servo/components/script/dom/webgl_extensions/wrapper.rs
2017-05-18 18:44:07 +02:00

85 lines
2.7 KiB
Rust

/* 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()
}
}