Auto merge of #6380 - ecoal95:webgl-refactoring, r=jdm

Refactor WebGL implementation to move logic inside the DOM interfaces

This improves the encapsulation and consistency in our WebGL
implementation.

Also allows to implement new methods such as `getShaderSource()`.

It will also allow us to use `delete()` in the destructors of them (note
that we will probably want to keep track of them from the context before).

Some concerns:

**Trait method repetition**:
I'm aware that the traits `WebGL{Buffer,Renderbuffer,Framebuffer,Texture}Helpers` are basically the same, but `delete()` and `id()` methods are everywhere. I've thought something like:

```rust
pub trait WebGLIdentifiable {
    type WebGLId; // id is sometimes i32 (see WebGLUniformLocation)
    fn id(&self) -> Self::WebGLId;
}

pub trait WebGLBindable {
    fn bind(&self);
}

pub trait WebGLDeletable {
    fn delete(&self);
}
```

But I'd want to know your opinion first.

**`renderer` repetition**:
Thought of moving the field: `renderer: Sender<CanvasMsg>` to `WebGLObject`, but I think it makes it way more complicated to read, and also a bit unnecessary, at least IMO (`WebGLObject` will never interact with the field directly). It would also mean that all `WebGLObject`s should have one, which is true at this moment, but maybe not with WebGL 2, for example.

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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)]
-pub enum CanvasCommonMsg {
-    Close,
-    Recreate(Size2D<i32>),
-    SendPixelContents(Sender<Vec<u8>>),
-    SendNativeSurface(Sender<NativeSurface>),
+#[derive(Clone, Copy, PartialEq)]
+pub enum WebGLError {
+    InvalidEnum,
+    InvalidOperation,
+    InvalidValue,
+    OutOfMemory,
+    ContextLost,
 }
 
+pub type WebGLResult<T> = Result<T, WebGLError>;
+
+#[derive(Clone)]
+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();
+        }
+    }
 }

components/script/dom/webglprogram.rs

@@ -5,35 +5,131 @@
 // https://www.khronos.org/registry/webgl/specs/latest/1.0/webgl.idl
 use dom::bindings::codegen::Bindings::WebGLProgramBinding;
 use dom::bindings::global::GlobalRef;
-use dom::bindings::js::Root;
+use dom::bindings::js::{JS, MutNullableHeap, Root};
 use dom::bindings::utils::reflect_dom_object;
 use dom::webglobject::WebGLObject;
+use dom::webglshader::{WebGLShader, WebGLShaderHelpers};
+use dom::webglrenderingcontext::MAX_UNIFORM_AND_ATTRIBUTE_LEN;
+
+use dom::bindings::codegen::Bindings::WebGLRenderingContextBinding::WebGLRenderingContextConstants as constants;
+
+use canvas_traits::{CanvasMsg, CanvasWebGLMsg, WebGLResult, WebGLError};
+use std::sync::mpsc::{channel, Sender};
+use std::cell::Cell;
 
 #[dom_struct]
 pub struct WebGLProgram {
     webgl_object: WebGLObject,
     id: u32,
+    is_deleted: Cell<bool>,
+    fragment_shader: MutNullableHeap<JS<WebGLShader>>,
+    vertex_shader: MutNullableHeap<JS<WebGLShader>>,
+    renderer: Sender<CanvasMsg>,
 }
 
 impl WebGLProgram {
-    fn new_inherited(id: u32) -> WebGLProgram {
+    fn new_inherited(renderer: Sender<CanvasMsg>, id: u32) -> WebGLProgram {
         WebGLProgram {
             webgl_object: WebGLObject::new_inherited(),
             id: id,
+            is_deleted: Cell::new(false),
+            fragment_shader: Default::default(),
+            vertex_shader: Default::default(),
+            renderer: renderer,
         }
     }
 
-    pub fn new(global: GlobalRef, id: u32) -> Root<WebGLProgram> {
-        reflect_dom_object(box WebGLProgram::new_inherited(id), global, WebGLProgramBinding::Wrap)
+    pub fn maybe_new(global: GlobalRef, renderer: Sender<CanvasMsg>) -> Option<Root<WebGLProgram>> {
+        let (sender, receiver) = channel();
+        renderer.send(CanvasMsg::WebGL(CanvasWebGLMsg::CreateProgram(sender))).unwrap();
+
+        let result = receiver.recv().unwrap();
+        result.map(|program_id| WebGLProgram::new(global, renderer, *program_id))
+    }
+
+    pub fn new(global: GlobalRef, renderer: Sender<CanvasMsg>, id: u32) -> Root<WebGLProgram> {
+        reflect_dom_object(box WebGLProgram::new_inherited(renderer, id), global, WebGLProgramBinding::Wrap)
     }
 }
 
 pub trait WebGLProgramHelpers {
-    fn get_id(self) -> u32;
+    fn delete(self);
+    fn link(self);
+    fn use_program(self);
+    fn attach_shader(self, shader: &WebGLShader) -> WebGLResult<()>;
+    fn get_attrib_location(self, name: String) -> WebGLResult<Option<i32>>;
+    fn get_uniform_location(self, name: String) -> WebGLResult<Option<i32>>;
 }
 
