Add GrEllipseEdgeEffect

src/gpu/gl/GrGLEffect.cpp

 /*
  * Copyright 2012 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "GrGLSL.h"
 #include "GrGLEffect.h"
 
@@ skipping 13 matching lines @@
                                                 const GrGLCaps& caps) {
     EffectKey key = 0;
     for (int index = 0; index < (*effect)->numTextures(); ++index) {
         const GrTextureAccess& access = (*effect)->textureAccess(index);
         EffectKey value = GrGLShaderBuilder::KeyForTextureAccess(access, caps) << index;
         GrAssert(0 == (value & key)); // keys for each access ought not to overlap
         key |= value;
     }
     return key;
 }
+
+GrGLEffect::EffectKey GrGLEffect::GenAttribKey(const GrEffectStage& stage) {
+    EffectKey key = 0;
+
+    int numAttributes = stage.getVertexAttribIndexCount();
+    GrAssert(numAttributes <= 2);
+    const int* attributeIndices = stage.getVertexAttribIndices();
+    for (int index = 0; index < numAttributes; ++index) {
+        EffectKey value = attributeIndices[index] << 2*index;
+        GrAssert(0 == (value & key)); // keys for each attribute ought not to overlap
+        key |= value;
+    }
+
+    return key;
+}