Implement WebGL extensions.

components/script/dom/webgl_extensions/ext/mod.rs

@@ -0,0 +1,13 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * 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 dom::bindings::codegen::Bindings::WebGLRenderingContextBinding::WebGLRenderingContextConstants as constants;
+use super::{ext_constants, WebGLExtension, WebGLExtensions};
+
+pub mod oestexturefloat;
+pub mod oestexturefloatlinear;
+pub mod oestexturehalffloat;
+pub mod oestexturehalffloatlinear;
+pub mod oesvertexarrayobject;
+pub mod webglvertexarrayobjectoes;

components/script/dom/webgl_extensions/ext/oestexturefloat.rs

@@ -0,0 +1,56 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * 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 dom::bindings::codegen::Bindings::OESTextureFloatBinding;
+use dom::bindings::js::Root;
+use dom::bindings::reflector::{DomObject, Reflector, reflect_dom_object};
+use dom::webglrenderingcontext::WebGLRenderingContext;
+use dom_struct::dom_struct;
+use super::{constants as webgl, ext_constants as gl, WebGLExtension, WebGLExtensions};
+
+#[dom_struct]
+pub struct OESTextureFloat {
+    reflector_: Reflector,
+}
+
+impl OESTextureFloat {
+    fn new_inherited() -> OESTextureFloat {
+        Self {
+            reflector_: Reflector::new(),
+        }
+    }
+}
+
+impl WebGLExtension for OESTextureFloat {
+    type Extension = OESTextureFloat;
+    fn new(ctx: &WebGLRenderingContext) -> Root<OESTextureFloat> {
+        reflect_dom_object(box OESTextureFloat::new_inherited(),
+                           &*ctx.global(),
+                           OESTextureFloatBinding::Wrap)
+    }
+
+    fn is_supported(ext: &WebGLExtensions) -> bool {
+        ext.supports_any_gl_extension(&["GL_OES_texture_float",
+                                        "GL_ARB_texture_float"])
+    }
+
+    fn enable(ext: &WebGLExtensions) {
+        // Enable FLOAT text data type
+        ext.enable_tex_type(webgl::FLOAT);
+        let needs_replace = !ext.supports_gl_extension("GL_OES_texture_float");
+        if needs_replace {
+            // Special internal formats must be used to avoid clamped float values
+            ext.add_effective_tex_internal_format(webgl::RGBA, webgl::FLOAT, gl::RGBA32F);
+            ext.add_effective_tex_internal_format(webgl::RGB, webgl::FLOAT, gl::RGB32F);
+            ext.add_effective_tex_internal_format(webgl::LUMINANCE, webgl::FLOAT, gl::LUMINANCE32F_ARB);
+            ext.add_effective_tex_internal_format(webgl::ALPHA, webgl::FLOAT, gl::ALPHA32F_ARB);
+            ext.add_effective_tex_internal_format(webgl::LUMINANCE_ALPHA, webgl::FLOAT,
+                                                  gl::LUMINANCE_ALPHA32F_ARB);
+        }
+    }
+
+    fn name() -> &'static str {
+        "OES_texture_float"
+    }
+}

components/script/dom/webgl_extensions/ext/oestexturefloatlinear.rs

@@ -0,0 +1,45 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * 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 dom::bindings::codegen::Bindings::OESTextureFloatLinearBinding;
+use dom::bindings::js::Root;
+use dom::bindings::reflector::{DomObject, Reflector, reflect_dom_object};
+use dom::webglrenderingcontext::WebGLRenderingContext;
+use dom_struct::dom_struct;
+use super::{constants as webgl, WebGLExtension, WebGLExtensions};
+
+#[dom_struct]
+pub struct OESTextureFloatLinear {
+    reflector_: Reflector,
+}
+
+impl OESTextureFloatLinear {
+    fn new_inherited() -> OESTextureFloatLinear {
+        Self {
+            reflector_: Reflector::new(),
+        }
+    }
+}
+
+impl WebGLExtension for OESTextureFloatLinear {
+    type Extension = OESTextureFloatLinear;
+    fn new(ctx: &WebGLRenderingContext) -> Root<OESTextureFloatLinear> {
+        reflect_dom_object(box OESTextureFloatLinear::new_inherited(),
+                           &*ctx.global(),
+                           OESTextureFloatLinearBinding::Wrap)
+    }
+
+    fn is_supported(ext: &WebGLExtensions) -> bool {
+        ext.supports_any_gl_extension(&["GL_OES_texture_float_linear",
+                                        "GL_ARB_texture_float"])
+    }
+
+    fn enable(ext: &WebGLExtensions) {
+        ext.enable_filterable_tex_type(webgl::FLOAT);
+    }
+
+    fn name() -> &'static str {
+        "OES_texture_float_linear"
+    }
+}

