   >
     <option name="command" value="clippy --all-targets --target wasm32-unknown-unknown --target-dir dist/intellij_wasm --package debug-scene-text-grid-visualization" />
     <option name="workingDirectory" value="file://$PROJECT_DIR$" />
diff --git a/.idea/runConfigurations/clippy-debug-scene-visualization-wasm-linux.xml b/.idea/runConfigurations/clippy-debug-scene-visualization-wasm-linux.xml
index 7ccb2f2d734b..444bc83743fd 100644
--- a/.idea/runConfigurations/clippy-debug-scene-visualization-wasm-linux.xml
+++ b/.idea/runConfigurations/clippy-debug-scene-visualization-wasm-linux.xml
@@ -5,7 +5,7 @@
     name="clippy/debug-scene-visualization [wasm, linux]"
     type="CargoCommandRunConfiguration" 
     factoryName="Cargo Command"
-    folderName="🚥 GUI            view/debug_scene/visualization"
+    folderName="🚥 GUI            view/examples/visualization"
   >
     <option name="command" value="clippy --all-targets --target wasm32-unknown-unknown --target x86_64-unknown-linux-gnu --target-dir dist/intellij_wasm_linux --package debug-scene-visualization" />
     <option name="workingDirectory" value="file://$PROJECT_DIR$" />
diff --git a/.idea/runConfigurations/clippy-debug-scene-visualization-wasm-macos.xml b/.idea/runConfigurations/clippy-debug-scene-visualization-wasm-macos.xml
index a459c1825cbd..7d02ab8a3e55 100644
--- a/.idea/runConfigurations/clippy-debug-scene-visualization-wasm-macos.xml
+++ b/.idea/runConfigurations/clippy-debug-scene-visualization-wasm-macos.xml
@@ -5,7 +5,7 @@
     name="clippy/debug-scene-visualization [wasm, macos]"
     type="CargoCommandRunConfiguration" 
     factoryName="Cargo Command"
-    folderName="🚥 GUI            view/debug_scene/visualization"
+    folderName="🚥 GUI            view/examples/visualization"
   >
     <option name="command" value="clippy --all-targets --target wasm32-unknown-unknown --target aarch64-apple-darwin --target-dir dist/intellij_wasm_macos --package debug-scene-visualization" />
     <option name="workingDirectory" value="file://$PROJECT_DIR$" />
diff --git a/.idea/runConfigurations/clippy-debug-scene-visualization-wasm-windows.xml b/.idea/runConfigurations/clippy-debug-scene-visualization-wasm-windows.xml
index 4948525dbe5e..a8584e8f26a3 100644
--- a/.idea/runConfigurations/clippy-debug-scene-visualization-wasm-windows.xml
+++ b/.idea/runConfigurations/clippy-debug-scene-visualization-wasm-windows.xml
@@ -5,7 +5,7 @@
     name="clippy/debug-scene-visualization [wasm, windows]"
     type="CargoCommandRunConfiguration" 
     factoryName="Cargo Command"
-    folderName="🚥 GUI            view/debug_scene/visualization"
+    folderName="🚥 GUI            view/examples/visualization"
   >
     <option name="command" value="clippy --all-targets --target wasm32-unknown-unknown --target x86_64-pc-windows-msvc --target-dir dist/intellij_wasm_windows --package debug-scene-visualization" />
     <option name="workingDirectory" value="file://$PROJECT_DIR$" />
diff --git a/.idea/runConfigurations/clippy-debug-scene-visualization-wasm.xml b/.idea/runConfigurations/clippy-debug-scene-visualization-wasm.xml
index 5fa5540ca49b..748d67b96a3e 100644
--- a/.idea/runConfigurations/clippy-debug-scene-visualization-wasm.xml
+++ b/.idea/runConfigurations/clippy-debug-scene-visualization-wasm.xml
@@ -5,7 +5,7 @@
     name="clippy/debug-scene-visualization [wasm]"
     type="CargoCommandRunConfiguration" 
     factoryName="Cargo Command"
-    folderName="🚥 GUI            view/debug_scene/visualization"
+    folderName="🚥 GUI            view/examples/visualization"
   >
     <option name="command" value="clippy --all-targets --target wasm32-unknown-unknown --target-dir dist/intellij_wasm --package debug-scene-visualization" />
     <option name="workingDirectory" value="file://$PROJECT_DIR$" />
diff --git a/.idea/runConfigurations/clippy-enso-debug-scene-wasm-linux.xml b/.idea/runConfigurations/clippy-enso-debug-scene-wasm-linux.xml
index fb6937175aa8..e9f4aab3d499 100644
--- a/.idea/runConfigurations/clippy-enso-debug-scene-wasm-linux.xml
+++ b/.idea/runConfigurations/clippy-enso-debug-scene-wasm-linux.xml
@@ -5,7 +5,7 @@
     name="clippy/enso-debug-scene [wasm, linux]"
     type="CargoCommandRunConfiguration" 
     factoryName="Cargo Command"
-    folderName="🚥 GUI            view/debug_scene"
+    folderName="🚥 GUI            view/examples"
   >
     <option name="command" value="clippy --all-targets --target wasm32-unknown-unknown --target x86_64-unknown-linux-gnu --target-dir dist/intellij_wasm_linux --package enso-debug-scene" />
     <option name="workingDirectory" value="file://$PROJECT_DIR$" />
diff --git a/.idea/runConfigurations/clippy-enso-debug-scene-wasm-macos.xml b/.idea/runConfigurations/clippy-enso-debug-scene-wasm-macos.xml
index d4c1bcfbb547..5af448dee27d 100644
--- a/.idea/runConfigurations/clippy-enso-debug-scene-wasm-macos.xml
+++ b/.idea/runConfigurations/clippy-enso-debug-scene-wasm-macos.xml
@@ -5,7 +5,7 @@
     name="clippy/enso-debug-scene [wasm, macos]"
     type="CargoCommandRunConfiguration" 
     factoryName="Cargo Command"
-    folderName="🚥 GUI            view/debug_scene"
+    folderName="🚥 GUI            view/examples"
   >
