Add GrProcOptInfo class to track various output information for color and coverage stages.

src/gpu/GrOptDrawState.cpp

 /*
  * Copyright 2014 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "GrOptDrawState.h"
 
 #include "GrDefaultGeoProcFactory.h"
 #include "GrDrawState.h"
 #include "GrDrawTargetCaps.h"
 #include "GrGpu.h"
-#include "GrInvariantOutput.h"
+#include "GrProcOptInfo.h"
 
 GrOptDrawState::GrOptDrawState(const GrDrawState& drawState,
                                BlendOptFlags blendOptFlags,
                                GrBlendCoeff optSrcCoeff,
                                GrBlendCoeff optDstCoeff,
                                GrGpu* gpu,
                                const GrDeviceCoordTexture* dstCopy,
                                GrGpu::DrawType drawType) {
     fRenderTarget.set(SkSafeRef(drawState.getRenderTarget()), kWrite_GrIOType);
     fColor = drawState.getColor();
@@ skipping 207 matching lines @@
     } else {
         if (ds.vertexColorsAreOpaque()) {
             color = 0xFF << GrColor_SHIFT_A;
             flags = kA_GrColorComponentFlag;
         } else {
             flags = static_cast<GrColorComponentFlags>(0);
             // not strictly necessary but we get false alarms from tools about uninit.
             color = 0;
         }
     }
-    GrInvariantOutput inout(color, flags, false);
-
-    for (int i = 0; i < ds.numColorStages(); ++i) {
-        const GrFragmentProcessor* fp = ds.getColorStage(i).getProcessor();
-        fp->computeInvariantOutput(&inout);
-        if (!inout.willUseInputColor()) {
-            *firstColorStageIdx = i;
-            descInfo->fInputColorIsUsed = false;
-        }
-        if (kRGBA_GrColorComponentFlags == inout.validFlags()) {
-            *firstColorStageIdx = i + 1;
-            fColor = inout.color();
-            descInfo->fInputColorIsUsed = true;
+    GrProcOptInfo poi;
+    if (ds.numColorStages() > 0) {
+        poi.calcWithInitialValues(&ds.getColorStage(0), ds.numColorStages(), color, flags, false);
+        *firstColorStageIdx = poi.firstEffectiveStageIndex();
+        descInfo->fInputColorIsUsed = poi.inputColorIsUsed();
+        fColor = poi.inputColorToEffectiveStage();
+        if (poi.removeVertexAttrib()) {
             *fixedFunctionVAToRemove |= 0x1 << kColor_GrVertexAttribBinding;
-            // Since we are clearing all previous color stages we are in a state where we have found
-            // zero stages that don't multiply the inputColor.
-            inout.resetNonMulStageFound();
         }
     }
 }
 
 void GrOptDrawState::computeEffectiveCoverageStages(const GrDrawState& ds,
                                                     GrProgramDesc::DescInfo* descInfo,
                                                     int* firstCoverageStageIdx) {
     // We do not try to optimize out constantColor coverage effects here. It is extremely rare
     // to have a coverage effect that returns a constant value for all four channels. Thus we
     // save having to make extra virtual calls by not checking for it.
@@ skipping 93 matching lines @@
     bool explicitLocalCoords = this->fDesc.header().fLocalCoordAttributeIndex != -1;
     for (int i = 0; i < this->numFragmentStages(); i++) {
         if (!GrFragmentStage::AreCompatible(this->getFragmentStage(i), that.getFragmentStage(i),
                                             explicitLocalCoords)) {
             return false;
         }
     }
     return true;
 }