components/script/dom/webgl_extensions/ext/oestexturehalffloat.rs

@@ -0,0 +1,57 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * 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 dom::bindings::codegen::Bindings::OESTextureHalfFloatBinding::{self, OESTextureHalfFloatConstants};
+use dom::bindings::js::Root;
+use dom::bindings::reflector::{DomObject, Reflector, reflect_dom_object};
+use dom::webglrenderingcontext::WebGLRenderingContext;
+use dom_struct::dom_struct;
+use super::{constants as webgl, ext_constants as gl, WebGLExtension, WebGLExtensions};
+
+#[dom_struct]
+pub struct OESTextureHalfFloat {
+    reflector_: Reflector,
+}
+
+impl OESTextureHalfFloat {
+    fn new_inherited() -> OESTextureHalfFloat {
+        Self {
+            reflector_: Reflector::new(),
+        }
+    }
+}
+
+impl WebGLExtension for OESTextureHalfFloat {
+    type Extension = OESTextureHalfFloat;
+    fn new(ctx: &WebGLRenderingContext) -> Root<OESTextureHalfFloat> {
+        reflect_dom_object(box OESTextureHalfFloat::new_inherited(),
+                           &*ctx.global(),
+                           OESTextureHalfFloatBinding::Wrap)
+    }
+
+    fn is_supported(ext: &WebGLExtensions) -> bool {
+        ext.supports_any_gl_extension(&["GL_OES_texture_half_float",
+                                        "GL_ARB_half_float_pixel",
+                                        "GL_NV_half_float"])
+    }
+
+    fn enable(ext: &WebGLExtensions) {
+        // Enable FLOAT text data type
+        let hf = OESTextureHalfFloatConstants::HALF_FLOAT_OES;
+        ext.enable_tex_type(hf);
+        let needs_replace = !ext.supports_gl_extension("GL_OES_texture_float");
+        if needs_replace {
+            // Special internal formats must be used to avoid clamped float values
+            ext.add_effective_tex_internal_format(webgl::RGBA, hf, gl::RGBA16F);
+            ext.add_effective_tex_internal_format(webgl::RGB, hf, gl::RGB16F);
+            ext.add_effective_tex_internal_format(webgl::LUMINANCE, hf, gl::LUMINANCE16F_ARB);
+            ext.add_effective_tex_internal_format(webgl::ALPHA, hf, gl::ALPHA16F_ARB);
+            ext.add_effective_tex_internal_format(webgl::LUMINANCE_ALPHA, hf, gl::LUMINANCE_ALPHA16F_ARB);
+        }
+    }
+
+    fn name() -> &'static str {
+        "OES_texture_half_float"
+    }
+}

components/script/dom/webgl_extensions/ext/oestexturehalffloatlinear.rs

@@ -0,0 +1,47 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * 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 dom::bindings::codegen::Bindings::OESTextureHalfFloatBinding::OESTextureHalfFloatConstants;
+use dom::bindings::codegen::Bindings::OESTextureHalfFloatLinearBinding;
+use dom::bindings::js::Root;
+use dom::bindings::reflector::{DomObject, Reflector, reflect_dom_object};
+use dom::webglrenderingcontext::WebGLRenderingContext;
+use dom_struct::dom_struct;
+use super::{WebGLExtension, WebGLExtensions};
+
+#[dom_struct]
+pub struct OESTextureHalfFloatLinear {
+    reflector_: Reflector,
+}
+
+impl OESTextureHalfFloatLinear {
+    fn new_inherited() -> OESTextureHalfFloatLinear {
+        Self {
+            reflector_: Reflector::new(),
+        }
+    }
+}
+
+impl WebGLExtension for OESTextureHalfFloatLinear {
+    type Extension = OESTextureHalfFloatLinear;
+    fn new(ctx: &WebGLRenderingContext) -> Root<OESTextureHalfFloatLinear> {
+        reflect_dom_object(box OESTextureHalfFloatLinear::new_inherited(),
+                           &*ctx.global(),
+                           OESTextureHalfFloatLinearBinding::Wrap)
+    }
+
+    fn is_supported(ext: &WebGLExtensions) -> bool {
+        ext.supports_any_gl_extension(&["GL_OES_texture_float_linear",
+                                        "GL_ARB_half_float_pixel",
+                                        "GL_NV_half_float"])
+    }
+
+    fn enable(ext: &WebGLExtensions) {
+        ext.enable_filterable_tex_type(OESTextureHalfFloatConstants::HALF_FLOAT_OES);
+    }
+
+    fn name() -> &'static str {
+        "OES_texture_half_float_linear"
+    }
+}

