Implement color filter as GrGLEffect

src/gpu/gl/GrGLProgramDesc.cpp

Index: src/gpu/gl/GrGLProgramDesc.cpp
diff --git a/src/gpu/gl/GrGLProgramDesc.cpp b/src/gpu/gl/GrGLProgramDesc.cpp
index 8b731fbc2c71244e80a6f6dc87262280e31e214a..afa3f1df9b3e56e57c4ecbc902dfd3dbd049d4a6 100644
--- a/src/gpu/gl/GrGLProgramDesc.cpp
+++ b/src/gpu/gl/GrGLProgramDesc.cpp
@@ -70,10 +70,11 @@ void GrGLProgramDesc::Build(const GrDrawState& drawState,
 
     bool colorIsTransBlack = SkToBool(blendOpts & GrDrawState::kEmitTransBlack_BlendOptFlag);
     bool colorIsSolidWhite = (blendOpts & GrDrawState::kEmitCoverage_BlendOptFlag) ||
-                             (!requiresColorAttrib && 0xffffffff == drawState.getColor());
+                             (!requiresColorAttrib && 0xffffffff == drawState.getColor()) ||
+                             (drawState.effectiveColorStageCount() > 0 && !(*drawState.getEffectiveColorStage(0).getEffect())->willUseInputColor());
 
-    int numEffects = (skipColor ? 0 : drawState.numColorStages()) +
-                     (skipCoverage ? 0 : drawState.numCoverageStages());
+    int numEffects = (skipColor ? 0 : drawState.effectiveColorStageCount()) +
+                     (skipCoverage ? 0 : drawState.effectiveCoverageStageCount());
 
     size_t newKeyLength = KeyLength(numEffects);
     bool allocChanged;
@@ -93,17 +94,17 @@ void GrGLProgramDesc::Build(const GrDrawState& drawState,
     bool readFragPosition = false;
     bool hasVertexCode = false;
     if (!skipColor) {
-        for (int s = 0; s < drawState.numColorStages(); ++s) {
+        for (int s = 0; s < drawState.effectiveColorStageCount(); ++s) {
             effectKeys[currEffectKey++] =
-                get_key_and_update_stats(drawState.getColorStage(s), gpu->glCaps(),
+                get_key_and_update_stats(drawState.getEffectiveColorStage(s), gpu->glCaps(),
                                          requiresLocalCoordAttrib, &readsDst, &readFragPosition,
                                          &hasVertexCode);
         }
     }
     if (!skipCoverage) {
-        for (int s = 0; s < drawState.numCoverageStages(); ++s) {
+        for (int s = 0; s < drawState.effectiveCoverageStageCount(); ++s) {
             effectKeys[currEffectKey++] =
-                get_key_and_update_stats(drawState.getCoverageStage(s), gpu->glCaps(),
+                get_key_and_update_stats(drawState.getEffectiveCoverageStage(s), gpu->glCaps(),
                                          requiresLocalCoordAttrib, &readsDst, &readFragPosition,
                                          &hasVertexCode);
         }
@@ -111,7 +112,6 @@ void GrGLProgramDesc::Build(const GrDrawState& drawState,
 
     header->fHasVertexCode = hasVertexCode || requiresLocalCoordAttrib;
     header->fEmitsPointSize = isPoints;
-    header->fColorFilterXfermode = skipColor ? SkXfermode::kDst_Mode : drawState.getColorFilterMode();
 
     // Currently the experimental GS will only work with triangle prims (and it doesn't do anything
     // other than pass through values from the VS to the FS anyway).
@@ -199,12 +199,7 @@ void GrGLProgramDesc::Build(const GrDrawState& drawState,
     // If we do have coverage determine whether it matters.
     bool separateCoverageFromColor = false;
     if (!drawState.isCoverageDrawing() && !skipCoverage &&
-        (drawState.numCoverageStages() > 0 || requiresCoverageAttrib)) {
-        // color filter is applied between color/coverage computation
-        if (SkXfermode::kDst_Mode != header->fColorFilterXfermode) {
-            separateCoverageFromColor = true;
-        }
-
+        (drawState.effectiveCoverageStageCount() > 0 || requiresCoverageAttrib)) {
         // If we're stenciling then we want to discard samples that have zero coverage
         if (drawState.getStencil().doesWrite()) {
             header->fDiscardIfZeroCoverage = true;
@@ -235,22 +230,22 @@ void GrGLProgramDesc::Build(const GrDrawState& drawState,
         }
     }
     if (!skipColor) {
-        for (int s = 0; s < drawState.numColorStages(); ++s) {
-            colorStages->push_back(&drawState.getColorStage(s));
+        for (int s = 0; s < drawState.effectiveColorStageCount(); ++s) {
+            colorStages->push_back(&drawState.getEffectiveColorStage(s));
         }
-        header->fColorEffectCnt = drawState.numColorStages();
+        header->fColorEffectCnt = drawState.effectiveColorStageCount();
     }
     if (!skipCoverage) {
         SkTArray<const GrEffectStage*, true>* array;
         if (separateCoverageFromColor) {
             array = coverageStages;
-            header->fCoverageEffectCnt = drawState.numCoverageStages();
+            header->fCoverageEffectCnt = drawState.effectiveCoverageStageCount();
         } else {
             array = colorStages;
-            header->fColorEffectCnt += drawState.numCoverageStages();
+            header->fColorEffectCnt += drawState.effectiveCoverageStageCount();
         }
-        for (int s = 0; s < drawState.numCoverageStages(); ++s) {
-            array->push_back(&drawState.getCoverageStage(s));
+        for (int s = 0; s < drawState.effectiveCoverageStageCount(); ++s) {
+            array->push_back(&drawState.getEffectiveCoverageStage(s));
         }
     }