Remove GP from drawstate, revision of invariant output for GP

include/gpu/GrXferProcessor.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 GrXferProcessor_DEFINED
 #define GrXferProcessor_DEFINED
 
@@ skipping 69 matching lines @@
         GrBlendCoeff fSrcBlend;
         GrBlendCoeff fDstBlend;
         GrColor      fBlendConstant;
     };
 
     virtual void getBlendInfo(BlendInfo* blendInfo) const = 0;
 
     /** Will this prceossor read the destination pixel value? */
     bool willReadDstColor() const { return fWillReadDstColor; }
 
+    /**
+     * This function is used to perform optimizations. When called the invarientOuput param
+     * indicate whether the input components to this processor in the FS will have known values.
+     * In inout the validFlags member is a bitfield of GrColorComponentFlags. The isSingleComponent
+     * member indicates whether the input will be 1 or 4 bytes. The function updates the members of
+     * inout to indicate known values of its output. A component of the color member only has
+     * meaning if the corresponding bit in validFlags is set.
+     */
+    void computeInvariantOutput(GrInvariantOutput* inout) const;

[bsalomon, 2014/12/09 20:39:50]

Do we need this at all?

+
 protected:
     GrXferProcessor() : fWillReadDstColor(false) {}
 
     /**
      * If the prceossor subclass will read the destination pixel value then it must call this
      * function from its constructor. Otherwise, when its generated backend-specific prceossor class
      * attempts to generate code that reads the destination pixel it will fail.
      */
     void setWillReadDstColor() { fWillReadDstColor = true; }
 
+    /**
+     * Subclass implements this to support getConstantColorComponents(...).

[bsalomon, 2014/12/09 20:39:50]

comment is wrong?

+     */
+    virtual void onComputeInvariantOutput(GrInvariantOutput* inout) const = 0;
+
 private:
 
     bool         fWillReadDstColor;
 
     typedef GrFragmentProcessor INHERITED;
 };
 
 GR_MAKE_BITFIELD_OPS(GrXferProcessor::OptFlags);
 
 /**
@@ skipping 95 matching lines @@
     enum {
         kIllegalXPFClassID = 0,
     };
     static int32_t gCurrXPFClassID;
 
     typedef GrProgramElement INHERITED;
 };
 
 #endif