components/script/dom/webgl_extensions/ext/oesvertexarrayobject.rs

@@ -0,0 +1,166 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * 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;
+use dom::bindings::codegen::Bindings::OESVertexArrayObjectBinding::{self, OESVertexArrayObjectMethods};
+use dom::bindings::codegen::Bindings::OESVertexArrayObjectBinding::OESVertexArrayObjectConstants;
+use dom::bindings::js::{JS, MutNullableJS, Root};
+use dom::bindings::reflector::{DomObject, Reflector, reflect_dom_object};
+use dom::webglrenderingcontext::WebGLRenderingContext;
+use dom::webglvertexarrayobjectoes::WebGLVertexArrayObjectOES;
+use dom_struct::dom_struct;
+use js::conversions::ToJSValConvertible;
+use js::jsapi::JSContext;
+use js::jsval::{JSVal, NullValue};
+use std::iter;
+use super::{WebGLExtension, WebGLExtensions};
+use webrender_traits::{self, WebGLCommand, WebGLError};
+
+#[dom_struct]
+pub struct OESVertexArrayObject {
+    reflector_: Reflector,
+    ctx: JS<WebGLRenderingContext>,
+    bound_vao: MutNullableJS<WebGLVertexArrayObjectOES>,
+}
+
+impl OESVertexArrayObject {
+    fn new_inherited(ctx: &WebGLRenderingContext) -> OESVertexArrayObject {
+        Self {
+            reflector_: Reflector::new(),
+            ctx: JS::from_ref(ctx),
+            bound_vao: MutNullableJS::new(None)
+        }
+    }
+
+    #[allow(unsafe_code)]
+    fn get_current_binding(&self, cx:*mut JSContext) -> JSVal {
+        rooted!(in(cx) let mut rval = NullValue());
+        if let Some(bound_vao) = self.bound_vao.get() {
+            unsafe {
+                bound_vao.to_jsval(cx, rval.handle_mut());
+            }
+        }
+        rval.get()
+    }
+}
+
+impl OESVertexArrayObjectMethods for OESVertexArrayObject {
+    // https://www.khronos.org/registry/webgl/extensions/OES_vertex_array_object/
+    fn CreateVertexArrayOES(&self) -> Option<Root<WebGLVertexArrayObjectOES>> {
+        let (sender, receiver) = webrender_traits::channel::msg_channel().unwrap();
+        self.ctx.send_renderer_message(CanvasMsg::WebGL(WebGLCommand::CreateVertexArray(sender)));
+
+        let result = receiver.recv().unwrap();
+        result.map(|vao_id| WebGLVertexArrayObjectOES::new(&self.global(), vao_id))
+    }
+
+    // https://www.khronos.org/registry/webgl/extensions/OES_vertex_array_object/
+    fn DeleteVertexArrayOES(&self, vao: Option<&WebGLVertexArrayObjectOES>) {
+        if let Some(vao) = vao {
+            if vao.is_deleted() {
+                return;
+            }
+
+            // Unbind deleted VAO if currently bound
+            if let Some(bound_vao) = self.bound_vao.get() {
+                if bound_vao.id() == vao.id() {
+                    self.bound_vao.set(None);
+                    self.ctx.send_renderer_message(CanvasMsg::WebGL(WebGLCommand::BindVertexArray(None)));
+                }
+            }
+
+            // Remove VAO references from buffers
+            let buffers = vao.bound_attrib_buffers();
+            for buffer in buffers {
+                buffer.remove_vao_reference(vao.id());
+            }
+            if let Some(buffer) = vao.bound_buffer_element_array() {
+                buffer.remove_vao_reference(vao.id());
+            }
+
+            // Delete the vao
+            self.ctx.send_renderer_message(CanvasMsg::WebGL(WebGLCommand::DeleteVertexArray(vao.id())));
+            vao.set_deleted();
+        }
+    }
+