 impl<'a> WebGLProgramHelpers for &'a WebGLProgram {
-    fn get_id(self) -> u32 {
-        self.id
+    /// glDeleteProgram
+    fn delete(self) {
+        if !self.is_deleted.get() {
+            self.is_deleted.set(true);
+            self.renderer.send(CanvasMsg::WebGL(CanvasWebGLMsg::DeleteProgram(self.id))).unwrap();
+        }
+    }
+
+    /// glLinkProgram
+    fn link(self) {
+        self.renderer.send(CanvasMsg::WebGL(CanvasWebGLMsg::LinkProgram(self.id))).unwrap();
+    }
+
+    /// glUseProgram
+    fn use_program(self) {
+        self.renderer.send(CanvasMsg::WebGL(CanvasWebGLMsg::UseProgram(self.id))).unwrap();
+    }
+
+    /// glAttachShader
+    fn attach_shader(self, shader: &WebGLShader) -> WebGLResult<()> {
+        let shader_slot = match shader.gl_type() {
+            constants::FRAGMENT_SHADER => &self.fragment_shader,
+            constants::VERTEX_SHADER => &self.vertex_shader,
+            _ => return Err(WebGLError::InvalidOperation),
+        };
+
+        // TODO(ecoal95): Differentiate between same shader already assigned and other previous
+        // shader.
+        if shader_slot.get().is_some() {
+            return Err(WebGLError::InvalidOperation);
+        }
+
+        shader_slot.set(Some(JS::from_ref(shader)));
+
+        self.renderer.send(CanvasMsg::WebGL(CanvasWebGLMsg::AttachShader(self.id, shader.id()))).unwrap();
+
+        Ok(())
+    }
+
+    /// glGetAttribLocation
+    fn get_attrib_location(self, name: String) -> WebGLResult<Option<i32>> {
+        if name.len() > MAX_UNIFORM_AND_ATTRIBUTE_LEN {
+            return Err(WebGLError::InvalidValue);
+        }
+
+        // Check if the name is reserved
+        if name.starts_with("webgl") || name.starts_with("_webgl_") {
+            return Ok(None);
+        }
+
+        let (sender, receiver) = channel();
+        self.renderer.send(CanvasMsg::WebGL(CanvasWebGLMsg::GetAttribLocation(self.id, name, sender))).unwrap();
+        Ok(receiver.recv().unwrap())
+    }
+
+    /// glGetUniformLocation
+    fn get_uniform_location(self, name: String) -> WebGLResult<Option<i32>> {
+        if name.len() > MAX_UNIFORM_AND_ATTRIBUTE_LEN {
+            return Err(WebGLError::InvalidValue);
+        }
+
+        // Check if the name is reserved
+        if name.starts_with("webgl") || name.starts_with("_webgl_") {
+            return Ok(None);
+        }
+
+        let (sender, receiver) = channel();
+        self.renderer.send(CanvasMsg::WebGL(CanvasWebGLMsg::GetUniformLocation(self.id, name, sender))).unwrap();
+        Ok(receiver.recv().unwrap())
     }
 }

components/script/dom/webglrenderbuffer.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 WebGLRenderbuffer {
     webgl_object: WebGLObject,
     id: u32,
+    is_deleted: Cell<bool>,
+    renderer: Sender<CanvasMsg>,
 }
 
 impl WebGLRenderbuffer {
-    fn new_inherited(id: u32) -> WebGLRenderbuffer {
+    fn new_inherited(renderer: Sender<CanvasMsg>, id: u32) -> WebGLRenderbuffer {
         WebGLRenderbuffer {
             webgl_object: WebGLObject::new_inherited(),
             id: id,
+            is_deleted: Cell::new(false),
+            renderer: renderer,
         }
     }
 
-    pub fn new(global: GlobalRef, id: u32) -> Root<WebGLRenderbuffer> {
-        reflect_dom_object(box WebGLRenderbuffer::new_inherited(id), global, WebGLRenderbufferBinding::Wrap)
+    pub fn maybe_new(global: GlobalRef, renderer: Sender<CanvasMsg>) -> Option<Root<WebGLRenderbuffer>> {
+        let (sender, receiver) = channel();
+        renderer.send(CanvasMsg::WebGL(CanvasWebGLMsg::CreateRenderbuffer(sender))).unwrap();
+
+        let result = receiver.recv().unwrap();
+        result.map(|renderbuffer_id| WebGLRenderbuffer::new(global, renderer, *renderbuffer_id))
+    }
+
+    pub fn new(global: GlobalRef, renderer: Sender<CanvasMsg>, id: u32) -> Root<WebGLRenderbuffer> {
+        reflect_dom_object(box WebGLRenderbuffer::new_inherited(renderer, id), global, WebGLRenderbufferBinding::Wrap)
     }
 }
 
 pub trait WebGLRenderbufferHelpers {
-    fn get_id(self) -> u32;
+    fn id(self) -> u32;
+    fn bind(self, target: u32);
+    fn delete(self);
 }
 