     <option name="command" value="clippy --all-targets --target wasm32-unknown-unknown --target aarch64-apple-darwin --target-dir dist/intellij_wasm_macos --package enso-debug-scene" />
     <option name="workingDirectory" value="file://$PROJECT_DIR$" />
diff --git a/.idea/runConfigurations/clippy-enso-debug-scene-wasm-windows.xml b/.idea/runConfigurations/clippy-enso-debug-scene-wasm-windows.xml
index 0e591365b8a2..2a775cc59921 100644
--- a/.idea/runConfigurations/clippy-enso-debug-scene-wasm-windows.xml
+++ b/.idea/runConfigurations/clippy-enso-debug-scene-wasm-windows.xml
@@ -5,7 +5,7 @@
     name="clippy/enso-debug-scene [wasm, windows]"
     type="CargoCommandRunConfiguration" 
     factoryName="Cargo Command"
-    folderName="🚥 GUI            view/debug_scene"
+    folderName="🚥 GUI            view/examples"
   >
     <option name="command" value="clippy --all-targets --target wasm32-unknown-unknown --target x86_64-pc-windows-msvc --target-dir dist/intellij_wasm_windows --package enso-debug-scene" />
     <option name="workingDirectory" value="file://$PROJECT_DIR$" />
diff --git a/.idea/runConfigurations/clippy-enso-debug-scene-wasm.xml b/.idea/runConfigurations/clippy-enso-debug-scene-wasm.xml
index b2cffe3e47e9..fd2e311f6f5d 100644
--- a/.idea/runConfigurations/clippy-enso-debug-scene-wasm.xml
+++ b/.idea/runConfigurations/clippy-enso-debug-scene-wasm.xml
@@ -5,7 +5,7 @@
     name="clippy/enso-debug-scene [wasm]"
     type="CargoCommandRunConfiguration" 
     factoryName="Cargo Command"
-    folderName="🚥 GUI            view/debug_scene"
+    folderName="🚥 GUI            view/examples"
   >
     <option name="command" value="clippy --all-targets --target wasm32-unknown-unknown --target-dir dist/intellij_wasm --package enso-debug-scene" />
     <option name="workingDirectory" value="file://$PROJECT_DIR$" />
diff --git a/.idea/runConfigurations/doc-test-debug-scene-component-list-panel-view-native.xml b/.idea/runConfigurations/doc-test-debug-scene-component-list-panel-view-native.xml
index c33f35e017a5..6ef3f01d3182 100644
--- a/.idea/runConfigurations/doc-test-debug-scene-component-list-panel-view-native.xml
+++ b/.idea/runConfigurations/doc-test-debug-scene-component-list-panel-view-native.xml
@@ -5,7 +5,7 @@
     name="doc-test/debug-scene-component-list-panel-view [native]"
     type="CargoCommandRunConfiguration" 
     factoryName="Cargo Command"
-    folderName="🚥 GUI            view/debug_scene/component-list-panel-view"
+    folderName="🚥 GUI            view/examples/component-list-panel-view"
   >
     <option name="command" value="test --doc  --target-dir dist/intellij_native --package debug-scene-component-list-panel-view" />
     <option name="workingDirectory" value="file://$PROJECT_DIR$" />
diff --git a/.idea/runConfigurations/doc-test-debug-scene-icons-native.xml b/.idea/runConfigurations/doc-test-debug-scene-icons-native.xml
index 62fe1d22efa8..06083d94f045 100644
--- a/.idea/runConfigurations/doc-test-debug-scene-icons-native.xml
+++ b/.idea/runConfigurations/doc-test-debug-scene-icons-native.xml
@@ -5,7 +5,7 @@
     name="doc-test/debug-scene-icons [native]"
     type="CargoCommandRunConfiguration" 
     factoryName="Cargo Command"
-    folderName="🚥 GUI            view/debug_scene/icons"
+    folderName="🚥 GUI            view/examples/icons"
   >
     <option name="command" value="test --doc  --target-dir dist/intellij_native --package debug-scene-icons" />
     <option name="workingDirectory" value="file://$PROJECT_DIR$" />
diff --git a/.idea/runConfigurations/doc-test-debug-scene-interface-native.xml b/.idea/runConfigurations/doc-test-debug-scene-interface-native.xml
index cfc19f8625a0..ba37bb71b196 100644
--- a/.idea/runConfigurations/doc-test-debug-scene-interface-native.xml
+++ b/.idea/runConfigurations/doc-test-debug-scene-interface-native.xml
@@ -5,7 +5,7 @@
     name="doc-test/debug-scene-interface [native]"
     type="CargoCommandRunConfiguration" 
     factoryName="Cargo Command"
-    folderName="🚥 GUI            view/debug_scene/interface"
+    folderName="🚥 GUI            view/examples/interface"
   >
     <option name="command" value="test --doc  --target-dir dist/intellij_native --package debug-scene-interface" />
     <option name="workingDirectory" value="file://$PROJECT_DIR$" />
diff --git a/.idea/runConfigurations/doc-test-debug-scene-text-grid-visualization-native.xml b/.idea/runConfigurations/doc-test-debug-scene-text-grid-visualization-native.xml
index 21b229309bc3..52413f81c259 100644
--- a/.idea/runConfigurations/doc-test-debug-scene-text-grid-visualization-native.xml
+++ b/.idea/runConfigurations/doc-test-debug-scene-text-grid-visualization-native.xml
@@ -5,7 +5,7 @@
     name="doc-test/debug-scene-text-grid-visualization [native]"
     type="CargoCommandRunConfiguration" 
     factoryName="Cargo Command"
-    folderName="🚥 GUI            view/debug_scene/text-grid-visualization"
+    folderName="🚥 GUI            view/examples/text-grid-visualization"
   >
     <option name="command" value="test --doc  --target-dir dist/intellij_native --package debug-scene-text-grid-visualization" />
     <option name="workingDirectory" value="file://$PROJECT_DIR$" />