+    // https://www.khronos.org/registry/webgl/extensions/OES_vertex_array_object/
+    fn IsVertexArrayOES(&self, vao: Option<&WebGLVertexArrayObjectOES>) -> bool {
+        // Conformance tests expect false if vao never bound
+        vao.map_or(false, |vao| !vao.is_deleted() && vao.ever_bound())
+    }
+
+    // https://www.khronos.org/registry/webgl/extensions/OES_vertex_array_object/
+    fn BindVertexArrayOES(&self, vao: Option<&WebGLVertexArrayObjectOES>) {
+        if let Some(bound_vao) = self.bound_vao.get() {
+            // Store buffers attached to attrib pointers
+            let buffers = self.ctx.borrow_bound_attrib_buffers();
+            bound_vao.set_bound_attrib_buffers(buffers.iter().map(|(key, buffer)| {
+                (*buffer).add_vao_reference(bound_vao.id());
+                (*key, &**buffer)
+            }));
+            // Store element array buffer
+            let element_array = self.ctx.bound_buffer_element_array();
+            bound_vao.set_bound_buffer_element_array(element_array.as_ref().map(|buffer| {
+                buffer.add_vao_reference(bound_vao.id());
+                &**buffer
+            }));
+        }
+
+        if let Some(vao) = vao {
+            if vao.is_deleted() {
+                self.ctx.webgl_error(WebGLError::InvalidOperation);
+                return;
+            }
+
+            self.ctx.send_renderer_message(CanvasMsg::WebGL(WebGLCommand::BindVertexArray(Some(vao.id()))));
+            vao.set_ever_bound();
+            self.bound_vao.set(Some(&vao));
+
+            // Restore WebGLRenderingContext current bindings
+            let buffers = vao.borrow_bound_attrib_buffers();
+            self.ctx.set_bound_attrib_buffers(buffers.iter().map(|(k, v)| (*k, &**v)));
+            let element_array = vao.bound_buffer_element_array();
+            self.ctx.set_bound_buffer_element_array(element_array.as_ref().map(|buffer| &**buffer));
+        } else {
+            self.ctx.send_renderer_message(CanvasMsg::WebGL(WebGLCommand::BindVertexArray(None)));
+            self.bound_vao.set(None);
+            self.ctx.set_bound_attrib_buffers(iter::empty());
+        }
+    }
+}
+
+impl WebGLExtension for OESVertexArrayObject {
+    type Extension = OESVertexArrayObject;
+    fn new(ctx: &WebGLRenderingContext) -> Root<OESVertexArrayObject> {
+        reflect_dom_object(box OESVertexArrayObject::new_inherited(ctx),
+                           &*ctx.global(),
+                           OESVertexArrayObjectBinding::Wrap)
+    }
+
+    fn is_supported(ext: &WebGLExtensions) -> bool {
+        ext.supports_any_gl_extension(&["GL_OES_vertex_array_object",
+                                        "GL_ARB_vertex_array_object",
+                                        "GL_APPLE_vertex_array_object"])
+    }
+
+    fn enable(ext: &WebGLExtensions) {
+        let query = OESVertexArrayObjectConstants::VERTEX_ARRAY_BINDING_OES;
+        ext.add_query_parameter_handler(query, Box::new(|cx, webgl_ctx| {
+            match webgl_ctx.get_extension_manager().get_dom_object::<OESVertexArrayObject>() {
+                Some(dom_object) => {
+                    Ok(dom_object.get_current_binding(cx))
+                },
+                None => {
+                    // Extension instance not found!
+                    Err(WebGLError::InvalidOperation)
+                }
+            }
+        }));
+    }
+
+    fn name() -> &'static str {
+        "OES_vertex_array_object"
+    }
+}