 impl<'a> WebGLRenderbufferHelpers for &'a WebGLRenderbuffer {
-    fn get_id(self) -> u32 {
+    fn id(self) -> u32 {
         self.id
     }
+
+    fn bind(self, target: u32) {
+        self.renderer.send(CanvasMsg::WebGL(CanvasWebGLMsg::BindRenderbuffer(target, self.id))).unwrap();
+    }
+
+    fn delete(self) {
+        if !self.is_deleted.get() {
+            self.is_deleted.set(true);
+            self.renderer.send(CanvasMsg::WebGL(CanvasWebGLMsg::DeleteRenderbuffer(self.id))).unwrap();
+        }
+    }
 }

components/script/dom/webglrenderingcontext.rs

@@ -3,10 +3,13 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 use canvas::webgl_paint_task::WebGLPaintTask;
-use canvas_traits::{CanvasMsg, CanvasWebGLMsg, CanvasCommonMsg};
-use dom::bindings::codegen::Bindings::WebGLRenderingContextBinding;
-use dom::bindings::codegen::Bindings::WebGLRenderingContextBinding::{
-    WebGLContextAttributes, WebGLRenderingContextMethods, WebGLRenderingContextConstants};
+use canvas_traits::
+            {CanvasMsg, CanvasWebGLMsg, CanvasCommonMsg, WebGLError,
+             WebGLShaderParameter, WebGLFramebufferBindingRequest};
+use dom::bindings::codegen::Bindings::WebGLRenderingContextBinding::
+            {self, WebGLContextAttributes, WebGLRenderingContextMethods};
+use dom::bindings::codegen::Bindings::WebGLRenderingContextBinding::WebGLRenderingContextConstants as constants;
+
 use dom::bindings::global::{GlobalRef, GlobalField};
 use dom::bindings::js::{JS, LayoutJS, Root};
 use dom::bindings::utils::{Reflector, reflect_dom_object};
@@ -22,7 +25,8 @@ use dom::webgluniformlocation::{WebGLUniformLocation, WebGLUniformLocationHelper
 use euclid::size::Size2D;
 use js::jsapi::{JSContext, JSObject, RootedValue};
 use js::jsapi::{JS_GetFloat32ArrayData, JS_GetObjectAsArrayBufferView};
-use js::jsval::{JSVal, UndefinedValue, NullValue, Int32Value};
+use js::jsval::{JSVal, UndefinedValue, NullValue, Int32Value, BooleanValue};
+use std::cell::Cell;
 use std::mem;
 use std::ptr;
 use std::slice;
@@ -30,12 +34,27 @@ use std::sync::mpsc::{channel, Sender};
 use util::str::DOMString;
 use offscreen_gl_context::GLContextAttributes;
 
+pub const MAX_UNIFORM_AND_ATTRIBUTE_LEN: usize = 256;
+
+macro_rules! handle_potential_webgl_error {
+    ($context:ident, $call:expr, $return_on_error:expr) => {
+        match $call {
+            Ok(ret) => ret,
+            Err(error) => {
+                $context.handle_webgl_error(error);
+                $return_on_error
+            }
+        }
+    }
+}
+
 #[dom_struct]
 pub struct WebGLRenderingContext {
     reflector_: Reflector,
     global: GlobalField,
     renderer: Sender<CanvasMsg>,
     canvas: JS<HTMLCanvasElement>,
+    last_error: Cell<Option<WebGLError>>,
 }
 
 impl WebGLRenderingContext {
@@ -50,6 +69,7 @@ impl WebGLRenderingContext {
             reflector_: Reflector::new(),
             global: GlobalField::from_rooted(&global),
             renderer: chan,
+            last_error: Cell::new(None),
             canvas: JS::from_ref(canvas),
         })
     }
@@ -102,16 +122,33 @@ impl<'a> WebGLRenderingContextMethods for &'a WebGLRenderingContext {
         // TODO(ecoal95): Implement the missing parameters from the spec
         let mut rval = RootedValue::new(cx, UndefinedValue());
         match parameter {
-            WebGLRenderingContextConstants::VERSION =>
+            constants::VERSION =>
                 "WebGL 1.0".to_jsval(cx, rval.handle_mut()),
-            WebGLRenderingContextConstants::RENDERER |
-            WebGLRenderingContextConstants::VENDOR =>
+            constants::RENDERER |
+            constants::VENDOR =>
                 "Mozilla/Servo".to_jsval(cx, rval.handle_mut()),
             _ => rval.ptr = NullValue(),
         }
         rval.ptr
     }
 
+    // https://www.khronos.org/registry/webgl/specs/latest/1.0/#5.14.3
+    fn GetError(self) -> u32 {
+        let error_code = if let Some(error) = self.last_error.get() {
+            match error {
+                WebGLError::InvalidEnum => constants::INVALID_ENUM,
+                WebGLError::InvalidValue => constants::INVALID_VALUE,
+                WebGLError::InvalidOperation => constants::INVALID_OPERATION,
+                WebGLError::OutOfMemory => constants::OUT_OF_MEMORY,
+                WebGLError::ContextLost => constants::CONTEXT_LOST_WEBGL,
+            }
+        } else {
+            constants::NO_ERROR
+        };
+        self.last_error.set(None);
+        error_code
+    }
+
     // https://www.khronos.org/registry/webgl/specs/latest/1.0/#5.14.2
     fn GetContextAttributes(self) -> Option<WebGLContextAttributes> {
         let (sender, receiver) = channel();
@@ -174,43 +211,49 @@ impl<'a> WebGLRenderingContextMethods for &'a WebGLRenderingContext {
 
