Implement WebGL OES_standard_derivatives extension.

9 files changed, 127 insertions, 20 deletions

diff --git a/components/canvas/webgl_thread.rs b/components/canvas/webgl_thread.rs
index 907233a3b89..b4a612103c2 100644
--- a/components/canvas/webgl_thread.rs
+++ b/components/canvas/webgl_thread.rs
@@ -892,7 +892,8 @@ impl WebGLImpl {
             gl::STENCIL_VALUE_MASK |
             gl::STENCIL_WRITEMASK |
             gl::SUBPIXEL_BITS |
-            gl::UNPACK_ALIGNMENT =>
+            gl::UNPACK_ALIGNMENT |
+            gl::FRAGMENT_SHADER_DERIVATIVE_HINT =>
             //gl::UNPACK_COLORSPACE_CONVERSION_WEBGL =>
                 Ok(WebGLParameter::Int(gl.get_integer_v(param_id))),
 
diff --git a/components/script/dom/webgl_extensions/ext/mod.rs b/components/script/dom/webgl_extensions/ext/mod.rs
index ed3c77977ac..38f642fb74b 100644
--- a/components/script/dom/webgl_extensions/ext/mod.rs
+++ b/components/script/dom/webgl_extensions/ext/mod.rs
@@ -5,6 +5,7 @@
 use dom::bindings::codegen::Bindings::WebGLRenderingContextBinding::WebGLRenderingContextConstants as constants;
 use super::{ext_constants, WebGLExtension, WebGLExtensions};
 
+pub mod oesstandardderivatives;
 pub mod oestexturefloat;
 pub mod oestexturefloatlinear;
 pub mod oestexturehalffloat;
diff --git a/components/script/dom/webgl_extensions/ext/oesstandardderivatives.rs b/components/script/dom/webgl_extensions/ext/oesstandardderivatives.rs
new file mode 100644
index 00000000000..573ebe8387d
--- /dev/null
+++ b/components/script/dom/webgl_extensions/ext/oesstandardderivatives.rs
@@ -0,0 +1,50 @@
+/* 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::OESStandardDerivativesBinding;
+use dom::bindings::codegen::Bindings::OESStandardDerivativesBinding::OESStandardDerivativesConstants;
+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 OESStandardDerivatives {
+    reflector_: Reflector,
+}
+
+impl OESStandardDerivatives {
+    fn new_inherited() -> OESStandardDerivatives {
+        Self {
+            reflector_: Reflector::new(),
+        }
+    }
+}
+
+impl WebGLExtension for OESStandardDerivatives {
+    type Extension = OESStandardDerivatives;
+    fn new(ctx: &WebGLRenderingContext) -> Root<OESStandardDerivatives> {
+        reflect_dom_object(box OESStandardDerivatives::new_inherited(),
+                           &*ctx.global(),
+                           OESStandardDerivativesBinding::Wrap)
+    }
+
+    fn is_supported(ext: &WebGLExtensions) -> bool {
+        if cfg!(any(target_os = "android", target_os = "ios")) {
+            return ext.supports_any_gl_extension(&["GL_OES_standard_derivatives"]);
+        }
+        // The standard derivatives are always available in desktop OpenGL.
+        true
+    }
+
+    fn enable(ext: &WebGLExtensions) {
+        ext.enable_hint_target(OESStandardDerivativesConstants::FRAGMENT_SHADER_DERIVATIVE_HINT_OES);
+        ext.enable_get_parameter_name(OESStandardDerivativesConstants::FRAGMENT_SHADER_DERIVATIVE_HINT_OES);
+    }
+
+    fn name() -> &'static str {
+        "OES_standard_derivatives"
+    }
+}
diff --git a/components/script/dom/webgl_extensions/extensions.rs b/components/script/dom/webgl_extensions/extensions.rs
index 2a780b129ff..3b702bec37a 100644
--- a/components/script/dom/webgl_extensions/extensions.rs
+++ b/components/script/dom/webgl_extensions/extensions.rs
@@ -6,6 +6,7 @@ use canvas_traits::webgl::WebGLError;
 use core::iter::FromIterator;
 use core::nonzero::NonZero;
 use dom::bindings::cell::DOMRefCell;
+use dom::bindings::codegen::Bindings::OESStandardDerivativesBinding::OESStandardDerivativesConstants;
 use dom::bindings::codegen::Bindings::OESTextureHalfFloatBinding::OESTextureHalfFloatConstants;
 use dom::bindings::codegen::Bindings::WebGLRenderingContextBinding::WebGLRenderingContextConstants as constants;
 use dom::bindings::js::Root;
@@ -35,6 +36,13 @@ const DEFAULT_NOT_FILTERABLE_TEX_TYPES: [GLenum; 2] = [
     constants::FLOAT, OESTextureHalfFloatConstants::HALF_FLOAT_OES
 ];
 