components/script/dom/webgl_extensions/ext/webglvertexarrayobjectoes.rs

@@ -0,0 +1,87 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * 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 core::cell::Ref;
+use core::iter::FromIterator;
+use dom::bindings::cell::DOMRefCell;
+use dom::bindings::codegen::Bindings::WebGLVertexArrayObjectOESBinding;
+use dom::bindings::js::{JS, MutNullableJS};
+use dom::bindings::js::Root;
+use dom::bindings::reflector::reflect_dom_object;
+use dom::globalscope::GlobalScope;
+use dom::webglbuffer::WebGLBuffer;
+use dom::webglobject::WebGLObject;
+use dom_struct::dom_struct;
+use std::cell::Cell;
+use std::collections::HashMap;
+use webrender_traits::WebGLVertexArrayId;
+
+#[dom_struct]
+pub struct WebGLVertexArrayObjectOES {
+    webgl_object_: WebGLObject,
+    id: WebGLVertexArrayId,
+    ever_bound: Cell<bool>,
+    is_deleted: Cell<bool>,
+    bound_attrib_buffers: DOMRefCell<HashMap<u32, JS<WebGLBuffer>>>,
+    bound_buffer_element_array: MutNullableJS<WebGLBuffer>,
+}
+
+impl WebGLVertexArrayObjectOES {
+    fn new_inherited(id: WebGLVertexArrayId) -> WebGLVertexArrayObjectOES {
+        Self {
+            webgl_object_: WebGLObject::new_inherited(),
+            id: id,
+            ever_bound: Cell::new(false),
+            is_deleted: Cell::new(false),
+            bound_attrib_buffers: DOMRefCell::new(HashMap::new()),
+            bound_buffer_element_array: MutNullableJS::new(None),
+        }
+    }
+
+    pub fn new(global: &GlobalScope, id: WebGLVertexArrayId) -> Root<WebGLVertexArrayObjectOES> {
+        reflect_dom_object(box WebGLVertexArrayObjectOES::new_inherited(id),
+                           global,
+                           WebGLVertexArrayObjectOESBinding::Wrap)
+    }
+
+    pub fn id(&self) -> WebGLVertexArrayId {
+        self.id
+    }
+
+    pub fn is_deleted(&self) -> bool {
+        self.is_deleted.get()
+    }
+
+    pub fn set_deleted(&self) {
+        self.is_deleted.set(true)
+    }
+
+    pub fn ever_bound(&self) -> bool {
+        return self.ever_bound.get()
+    }
+
+    pub fn set_ever_bound(&self) {
+        self.ever_bound.set(true);
+    }
+
+    pub fn borrow_bound_attrib_buffers(&self) -> Ref<HashMap<u32, JS<WebGLBuffer>>> {
+        self.bound_attrib_buffers.borrow()
+    }
+
+    pub fn bound_attrib_buffers(&self) -> Vec<Root<WebGLBuffer>> {
+        self.bound_attrib_buffers.borrow().iter().map(|(_, b)| Root::from_ref(&**b)).collect()
+    }
+
+    pub fn set_bound_attrib_buffers<'a, T>(&self, iter: T) where T: Iterator<Item=(u32, &'a WebGLBuffer)> {
+        *self.bound_attrib_buffers.borrow_mut() = HashMap::from_iter(iter.map(|(k,v)| (k, JS::from_ref(v))));
+    }
+
+    pub fn bound_buffer_element_array(&self) -> Option<Root<WebGLBuffer>> {
+        self.bound_buffer_element_array.get()
+    }
+
+    pub fn set_bound_buffer_element_array(&self, buffer: Option<&WebGLBuffer>) {
+        self.bound_buffer_element_array.set(buffer);
+    }
+}

components/script/dom/webgl_extensions/extension.rs

@@ -0,0 +1,26 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * 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 dom::bindings::js::Root;
+use dom::bindings::reflector::DomObject;
+use dom::bindings::trace::JSTraceable;
+use dom::webglrenderingcontext::WebGLRenderingContext;
+use super::WebGLExtensions;
+
+/// Trait implemented by WebGL extensions.
+pub trait WebGLExtension: Sized where Self::Extension: DomObject + JSTraceable {
+    type Extension;
+
+    /// Creates the DOM object of the WebGL extension.
+    fn new(ctx: &WebGLRenderingContext) -> Root<Self::Extension>;
+
+    /// Checks if the extension is supported.
+    fn is_supported(ext: &WebGLExtensions) -> bool;
+
+    /// Enable the extension.
+    fn enable(ext: &WebGLExtensions);
+
+    /// Name of the WebGL Extension.
+    fn name() -> &'static str;
+}

