Cache maximum enabled vertex attribute.

src/libANGLE/State.cpp

@@ -1418,7 +1418,8 @@ bool State::hasMappedBuffer(GLenum target) const
     {
         const VertexArray *vao = getVertexArray();
         const auto &vertexAttribs = vao->getVertexAttributes();
-        for (size_t attribIndex = 0; attribIndex < vertexAttribs.size(); attribIndex++)
+        unsigned int maxEnabledAttrib = vao->getMaxEnabledAttribute();
+        for (size_t attribIndex = 0; attribIndex < maxEnabledAttrib; attribIndex++)
         {
             const gl::VertexAttribute &vertexAttrib = vertexAttribs[attribIndex];
             gl::Buffer *boundBuffer = vertexAttrib.buffer.get();

src/libANGLE/VertexArray.cpp

@@ -16,7 +16,8 @@ namespace gl
 VertexArray::VertexArray(rx::VertexArrayImpl *impl, GLuint id, size_t maxAttribs)
     : mId(id),
       mVertexArray(impl),
-      mVertexAttributes(maxAttribs)
+      mVertexAttributes(maxAttribs),
+      mMaxEnabledAttribute(0)
 {
     ASSERT(impl != NULL);
 }
@@ -76,6 +77,19 @@ void VertexArray::enableAttribute(unsigned int attributeIndex, bool enabledState
     ASSERT(attributeIndex < getMaxAttribs());
     mVertexAttributes[attributeIndex].enabled = enabledState;
     mVertexArray->enableAttribute(attributeIndex, enabledState);
+
+    // Update state cache
+    if (enabledState)
+    {
+        mMaxEnabledAttribute = std::max(attributeIndex, mMaxEnabledAttribute);
+    }
+    else if (mMaxEnabledAttribute == attributeIndex)
+    {
+        while (mMaxEnabledAttribute > 0 && !mVertexAttributes[mMaxEnabledAttribute].enabled)
+        {
+            --mMaxEnabledAttribute;
+        }
+    }
 }
 
 void VertexArray::setAttributeState(unsigned int attributeIndex, gl::Buffer *boundBuffer, GLint size, GLenum type,

src/libANGLE/VertexArray.h

@@ -53,12 +53,15 @@ class VertexArray
     rx::VertexArrayImpl *getImplementation() { return mVertexArray; }
     const rx::VertexArrayImpl *getImplementation() const { return mVertexArray; }
 
+    unsigned int getMaxEnabledAttribute() const { return mMaxEnabledAttribute; }
+
   private:
     GLuint mId;
 
     rx::VertexArrayImpl *mVertexArray;
     std::vector<VertexAttribute> mVertexAttributes;
     BindingPointer<Buffer> mElementArrayBuffer;
+    unsigned int mMaxEnabledAttribute;
 };
 
 }

src/libANGLE/validationES.cpp

@@ -1407,7 +1407,8 @@ static bool ValidateDrawBase(Context *context, GLenum mode, GLsizei count, GLsiz
     const VertexArray *vao = state.getVertexArray();
     const auto &vertexAttribs = vao->getVertexAttributes();
     const int *semanticIndexes = program->getSemanticIndexes();
-    for (size_t attributeIndex = 0; attributeIndex < vertexAttribs.size(); ++attributeIndex)
+    unsigned int maxEnabledAttrib = vao->getMaxEnabledAttribute();
+    for (size_t attributeIndex = 0; attributeIndex < maxEnabledAttrib; ++attributeIndex)
     {
         const VertexAttribute &attrib = vertexAttribs[attributeIndex];
         bool attribActive = (semanticIndexes[attributeIndex] != -1);