expose user textures, add repeat to sampling for wgpu backend

crates/egui_render_glow/egui.vert

@@ -0,0 +1,27 @@
+#version 300 es
+
+
+// vertex input
+layout(location = 0) in vec2 vin_pos; // vertex in position
+layout(location = 1) in vec2 vin_tc; // vertex in texture coordinates
+layout(location = 2) in vec4 vin_sc; // vertex in normalized srgba color 
+
+// vertex output
+out vec2 vout_tc; // vertex out texture coordinates
+out vec4 vout_sc; // srgb color
+
+// vertex uniform
+uniform vec2 u_screen_size; // in physical pixels
+
+
+void main() {
+    gl_Position = vec4(
+                      2.0 * vin_pos.x / u_screen_size.x - 1.0,
+                      1.0 - 2.0 * vin_pos.y / u_screen_size.y,
+                      0.0,
+                      1.0);
+    vout_tc = vin_tc;
+    // egui does everything in srgb space
+    vout_sc = vin_sc;
+
+}

crates/egui_render_glow/egui_linear_output.frag

@@ -0,0 +1,38 @@
+#version 300 es
+
+precision highp float;
+// fragment shader uniforms. texture and sampler
+uniform sampler2D u_sampler;
+
+// fragment inputs
+in vec2 vout_tc;
+in vec4 vout_sc; // srgb color
+
+out vec4 fout_color;
+
+// Converts a color from linear light gamma to sRGB gamma
+vec4 from_linear(vec4 linearRGB)
+{
+    bvec3 cutoff = lessThan(linearRGB.rgb, vec3(0.0031308));
+    vec3 higher = vec3(1.055)*pow(linearRGB.rgb, vec3(1.0/2.4)) - vec3(0.055);
+    vec3 lower = linearRGB.rgb * vec3(12.92);
+
+    return vec4(mix(higher, lower, cutoff), linearRGB.a);
+}
+
+// Converts a color from sRGB gamma to linear light gamma
+vec4 to_linear(vec4 sRGB)
+{
+    bvec3 cutoff = lessThan(sRGB.rgb, vec3(0.04045));
+    vec3 higher = pow((sRGB.rgb + vec3(0.055))/vec3(1.055), vec3(2.4));
+    vec3 lower = sRGB.rgb/vec3(12.92);
+
+    return vec4(mix(higher, lower, cutoff), sRGB.a);
+}
+
+void main() {
+    // we output in linear. so that gpu can convert it into srgb for srgb framebuffers
+    fout_color = to_linear(vout_sc * from_linear(texture(u_sampler, vout_tc)));
+}
+
+

crates/egui_render_glow/egui_srgb_output.frag

@@ -0,0 +1,27 @@
+#version 300 es
+
+precision highp float;
+// fragment shader uniforms. texture and sampler
+uniform sampler2D u_sampler;
+
+// fragment inputs
+in vec2 vout_tc;
+in vec4 vout_sc; // srgb color
+
+out vec4 fout_color;
+
+
+// Converts a color from linear light gamma to sRGB gamma
+vec4 from_linear(vec4 linearRGB)
+{
+    bvec3 cutoff = lessThan(linearRGB.rgb, vec3(0.0031308));
+    vec3 higher = vec3(1.055)*pow(linearRGB.rgb, vec3(1.0/2.4)) - vec3(0.055);
+    vec3 lower = linearRGB.rgb * vec3(12.92);
+
+    return vec4(mix(higher, lower, cutoff), linearRGB.a);
+}
+
+void main() {
+    // we output in srgb space to write to linear framebuffers without gpu doing any conversion
+    fout_color = vout_sc * from_linear(texture(u_sampler, vout_tc));
+}

crates/egui_render_glow/src/helpers.rs

@@ -161,7 +161,7 @@ pub unsafe fn create_egui_vao_buffers(
     (vao, vbo, ebo)
 }
 
-pub unsafe fn create_samplers(glow_context: &glow::Context) -> (Sampler, Sampler) {
+pub unsafe fn create_samplers(glow_context: &glow::Context) -> (Sampler, Sampler, Sampler) {
     let nearest_sampler = glow_context
         .create_sampler()
         .expect("failed to create nearest sampler");
@@ -186,6 +186,42 @@ pub unsafe fn create_samplers(glow_context: &glow::Context) -> (Sampler, Sampler
     );
     glow_error!(glow_context);
 
