Refactor WebGL implementation to move logic inside the DOM interfaces

components/canvas/webgl_paint_task.rs

@@ -2,7 +2,7 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
-use canvas_traits::{CanvasMsg, CanvasWebGLMsg, CanvasCommonMsg};
+use canvas_traits::{CanvasMsg, CanvasWebGLMsg, CanvasCommonMsg, WebGLShaderParameter, WebGLFramebufferBindingRequest};
 use euclid::size::Size2D;
 use core::nonzero::NonZero;
 use gleam::gl;
@@ -109,8 +109,8 @@ impl WebGLPaintTask {
                 self.delete_shader(id),
             CanvasWebGLMsg::BindBuffer(target, id) =>
                 self.bind_buffer(target, id),
-            CanvasWebGLMsg::BindFramebuffer(target, id) =>
-                self.bind_framebuffer(target, id),
+            CanvasWebGLMsg::BindFramebuffer(target, request) =>
+                self.bind_framebuffer(target, request),
             CanvasWebGLMsg::BindRenderbuffer(target, id) =>
                 self.bind_renderbuffer(target, id),
             CanvasWebGLMsg::BindTexture(target, id) =>
@@ -329,7 +329,13 @@ impl WebGLPaintTask {
     }
 
     #[inline]
-    fn bind_framebuffer(&self, target: u32, id: u32) {
+    fn bind_framebuffer(&self, target: u32, request: WebGLFramebufferBindingRequest) {
+        let id = match request {
+            WebGLFramebufferBindingRequest::Explicit(id) => id,
+            WebGLFramebufferBindingRequest::Default =>
+                self.gl_context.borrow_draw_buffer().unwrap().get_framebuffer(),
+        };
+
         gl::bind_framebuffer(target, id);
     }
 
@@ -361,19 +367,35 @@ impl WebGLPaintTask {
         gl::enable_vertex_attrib_array(attrib_id);
     }
 
-    fn get_attrib_location(&self, program_id: u32, name: String, chan: Sender<i32> ) {
+    fn get_attrib_location(&self, program_id: u32, name: String, chan: Sender<Option<i32>> ) {
         let attrib_location = gl::get_attrib_location(program_id, &name);
+
+        let attrib_location = if attrib_location == -1 {
+            None
+        } else {
+            Some(attrib_location)
+        };
+
         chan.send(attrib_location).unwrap();
     }
 
-    fn get_shader_info_log(&self, shader_id: u32, chan: Sender<String>) {
+    fn get_shader_info_log(&self, shader_id: u32, chan: Sender<Option<String>>) {
+        // TODO(ecoal95): Right now we always return a value, we should
+        // check for gl errors and return None there
         let info = gl::get_shader_info_log(shader_id);
-        chan.send(info).unwrap();
+        chan.send(Some(info)).unwrap();
     }
 
-    fn get_shader_parameter(&self, shader_id: u32, param_id: u32, chan: Sender<i32>) {
-        let parameter = gl::get_shader_iv(shader_id, param_id);
-        chan.send(parameter as i32).unwrap();
+    fn get_shader_parameter(&self, shader_id: u32, param_id: u32, chan: Sender<WebGLShaderParameter>) {
+        let result = match param_id {
+            gl::SHADER_TYPE =>
+                WebGLShaderParameter::Int(gl::get_shader_iv(shader_id, param_id)),
+            gl::DELETE_STATUS | gl::COMPILE_STATUS =>
+                WebGLShaderParameter::Bool(gl::get_shader_iv(shader_id, param_id) != 0),
+            _ => panic!("Unexpected shader parameter type"),
+        };
+
+        chan.send(result).unwrap();
     }
 
     fn get_uniform_location(&self, program_id: u32, name: String, chan: Sender<Option<i32>>) {