diff --git a/.idea/runConfigurations/doc-test-debug-scene-visualization-native.xml b/.idea/runConfigurations/doc-test-debug-scene-visualization-native.xml
index fcd721cc1b1f..ffd52df3da94 100644
--- a/.idea/runConfigurations/doc-test-debug-scene-visualization-native.xml
+++ b/.idea/runConfigurations/doc-test-debug-scene-visualization-native.xml
@@ -5,7 +5,7 @@
     name="doc-test/debug-scene-visualization [native]"
     type="CargoCommandRunConfiguration" 
     factoryName="Cargo Command"
-    folderName="🚥 GUI            view/debug_scene/visualization"
+    folderName="🚥 GUI            view/examples/visualization"
   >
     <option name="command" value="test --doc  --target-dir dist/intellij_native --package debug-scene-visualization" />
     <option name="workingDirectory" value="file://$PROJECT_DIR$" />
diff --git a/.idea/runConfigurations/doc-test-enso-debug-scene-native.xml b/.idea/runConfigurations/doc-test-enso-debug-scene-native.xml
index 5ce6d68f6a84..42d9e7620956 100644
--- a/.idea/runConfigurations/doc-test-enso-debug-scene-native.xml
+++ b/.idea/runConfigurations/doc-test-enso-debug-scene-native.xml
@@ -5,7 +5,7 @@
     name="doc-test/enso-debug-scene [native]"
     type="CargoCommandRunConfiguration" 
     factoryName="Cargo Command"
-    folderName="🚥 GUI            view/debug_scene"
+    folderName="🚥 GUI            view/examples"
   >
     <option name="command" value="test --doc  --target-dir dist/intellij_native --package enso-debug-scene" />
     <option name="workingDirectory" value="file://$PROJECT_DIR$" />
diff --git a/.idea/runConfigurations/test-debug-scene-component-list-panel-view-native.xml b/.idea/runConfigurations/test-debug-scene-component-list-panel-view-native.xml
index 37deabe81c5b..6abe6ad07360 100644
--- a/.idea/runConfigurations/test-debug-scene-component-list-panel-view-native.xml
+++ b/.idea/runConfigurations/test-debug-scene-component-list-panel-view-native.xml
@@ -5,7 +5,7 @@
     name="test/debug-scene-component-list-panel-view [native]"
     type="CargoCommandRunConfiguration" 
     factoryName="Cargo Command"
-    folderName="🚥 GUI            view/debug_scene/component-list-panel-view"
+    folderName="🚥 GUI            view/examples/component-list-panel-view"
   >
     <option name="command" value="test --all-targets  --target-dir dist/intellij_native --package debug-scene-component-list-panel-view" />
     <option name="workingDirectory" value="file://$PROJECT_DIR$" />
diff --git a/.idea/runConfigurations/test-debug-scene-icons-native.xml b/.idea/runConfigurations/test-debug-scene-icons-native.xml
index 7ba574edfba5..6b9f2b80a58c 100644
--- a/.idea/runConfigurations/test-debug-scene-icons-native.xml
+++ b/.idea/runConfigurations/test-debug-scene-icons-native.xml
@@ -5,7 +5,7 @@
     name="test/debug-scene-icons [native]"
     type="CargoCommandRunConfiguration" 
     factoryName="Cargo Command"
-    folderName="🚥 GUI            view/debug_scene/icons"
+    folderName="🚥 GUI            view/examples/icons"
   >
     <option name="command" value="test --all-targets  --target-dir dist/intellij_native --package debug-scene-icons" />
     <option name="workingDirectory" value="file://$PROJECT_DIR$" />
diff --git a/.idea/runConfigurations/test-debug-scene-interface-native.xml b/.idea/runConfigurations/test-debug-scene-interface-native.xml
index b0964576f53e..711317b7a6f9 100644
--- a/.idea/runConfigurations/test-debug-scene-interface-native.xml
+++ b/.idea/runConfigurations/test-debug-scene-interface-native.xml
@@ -5,7 +5,7 @@
     name="test/debug-scene-interface [native]"
     type="CargoCommandRunConfiguration" 
     factoryName="Cargo Command"
-    folderName="🚥 GUI            view/debug_scene/interface"
+    folderName="🚥 GUI            view/examples/interface"
   >
     <option name="command" value="test --all-targets  --target-dir dist/intellij_native --package debug-scene-interface" />
     <option name="workingDirectory" value="file://$PROJECT_DIR$" />
diff --git a/.idea/runConfigurations/test-debug-scene-text-grid-visualization-native.xml b/.idea/runConfigurations/test-debug-scene-text-grid-visualization-native.xml
index f2a3d562381b..91ed3362e7cf 100644
--- a/.idea/runConfigurations/test-debug-scene-text-grid-visualization-native.xml
+++ b/.idea/runConfigurations/test-debug-scene-text-grid-visualization-native.xml
@@ -5,7 +5,7 @@
     name="test/debug-scene-text-grid-visualization [native]"
     type="CargoCommandRunConfiguration" 
     factoryName="Cargo Command"
-    folderName="🚥 GUI            view/debug_scene/text-grid-visualization"
+    folderName="🚥 GUI            view/examples/text-grid-visualization"
   >
     <option name="command" value="test --all-targets  --target-dir dist/intellij_native --package debug-scene-text-grid-visualization" />
     <option name="workingDirectory" value="file://$PROJECT_DIR$" />
diff --git a/.idea/runConfigurations/test-debug-scene-visualization-native.xml b/.idea/runConfigurations/test-debug-scene-visualization-native.xml
index 047bec1902fb..21dd42b146dc 100644
--- a/.idea/runConfigurations/test-debug-scene-visualization-native.xml
+++ b/.idea/runConfigurations/test-debug-scene-visualization-native.xml
@@ -5,7 +5,7 @@
     name="test/debug-scene-visualization [native]"
     type="CargoCommandRunConfiguration" 
