Bug 973815 - Implements WebGL draft extension EXT_blend_minmax - r=jgilbert,bzbarsky

content/canvas/src/WebGL2Context.cpp

@@ -64,6 +64,7 @@ WebGLContext::InitWebGL2()
 
     const WebGLExtensionID sExtensionNativelySupportedArr[] = {
         WebGLExtensionID::ANGLE_instanced_arrays,
+        WebGLExtensionID::EXT_blend_minmax,
         WebGLExtensionID::OES_element_index_uint,
         WebGLExtensionID::OES_standard_derivatives,
         WebGLExtensionID::OES_texture_float,
@@ -73,7 +74,6 @@ WebGLContext::InitWebGL2()
         WebGLExtensionID::WEBGL_draw_buffers
     };
     const GLFeature sFeatureRequiredArr[] = {
-        GLFeature::blend_minmax,
         GLFeature::instanced_non_arrays,
         GLFeature::transform_feedback
     };

content/canvas/src/WebGLContextExtensions.cpp

@@ -31,6 +31,7 @@ WebGLContext::GetExtensionString(WebGLExtensionID ext)
         sExtensionNamesEnumeratedArray[WebGLExtensionID::x] = #x;
 
         WEBGL_EXTENSION_IDENTIFIER(ANGLE_instanced_arrays)
+        WEBGL_EXTENSION_IDENTIFIER(EXT_blend_minmax)
         WEBGL_EXTENSION_IDENTIFIER(EXT_color_buffer_half_float)
         WEBGL_EXTENSION_IDENTIFIER(EXT_frag_depth)
         WEBGL_EXTENSION_IDENTIFIER(EXT_sRGB)
@@ -162,16 +163,16 @@ bool WebGLContext::IsExtensionSupported(WebGLExtensionID ext) const
             // For warnings-as-errors.
             break;
     }
-// Uncomment this switch for any new extensions
-#if 0
+
     if (Preferences::GetBool("webgl.enable-draft-extensions", false) || IsWebGL2()) {
         switch (ext) {
+            case WebGLExtensionID::EXT_blend_minmax:
+                return WebGLExtensionBlendMinMax::IsSupported(this);
             default:
                 // For warnings-as-errors.
                 break;
         }
     }
-#endif
 
     return false;
 }
@@ -330,6 +331,9 @@ WebGLContext::EnableExtension(WebGLExtensionID ext)
         case WebGLExtensionID::EXT_frag_depth:
             obj = new WebGLExtensionFragDepth(this);
             break;
+        case WebGLExtensionID::EXT_blend_minmax:
+            obj = new WebGLExtensionBlendMinMax(this);
+            break;
         default:
             MOZ_ASSERT(false, "should not get there.");
     }

content/canvas/src/WebGLContextValidate.cpp

@@ -328,8 +328,7 @@ bool WebGLContext::ValidateBlendEquationEnum(GLenum mode, const char *info)
             return true;
         case LOCAL_GL_MIN:
         case LOCAL_GL_MAX:
-            if (IsWebGL2()) {
-                // http://www.opengl.org/registry/specs/EXT/blend_minmax.txt
+            if (IsExtensionEnabled(WebGLExtensionID::EXT_blend_minmax)) {
                 return true;
             }
             break;

content/canvas/src/WebGLExtensionBlendMinMax.cpp

@@ -0,0 +1,28 @@
+/* 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/. */
+
+#include "WebGLContext.h"
+#include "WebGLExtensions.h"
+
+#include "GLContext.h"
+
+#include "mozilla/dom/WebGLRenderingContextBinding.h"
+
+using namespace mozilla;
+
+WebGLExtensionBlendMinMax::WebGLExtensionBlendMinMax(WebGLContext* context)
+    : WebGLExtensionBase(context)
+{
+}
+
+WebGLExtensionBlendMinMax::~WebGLExtensionBlendMinMax()
+{
+}
+
+bool WebGLExtensionBlendMinMax::IsSupported(const WebGLContext* context)
+{
+    return context->GL()->IsSupported(gl::GLFeature::blend_minmax);
+}
+
+IMPL_WEBGL_EXTENSION_GOOP(WebGLExtensionBlendMinMax)

content/canvas/src/WebGLExtensions.h

@@ -309,6 +309,18 @@ public:
     DECL_WEBGL_EXTENSION_GOOP
 };
 
+class WebGLExtensionBlendMinMax
+    : public WebGLExtensionBase
+{
+public:
+    WebGLExtensionBlendMinMax(WebGLContext*);
+    virtual ~WebGLExtensionBlendMinMax();
+
+    static bool IsSupported(const WebGLContext*);
+
+    DECL_WEBGL_EXTENSION_GOOP
+};
+
 } // namespace mozilla
 
 #endif // WEBGLEXTENSIONS_H_

content/canvas/src/WebGLTypes.h

@@ -146,6 +146,7 @@ MOZ_END_ENUM_CLASS(WebGLTexImageFunc)
 // Please keep extensions in alphabetic order.
 MOZ_BEGIN_ENUM_CLASS(WebGLExtensionID, uint8_t)
     ANGLE_instanced_arrays,
+    EXT_blend_minmax,
     EXT_color_buffer_half_float,
     EXT_frag_depth,
     EXT_sRGB,

content/canvas/src/moz.build

@@ -45,6 +45,7 @@ if CONFIG['MOZ_WEBGL']:
         'WebGLContextVertices.cpp',
         'WebGLElementArrayCache.cpp',
         'WebGLExtensionBase.cpp',
+        'WebGLExtensionBlendMinMax.cpp',
         'WebGLExtensionColorBufferFloat.cpp',
         'WebGLExtensionColorBufferHalfFloat.cpp',
         'WebGLExtensionCompressedTextureATC.cpp',

dom/bindings/Bindings.conf

@@ -1489,6 +1489,11 @@ DOMInterfaces = {
     'headerFile': 'WebGLExtensions.h'
 },
 
+'WebGLExtensionBlendMinMax': {
+    'nativeType': 'mozilla::WebGLExtensionBlendMinMax',
+    'headerFile': 'WebGLExtensions.h'
+},
+
 'WebGLFramebuffer': {
     'nativeType': 'mozilla::WebGLFramebuffer',
     'headerFile': 'WebGLFramebuffer.h'

dom/webidl/WebGLRenderingContext.webidl

@@ -959,3 +959,9 @@ interface WebGLExtensionInstancedArrays {
     void drawElementsInstancedANGLE(GLenum mode, GLsizei count, GLenum type, GLintptr offset, GLsizei primcount);
     void vertexAttribDivisorANGLE(GLuint index, GLuint divisor);
 };
+
+[NoInterfaceObject]
+interface WebGLExtensionBlendMinMax {
+    const GLenum MIN_EXT = 0x8007;
+    const GLenum MAX_EXT = 0x8008;
+};