components/canvas_traits/lib.rs

@@ -37,6 +37,14 @@ pub enum CanvasMsg {
     WebGL(CanvasWebGLMsg),
 }
 
+#[derive(Clone)]
+pub enum CanvasCommonMsg {
+    Close,
+    Recreate(Size2D<i32>),
+    SendPixelContents(Sender<Vec<u8>>),
+    SendNativeSurface(Sender<NativeSurface>),
+}
+
 #[derive(Clone)]
 pub enum Canvas2dMsg {
     Arc(Point2D<f32>, f32, f32, f32, bool),
@@ -102,14 +110,14 @@ pub enum CanvasWebGLMsg {
     DeleteProgram(u32),
     DeleteShader(u32),
     BindBuffer(u32, u32),
-    BindFramebuffer(u32, u32),
+    BindFramebuffer(u32, WebGLFramebufferBindingRequest),
     BindRenderbuffer(u32, u32),
     BindTexture(u32, u32),
     DrawArrays(u32, i32, i32),
     EnableVertexAttribArray(u32),
-    GetAttribLocation(u32, String, Sender<i32>),
-    GetShaderInfoLog(u32, Sender<String>),
-    GetShaderParameter(u32, u32, Sender<i32>),
+    GetShaderInfoLog(u32, Sender<Option<String>>),
+    GetShaderParameter(u32, u32, Sender<WebGLShaderParameter>),
+    GetAttribLocation(u32, String, Sender<Option<i32>>),
     GetUniformLocation(u32, String, Sender<Option<i32>>),
     LinkProgram(u32),
     ShaderSource(u32, String),
@@ -121,14 +129,29 @@ pub enum CanvasWebGLMsg {
     DrawingBufferHeight(Sender<i32>),
 }
 
+#[derive(Clone, Copy, PartialEq)]
+pub enum WebGLError {
+    InvalidEnum,
+    InvalidOperation,
+    InvalidValue,
+    OutOfMemory,
+    ContextLost,
+}
+
+pub type WebGLResult<T> = Result<T, WebGLError>;
+
 #[derive(Clone)]
-pub enum CanvasCommonMsg {
-    Close,
-    Recreate(Size2D<i32>),
-    SendPixelContents(Sender<Vec<u8>>),
-    SendNativeSurface(Sender<NativeSurface>),
+pub enum WebGLFramebufferBindingRequest {
+    Explicit(u32),
+    Default,
 }
 
+#[derive(Clone)]
+pub enum WebGLShaderParameter {
+    Int(i32),
+    Bool(bool),
+    Invalid,
+}
 
 #[derive(Clone)]
 pub struct CanvasGradientStop {

components/script/dom/bindings/trace.rs

@@ -36,6 +36,7 @@ use script_task::ScriptChan;
 
 use canvas_traits::{CanvasGradientStop, LinearGradientStyle, RadialGradientStyle};
 use canvas_traits::{LineCapStyle, LineJoinStyle, CompositionOrBlending, RepetitionStyle};
+use canvas_traits::WebGLError;
 use cssparser::RGBA;
 use encoding::types::EncodingRef;
 use euclid::matrix2d::Matrix2D;
@@ -297,6 +298,7 @@ no_jsmanaged_fields!(StorageType);
 no_jsmanaged_fields!(CanvasGradientStop, LinearGradientStyle, RadialGradientStyle);
 no_jsmanaged_fields!(LineCapStyle, LineJoinStyle, CompositionOrBlending);
 no_jsmanaged_fields!(RepetitionStyle);
+no_jsmanaged_fields!(WebGLError);
 
 impl JSTraceable for Box<ScriptChan+Send> {
     #[inline]

components/script/dom/webglbuffer.rs

@@ -9,31 +9,60 @@ use dom::bindings::js::Root;
 use dom::bindings::utils::reflect_dom_object;
 use dom::webglobject::WebGLObject;
 
+use canvas_traits::{CanvasMsg, CanvasWebGLMsg};
+use std::sync::mpsc::{channel, Sender};
+use std::cell::Cell;
+
 #[dom_struct]
 pub struct WebGLBuffer {
     webgl_object: WebGLObject,
     id: u32,
+    is_deleted: Cell<bool>,
+    renderer: Sender<CanvasMsg>,
 }
 
 impl WebGLBuffer {
-    fn new_inherited(id: u32) -> WebGLBuffer {
+    fn new_inherited(renderer: Sender<CanvasMsg>, id: u32) -> WebGLBuffer {
         WebGLBuffer {
             webgl_object: WebGLObject::new_inherited(),
             id: id,
+            is_deleted: Cell::new(false),
+            renderer: renderer,
         }
     }
 