components/script/dom/webgl_extensions/extensions.rs

@@ -0,0 +1,197 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * 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 core::iter::FromIterator;
+use core::nonzero::NonZero;
+use dom::bindings::cell::DOMRefCell;
+use dom::bindings::codegen::Bindings::OESTextureHalfFloatBinding::OESTextureHalfFloatConstants;
+use dom::bindings::codegen::Bindings::WebGLRenderingContextBinding::WebGLRenderingContextConstants as constants;
+use dom::bindings::js::Root;
+use dom::bindings::trace::JSTraceable;
+use dom::webglrenderingcontext::WebGLRenderingContext;
+use gleam::gl::GLenum;
+use heapsize::HeapSizeOf;
+use js::jsapi::{JSContext, JSObject};
+use js::jsval::JSVal;
+use ref_filter_map::ref_filter_map;
+use std::cell::Ref;
+use std::collections::{HashMap, HashSet};
+use super::{ext, WebGLExtension};
+use super::wrapper::{WebGLExtensionWrapper, TypedWebGLExtensionWrapper};
+use webrender_traits::WebGLError;
+
+// Data types that are implemented for texImage2D and texSubImage2D in WebGLRenderingContext
+// but must trigger a InvalidValue error until the related WebGL Extensions are enabled.
+// Example: https://www.khronos.org/registry/webgl/extensions/OES_texture_float/
+const DEFAULT_DISABLED_TEX_TYPES: [GLenum; 2] = [
+    constants::FLOAT, OESTextureHalfFloatConstants::HALF_FLOAT_OES
+];
+
+// Data types that are implemented for textures in WebGLRenderingContext
+// but not allowed to use with linear filtering until the related WebGL Extensions are enabled.
+// Example: https://www.khronos.org/registry/webgl/extensions/OES_texture_float_linear/
+const DEFAULT_NOT_FILTERABLE_TEX_TYPES: [GLenum; 2] = [
+    constants::FLOAT, OESTextureHalfFloatConstants::HALF_FLOAT_OES
+];
+
+/// WebGL features that are enabled/disabled by WebGL Extensions.
+#[derive(JSTraceable, HeapSizeOf)]
+struct WebGLExtensionFeatures {
+    gl_extensions: HashSet<String>,
+    disabled_tex_types: HashSet<GLenum>,
+    not_filterable_tex_types: HashSet<GLenum>,
+    effective_tex_internal_formats: HashMap<TexFormatType, u32>,
+    query_parameter_handlers: HashMap<GLenum, WebGLQueryParameterHandler>
+}
+
+impl Default for WebGLExtensionFeatures {
+    fn default() -> WebGLExtensionFeatures {
+        WebGLExtensionFeatures {
+            gl_extensions: HashSet::new(),
+            disabled_tex_types: DEFAULT_DISABLED_TEX_TYPES.iter().cloned().collect(),
+            not_filterable_tex_types: DEFAULT_NOT_FILTERABLE_TEX_TYPES.iter().cloned().collect(),
+            effective_tex_internal_formats: HashMap::new(),
+            query_parameter_handlers: HashMap::new()
+        }
+    }
+}
+
+/// Handles the list of implemented, supported and enabled WebGL extensions.
+#[must_root]
+#[derive(JSTraceable, HeapSizeOf)]
+pub struct WebGLExtensions {
+    extensions: DOMRefCell<HashMap<String, Box<WebGLExtensionWrapper>>>,
+    features: DOMRefCell<WebGLExtensionFeatures>,
+}
+
+impl WebGLExtensions {
+    pub fn new() -> WebGLExtensions {
+        Self {
+            extensions: DOMRefCell::new(HashMap::new()),
+            features: DOMRefCell::new(Default::default())
+        }
+    }
+
+    pub fn init_once<F>(&self, cb: F) where F: FnOnce() -> String {
+        if self.extensions.borrow().len() == 0 {
+            let gl_str = cb();
+            self.features.borrow_mut().gl_extensions = HashSet::from_iter(gl_str.split(&[',', ' '][..])
+                                                                                .map(|s| s.into()));
+            self.register_all_extensions();
+        }
+    }
+
+    pub fn register<T:'static + WebGLExtension + JSTraceable + HeapSizeOf>(&self) {
+        let name = T::name().to_uppercase();
+        self.extensions.borrow_mut().insert(name, box TypedWebGLExtensionWrapper::<T>::new());
+    }
+
+    pub fn get_suported_extensions(&self) -> Vec<&'static str> {
+        self.extensions.borrow().iter()
+                                .filter(|ref v| v.1.is_supported(&self))
+                                .map(|ref v| v.1.name())
+                                .collect()
+    }
+
+    pub fn get_or_init_extension(&self, name: &str, ctx: &WebGLRenderingContext) -> Option<NonZero<*mut JSObject>> {
