Add initial support for WebGL compressed textures

components/script/dom/webgl_extensions/ext/webglcompressedtextureetc1.rs

@@ -0,0 +1,58 @@
+/* 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 https://mozilla.org/MPL/2.0/. */
+
+use super::{WebGLExtension, WebGLExtensionSpec, WebGLExtensions};
+use crate::dom::bindings::codegen::Bindings::WEBGLCompressedTextureETC1Binding;
+use crate::dom::bindings::reflector::{reflect_dom_object, DomObject, Reflector};
+use crate::dom::bindings::root::DomRoot;
+use crate::dom::webglrenderingcontext::WebGLRenderingContext;
+use crate::dom::webgltexture::{TexCompression, TexCompressionValidation};
+use canvas_traits::webgl::{TexFormat, WebGLVersion};
+use dom_struct::dom_struct;
+
+#[dom_struct]
+pub struct WEBGLCompressedTextureETC1 {
+    reflector_: Reflector,
+}
+
+impl WEBGLCompressedTextureETC1 {
+    fn new_inherited() -> WEBGLCompressedTextureETC1 {
+        Self {
+            reflector_: Reflector::new(),
+        }
+    }
+}
+
+impl WebGLExtension for WEBGLCompressedTextureETC1 {
+    type Extension = WEBGLCompressedTextureETC1;
+    fn new(ctx: &WebGLRenderingContext) -> DomRoot<WEBGLCompressedTextureETC1> {
+        reflect_dom_object(
+            Box::new(WEBGLCompressedTextureETC1::new_inherited()),
+            &*ctx.global(),
+            WEBGLCompressedTextureETC1Binding::Wrap,
+        )
+    }
+
+    fn spec() -> WebGLExtensionSpec {
+        WebGLExtensionSpec::Specific(WebGLVersion::WebGL1)
+    }
+
+    fn is_supported(ext: &WebGLExtensions) -> bool {
+        ext.supports_gl_extension("GL_OES_compressed_ETC1_RGB8_texture")
+    }
+
+    fn enable(ext: &WebGLExtensions) {
+        ext.add_tex_compression_formats(&[TexCompression {
+            format: TexFormat::CompressedRgbEtc1,
+            bytes_per_block: 8,
+            block_width: 4,
+            block_height: 4,
+            validation: TexCompressionValidation::None,
+        }]);
+    }
+
+    fn name() -> &'static str {
+        "WEBGL_compressed_texture_etc1"
+    }
+}