+    let font_sampler = glow_context
+        .create_sampler()
+        .expect("failed to create linear sampler");
+    glow_context.bind_sampler(0, Some(font_sampler));
+    glow_error!(glow_context);
+
+    glow_context.sampler_parameter_i32(
+        font_sampler,
+        glow::TEXTURE_MAG_FILTER,
+        glow::LINEAR
+            .try_into()
+            .expect("failed to fit LINEAR MIPMAP NEAREST in i32"),
+    );
+    glow_error!(glow_context);
+
+    glow_context.sampler_parameter_i32(
+        font_sampler,
+        glow::TEXTURE_MIN_FILTER,
+        glow::LINEAR
+            .try_into()
+            .expect("failed to fit LINEAR MIPMAP NEAREST in i32"),
+    );
+    glow_error!(glow_context);
+    glow_context.sampler_parameter_i32(
+        font_sampler,
+        glow::TEXTURE_WRAP_S,
+        glow::CLAMP_TO_EDGE as i32,
+    );
+    glow_error!(glow_context);
+
+    glow_context.sampler_parameter_i32(
+        font_sampler,
+        glow::TEXTURE_WRAP_T,
+        glow::CLAMP_TO_EDGE as i32,
+    );
+    glow_error!(glow_context);
     let linear_sampler = glow_context
         .create_sampler()
         .expect("failed to create linear sampler");
@@ -209,7 +245,13 @@ pub unsafe fn create_samplers(glow_context: &glow::Context) -> (Sampler, Sampler
             .expect("failed to fit LINEAR MIPMAP NEAREST in i32"),
     );
     glow_error!(glow_context);
-    (linear_sampler, nearest_sampler)
+    glow_context.sampler_parameter_i32(linear_sampler, glow::TEXTURE_WRAP_S, glow::REPEAT as i32);
+    glow_error!(glow_context);
+
+    glow_context.sampler_parameter_i32(linear_sampler, glow::TEXTURE_WRAP_T, glow::REPEAT as i32);
+    glow_error!(glow_context);
+
+    (linear_sampler, nearest_sampler, font_sampler)
 }
 
 #[allow(unused)]

crates/egui_render_glow/src/lib.rs

@@ -177,6 +177,7 @@ pub struct Painter {
     /// Most of these objects are created at startup
     pub linear_sampler: Sampler,
     pub nearest_sampler: Sampler,
+    pub font_sampler: Sampler,
     pub managed_textures: IntMap<GpuTexture>,
     pub egui_program: Program,
     pub vao: VertexArray,
@@ -233,7 +234,7 @@ impl Painter {
             gl.use_program(Some(egui_program));
             let (vao, vbo, ebo) = create_egui_vao_buffers(gl, egui_program);
             debug!("created egui vao, vbo, ebo");
-            let (linear_sampler, nearest_sampler) = create_samplers(gl);
+            let (linear_sampler, nearest_sampler, font_sampler) = create_samplers(gl);
             debug!("created linear and nearest samplers");
             Self {
                 managed_textures: Default::default(),
@@ -243,6 +244,7 @@ impl Painter {
                 ebo,
                 linear_sampler,
                 nearest_sampler,
+                font_sampler,
                 u_screen_size,
                 u_sampler,
                 clipped_primitives: Vec::new(),
@@ -270,6 +272,10 @@ impl Painter {
 
         // update textures
         for (texture_id, delta) in textures_delta.set {
+            let sampler = match delta.options.minification {
+                egui::TextureFilter::Nearest => self.nearest_sampler,
+                egui::TextureFilter::Linear => self.linear_sampler,
+            };
             match texture_id {
                 TextureId::Managed(managed) => {
                     glow_context.bind_texture(
@@ -285,9 +291,10 @@ impl Painter {
                                     width: 0,
                                     height: 0,
                                     sampler: if managed == 0 {
-                                        self.nearest_sampler
+                                        // special sampler for font that would clamp to edge
+                                        self.font_sampler
                                     } else {
-                                        self.linear_sampler
+                                        sampler
                                     },
                                 })
                                 .handle

crates/egui_render_wgpu/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "egui_render_wgpu"
-version = "0.4.4"
+version = "0.4.5"
 edition = "2021"
 description = "egui rendering backend using wgpu"
 license = "MIT"