1 files changed, 197 insertions, 0 deletions
diff --git a/components/script/dom/webgl_extensions/extensions.rs b/components/script/dom/webgl_extensions/extensions.rs
new file mode 100644
index 00000000000..575597b84f3
--- /dev/null
+++ b/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);