script: Make most of 2D canvas and WebGL run over IPC.

To actually make the multiprocess communication work, we'll need to
reroute the task creation to the pipeline or the compositor. But this
works as a first step.

components/canvas_traits/lib.rs

@@ -5,7 +5,11 @@
 #![crate_name = "canvas_traits"]
 #![crate_type = "rlib"]
 #![feature(core)]
+#![feature(custom_derive)]
 #![feature(nonzero)]
+#![feature(plugin)]
+#![plugin(serde_macros)]
+
 extern crate core;
 extern crate azure;
 extern crate euclid;
@@ -14,6 +18,7 @@ extern crate gfx_traits;
 extern crate ipc_channel;
 extern crate layers;
 extern crate offscreen_gl_context;
+extern crate serde;
 
 use azure::azure::{AzFloat, AzColor};
 use azure::azure_hl::{DrawTarget, Pattern, ColorPattern};
@@ -26,28 +31,51 @@ use euclid::point::Point2D;
 use euclid::rect::Rect;
 use euclid::size::Size2D;
 use gfx_traits::color;
-use std::sync::mpsc::{Sender};
+use ipc_channel::ipc::{IpcSender, IpcSharedMemory};
+use std::sync::mpsc::Sender;
 use layers::platform::surface::NativeSurface;
 use offscreen_gl_context::GLContextAttributes;
+use serde::{Deserialize, Deserializer, Serialize, Serializer};
 use core::nonzero::NonZero;
-use ipc_channel::ipc::IpcSharedMemory;
 
-#[derive(Clone)]
+#[derive(Clone, Deserialize, Serialize)]
 pub enum CanvasMsg {
     Canvas2d(Canvas2dMsg),
     Common(CanvasCommonMsg),
+    FromLayout(FromLayoutMsg),
+    FromPaint(FromPaintMsg),
     WebGL(CanvasWebGLMsg),
 }
 
-#[derive(Clone)]
+#[derive(Clone, Deserialize, Serialize)]
 pub enum CanvasCommonMsg {
     Close,
     Recreate(Size2D<i32>),
-    SendPixelContents(Sender<IpcSharedMemory>),
-    SendNativeSurface(Sender<NativeSurface>),
+}
+
+#[derive(Clone, Deserialize, Serialize)]
+pub enum FromLayoutMsg {
+    SendPixelContents(IpcSender<IpcSharedMemory>),
 }
 
 #[derive(Clone)]
+pub enum FromPaintMsg {
+    SendNativeSurface(Sender<NativeSurface>),
+}
+
+impl Serialize for FromPaintMsg {
+    fn serialize<S>(&self, _: &mut S) -> Result<(),S::Error> where S: Serializer {
+        panic!("can't serialize a `FromPaintMsg`!")
+    }
+}
+
+impl Deserialize for FromPaintMsg {
+    fn deserialize<D>(_: &mut D) -> Result<FromPaintMsg,D::Error> where D: Deserializer {
+        panic!("can't deserialize a `FromPaintMsg`!")
+    }
+}
+
+#[derive(Clone, Deserialize, Serialize)]
 pub enum Canvas2dMsg {
     Arc(Point2D<f32>, f32, f32, f32, bool),
     ArcTo(Point2D<f32>, Point2D<f32>, f32),
@@ -60,7 +88,7 @@ pub enum Canvas2dMsg {
     ClosePath,
     Fill,
     FillRect(Rect<f32>),
-    GetImageData(Rect<f64>, Size2D<f64>, Sender<Vec<u8>>),
+    GetImageData(Rect<f64>, Size2D<f64>, IpcSender<Vec<u8>>),
     LineTo(Point2D<f32>),
     MoveTo(Point2D<f32>),
     PutImageData(Vec<u8>, Rect<f64>, Option<Rect<f64>>),
@@ -85,9 +113,9 @@ pub enum Canvas2dMsg {
     SetShadowColor(RGBA),
 }
 