+// Param names that are implemented for getParameter WebGL function
+// but must trigger a InvalidEnum error until the related WebGL Extensions are enabled.
+// Example: https://www.khronos.org/registry/webgl/extensions/OES_standard_derivatives/
+const DEFAULT_DISABLED_GET_PARAMETER_NAMES: [GLenum; 1] = [
+    OESStandardDerivativesConstants::FRAGMENT_SHADER_DERIVATIVE_HINT_OES
+];
+
 /// WebGL features that are enabled/disabled by WebGL Extensions.
 #[derive(JSTraceable, HeapSizeOf)]
 struct WebGLExtensionFeatures {
@@ -42,7 +50,11 @@ struct WebGLExtensionFeatures {
     disabled_tex_types: HashSet<GLenum>,
     not_filterable_tex_types: HashSet<GLenum>,
     effective_tex_internal_formats: HashMap<TexFormatType, u32>,
-    query_parameter_handlers: HashMap<GLenum, WebGLQueryParameterHandler>
+    query_parameter_handlers: HashMap<GLenum, WebGLQueryParameterHandler>,
+    /// WebGL Hint() targets enabled by extensions.
+    hint_targets: HashSet<GLenum>,
+    /// WebGL GetParameter() names enabled by extensions.
+    disabled_get_parameter_names: HashSet<GLenum>,
 }
 
 impl Default for WebGLExtensionFeatures {
@@ -52,7 +64,9 @@ impl Default for WebGLExtensionFeatures {
             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()
+            query_parameter_handlers: HashMap::new(),
+            hint_targets: HashSet::new(),
+            disabled_get_parameter_names: DEFAULT_DISABLED_GET_PARAMETER_NAMES.iter().cloned().collect(),
         }
     }
 }
@@ -105,8 +119,18 @@ impl WebGLExtensions {
         })
     }
 
+    pub fn is_enabled<T>(&self) -> bool
+    where
+        T: 'static + WebGLExtension + JSTraceable + HeapSizeOf
+    {
+        let name = T::name().to_uppercase();
+        self.extensions.borrow().get(&name).map_or(false, |ext| { ext.is_enabled() })
+    }
+
     pub fn get_dom_object<T>(&self) -> Option<Root<T::Extension>>
-           where T: 'static + WebGLExtension + JSTraceable + HeapSizeOf {
+    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| {
@@ -172,7 +196,24 @@ impl WebGLExtensions {
         })
     }
 
+    pub fn enable_hint_target(&self, name: GLenum) {
+        self.features.borrow_mut().hint_targets.insert(name);
+    }
+
+    pub fn is_hint_target_enabled(&self, name: GLenum) -> bool {
+        self.features.borrow().hint_targets.contains(&name)
+    }
+
+    pub fn enable_get_parameter_name(&self, name: GLenum) {
+        self.features.borrow_mut().disabled_get_parameter_names.remove(&name);
+    }
+
+    pub fn is_get_parameter_name_enabled(&self, name: GLenum) -> bool {
+        !self.features.borrow().disabled_get_parameter_names.contains(&name)
+    }
+
     fn register_all_extensions(&self) {
+        self.register::<ext::oesstandardderivatives::OESStandardDerivatives>();
         self.register::<ext::oestexturefloat::OESTextureFloat>();
         self.register::<ext::oestexturefloatlinear::OESTextureFloatLinear>();
         self.register::<ext::oestexturehalffloat::OESTextureHalfFloat>();
diff --git a/components/script/dom/webgl_extensions/wrapper.rs b/components/script/dom/webgl_extensions/wrapper.rs
index 5741597cd85..684daef7556 100644
--- a/components/script/dom/webgl_extensions/wrapper.rs
+++ b/components/script/dom/webgl_extensions/wrapper.rs
@@ -20,6 +20,7 @@ pub trait WebGLExtensionWrapper: JSTraceable + HeapSizeOf {
                         ext: &WebGLExtensions)
                         -> NonZero<*mut JSObject>;
     fn is_supported(&self, &WebGLExtensions) -> bool;
+    fn is_enabled(&self) -> bool;
     fn enable(&self, ext: &WebGLExtensions);
     fn name(&self) -> &'static str;
     fn as_any(&self) -> &Any;
@@ -62,7 +63,11 @@ impl<T> WebGLExtensionWrapper for TypedWebGLExtensionWrapper<T>
     }
 
     fn is_supported(&self, ext: &WebGLExtensions) -> bool {
-        self.extension.get().is_some() || T::is_supported(ext)
+        self.is_enabled() || T::is_supported(ext)
+    }
+
+    fn is_enabled(&self) -> bool {
+        self.extension.get().is_some()
     }
 
     fn enable(&self, ext: &WebGLExtensions) {
diff --git a/components/script/dom/webglrenderingcontext.rs b/components/script/dom/webglrenderingcontext.rs
index 78e6c1e312c..a4e11c89c5e 100644
--- a/components/script/dom/webglrenderingcontext.rs
+++ b/components/script/dom/webglrenderingcontext.rs
@@ -1222,7 +1222,12 @@ impl WebGLRenderingContextMethods for WebGLRenderingContext {
                     return Int32Value(constants::UNSIGNED_BYTE as i32);
                 }
             }
-            _ => {}
+            _ => {
+                if !self.extension_manager.is_get_parameter_name_enabled(parameter) {
+                    self.webgl_error(WebGLError::InvalidEnum);
+                    return NullValue();
+                }
+            }
         }
 