-    pub fn new(global: GlobalRef, id: u32) -> Root<WebGLBuffer> {
-        reflect_dom_object(box WebGLBuffer::new_inherited(id), global, WebGLBufferBinding::Wrap)
+    pub fn maybe_new(global: GlobalRef, renderer: Sender<CanvasMsg>) -> Option<Root<WebGLBuffer>> {
+        let (sender, receiver) = channel();
+        renderer.send(CanvasMsg::WebGL(CanvasWebGLMsg::CreateBuffer(sender))).unwrap();
+
+        let result = receiver.recv().unwrap();
+        result.map(|buffer_id| WebGLBuffer::new(global, renderer, *buffer_id))
+    }
+
+    pub fn new(global: GlobalRef, renderer: Sender<CanvasMsg>, id: u32) -> Root<WebGLBuffer> {
+        reflect_dom_object(box WebGLBuffer::new_inherited(renderer, id), global, WebGLBufferBinding::Wrap)
     }
 }
 
 pub trait WebGLBufferHelpers {
-    fn get_id(self) -> u32;
+    fn id(self) -> u32;
+    fn bind(self, target: u32);
+    fn delete(self);
 }
 
 impl<'a> WebGLBufferHelpers for &'a WebGLBuffer {
-    fn get_id(self) -> u32 {
+    fn id(self) -> u32 {
         self.id
     }
+
+    fn bind(self, target: u32) {
+        self.renderer.send(CanvasMsg::WebGL(CanvasWebGLMsg::BindBuffer(target, self.id))).unwrap();
+    }
+
+    fn delete(self) {
+        if !self.is_deleted.get() {
+            self.is_deleted.set(true);
+            self.renderer.send(CanvasMsg::WebGL(CanvasWebGLMsg::DeleteBuffer(self.id))).unwrap();
+        }
+    }
 }

components/script/dom/webglframebuffer.rs

@@ -9,31 +9,61 @@ use dom::bindings::js::Root;
 use dom::bindings::utils::reflect_dom_object;
 use dom::webglobject::WebGLObject;
 
+use canvas_traits::{CanvasMsg, CanvasWebGLMsg, WebGLFramebufferBindingRequest};
+use std::sync::mpsc::{channel, Sender};
+use std::cell::Cell;
+
 #[dom_struct]
 pub struct WebGLFramebuffer {
     webgl_object: WebGLObject,
     id: u32,
+    is_deleted: Cell<bool>,
+    renderer: Sender<CanvasMsg>,
 }
 
 impl WebGLFramebuffer {
-    fn new_inherited(id: u32) -> WebGLFramebuffer {
+    fn new_inherited(renderer: Sender<CanvasMsg>, id: u32) -> WebGLFramebuffer {
         WebGLFramebuffer {
             webgl_object: WebGLObject::new_inherited(),
             id: id,
+            is_deleted: Cell::new(false),
+            renderer: renderer,
         }
     }
 
-    pub fn new(global: GlobalRef, id: u32) -> Root<WebGLFramebuffer> {
-        reflect_dom_object(box WebGLFramebuffer::new_inherited(id), global, WebGLFramebufferBinding::Wrap)
+    pub fn maybe_new(global: GlobalRef, renderer: Sender<CanvasMsg>) -> Option<Root<WebGLFramebuffer>> {
+        let (sender, receiver) = channel();
+        renderer.send(CanvasMsg::WebGL(CanvasWebGLMsg::CreateFramebuffer(sender))).unwrap();
+
+        let result = receiver.recv().unwrap();
+        result.map(|fb_id| WebGLFramebuffer::new(global, renderer, *fb_id))
+    }
+
+    pub fn new(global: GlobalRef, renderer: Sender<CanvasMsg>, id: u32) -> Root<WebGLFramebuffer> {
+        reflect_dom_object(box WebGLFramebuffer::new_inherited(renderer, id), global, WebGLFramebufferBinding::Wrap)
     }
 }
 
 pub trait WebGLFramebufferHelpers {
-    fn get_id(self) -> u32;
+    fn id(self) -> u32;
+    fn bind(self, target: u32);
+    fn delete(self);
 }
 
 impl<'a> WebGLFramebufferHelpers for &'a WebGLFramebuffer {
-    fn get_id(self) -> u32 {
+    fn id(self) -> u32 {
         self.id
     }
+
+    fn bind(self, target: u32) {
+        let cmd = CanvasWebGLMsg::BindFramebuffer(target, WebGLFramebufferBindingRequest::Explicit(self.id));
+        self.renderer.send(CanvasMsg::WebGL(cmd)).unwrap();
+    }
+
+    fn delete(self) {
+        if !self.is_deleted.get() {
+            self.is_deleted.set(true);
+            self.renderer.send(CanvasMsg::WebGL(CanvasWebGLMsg::DeleteFramebuffer(self.id))).unwrap();
+        }
+    }
 }