     // https://www.khronos.org/registry/webgl/specs/latest/1.0/#5.14.9
     fn AttachShader(self, program: Option<&WebGLProgram>, shader: Option<&WebGLShader>) {
-        let program_id = match program {
-            Some(program) => program.get_id(),
-            None => return,
-        };
-        let shader_id = match shader {
-            Some(shader) => shader.get_id(),
-            None => return,
-        };
-        self.renderer.send(CanvasMsg::WebGL(CanvasWebGLMsg::AttachShader(program_id, shader_id))).unwrap()
+        if let Some(program) = program {
+            if let Some(shader) = shader {
+                handle_potential_webgl_error!(self, program.attach_shader(shader), ());
+            }
+        }
     }
 
     // https://www.khronos.org/registry/webgl/specs/latest/1.0/#5.14.5
     fn BindBuffer(self, target: u32, buffer: Option<&WebGLBuffer>) {
-        let id = buffer.map(|buf| buf.get_id()).unwrap_or(0);
-        self.renderer.send(
-            CanvasMsg::WebGL(CanvasWebGLMsg::BindBuffer(target, id))).unwrap()
+        if let Some(buffer) = buffer {
+            buffer.bind(target)
+        } else {
+            // Unbind the current buffer
+            self.renderer.send(CanvasMsg::WebGL(CanvasWebGLMsg::BindBuffer(target, 0))).unwrap()
+        }
     }
 
     // https://www.khronos.org/registry/webgl/specs/latest/1.0/#5.14.6
     fn BindFramebuffer(self, target: u32, framebuffer: Option<&WebGLFramebuffer>) {
-        let id = framebuffer.map(|fb| fb.get_id()).unwrap_or(0);
-        self.renderer.send(
-            CanvasMsg::WebGL(CanvasWebGLMsg::BindFramebuffer(target, id))).unwrap()
+        if let Some(framebuffer) = framebuffer {
+            framebuffer.bind(target)
+        } else {
+            // Bind the default framebuffer
+            let cmd = CanvasWebGLMsg::BindFramebuffer(target, WebGLFramebufferBindingRequest::Default);
+            self.renderer.send(CanvasMsg::WebGL(cmd)).unwrap();
+        }
     }
 
     // https://www.khronos.org/registry/webgl/specs/latest/1.0/#5.14.7
     fn BindRenderbuffer(self, target: u32, renderbuffer: Option<&WebGLRenderbuffer>) {
-        let id = renderbuffer.map(|rb| rb.get_id()).unwrap_or(0);
-        self.renderer.send(
-            CanvasMsg::WebGL(CanvasWebGLMsg::BindRenderbuffer(target, id))).unwrap()
+        if let Some(renderbuffer) = renderbuffer {
+            renderbuffer.bind(target)
+        } else {
+            // Unbind the currently bound renderbuffer
+            self.renderer.send(CanvasMsg::WebGL(CanvasWebGLMsg::BindRenderbuffer(target, 0))).unwrap()
+        }
     }
 
     // https://www.khronos.org/registry/webgl/specs/latest/1.0/#5.14.8
     fn BindTexture(self, target: u32, texture: Option<&WebGLTexture>) {
-        let id = texture.map(|tex| tex.get_id()).unwrap_or(0);
-        self.renderer.send(
-            CanvasMsg::WebGL(CanvasWebGLMsg::BindTexture(target, id))).unwrap()
+        if let Some(texture) = texture {
+            texture.bind(target)
+        }
     }
 
     // https://www.khronos.org/registry/webgl/specs/latest/1.0/#5.14.5
@@ -246,104 +289,84 @@ impl<'a> WebGLRenderingContextMethods for &'a WebGLRenderingContext {
 
     // https://www.khronos.org/registry/webgl/specs/latest/1.0/#5.14.9
     fn CompileShader(self, shader: Option<&WebGLShader>) {
-        let shader_id = match shader {
-            Some(shader) => shader.get_id(),
-            None => return,
-        };
-        self.renderer.send(CanvasMsg::WebGL(CanvasWebGLMsg::CompileShader(shader_id))).unwrap()
+        if let Some(shader) = shader {
+            shader.compile()
+        }
     }
 
     // TODO(ecoal95): Probably in the future we should keep track of the
     // generated objects, either here or in the webgl task
     // https://www.khronos.org/registry/webgl/specs/latest/1.0/#5.14.5
     fn CreateBuffer(self) -> Option<Root<WebGLBuffer>> {
-        let (sender, receiver) = channel();
-        self.renderer.send(CanvasMsg::WebGL(CanvasWebGLMsg::CreateBuffer(sender))).unwrap();
-        receiver.recv().unwrap()
-            .map(|buffer_id| WebGLBuffer::new(self.global.root().r(), *buffer_id))
+        WebGLBuffer::maybe_new(self.global.root().r(), self.renderer.clone())
     }
 
     // https://www.khronos.org/registry/webgl/specs/latest/1.0/#5.14.6
     fn CreateFramebuffer(self) -> Option<Root<WebGLFramebuffer>> {
-        let (sender, receiver) = channel();
-        self.renderer.send(CanvasMsg::WebGL(CanvasWebGLMsg::CreateFramebuffer(sender))).unwrap();
-        receiver.recv().unwrap()
-            .map(|fb_id| WebGLFramebuffer::new(self.global.root().r(), *fb_id))
+        WebGLFramebuffer::maybe_new(self.global.root().r(), self.renderer.clone())
     }
 
