Bug 823454 - Implement EXT_frag_depth for WebGL. - r=kamidphish

content/canvas/src/WebGLContext.h

@@ -895,6 +895,7 @@ protected:
     // -------------------------------------------------------------------------
     // WebGL extensions (implemented in WebGLContextExtensions.cpp)
     enum WebGLExtensionID {
+        EXT_frag_depth,
         EXT_sRGB,
         EXT_texture_filter_anisotropic,
         OES_element_index_uint,

content/canvas/src/WebGLContextExtensions.cpp

@@ -17,6 +17,7 @@ using namespace mozilla::gl;
 
 // must match WebGLContext::WebGLExtensionID
 static const char *sExtensionNames[] = {
+    "EXT_frag_depth",
     "EXT_sRGB",
     "EXT_texture_filter_anisotropic",
     "OES_element_index_uint",
@@ -139,6 +140,8 @@ bool WebGLContext::IsExtensionSupported(WebGLExtensionID ext) const
             return WebGLExtensionSRGB::IsSupported(this);
         case WEBGL_draw_buffers:
             return WebGLExtensionDrawBuffers::IsSupported(this);
+        case EXT_frag_depth:
+            return WebGLExtensionFragDepth::IsSupported(this);
         default:
             // For warnings-as-errors.
             break;
@@ -295,6 +298,9 @@ WebGLContext::EnableExtension(WebGLExtensionID ext)
         case EXT_sRGB:
             obj = new WebGLExtensionSRGB(this);
             break;
+        case EXT_frag_depth:
+            obj = new WebGLExtensionFragDepth(this);
+            break;
         default:
             MOZ_ASSERT(false, "should not get there.");
     }

content/canvas/src/WebGLContextGL.cpp

@@ -3087,6 +3087,9 @@ WebGLContext::CompileShader(WebGLShader *shader)
         resources.MaxFragmentUniformVectors = mGLMaxFragmentUniformVectors;
         resources.MaxDrawBuffers = mGLMaxDrawBuffers;
 
+        if (IsExtensionEnabled(EXT_frag_depth))
+            resources.EXT_frag_depth = 1;
+
         if (IsExtensionEnabled(OES_standard_derivatives))
             resources.OES_standard_derivatives = 1;
 

content/canvas/src/WebGLExtensionFragDepth.cpp

@@ -0,0 +1,33 @@
+/* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/* 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 "mozilla/dom/WebGLRenderingContextBinding.h"
+#include "GLContext.h"
+
+using namespace mozilla;
+
+WebGLExtensionFragDepth::WebGLExtensionFragDepth(WebGLContext* context)
+    : WebGLExtensionBase(context)
+{
+    MOZ_ASSERT(IsSupported(context),
+               "Should not construct extension object if unsupported.");
+}
+
+WebGLExtensionFragDepth::~WebGLExtensionFragDepth()
+{
+}
+
+bool
+WebGLExtensionFragDepth::IsSupported(const WebGLContext* context)
+{
+    gl::GLContext* gl = context->GL();
+
+    return gl->IsSupported(gl::GLFeature::frag_depth);
+}
+
+
+IMPL_WEBGL_EXTENSION_GOOP(WebGLExtensionFragDepth)

content/canvas/src/WebGLExtensions.h

@@ -108,6 +108,18 @@ public:
     DECL_WEBGL_EXTENSION_GOOP
 };
 
+class WebGLExtensionFragDepth
+    : public WebGLExtensionBase
+{
+public:
+    WebGLExtensionFragDepth(WebGLContext*);
+    virtual ~WebGLExtensionFragDepth();
+
+    static bool IsSupported(const WebGLContext* context);
+
+    DECL_WEBGL_EXTENSION_GOOP
+};
+
 class WebGLExtensionLoseContext
     : public WebGLExtensionBase
 {

content/canvas/src/moz.build

@@ -52,6 +52,7 @@ if CONFIG['MOZ_WEBGL']:
         'WebGLExtensionDepthTexture.cpp',
         'WebGLExtensionDrawBuffers.cpp',
         'WebGLExtensionElementIndexUint.cpp',
+        'WebGLExtensionFragDepth.cpp',
         'WebGLExtensionInstancedArrays.cpp',
         'WebGLExtensionLoseContext.cpp',
         'WebGLExtensionSRGB.cpp',

dom/bindings/Bindings.conf

@@ -1380,6 +1380,11 @@ DOMInterfaces = {
     'headerFile': 'WebGLExtensions.h'
 },
 
+'WebGLExtensionFragDepth': {
+    'nativeType': 'mozilla::WebGLExtensionFragDepth',
+    'headerFile': 'WebGLExtensions.h'
+},
+
 'WebGLExtensionLoseContext': {
     'nativeType': 'mozilla::WebGLExtensionLoseContext',
     'headerFile': 'WebGLExtensions.h'

dom/webidl/WebGLRenderingContext.webidl

@@ -822,6 +822,11 @@ interface WebGLExtensionElementIndexUint
 {
 };
 
+[NoInterfaceObject]
+interface WebGLExtensionFragDepth
+{
+};
+
 [NoInterfaceObject]
 interface WebGLExtensionLoseContext {
     void loseContext();

gfx/gl/GLContext.cpp

@@ -133,6 +133,7 @@ static const char *sExtensionNames[] = {
     "GL_EXT_framebuffer_sRGB",
     "GL_KHR_debug",
     "GL_ARB_half_float_pixel",
+    "GL_EXT_frag_depth",
     nullptr
 };
 

gfx/gl/GLContext.h

@@ -90,6 +90,7 @@ MOZ_BEGIN_ENUM_CLASS(GLFeature)
     element_index_uint,
     ES2_compatibility,
     ES3_compatibility,
+    frag_depth,
     framebuffer_blit,
     framebuffer_multisample,
     framebuffer_object,
@@ -410,6 +411,7 @@ public:
         EXT_framebuffer_sRGB,
         KHR_debug,
         ARB_half_float_pixel,
+        EXT_frag_depth,
         Extensions_Max,
         Extensions_End
     };

gfx/gl/GLContextFeatures.cpp

@@ -111,6 +111,15 @@ static const FeatureInfo sFeatureInfoArr[] = {
             GLContext::Extensions_End
         }
     },
+    {
+        "frag_depth",
+        200, // OpenGL version
+        300, // OpenGL ES version
+        {
+            GLContext::EXT_frag_depth,
+            GLContext::Extensions_End
+        }
+    },
     {
         "framebuffer_blit",
         300, // OpenGL version