     factoryName="Cargo Command"
-    folderName="🚥 GUI            view/debug_scene/visualization"
+    folderName="🚥 GUI            view/examples/visualization"
   >
     <option name="command" value="test --all-targets  --target-dir dist/intellij_native --package debug-scene-visualization" />
     <option name="workingDirectory" value="file://$PROJECT_DIR$" />
diff --git a/.idea/runConfigurations/test-enso-debug-scene-native.xml b/.idea/runConfigurations/test-enso-debug-scene-native.xml
index dc51619de249..61a4e2cb4188 100644
--- a/.idea/runConfigurations/test-enso-debug-scene-native.xml
+++ b/.idea/runConfigurations/test-enso-debug-scene-native.xml
@@ -5,7 +5,7 @@
     name="test/enso-debug-scene [native]"
     type="CargoCommandRunConfiguration" 
     factoryName="Cargo Command"
-    folderName="🚥 GUI            view/debug_scene"
+    folderName="🚥 GUI            view/examples"
   >
     <option name="command" value="test --all-targets  --target-dir dist/intellij_native --package enso-debug-scene" />
     <option name="workingDirectory" value="file://$PROJECT_DIR$" />
diff --git a/app/gui/Cargo.toml b/app/gui/Cargo.toml
index 124f1657f23d..8629e92f6c5b 100644
--- a/app/gui/Cargo.toml
+++ b/app/gui/Cargo.toml
@@ -14,7 +14,7 @@ enso-config = { path = "config" }
 enso-callback = { path = "../../lib/rust/callback" }
 enso-data-structures = { path = "../../lib/rust/data-structures" }
 enso-debug-api = { path = "../../lib/rust/debug-api" }
-enso-debug-scene = { path = "view/debug_scene" }
+enso-debug-scene = { path = "view/examples" }
 enso-frp = { path = "../../lib/rust/frp" }
 enso-prelude = { path = "../../lib/rust/prelude" }
 enso-profiler = { path = "../../lib/rust/profiler" }
diff --git a/app/gui/view/debug_scene/Cargo.toml b/app/gui/view/examples/Cargo.toml
similarity index 100%
rename from app/gui/view/debug_scene/Cargo.toml
rename to app/gui/view/examples/Cargo.toml
diff --git a/app/gui/view/debug_scene/component-list-panel-view/Cargo.toml b/app/gui/view/examples/component-list-panel-view/Cargo.toml
similarity index 100%
rename from app/gui/view/debug_scene/component-list-panel-view/Cargo.toml
rename to app/gui/view/examples/component-list-panel-view/Cargo.toml
diff --git a/app/gui/view/debug_scene/component-list-panel-view/src/lib.rs b/app/gui/view/examples/component-list-panel-view/src/lib.rs
similarity index 100%
rename from app/gui/view/debug_scene/component-list-panel-view/src/lib.rs
rename to app/gui/view/examples/component-list-panel-view/src/lib.rs
diff --git a/app/gui/view/debug_scene/documentation/Cargo.toml b/app/gui/view/examples/documentation/Cargo.toml
similarity index 100%
rename from app/gui/view/debug_scene/documentation/Cargo.toml
rename to app/gui/view/examples/documentation/Cargo.toml
diff --git a/app/gui/view/debug_scene/documentation/src/lib.rs b/app/gui/view/examples/documentation/src/lib.rs
similarity index 100%
rename from app/gui/view/debug_scene/documentation/src/lib.rs
rename to app/gui/view/examples/documentation/src/lib.rs
diff --git a/app/gui/view/debug_scene/icons/Cargo.toml b/app/gui/view/examples/icons/Cargo.toml
similarity index 100%
rename from app/gui/view/debug_scene/icons/Cargo.toml
rename to app/gui/view/examples/icons/Cargo.toml
diff --git a/app/gui/view/debug_scene/icons/src/lib.rs b/app/gui/view/examples/icons/src/lib.rs
similarity index 100%
rename from app/gui/view/debug_scene/icons/src/lib.rs
rename to app/gui/view/examples/icons/src/lib.rs
diff --git a/app/gui/view/debug_scene/interface/Cargo.toml b/app/gui/view/examples/interface/Cargo.toml
similarity index 100%
rename from app/gui/view/debug_scene/interface/Cargo.toml
rename to app/gui/view/examples/interface/Cargo.toml
diff --git a/app/gui/view/debug_scene/interface/src/lib.rs b/app/gui/view/examples/interface/src/lib.rs
similarity index 100%
rename from app/gui/view/debug_scene/interface/src/lib.rs
rename to app/gui/view/examples/interface/src/lib.rs
diff --git a/app/gui/view/debug_scene/src/lib.rs b/app/gui/view/examples/src/lib.rs
similarity index 100%
rename from app/gui/view/debug_scene/src/lib.rs
rename to app/gui/view/examples/src/lib.rs
diff --git a/app/gui/view/debug_scene/text-grid-visualization/Cargo.toml b/app/gui/view/examples/text-grid-visualization/Cargo.toml
similarity index 100%
rename from app/gui/view/debug_scene/text-grid-visualization/Cargo.toml
rename to app/gui/view/examples/text-grid-visualization/Cargo.toml
diff --git a/app/gui/view/debug_scene/text-grid-visualization/src/lib.rs b/app/gui/view/examples/text-grid-visualization/src/lib.rs
similarity index 100%
rename from app/gui/view/debug_scene/text-grid-visualization/src/lib.rs
rename to app/gui/view/examples/text-grid-visualization/src/lib.rs
diff --git a/app/gui/view/debug_scene/visualization/Cargo.toml b/app/gui/view/examples/visualization/Cargo.toml
similarity index 100%
rename from app/gui/view/debug_scene/visualization/Cargo.toml
rename to app/gui/view/examples/visualization/Cargo.toml
diff --git a/app/gui/view/debug_scene/visualization/src/lib.rs b/app/gui/view/examples/visualization/src/lib.rs
similarity index 100%
rename from app/gui/view/debug_scene/visualization/src/lib.rs
rename to app/gui/view/examples/visualization/src/lib.rs