     // https://www.khronos.org/registry/webgl/specs/latest/1.0/#5.14.7
     fn CreateRenderbuffer(self) -> Option<Root<WebGLRenderbuffer>> {
-        let (sender, receiver) = channel();
-        self.renderer.send(CanvasMsg::WebGL(CanvasWebGLMsg::CreateRenderbuffer(sender))).unwrap();
-        receiver.recv().unwrap()
-            .map(|program_id| WebGLRenderbuffer::new(self.global.root().r(), *program_id))
+        WebGLRenderbuffer::maybe_new(self.global.root().r(), self.renderer.clone())
     }
 
     // https://www.khronos.org/registry/webgl/specs/latest/1.0/#5.14.8
     fn CreateTexture(self) -> Option<Root<WebGLTexture>> {
-        let (sender, receiver) = channel();
-        self.renderer.send(CanvasMsg::WebGL(CanvasWebGLMsg::CreateTexture(sender))).unwrap();
-        receiver.recv().unwrap()
-            .map(|texture_id| WebGLTexture::new(self.global.root().r(), *texture_id))
+        WebGLTexture::maybe_new(self.global.root().r(), self.renderer.clone())
     }
 
     // https://www.khronos.org/registry/webgl/specs/latest/1.0/#5.14.9
     fn CreateProgram(self) -> Option<Root<WebGLProgram>> {
-        let (sender, receiver) = channel();
-        self.renderer.send(CanvasMsg::WebGL(CanvasWebGLMsg::CreateProgram(sender))).unwrap();
-        receiver.recv().unwrap()
-            .map(|program_id| WebGLProgram::new(self.global.root().r(), *program_id))
+        WebGLProgram::maybe_new(self.global.root().r(), self.renderer.clone())
     }
 
     // https://www.khronos.org/registry/webgl/specs/latest/1.0/#5.14.9
     // TODO(ecoal95): Check if constants are cross-platform or if we must make a translation
     // between WebGL constants and native ones.
     fn CreateShader(self, shader_type: u32) -> Option<Root<WebGLShader>> {
-        let (sender, receiver) = channel();
-        self.renderer.send(CanvasMsg::WebGL(CanvasWebGLMsg::CreateShader(shader_type, sender))).unwrap();
-        receiver.recv().unwrap()
-            .map(|shader_id| WebGLShader::new(self.global.root().r(), *shader_id))
+        WebGLShader::maybe_new(self.global.root().r(), self.renderer.clone(), shader_type)
     }
 
     // https://www.khronos.org/registry/webgl/specs/latest/1.0/#5.14.5
     fn DeleteBuffer(self, buffer: Option<&WebGLBuffer>) {
         if let Some(buffer) = buffer {
-            self.renderer.send(CanvasMsg::WebGL(CanvasWebGLMsg::DeleteBuffer(buffer.get_id()))).unwrap();
+            buffer.delete()
         }
     }
 
     // https://www.khronos.org/registry/webgl/specs/latest/1.0/#5.14.6
     fn DeleteFramebuffer(self, framebuffer: Option<&WebGLFramebuffer>) {
         if let Some(framebuffer) = framebuffer {
-            self.renderer.send(CanvasMsg::WebGL(CanvasWebGLMsg::DeleteFramebuffer(framebuffer.get_id()))).unwrap();
+            framebuffer.delete()
         }
     }
 
     // https://www.khronos.org/registry/webgl/specs/latest/1.0/#5.14.7
     fn DeleteRenderbuffer(self, renderbuffer: Option<&WebGLRenderbuffer>) {
         if let Some(renderbuffer) = renderbuffer {
-            self.renderer.send(CanvasMsg::WebGL(CanvasWebGLMsg::DeleteRenderbuffer(renderbuffer.get_id()))).unwrap();
+            renderbuffer.delete()
         }
     }
 
     // https://www.khronos.org/registry/webgl/specs/latest/1.0/#5.14.8
     fn DeleteTexture(self, texture: Option<&WebGLTexture>) {
         if let Some(texture) = texture {
-            self.renderer.send(CanvasMsg::WebGL(CanvasWebGLMsg::DeleteTexture(texture.get_id()))).unwrap();
+            texture.delete()
         }
     }
 
     // https://www.khronos.org/registry/webgl/specs/latest/1.0/#5.14.9
     fn DeleteProgram(self, program: Option<&WebGLProgram>) {
         if let Some(program) = program {
-            self.renderer.send(CanvasMsg::WebGL(CanvasWebGLMsg::DeleteProgram(program.get_id()))).unwrap();
+            program.delete()
         }
     }
 
     // https://www.khronos.org/registry/webgl/specs/latest/1.0/#5.14.9
     fn DeleteShader(self, shader: Option<&WebGLShader>) {
         if let Some(shader) = shader {
-            self.renderer.send(CanvasMsg::WebGL(CanvasWebGLMsg::DeleteShader(shader.get_id()))).unwrap();
+            shader.delete()
         }
     }
 