+        let name = name.to_uppercase();
+        self.extensions.borrow().get(&name).and_then(|extension| {
+            if extension.is_supported(self) {
+                Some(extension.instance_or_init(ctx, self))
+            } else {
+                None
+            }
+        })
+    }
+
+    pub fn get_dom_object<T>(&self) -> Option<Root<T::Extension>>
+           where T: 'static + WebGLExtension + JSTraceable + HeapSizeOf {
+        let name = T::name().to_uppercase();
+        self.extensions.borrow().get(&name).and_then(|extension| {
+            extension.as_any().downcast_ref::<TypedWebGLExtensionWrapper<T>>().and_then(|extension| {
+                extension.dom_object()
+            })
+        })
+    }
+
+    pub fn supports_gl_extension(&self, name: &str) -> bool {
+        self.features.borrow().gl_extensions.contains(name)
+    }
+
+    pub fn supports_any_gl_extension(&self, names: &[&str]) -> bool {
+        let features = self.features.borrow();
+        names.iter().any(|name| features.gl_extensions.contains(*name))
+    }
+
+    pub fn enable_tex_type(&self, data_type: GLenum) {
+        self.features.borrow_mut().disabled_tex_types.remove(&data_type);
+    }
+
+    pub fn is_tex_type_enabled(&self, data_type: GLenum) -> bool {
+        self.features.borrow().disabled_tex_types.get(&data_type).is_none()
+    }
+
+    pub fn add_effective_tex_internal_format(&self,
+                                             source_internal_format: u32,
+                                             source_data_type: u32,
+                                             effective_internal_format: u32)
+    {
+        let format = TexFormatType(source_internal_format, source_data_type);
+        self.features.borrow_mut().effective_tex_internal_formats.insert(format,
+                                                                         effective_internal_format);
+
+    }
+
+    pub fn get_effective_tex_internal_format(&self,
+                                             source_internal_format: u32,
+                                             source_data_type: u32) -> u32 {
+        let format = TexFormatType(source_internal_format, source_data_type);
+        *(self.features.borrow().effective_tex_internal_formats.get(&format)
+                                                               .unwrap_or(&source_internal_format))
+    }
+
+    pub fn enable_filterable_tex_type(&self, text_data_type: GLenum) {
+        self.features.borrow_mut().not_filterable_tex_types.remove(&text_data_type);
+    }
+
+    pub fn is_filterable(&self, text_data_type: u32) -> bool {
+        self.features.borrow().not_filterable_tex_types.get(&text_data_type).is_none()
+    }
+
+    pub fn add_query_parameter_handler(&self, name: GLenum, f: Box<WebGLQueryParameterFunc>) {
+        let handler = WebGLQueryParameterHandler {
+            func: f
+        };
+        self.features.borrow_mut().query_parameter_handlers.insert(name, handler);
+    }
+
+    pub fn get_query_parameter_handler(&self, name: GLenum) -> Option<Ref<Box<WebGLQueryParameterFunc>>> {
+        ref_filter_map(self.features.borrow(), |features| {
+            features.query_parameter_handlers.get(&name).map(|item| &item.func)
+        })
+    }
+
+    fn register_all_extensions(&self) {
+        self.register::<ext::oestexturefloat::OESTextureFloat>();
+        self.register::<ext::oestexturefloatlinear::OESTextureFloatLinear>();
+        self.register::<ext::oestexturehalffloat::OESTextureHalfFloat>();
+        self.register::<ext::oestexturehalffloatlinear::OESTextureHalfFloatLinear>();
+        self.register::<ext::oesvertexarrayobject::OESVertexArrayObject>();
+    }
+}
+
+// Helper structs
+#[derive(JSTraceable, HeapSizeOf, PartialEq, Eq, Hash)]
+struct TexFormatType(u32, u32);
+
+type WebGLQueryParameterFunc = Fn(*mut JSContext, &WebGLRenderingContext)
+                               -> Result<JSVal, WebGLError>;
+
+#[derive(HeapSizeOf)]
+struct WebGLQueryParameterHandler {
+    #[ignore_heap_size_of = "Closures are hard"]
+    func: Box<WebGLQueryParameterFunc>
+}
+
+unsafe_no_jsmanaged_fields!(WebGLQueryParameterHandler);