From aa43189c1b9e71e433ab318f4e0989518227e05e Mon Sep 17 00:00:00 2001
From: Kaz Wesley <kaz@lambdaverse.org>
Date: Mon, 20 Feb 2023 19:05:34 +0000
Subject: [PATCH 14/16] Document crate path magic.

---
 Cargo.toml | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/Cargo.toml b/Cargo.toml
index 19626d1583fb..e80115f9db8a 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -3,6 +3,9 @@ resolver = "2"
 # Listing only the "root" crates of each app/library. All path dependencies are included in the workspace automatically.
 # If you want to add sub crate (like `app/gui/config` or `lib/rust/ensogl/examples`), just add it as a path dependency
 # where plausible.
+# Any GUI functionality that is not used by the main entry point should be defined somewhere with `examples` in the
+# path, e.g. `lib/rust/ensogl/examples`, or `app/gui/view/examples`; this is used to optimize the application for
+# loading the IDE.
 members = [
   "app/gui",
   "app/gui/language/parser",

From b186a53578ba606ebe1af6e5a518ffc2f63558d6 Mon Sep 17 00:00:00 2001
From: Kaz Wesley <kaz@lambdaverse.org>
Date: Tue, 21 Feb 2023 18:06:22 +0000
Subject: [PATCH 15/16] Use optimized vertex shaders.