-#[derive(Clone)]
+#[derive(Clone, Deserialize, Serialize)]
 pub enum CanvasWebGLMsg {
-    GetContextAttributes(Sender<GLContextAttributes>),
+    GetContextAttributes(IpcSender<GLContextAttributes>),
     ActiveTexture(u32),
     BlendColor(f32, f32, f32, f32),
     BlendEquation(u32),
@@ -99,12 +127,12 @@ pub enum CanvasWebGLMsg {
     Clear(u32),
     ClearColor(f32, f32, f32, f32),
     CompileShader(u32),
-    CreateBuffer(Sender<Option<NonZero<u32>>>),
-    CreateFramebuffer(Sender<Option<NonZero<u32>>>),
-    CreateRenderbuffer(Sender<Option<NonZero<u32>>>),
-    CreateTexture(Sender<Option<NonZero<u32>>>),
-    CreateProgram(Sender<Option<NonZero<u32>>>),
-    CreateShader(u32, Sender<Option<NonZero<u32>>>),
+    CreateBuffer(IpcSender<Option<NonZero<u32>>>),
+    CreateFramebuffer(IpcSender<Option<NonZero<u32>>>),
+    CreateRenderbuffer(IpcSender<Option<NonZero<u32>>>),
+    CreateTexture(IpcSender<Option<NonZero<u32>>>),
+    CreateProgram(IpcSender<Option<NonZero<u32>>>),
+    CreateShader(u32, IpcSender<Option<NonZero<u32>>>),
     DeleteBuffer(u32),
     DeleteFramebuffer(u32),
     DeleteRenderbuffer(u32),
@@ -117,21 +145,21 @@ pub enum CanvasWebGLMsg {
     BindTexture(u32, u32),
     DrawArrays(u32, i32, i32),
     EnableVertexAttribArray(u32),
-    GetShaderInfoLog(u32, Sender<Option<String>>),
-    GetShaderParameter(u32, u32, Sender<WebGLShaderParameter>),
-    GetAttribLocation(u32, String, Sender<Option<i32>>),
-    GetUniformLocation(u32, String, Sender<Option<i32>>),
+    GetShaderInfoLog(u32, IpcSender<Option<String>>),
+    GetShaderParameter(u32, u32, IpcSender<WebGLShaderParameter>),
+    GetAttribLocation(u32, String, IpcSender<Option<i32>>),
+    GetUniformLocation(u32, String, IpcSender<Option<i32>>),
     LinkProgram(u32),
     ShaderSource(u32, String),
     Uniform4fv(i32, Vec<f32>),
     UseProgram(u32),
     VertexAttribPointer2f(u32, i32, bool, i32, i64),
     Viewport(i32, i32, i32, i32),
-    DrawingBufferWidth(Sender<i32>),
-    DrawingBufferHeight(Sender<i32>),
+    DrawingBufferWidth(IpcSender<i32>),
+    DrawingBufferHeight(IpcSender<i32>),
 }
 
-#[derive(Clone, Copy, PartialEq)]
+#[derive(Clone, Copy, PartialEq, Deserialize, Serialize)]
 pub enum WebGLError {
     InvalidEnum,
     InvalidOperation,
@@ -142,26 +170,26 @@ pub enum WebGLError {
 
 pub type WebGLResult<T> = Result<T, WebGLError>;
 
-#[derive(Clone)]
+#[derive(Clone, Deserialize, Serialize)]
 pub enum WebGLFramebufferBindingRequest {
     Explicit(u32),
     Default,
 }
 
-#[derive(Clone)]
+#[derive(Clone, Deserialize, Serialize)]
 pub enum WebGLShaderParameter {
     Int(i32),
     Bool(bool),
     Invalid,
 }
 
-#[derive(Clone)]
+#[derive(Clone, Deserialize, Serialize)]
 pub struct CanvasGradientStop {
     pub offset: f64,
     pub color: RGBA,
 }
 
-#[derive(Clone)]
+#[derive(Clone, Deserialize, Serialize)]
 pub struct LinearGradientStyle {
     pub x0: f64,
     pub y0: f64,
@@ -183,7 +211,7 @@ impl LinearGradientStyle {
     }
 }
 
-#[derive(Clone)]
+#[derive(Clone, Deserialize, Serialize)]
 pub struct RadialGradientStyle {
     pub x0: f64,
     pub y0: f64,
@@ -209,7 +237,7 @@ impl RadialGradientStyle {
     }
 }
 
-#[derive(Clone)]
+#[derive(Clone, Deserialize, Serialize)]
 pub struct SurfaceStyle {
     pub surface_data: Vec<u8>,
     pub surface_size: Size2D<i32>,
@@ -230,7 +258,7 @@ impl SurfaceStyle {
 }
 
 
-#[derive(Clone)]
+#[derive(Clone, Deserialize, Serialize)]
 pub enum FillOrStrokeStyle {
     Color(RGBA),
     LinearGradient(LinearGradientStyle),
@@ -293,7 +321,7 @@ impl FillOrStrokeStyle {
     }
 }
 
-#[derive(Copy, Clone, PartialEq)]
+#[derive(Copy, Clone, PartialEq, Deserialize, Serialize)]
 pub enum LineCapStyle {
     Butt = 0,
     Round = 1,
@@ -319,7 +347,7 @@ impl LineCapStyle {
     }
 }
 
-#[derive(Copy, Clone, PartialEq)]
+#[derive(Copy, Clone, PartialEq, Deserialize, Serialize)]
 pub enum LineJoinStyle {
     Round = 0,
     Bevel = 1,
@@ -345,7 +373,7 @@ impl LineJoinStyle {
     }
 }
 
-#[derive(Copy, Clone, PartialEq)]
+#[derive(Copy, Clone, PartialEq, Deserialize, Serialize)]
 pub enum RepetitionStyle {
     Repeat,
     RepeatX,
@@ -365,7 +393,7 @@ impl RepetitionStyle {
     }
 }
 
-#[derive(Copy, Clone, PartialEq)]
+#[derive(Copy, Clone, PartialEq, Deserialize, Serialize)]
 pub enum CompositionStyle {
     SrcIn,
     SrcOut,
@@ -431,7 +459,7 @@ impl CompositionStyle {
     }
 }
 
-#[derive(Copy, Clone, PartialEq)]
+#[derive(Copy, Clone, PartialEq, Deserialize, Serialize)]
 pub enum BlendingStyle {
     Multiply,
     Screen,
@@ -513,7 +541,7 @@ impl BlendingStyle {
     }
 }
 
-#[derive(Copy, Clone, PartialEq)]
+#[derive(Copy, Clone, PartialEq, Deserialize, Serialize)]
 pub enum CompositionOrBlending {
     Composition(CompositionStyle),
     Blending(BlendingStyle),