components/script/dom/webgl_extensions/mod.rs

@@ -0,0 +1,25 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * 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/. */
+
+pub mod ext;
+mod extension;
+mod extensions;
+mod wrapper;
+
+// Some extra constants not exposed in WebGLRenderingContext constants
+pub mod ext_constants {
+   pub const ALPHA16F_ARB: u32 = 0x881C;
+   pub const ALPHA32F_ARB: u32 = 0x8816;
+   pub const LUMINANCE16F_ARB: u32 = 0x881E;
+   pub const LUMINANCE32F_ARB: u32 = 0x8818;
+   pub const LUMINANCE_ALPHA16F_ARB: u32 = 0x881F;
+   pub const LUMINANCE_ALPHA32F_ARB: u32 = 0x8819;
+   pub const RGBA16F: u32 = 0x881A;
+   pub const RGB16F: u32 = 0x881B;
+   pub const RGBA32F: u32 = 0x8814;
+   pub const RGB32F: u32 = 0x8815;
+}
+
+pub use self::extension::WebGLExtension;
+pub use self::extensions::WebGLExtensions;

components/script/dom/webgl_extensions/wrapper.rs

@@ -0,0 +1,85 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * 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 core::nonzero::NonZero;
+use dom::bindings::js::{MutNullableJS, Root};
+use dom::bindings::reflector::DomObject;
+use dom::bindings::trace::JSTraceable;
+use dom::webglrenderingcontext::WebGLRenderingContext;
+use heapsize::HeapSizeOf;
+use js::jsapi::JSObject;
+use std::any::Any;
+use super::{WebGLExtension, WebGLExtensions};
+
+/// Trait used internally by WebGLExtensions to store and
+/// handle the different WebGL extensions in a common list.
+pub trait WebGLExtensionWrapper: JSTraceable + HeapSizeOf {
+    fn instance_or_init(&self,
+                        ctx: &WebGLRenderingContext,
+                        ext: &WebGLExtensions)
+                        -> NonZero<*mut JSObject>;
+    fn is_supported(&self, &WebGLExtensions) -> bool;
+    fn enable(&self, ext: &WebGLExtensions);
+    fn name(&self) -> &'static str;
+    fn as_any(&self) -> &Any;
+}
+
+#[must_root]
+#[derive(JSTraceable, HeapSizeOf)]
+pub struct TypedWebGLExtensionWrapper<T: WebGLExtension> {
+    extension: MutNullableJS<T::Extension>
+}
+
+/// Typed WebGL Extension implementation.
+/// Exposes the exact MutNullableJS<DOMObject> type defined by the extension.
+impl<T: WebGLExtension> TypedWebGLExtensionWrapper<T> {
+    pub fn new() -> TypedWebGLExtensionWrapper<T> {
+        TypedWebGLExtensionWrapper {
+            extension: MutNullableJS::new(None)
+        }
+    }
+}
+
+impl<T> WebGLExtensionWrapper for TypedWebGLExtensionWrapper<T>
+                              where T: WebGLExtension + JSTraceable + HeapSizeOf + 'static {
+    #[allow(unsafe_code)]
+    fn instance_or_init(&self,
+                        ctx: &WebGLRenderingContext,
+                        ext: &WebGLExtensions)
+                        -> NonZero<*mut JSObject> {
+        let mut enabled = true;
+        let extension = self.extension.or_init(|| {
+            enabled = false;
+            T::new(ctx)
+        });
+        if !enabled {
+            self.enable(ext);
+        }
+        unsafe {
+            NonZero::new(extension.reflector().get_jsobject().get())
+        }
+    }
+
+    fn is_supported(&self, ext: &WebGLExtensions) -> bool {
+        self.extension.get().is_some() || T::is_supported(ext)
+    }
+
+    fn enable(&self, ext: &WebGLExtensions) {
+        T::enable(ext);
+    }
+
+    fn name(&self) -> &'static str {
+        T::name()
+    }
+
+    fn as_any<'a>(&'a self) -> &'a Any {
+        self
+    }
+}
+
+impl<T> TypedWebGLExtensionWrapper<T> where T: WebGLExtension + JSTraceable + HeapSizeOf + 'static {
+    pub fn dom_object(&self) -> Option<Root<T::Extension>> {
+        self.extension.get()
+    }
+}