Bug 982960 - Add GLContext support for draw_range_elements. r=kamidphish

gfx/gl/GLContext.cpp

@@ -138,6 +138,7 @@ static const char *sExtensionNames[] = {
     "GL_ARB_half_float_pixel",
     "GL_EXT_frag_depth",
     "GL_OES_compressed_ETC1_RGB8_texture",
+    "GL_EXT_draw_range_elements",
     nullptr
 };
 
@@ -1073,6 +1074,20 @@ GLContext::InitWithPrefix(const char *prefix, bool trygl)
             }
         }
 
+        if (IsSupported(GLFeature::draw_range_elements)) {
+            SymLoadStruct imageSymbols[] = {
+                { (PRFuncPtr*) &mSymbols.fDrawRangeElements, { "DrawRangeElementsEXT", "DrawRangeElements", nullptr } },
+                { nullptr, { nullptr } },
+            };
+
+            if (!LoadSymbols(&imageSymbols[0], trygl, prefix)) {
+                NS_ERROR("GL supports draw_range_elements without supplying its functions.");
+
+                MarkUnsupported(GLFeature::draw_range_elements);
+                mSymbols.fDrawRangeElements = nullptr;
+            }
+        }
+
         // Load developer symbols, don't fail if we can't find them.
         SymLoadStruct auxSymbols[] = {
                 { (PRFuncPtr*) &mSymbols.fGetTexImage, { "GetTexImage", nullptr } },

gfx/gl/GLContext.h

@@ -87,6 +87,7 @@ MOZ_BEGIN_ENUM_CLASS(GLFeature)
     depth_texture,
     draw_buffers,
     draw_instanced,
+    draw_range_elements,
     element_index_uint,
     ES2_compatibility,
     ES3_compatibility,
@@ -419,6 +420,7 @@ public:
         ARB_half_float_pixel,
         EXT_frag_depth,
         OES_compressed_ETC1_RGB8_texture,
+        EXT_draw_range_elements,
         Extensions_Max,
         Extensions_End
     };
@@ -2228,6 +2230,17 @@ public:
         AfterGLDrawCall();
     }
 
+// -----------------------------------------------------------------------------
+// Feature draw_range_elements
+public:
+    void fDrawRangeElements(GLenum mode, GLuint start, GLuint end,
+                            GLsizei count, GLenum type, const GLvoid* indices)
+    {
+        BEFORE_GL_CALL;
+        ASSERT_SYMBOL_PRESENT(fDrawRangeElements);
+        mSymbols.fDrawRangeElements(mode, start, end, count, type, indices);
+        AFTER_GL_CALL;
+    }
 
 // -----------------------------------------------------------------------------
 // Package XXX_framebuffer_blit
@@ -2698,7 +2711,7 @@ protected:
     // storage to support DebugMode on an arbitrary thread.
     static unsigned sCurrentGLContextTLS;
 #endif
-    
+
     ScopedDeletePtr<GLBlitHelper> mBlitHelper;
     ScopedDeletePtr<GLBlitTextureImageHelper> mBlitTextureImageHelper;
     ScopedDeletePtr<GLReadTexImageHelper> mReadTexImageHelper;

gfx/gl/GLContextFeatures.cpp

@@ -84,6 +84,15 @@ static const FeatureInfo sFeatureInfoArr[] = {
             GLContext::Extensions_End
         }
     },
+    {
+        "draw_range_elements",
+        200, // OpenGL version
+        300, // OpenGL ES version
+        {
+            GLContext::EXT_draw_range_elements,
+            GLContext::Extensions_End
+        }
+    },
     {
         "element_index_uint",
         200, // OpenGL version

gfx/gl/GLContextSymbols.h

@@ -493,6 +493,10 @@ struct GLContextSymbols
     PFNGLOBJECTPTRLABEL fObjectPtrLabel;
     typedef void (GLAPIENTRY * PFNGLGETOBJECTPTRLABEL) (const GLvoid* ptr, GLsizei bufSize, GLsizei* length, GLchar* label);
     PFNGLGETOBJECTPTRLABEL fGetObjectPtrLabel;
+
+    // draw_range_elements
+    typedef void (GLAPIENTRY * PFNGLDRAWRANGEELEMENTS) (GLenum mode, GLuint start, GLuint end, GLsizei count, GLenum type, const GLvoid* indices);
+    PFNGLDRAWRANGEELEMENTS fDrawRangeElements;
 };
 
 }