         // Handle GetParameter getters injected via WebGL extensions
@@ -1832,7 +1837,7 @@ impl WebGLRenderingContextMethods for WebGLRenderingContext {
     // https://www.khronos.org/registry/webgl/specs/latest/1.0/#5.14.9
     fn CompileShader(&self, shader: Option<&WebGLShader>) {
         if let Some(shader) = shader {
-            shader.compile()
+            shader.compile(&self.extension_manager)
         }
     }
 
@@ -2284,7 +2289,7 @@ impl WebGLRenderingContextMethods for WebGLRenderingContext {
 
     // https://www.khronos.org/registry/webgl/specs/latest/1.0/#5.14.3
     fn Hint(&self, target: u32, mode: u32) {
-        if target != constants::GENERATE_MIPMAP_HINT {
+        if target != constants::GENERATE_MIPMAP_HINT && !self.extension_manager.is_hint_target_enabled(target) {
             return self.webgl_error(InvalidEnum);
         }
 
diff --git a/components/script/dom/webglshader.rs b/components/script/dom/webglshader.rs
index cf6fc55072d..9bf76e91051 100644
--- a/components/script/dom/webglshader.rs
+++ b/components/script/dom/webglshader.rs
@@ -10,6 +10,8 @@ use dom::bindings::codegen::Bindings::WebGLShaderBinding;
 use dom::bindings::js::Root;
 use dom::bindings::reflector::reflect_dom_object;
 use dom::bindings::str::DOMString;
+use dom::webgl_extensions::WebGLExtensions;
+use dom::webgl_extensions::ext::oesstandardderivatives::OESStandardDerivatives;
 use dom::webglobject::WebGLObject;
 use dom::window::Window;
 use dom_struct::dom_struct;
@@ -97,7 +99,7 @@ impl WebGLShader {
     }
 
     /// glCompileShader
-    pub fn compile(&self) {
+    pub fn compile(&self, ext: &WebGLExtensions) {
         if self.compilation_status.get() != ShaderCompilationStatus::NotCompiled {
             debug!("Compiling already compiled shader {}", self.id);
         }
@@ -105,6 +107,7 @@ impl WebGLShader {
         if let Some(ref source) = *self.source.borrow() {
             let mut params = BuiltInResources::default();
             params.FragmentPrecisionHigh = 1;
+            params.OES_standard_derivatives = ext.is_enabled::<OESStandardDerivatives>() as i32;
             let validator = ShaderValidator::for_webgl(self.gl_type,
                                                        SHADER_OUTPUT_FORMAT,
                                                        &params).unwrap();
diff --git a/components/script/dom/webidls/OESStandardDerivatives.webidl b/components/script/dom/webidls/OESStandardDerivatives.webidl
new file mode 100644
index 00000000000..d4ce9837290
--- /dev/null
+++ b/components/script/dom/webidls/OESStandardDerivatives.webidl
@@ -0,0 +1,12 @@
+/* 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/. */
+/*
+ * WebGL IDL definitions from the Khronos specification:
+ * https://www.khronos.org/registry/webgl/extensions/OES_standard_derivatives/
+ */
+
+[NoInterfaceObject]
+interface OESStandardDerivatives {
+    const GLenum FRAGMENT_SHADER_DERIVATIVE_HINT_OES = 0x8B8B;
+};
diff --git a/tests/wpt/metadata/webgl/conformance-1.0.3/conformance/extensions/oes-standard-derivatives.html.ini b/tests/wpt/metadata/webgl/conformance-1.0.3/conformance/extensions/oes-standard-derivatives.html.ini
deleted file mode 100644
index f529c47fc16..00000000000
--- a/tests/wpt/metadata/webgl/conformance-1.0.3/conformance/extensions/oes-standard-derivatives.html.ini
+++ /dev/null
@@ -1,11 +0,0 @@
-[oes-standard-derivatives.html]
-  type: testharness
-  [WebGL test #3: successfullyParsed should be true (of type boolean). Was undefined (of type undefined).]
-    expected: FAIL
-
-  [WebGL test #0: Unable to fetch WebGL rendering context for Canvas]
-    expected: FAIL
-
-  [WebGL test #1: WebGL context does not exist]
-    expected: FAIL
-