Perform coverage blend with the dst in the shader when using a dst-reading xfermode.

tests/GLProgramsTest.cpp

 
 /*
  * Copyright 2011 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 // This is a GPU-backend specific test. It relies on static intializers to work
 
@@ skipping 36 matching lines @@
     fColorFilterXfermode = random->nextULessThan(SkXfermode::kCoeffModesCnt);
 
     fFirstCoverageStage = random->nextULessThan(GrDrawState::kNumStages);
 
 #if GR_GL_EXPERIMENTAL_GS
     fExperimentalGS = gpu->caps()->geometryShaderSupport() && random->nextBool();
 #endif
 
     fDiscardIfZeroCoverage = random->nextBool();
 
-    if (gpu->caps()->dualSourceBlendingSupport()) {
-        fDualSrcOutput = random->nextULessThan(kDualSrcOutputCnt);
-    } else {
-        fDualSrcOutput = kNone_DualSrcOutput;
-    }
-
     bool useLocalCoords = random->nextBool() && currAttribIndex < GrDrawState::kMaxVertexAttribCnt;
     fLocalCoordAttributeIndex = useLocalCoords ? currAttribIndex++ : -1;
 
     bool dstRead = false;
     for (int s = 0; s < GrDrawState::kNumStages; ++s) {
         if (NULL != stages[s].getEffect()) {
             const GrBackendEffectFactory& factory = (*stages[s].getEffect())->getFactory();
             GrDrawEffect drawEffect(stages[s], useLocalCoords);
             fEffectKeys[s] = factory.glEffectKey(drawEffect, gpu->glCaps());
             if ((*stages[s].getEffect())->willReadDst()) {
                 dstRead = true;
             }
         }
     }
 
     if (dstRead) {
         this->fDstRead = GrGLShaderBuilder::KeyForDstRead(dstTexture, gpu->glCaps());
     }
+
+    CoverageOutput coverageOutput;
+    bool illegalCoverageOutput;
+    do {
+        coverageOutput = static_cast<CoverageOutput>(random->nextULessThan(kCoverageOutputCnt));
+        illegalCoverageOutput = (!gpu->caps()->dualSourceBlendingSupport() &&
+                                 CoverageOutputUsesSecondaryOutput(coverageOutput)) ||
+                                !dstRead && kCombineWithDst_CoverageOutput == coverageOutput;
+    } while (illegalCoverageOutput);
+
+    fCoverageOutput = coverageOutput;
 }
 
 bool GrGpuGL::programUnitTest(int maxStages) {
 
     maxStages = GrMin(maxStages, (int)GrDrawState::kNumStages);
 
     GrTextureDesc dummyDesc;
     dummyDesc.fConfig = kSkia8888_GrPixelConfig;
     dummyDesc.fWidth = 34;
     dummyDesc.fHeight = 18;
@@ skipping 97 matching lines @@
     SkMagnifierImageFilter mag(SkRect::MakeWH(SK_Scalar1, SK_Scalar1), SK_Scalar1);
     GrConfigConversionEffect::Create(NULL,
                                      false,
                                      GrConfigConversionEffect::kNone_PMConversion,
                                      SkMatrix::I());
     SkScalar matrix[20];
     SkColorMatrixFilter cmf(matrix);
 }
 
 #endif