---
 .../src/display/shape/primitive/system.rs     |  2 ++
 .../src/display/symbol/gpu/shader/builder.rs  | 12 ++++---
 lib/rust/ensogl/core/src/display/world.rs     | 34 +++++++++++++++++++
 3 files changed, 44 insertions(+), 4 deletions(-)

diff --git a/lib/rust/ensogl/core/src/display/shape/primitive/system.rs b/lib/rust/ensogl/core/src/display/shape/primitive/system.rs
index 35216f877a5a..7e6c435e8350 100644
--- a/lib/rust/ensogl/core/src/display/shape/primitive/system.rs
+++ b/lib/rust/ensogl/core/src/display/shape/primitive/system.rs
@@ -457,6 +457,8 @@ impl ShapeSystemModel {
         {
             let code = crate::display::shader::builder::CodeTemplate::from_main(&shader.fragment);
             self.material.borrow_mut().set_code(code);
+            let code = crate::display::shader::builder::CodeTemplate::from_main(&shader.vertex);
+            self.geometry_material.borrow_mut().set_code(code);
         } else {
             if !display::world::with_context(|t| t.run_mode.get().is_shader_extraction()) {
                 let path = *self.definition_path;
diff --git a/lib/rust/ensogl/core/src/display/symbol/gpu/shader/builder.rs b/lib/rust/ensogl/core/src/display/symbol/gpu/shader/builder.rs
index 2418d00a35db..21ac8e6c9158 100644
--- a/lib/rust/ensogl/core/src/display/symbol/gpu/shader/builder.rs
+++ b/lib/rust/ensogl/core/src/display/symbol/gpu/shader/builder.rs
@@ -512,15 +512,19 @@ impl ShaderBuilder {
     }
 }
 
+pub const INPUT_PREFIX: &str = "input_";
+pub const OUTPUT_PREFIX: &str = "output_";
+pub const VERTEX_PREFIX: &str = "vertex_";
+
 pub fn mk_out_name<S: Str>(s: S) -> String {
-    format!("output_{}", s.as_ref())
+    format!("{OUTPUT_PREFIX}{}", s.as_ref())
 }
 pub fn mk_vertex_name<S: Str>(s: S) -> String {
-    format!("vertex_{}", s.as_ref())
+    format!("{VERTEX_PREFIX}{}", s.as_ref())
 }
 pub fn mk_fragment_name<S: Str>(s: S) -> String {
-    format!("input_{}", s.as_ref())
+    format!("{INPUT_PREFIX}{}", s.as_ref())
 }
 pub fn mk_uniform_name<S: Str>(s: S) -> String {
-    format!("input_{}", s.as_ref())
+    format!("{INPUT_PREFIX}{}", s.as_ref())
 }
diff --git a/lib/rust/ensogl/core/src/display/world.rs b/lib/rust/ensogl/core/src/display/world.rs
index e7e76e743d51..67741d5f0fdd 100644
--- a/lib/rust/ensogl/core/src/display/world.rs
+++ b/lib/rust/ensogl/core/src/display/world.rs
@@ -184,6 +184,7 @@ fn extract_shaders_from_js(value: JsValue) -> Result<(), JsValue> {
         let fragment_field = web::Reflect::get(&value, &"fragment".into())?;
         let vertex: String = vertex_field.dyn_into::<web::JsString>()?.into();
         let fragment: String = fragment_field.dyn_into::<web::JsString>()?.into();
+        let vertex = strip_instance_declarations(&vertex);
         let precompiled_shader = PrecompiledShader(shader::Code { vertex, fragment });
         debug!("Registering precompiled shaders for '{key}'.");
         PRECOMPILED_SHADERS.with_borrow_mut(move |map| {
@@ -193,6 +194,39 @@ fn extract_shaders_from_js(value: JsValue) -> Result<(), JsValue> {
     Ok(())
 }
 
+/// Remove initial instance variable declarations.
+///
+/// When pre-compiling vertex shaders we don't have full information about inputs, and instead treat
+/// all inputs as instance variables. After the program has been optimized, we need to strip these
+/// imprecise declarations so they don't conflict with the real declarations we add when building
+/// the shader.
+fn strip_instance_declarations(input: &str) -> String {
+    let mut code = String::with_capacity(input.len());
+    let mut preamble_ended = false;
+    let input_prefix = display::symbol::gpu::shader::builder::INPUT_PREFIX;
+    let vertex_prefix = display::symbol::gpu::shader::builder::VERTEX_PREFIX;
+    for line in input.lines() {
+        // Skip lines as long as they match the `input_foo = vertex_foo` pattern.
+        if !preamble_ended {
+            let trimmed = line.trim_start();
+            if trimmed.is_empty() {
+                continue;
+            }
+            let mut parts = trimmed.split(' ');
+            if let Some(part) = parts.next() && part.starts_with(input_prefix)
+                    && let Some(part) = parts.next() && part == "="
+                    && let Some(part) = parts.next() && part.starts_with(vertex_prefix)
+                    && let None = parts.next() {
+                continue;
+            }
+        }
+        preamble_ended = true;
+        code.push_str(line);
+        code.push('\n');
+    }
+    code
+}
+
 fn gather_shaders() -> HashMap<&'static str, shader::Code> {
     with_context(|t| t.run_mode.set(RunMode::ShaderExtraction));
     let mut map = HashMap::new();