@@ -359,21 +382,17 @@ impl<'a> WebGLRenderingContextMethods for &'a WebGLRenderingContext {
 
     // https://www.khronos.org/registry/webgl/specs/latest/1.0/#5.14.10
     fn GetAttribLocation(self, program: Option<&WebGLProgram>, name: DOMString) -> i32 {
-        let program_id = match program {
-            Some(program) => program.get_id(),
-            None => return -1,
-        };
-        let (sender, receiver) = channel();
-        self.renderer.send(CanvasMsg::WebGL(CanvasWebGLMsg::GetAttribLocation(program_id, name, sender))).unwrap();
-        receiver.recv().unwrap()
+        if let Some(program) = program {
+            handle_potential_webgl_error!(self, program.get_attrib_location(name), None).unwrap_or(-1)
+        } else {
+            -1
+        }
     }
 
     // https://www.khronos.org/registry/webgl/specs/latest/1.0/#5.14.9
     fn GetShaderInfoLog(self, shader: Option<&WebGLShader>) -> Option<DOMString> {
         if let Some(shader) = shader {
-            let (sender, receiver) = channel();
-            self.renderer.send(CanvasMsg::WebGL(CanvasWebGLMsg::GetShaderInfoLog(shader.get_id(), sender))).unwrap();
-            Some(receiver.recv().unwrap())
+            shader.info_log()
         } else {
             None
         }
@@ -382,10 +401,11 @@ impl<'a> WebGLRenderingContextMethods for &'a WebGLRenderingContext {
     // https://www.khronos.org/registry/webgl/specs/latest/1.0/#5.14.9
     fn GetShaderParameter(self, _: *mut JSContext, shader: Option<&WebGLShader>, param_id: u32) -> JSVal {
         if let Some(shader) = shader {
-            let (sender, receiver) = channel();
-            self.renderer.send(
-                CanvasMsg::WebGL(CanvasWebGLMsg::GetShaderParameter(shader.get_id(), param_id, sender))).unwrap();
-            Int32Value(receiver.recv().unwrap())
+            match handle_potential_webgl_error!(self, shader.parameter(param_id), WebGLShaderParameter::Invalid) {
+                WebGLShaderParameter::Int(val) => Int32Value(val),
+                WebGLShaderParameter::Bool(val) => BooleanValue(val),
+                WebGLShaderParameter::Invalid => NullValue(),
+            }
         } else {
             NullValue()
         }
@@ -396,10 +416,7 @@ impl<'a> WebGLRenderingContextMethods for &'a WebGLRenderingContext {
                           program: Option<&WebGLProgram>,
                           name: DOMString) -> Option<Root<WebGLUniformLocation>> {
         if let Some(program) = program {
-            let (sender, receiver) = channel();
-            self.renderer.send(
-                CanvasMsg::WebGL(CanvasWebGLMsg::GetUniformLocation(program.get_id(), name, sender))).unwrap();
-            receiver.recv().unwrap()
+            handle_potential_webgl_error!(self, program.get_uniform_location(name), None)
                 .map(|location| WebGLUniformLocation::new(self.global.root().r(), location))
         } else {
             None
@@ -409,15 +426,23 @@ impl<'a> WebGLRenderingContextMethods for &'a WebGLRenderingContext {
     // https://www.khronos.org/registry/webgl/specs/latest/1.0/#5.14.9
     fn LinkProgram(self, program: Option<&WebGLProgram>) {
         if let Some(program) = program {
-            self.renderer.send(CanvasMsg::WebGL(CanvasWebGLMsg::LinkProgram(program.get_id()))).unwrap()
+            program.link()
         }
     }
 
     // https://www.khronos.org/registry/webgl/specs/latest/1.0/#5.14.9
     fn ShaderSource(self, shader: Option<&WebGLShader>, source: DOMString) {
         if let Some(shader) = shader {
-            self.renderer.send(
-                CanvasMsg::WebGL(CanvasWebGLMsg::ShaderSource(shader.get_id(), source))).unwrap();
+            shader.set_source(source)
+        }
+    }
+
+    // https://www.khronos.org/registry/webgl/specs/latest/1.0/#5.14.9
+    fn GetShaderSource(self, shader: Option<&WebGLShader>) -> Option<DOMString> {
+        if let Some(shader) = shader {
+            shader.source()
+        } else {
+            None
         }
     }
 
@@ -428,7 +453,7 @@ impl<'a> WebGLRenderingContextMethods for &'a WebGLRenderingContext {
                   uniform: Option<&WebGLUniformLocation>,
                   data: Option<*mut JSObject>) {
         let uniform_id = match uniform {
-            Some(uniform) => uniform.get_id(),
+            Some(uniform) => uniform.id(),
             None => return,
         };
 
@@ -446,18 +471,16 @@ impl<'a> WebGLRenderingContextMethods for &'a WebGLRenderingContext {
 
     // https://www.khronos.org/registry/webgl/specs/latest/1.0/#5.14.9
     fn UseProgram(self, program: Option<&WebGLProgram>) {
-        let program_id = match program {
-            Some(program) => program.get_id(),
-            None => return,
-        };
-        self.renderer.send(CanvasMsg::WebGL(CanvasWebGLMsg::UseProgram(program_id as u32))).unwrap()
+        if let Some(program) = program {
+            program.use_program()
+        }
     }
 
