Create an optimized draw state but not hooked in yet to gpu pipeline

src/gpu/GrOptDrawState.h

+/*
+ * Copyright 2014 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#ifndef GrOptDrawState_DEFINED
+#define GrOptDrawState_DEFINED
+
+#include "GrRODrawState.h"
+
+class GrDrawState;
+
+/**
+ * Sub class that is derived from GrRODrawState. This class holds an optimized version of a

[bsalomon, 2014/08/26 18:41:44]

Subclass of GrRODrawState that holds an... ?

+ * drawState. Like it's parent it is meant to be an immutable class, and simply adds a few
+ * helpful data members not in the base class.
+ */
+class GrOptDrawState : public GrRODrawState {
+public:
+    /**
+     * Constructs and optimized drawState out of a GrRODrawState.
+     */
+    explicit GrOptDrawState(const GrDrawState& drawState);
+
+    bool operator== (const GrOptDrawState& that) const;
+
+private:
+    /*
+     * Loops through all the color stage effects to check if the stage will ignore color input or
+     * always output a constant color. In the ignore color input case we can ignore all previous
+     * stages. In the constant color case, we can ignore all previous stages and
+     * the current one and set the state color to the constant color. Once we determine the so
+     * called first effective stage, we copy all the effective stages into our optimized
+     * state.
+     */
+    void copyEffectiveColorStages(const GrDrawState& ds);
+    /*

[bsalomon, 2014/08/26 18:41:43]

\n

+     * Loops through all the coverage stage effects to check if the stage will ignore color input.
+     * If a coverage stage will ignore input, then we can ignore all coverage stages before it. We
+     * loop to determine the first effective coverage stage, and then copy all of our effective
+     * coverage stages into our optimized state.
+     */
+    void copyEffectiveCoverageStages(const GrDrawState& ds);
+
+    /*
+     * This function takes in a flag and removes the corresponding fixed function vertex attributes.
+     * The flags must be in the same order as GrVertexAttribBinding array. In otherwords the lowest

[bsalomon, 2014/08/26 18:41:43]

I think removeVAFlag should be plural since it can have multiple bits set.

"The flags mus be in" -> "The flags are in"?

Or maybe:

"If bit i of removeVAFlag is set then vertex attributes with binding
(GrVertexAttribBinding)i will be removed."?

+     * bit is for the position, the 2nd is for the local coord, and so on.
+     */
+    void removeFixedFunctionVertexAttribs(uint8_t removeVAFlag);
+
+    void removeColorVertexAttrib();
+
+    bool            fInputColorIsUsed;

[bsalomon, 2014/08/26 18:41:43]

What's the use case for these?

[egdaniel, 2014/08/26 18:50:52]

Ahh comment only made into last cl for these. Basically we must keep track of if
we using the input color so that we don't make a uniform color that is not used.
We will get a shader compile warning/error for unused uniforms

+    bool            fInputCoverageIsUsed;
+
+    SkAutoSTArray<4, GrVertexAttrib> fOptVA;
+
+    typedef GrRODrawState INHERITED;
+};
+
+#endif