From 681a1a98a64f94556d365e3a35cedb93b46f45e6 Mon Sep 17 00:00:00 2001
From: Kaz Wesley <kaz@lambdaverse.org>
Date: Tue, 21 Feb 2023 18:48:56 +0000
Subject: [PATCH 16/16] Support awaiting shader compilation

---
 Cargo.lock                                    |  1 +
 app/gui/view/src/project.rs                   |  1 +
 lib/rust/ensogl/core/Cargo.toml               |  1 +
 lib/rust/ensogl/core/src/display/scene.rs     | 67 +++++++++++++++++++
 lib/rust/ensogl/core/src/display/world.rs     | 22 +-----
 .../core/src/system/gpu/shader/compiler.rs    | 11 +++
 6 files changed, 82 insertions(+), 21 deletions(-)

diff --git a/Cargo.lock b/Cargo.lock
index 825cf6df505c..c68803847a53 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -2616,6 +2616,7 @@ dependencies = [
  "ensogl-text-embedded-fonts",
  "enum_dispatch",
  "failure",
+ "futures 0.3.26",
  "itertools",
  "js-sys",
  "nalgebra",
diff --git a/app/gui/view/src/project.rs b/app/gui/view/src/project.rs
index afc30fb58319..775e8e9c9895 100644
--- a/app/gui/view/src/project.rs
+++ b/app/gui/view/src/project.rs
@@ -467,6 +467,7 @@ impl View {
         };
 
         let scene = app.display.default_scene.clone_ref();
+        scene.begin_shader_initialization();
         let model = Model::new(app);
         let frp = Frp::new();
         let network = &frp.network;
diff --git a/lib/rust/ensogl/core/Cargo.toml b/lib/rust/ensogl/core/Cargo.toml
index 136f61c2a59e..b7fc1bd06932 100644
--- a/lib/rust/ensogl/core/Cargo.toml
+++ b/lib/rust/ensogl/core/Cargo.toml
@@ -31,6 +31,7 @@ bitflags = { version = "1.3.2" }
 console_error_panic_hook = { workspace = true }
 enum_dispatch = { version = "0.3.6" }
 failure = { workspace = true }
+futures = { workspace = true }
 Inflector = { version = "0.11.4" }
 itertools = { workspace = true }
 js-sys = { workspace = true }
diff --git a/lib/rust/ensogl/core/src/display/scene.rs b/lib/rust/ensogl/core/src/display/scene.rs
index 91cf84d9a8af..dd348fd205c2 100644
--- a/lib/rust/ensogl/core/src/display/scene.rs
+++ b/lib/rust/ensogl/core/src/display/scene.rs
@@ -716,6 +716,7 @@ pub struct SceneData {
     pub frp: Frp,
     pub pointer_position_changed: Rc<Cell<bool>>,
     pub shader_compiler: shader::compiler::Controller,
+    initial_shader_compilation: Rc<Cell<TaskState>>,
     display_mode: Rc<Cell<glsl::codes::DisplayModes>>,
     extensions: Extensions,
     disable_context_menu: Rc<EventListenerHandle>,
@@ -766,6 +767,7 @@ impl SceneData {
         let context_lost_handler = default();
         let pointer_position_changed = default();
         let shader_compiler = default();
+        let initial_shader_compilation = default();
         Self {
             display_object,
             display_mode,
@@ -789,6 +791,7 @@ impl SceneData {
             frp,
             pointer_position_changed,
             shader_compiler,
+            initial_shader_compilation,
             extensions,
             disable_context_menu,
         }
@@ -1047,6 +1050,59 @@ impl Scene {
     pub fn extension<T: Extension>(&self) -> T {
         self.extensions.get(self)
     }
+
+    /// Begin any preparation necessary to render, e.g. compilation of shaders. Returns when the
+    /// scene is ready to start being displayed.
+    #[profile(Task)]
+    pub async fn prepare_to_render(&self) {
+        match self.initial_shader_compilation.get() {
+            TaskState::Unstarted => {
+                self.begin_shader_initialization();
+                self.next_shader_compiler_idle().await;
+                self.initial_shader_compilation.set(TaskState::Completed);
+            }
+            TaskState::Running => self.next_shader_compiler_idle().await,
+            TaskState::Completed => (),
+        }
+    }
+
+    /// Begin compiling shaders.
+    #[profile(Task)]
+    pub fn begin_shader_initialization(&self) {
+        if self.initial_shader_compilation.get() != TaskState::Unstarted {
+            return;
+        }
+        world::SHAPES_DEFINITIONS.with_borrow(|shapes| {
+            for shape in shapes.iter().filter(|shape| shape.is_main_application_shape()) {
+                // Instantiate shape so that its shader program will be submitted to the
+                // shader compiler. The runtime compiles the shaders in background threads,
+                // and starting early ensures they will be ready when we want to render
+                // them.
+                let _shape = (shape.cons)();
+            }
+        });
+        self.initial_shader_compilation.set(TaskState::Running);
+    }
+
+    /// Wait until the next time the compiler goes from busy to idle. If the compiler is already
+    /// idle, this will complete during the next shader-compiler run.
+    pub async fn next_shader_compiler_idle(&self) {
+        if let Some(context) = &*self.context.borrow() {
+            // Ensure the callback will be run if the queue is already idle.
+            context.shader_compiler.submit_probe_job();
+        } else {
+            return;
+        };
+        // Register a callback that triggers a future, and await it.
+        let (sender, receiver) = futures::channel::oneshot::channel();
+        let sender = Box::new(RefCell::new(Some(sender)));
+        let _handle = self.shader_compiler.on_idle(move || {
+            if let Some(sender) = sender.take() {
+                sender.send(()).unwrap();
+            }
+        });
+        receiver.await.unwrap();
+    }
 }
 