     // https://www.khronos.org/registry/webgl/specs/latest/1.0/#5.14.10
     fn VertexAttribPointer(self, attrib_id: u32, size: i32, data_type: u32,
                            normalized: bool, stride: i32, offset: i64) {
         match data_type {
-            WebGLRenderingContextConstants::FLOAT => {
+            constants::FLOAT => {
                let msg = CanvasMsg::WebGL(
                    CanvasWebGLMsg::VertexAttribPointer2f(attrib_id, size, normalized, stride, offset));
                 self.renderer.send(msg).unwrap()
@@ -473,6 +496,20 @@ impl<'a> WebGLRenderingContextMethods for &'a WebGLRenderingContext {
     }
 }
 
+pub trait WebGLRenderingContextHelpers {
+    fn handle_webgl_error(&self, err: WebGLError);
+}
+
+impl<'a> WebGLRenderingContextHelpers for &'a WebGLRenderingContext {
+    fn handle_webgl_error(&self, err: WebGLError) {
+        // If an error has been detected no further errors must be
+        // recorded until `getError` has been called
+        if self.last_error.get().is_none() {
+            self.last_error.set(Some(err));
+        }
+    }
+}
+
 pub trait LayoutCanvasWebGLRenderingContextHelpers {
     #[allow(unsafe_code)]
     unsafe fn get_renderer(&self) -> Sender<CanvasMsg>;

components/script/dom/webglshader.rs

@@ -9,32 +9,118 @@ use dom::bindings::js::Root;
 use dom::bindings::utils::reflect_dom_object;
 use dom::webglobject::WebGLObject;
 
+use dom::bindings::codegen::Bindings::WebGLRenderingContextBinding::WebGLRenderingContextConstants as constants;
+
+use canvas_traits::{CanvasMsg, CanvasWebGLMsg, WebGLResult, WebGLError, WebGLShaderParameter};
+use std::sync::mpsc::{channel, Sender};
+use std::cell::Cell;
+use std::cell::RefCell;
+
 #[dom_struct]
 pub struct WebGLShader {
     webgl_object: WebGLObject,
     id: u32,
+    gl_type: u32,
+    source: RefCell<Option<String>>,
+    is_deleted: Cell<bool>,
+    // TODO(ecoal95): Evaluate moving this to `WebGLObject`
+    renderer: Sender<CanvasMsg>,
 }
 
 impl WebGLShader {
-    fn new_inherited(id: u32) -> WebGLShader {
+    fn new_inherited(renderer: Sender<CanvasMsg>, id: u32, shader_type: u32) -> WebGLShader {
         WebGLShader {
             webgl_object: WebGLObject::new_inherited(),
             id: id,
+            gl_type: shader_type,
+            source: RefCell::new(None),
+            is_deleted: Cell::new(false),
+            renderer: renderer,
         }
     }
 
-    pub fn new(global: GlobalRef, id: u32) -> Root<WebGLShader> {
-        reflect_dom_object(box WebGLShader::new_inherited(id), global, WebGLShaderBinding::Wrap)
+    pub fn maybe_new(global: GlobalRef,
+                     renderer: Sender<CanvasMsg>,
+                     shader_type: u32) -> Option<Root<WebGLShader>> {
+        let (sender, receiver) = channel();
+        renderer.send(CanvasMsg::WebGL(CanvasWebGLMsg::CreateShader(shader_type, sender))).unwrap();
+
+        let result = receiver.recv().unwrap();
+        result.map(|shader_id| WebGLShader::new(global, renderer, *shader_id, shader_type))
+    }
+
+    pub fn new(global: GlobalRef,
+               renderer: Sender<CanvasMsg>,
+               id: u32,
+               shader_type: u32) -> Root<WebGLShader> {
+        reflect_dom_object(
+            box WebGLShader::new_inherited(renderer, id, shader_type), global, WebGLShaderBinding::Wrap)
     }
 }
 
 pub trait WebGLShaderHelpers {
-    fn get_id(self) -> u32;
+    fn id(self) -> u32;
+    fn gl_type(self) -> u32;
+    fn compile(self);
+    fn delete(self);
+    fn info_log(self) -> Option<String>;
+    fn parameter(self, param_id: u32) -> WebGLResult<WebGLShaderParameter>;
+    fn source(self) -> Option<String>;
+    fn set_source(self, src: String);
 }
 