 impl system::gpu::context::Display for Scene {
@@ -1168,6 +1224,17 @@ impl<'t> DomPath for &'t str {
 }
 
 
+// === Initial shader compilation state ===
+
+#[derive(Copy, Clone, Default, Debug, PartialEq, Eq)]
+enum TaskState {
+    #[default]
+    Unstarted,
+    Running,
+    Completed,
+}
+
+
 
 // ==================
 // === Test Utils ===
diff --git a/lib/rust/ensogl/core/src/display/world.rs b/lib/rust/ensogl/core/src/display/world.rs
index 67741d5f0fdd..33ded1212d21 100644
--- a/lib/rust/ensogl/core/src/display/world.rs
+++ b/lib/rust/ensogl/core/src/display/world.rs
@@ -100,7 +100,7 @@ pub struct ShapeDefinition {
 
 impl ShapeDefinition {
     /// Return `true` if it is possible that this shape is used by the main application.
-    fn is_main_application_shape(&self) -> bool {
+    pub fn is_main_application_shape(&self) -> bool {
         // Shapes defined in `examples` directories are not used in the main application.
         !self.definition_path.contains("/examples/")
     }
@@ -244,25 +244,6 @@ fn gather_shaders() -> HashMap<&'static str, shader::Code> {
 
 
 
-// ===================================
-// === Eager shaders instantiation ===
-// ===================================
-
-/// Begin compilation of all shaders that will be needed for the default scene.
-#[profile(Task)]
-pub fn instantiate_shaders() {
-    SHAPES_DEFINITIONS.with_borrow(|shapes| {
-        for shape in shapes.iter().filter(|shape| shape.is_main_application_shape()) {
-            // Instantiate shape so that its shader program will be submitted to the shader
-            // compiler. The runtime compiles the shaders in background threads, and starting early
-            // ensures they will be ready when we want to render them.
-            let _shape = (shape.cons)();
-        }
-    });
-}
-
-
-
 // ================
 // === Uniforms ===
 // ================
@@ -517,7 +498,6 @@ impl WorldData {
         self.init_environment();
         self.init_composer();
         self.init_debug_hotkeys();
-        instantiate_shaders();
         self
     }
 
diff --git a/lib/rust/ensogl/core/src/system/gpu/shader/compiler.rs b/lib/rust/ensogl/core/src/system/gpu/shader/compiler.rs
index 94fde29afc63..7a40613d7070 100644
--- a/lib/rust/ensogl/core/src/system/gpu/shader/compiler.rs
+++ b/lib/rust/ensogl/core/src/system/gpu/shader/compiler.rs
@@ -251,6 +251,13 @@ impl Compiler {
         self.cell.borrow_mut().submit(input, profiler, None, None);
     }
 
+    /// Submit a no-op job to the queue. If the queue is otherwise empty, this will cause an
+    /// [`on_idle`] notification to occur next time jobs are processed.
+    pub fn submit_probe_job(&self) {
+        let input = shader::Sources { vertex: None, fragment: None };
+        self.submit_background_job(input);
+    }
+
     /// Returns `true` if the compiler has no jobs in progress or queued.
     fn idle(&self) -> bool {
         !self.cell.borrow().dirty
@@ -832,6 +839,10 @@ impl Controller {
 
     /// Add a callback to be run when the compiler goes from busy to idle. The callback will remain
     /// installed until the handle returned here is dropped.
+    ///
+    /// Note that if the queue is already idle when a callback is attached, the callback will not be
+    /// executed until work has been queued and completed.
+    #[must_use]
     pub fn on_idle(&self, f: impl FnMut() + 'static) -> callback::Handle {
         self.rc.borrow_mut().on_idle(f)
     }