 impl<'a> WebGLShaderHelpers for &'a WebGLShader {
-    fn get_id(self) -> u32 {
+    fn id(self) -> u32 {
         self.id
     }
+
+    fn gl_type(self) -> u32 {
+        self.gl_type
+    }
+
+    // TODO(ecoal95): Validate shaders to be conforming to the WebGL spec
+    /// glCompileShader
+    fn compile(self) {
+        self.renderer.send(CanvasMsg::WebGL(CanvasWebGLMsg::CompileShader(self.id))).unwrap()
+    }
+
+    /// Mark this shader as deleted (if it wasn't previously)
+    /// and delete it as if calling glDeleteShader.
+    fn delete(self) {
+        if !self.is_deleted.get() {
+            self.is_deleted.set(true);
+            self.renderer.send(CanvasMsg::WebGL(CanvasWebGLMsg::DeleteShader(self.id))).unwrap()
+        }
+    }
+
+    /// glGetShaderInfoLog
+    fn info_log(self) -> Option<String> {
+        let (sender, receiver) = channel();
+        self.renderer.send(CanvasMsg::WebGL(CanvasWebGLMsg::GetShaderInfoLog(self.id, sender))).unwrap();
+        receiver.recv().unwrap()
+    }
+
+    /// glGetShaderParameter
+    fn parameter(self, param_id: u32) -> WebGLResult<WebGLShaderParameter> {
+        match param_id {
+            constants::SHADER_TYPE | constants::DELETE_STATUS | constants::COMPILE_STATUS => {},
+            _ => return Err(WebGLError::InvalidEnum),
+        }
+
+        let (sender, receiver) = channel();
+        self.renderer.send(CanvasMsg::WebGL(CanvasWebGLMsg::GetShaderParameter(self.id, param_id, sender))).unwrap();
+        Ok(receiver.recv().unwrap())
+    }
+
+    /// Get the shader source
+    fn source(self) -> Option<String> {
+        self.source.borrow().clone()
+    }
+
+    /// glShaderSource
+    fn set_source(self, source: String) {
+        *self.source.borrow_mut() = Some(source.clone());
+        self.renderer.send(CanvasMsg::WebGL(CanvasWebGLMsg::ShaderSource(self.id, source))).unwrap()
+    }
 }
 

components/script/dom/webgltexture.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 WebGLTexture {
     webgl_object: WebGLObject,
     id: u32,
+    is_deleted: Cell<bool>,
+    renderer: Sender<CanvasMsg>,
 }
 
 impl WebGLTexture {
-    fn new_inherited(id: u32) -> WebGLTexture {
+    fn new_inherited(renderer: Sender<CanvasMsg>, id: u32) -> WebGLTexture {
         WebGLTexture {
             webgl_object: WebGLObject::new_inherited(),
             id: id,
+            is_deleted: Cell::new(false),
+            renderer: renderer,
         }
     }
 
-    pub fn new(global: GlobalRef, id: u32) -> Root<WebGLTexture> {
-        reflect_dom_object(box WebGLTexture::new_inherited(id), global, WebGLTextureBinding::Wrap)
+    pub fn maybe_new(global: GlobalRef, renderer: Sender<CanvasMsg>) -> Option<Root<WebGLTexture>> {
+        let (sender, receiver) = channel();
+        renderer.send(CanvasMsg::WebGL(CanvasWebGLMsg::CreateTexture(sender))).unwrap();
+
+        let result = receiver.recv().unwrap();
+        result.map(|texture_id| WebGLTexture::new(global, renderer, *texture_id))
+    }
+
+    pub fn new(global: GlobalRef, renderer: Sender<CanvasMsg>, id: u32) -> Root<WebGLTexture> {
+        reflect_dom_object(box WebGLTexture::new_inherited(renderer, id), global, WebGLTextureBinding::Wrap)
     }
 }
 
 pub trait WebGLTextureHelpers {
-    fn get_id(self) -> u32;
+    fn id(self) -> u32;
+    fn bind(self, target: u32);
+    fn delete(self);
 }
 
 impl<'a> WebGLTextureHelpers for &'a WebGLTexture {
-    fn get_id(self) -> u32 {
+    fn id(self) -> u32 {
         self.id
     }
+
+    fn bind(self, target: u32) {
+        self.renderer.send(CanvasMsg::WebGL(CanvasWebGLMsg::BindTexture(self.id, target))).unwrap();
+    }
+
+    fn delete(self) {
+        if !self.is_deleted.get() {
+            self.is_deleted.set(true);
+            self.renderer.send(CanvasMsg::WebGL(CanvasWebGLMsg::DeleteTexture(self.id))).unwrap();
+        }
+    }
 }

components/script/dom/webgluniformlocation.rs

@@ -28,11 +28,11 @@ impl WebGLUniformLocation {
 }
 
 pub trait WebGLUniformLocationHelpers {
-    fn get_id(self) -> i32;
+    fn id(self) -> i32;
 }
 
 impl<'a> WebGLUniformLocationHelpers for &'a WebGLUniformLocation {
-    fn get_id(self) -> i32 {
+    fn id(self) -> i32 {
         self.id
     }
 }

components/script/dom/webidls/WebGLRenderingContext.webidl

@@ -558,7 +558,7 @@ interface WebGLRenderingContextBase
     //any getBufferParameter(GLenum target, GLenum pname);
     any getParameter(GLenum pname);
 
-    //[WebGLHandlesContextLoss] GLenum getError();
+    [WebGLHandlesContextLoss] GLenum getError();
 
     //any getFramebufferAttachmentParameter(GLenum target, GLenum attachment,
     //                                      GLenum pname);
@@ -569,7 +569,7 @@ interface WebGLRenderingContextBase
     //WebGLShaderPrecisionFormat? getShaderPrecisionFormat(GLenum shadertype, GLenum precisiontype);
     DOMString? getShaderInfoLog(WebGLShader? shader);
 
-    //DOMString? getShaderSource(WebGLShader? shader);
+    DOMString? getShaderSource(WebGLShader? shader);
 
     //any getTexParameter(GLenum target, GLenum pname);