gl programs rewrite

BUG=skia:

Committed: https://skia.googlesource.com/skia/+/07a255310aca9f3e83bf741dc663a58818ad681c

Review URL: https://codereview.chromium.org/628633003

1 files changed, 388 insertions, 244 deletions

diff --git a/tests/GLProgramsTest.cpp b/tests/GLProgramsTest.cpp
index c31aa1e0da..4d1c59734b 100644
--- a/tests/GLProgramsTest.cpp
+++ b/tests/GLProgramsTest.cpp
@@ -12,7 +12,7 @@
 
 #if SK_SUPPORT_GPU && SK_ALLOW_STATIC_GLOBAL_INITIALIZERS
 
-#include "GrBackendProcessorFactory.h"
+#include "GrTBackendProcessorFactory.h"
 #include "GrContextFactory.h"
 #include "GrOptDrawState.h"
 #include "effects/GrConfigConversionEffect.h"
@@ -23,180 +23,122 @@
 #include "SkRandom.h"
 #include "Test.h"
 
-static void get_stage_stats(const GrFragmentStage stage, bool* readsDst,
-                            bool* readsFragPosition, bool* requiresVertexShader) {
-    if (stage.getProcessor()->willReadDstColor()) {
-        *readsDst = true;
-    }
-    if (stage.getProcessor()->willReadFragmentPosition()) {
-        *readsFragPosition = true;
-    }
-}
+/*
+ * A dummy effect which just tries to insert a massive key and verify that it can retrieve the
+ * whole thing correctly
+ */
+static const uint32_t kMaxKeySize = 1024;
 
-bool GrGLProgramDesc::setRandom(SkRandom* random,
-                                GrGpuGL* gpu,
-                                const GrRenderTarget* dstRenderTarget,
-                                const GrTexture* dstCopyTexture,
-                                const GrGeometryStage* geometryProcessor,
-                                const GrFragmentStage* stages[],
-                                int numColorStages,
-                                int numCoverageStages,
-                                int currAttribIndex,
-                                GrGpu::DrawType drawType) {
-    bool isPathRendering = GrGpu::IsPathRenderingDrawType(drawType);
-    bool useLocalCoords = !isPathRendering &&
-                          random->nextBool() &&
-                          currAttribIndex < GrDrawState::kMaxVertexAttribCnt;
-
-    int numStages = numColorStages + numCoverageStages;
-    fKey.reset();
-
-    GR_STATIC_ASSERT(0 == kEffectKeyOffsetsAndLengthOffset % sizeof(uint32_t));
-
-    // Make room for everything up to and including the array of offsets to effect keys.
-    fKey.push_back_n(kEffectKeyOffsetsAndLengthOffset + 2 * sizeof(uint16_t) * (numStages +
-            (geometryProcessor ? 1 : 0)));
-
-    bool dstRead = false;
-    bool fragPos = false;
-    bool vertexShader = SkToBool(geometryProcessor);
-    int offset = 0;
-    if (geometryProcessor) {
-        const GrGeometryStage* stage = geometryProcessor;
-        uint16_t* offsetAndSize = reinterpret_cast<uint16_t*>(fKey.begin() +
-                                                              kEffectKeyOffsetsAndLengthOffset +
-                                                              offset * 2 * sizeof(uint16_t));
-        uint32_t effectKeyOffset = fKey.count();
-        if (effectKeyOffset > SK_MaxU16) {
-            fKey.reset();
-            return false;
-        }
-        GrProcessorKeyBuilder b(&fKey);
-        uint16_t effectKeySize;
-        if (!GetProcessorKey(*stage, gpu->glCaps(), useLocalCoords, &b, &effectKeySize)) {
-            fKey.reset();
-            return false;
-        }
-        vertexShader = true;
-        fragPos = stage->getProcessor()->willReadFragmentPosition();
-        offsetAndSize[0] = effectKeyOffset;
-        offsetAndSize[1] = effectKeySize;
-        offset++;
-    }
+class GLBigKeyProcessor;
 
-    for (int s = 0; s < numStages; ++s, ++offset) {
-        const GrFragmentStage* stage = stages[s];
-        uint16_t* offsetAndSize = reinterpret_cast<uint16_t*>(fKey.begin() +
-                                                              kEffectKeyOffsetsAndLengthOffset +
-                                                              offset * 2 * sizeof(uint16_t));
-        uint32_t effectKeyOffset = fKey.count();
-        if (effectKeyOffset > SK_MaxU16) {
-            fKey.reset();
-            return false;
-        }
-        GrProcessorKeyBuilder b(&fKey);
-        uint16_t effectKeySize;
-        if (!GetProcessorKey(*stages[s], gpu->glCaps(), useLocalCoords, &b, &effectKeySize)) {
-            fKey.reset();
-            return false;
-        }
-        get_stage_stats(*stage, &dstRead, &fragPos, &vertexShader);
-        offsetAndSize[0] = effectKeyOffset;
-        offsetAndSize[1] = effectKeySize;
+class BigKeyProcessor : public GrFragmentProcessor {
+public:
+    static GrFragmentProcessor* Create() {
+        GR_CREATE_STATIC_FRAGMENT_PROCESSOR(gBigKeyProcessor, BigKeyProcessor, ())
+        return SkRef(gBigKeyProcessor);
     }
 
-    KeyHeader* header = this->header();
-    memset(header, 0, kHeaderSize);
-    header->fEmitsPointSize = random->nextBool();
+    static const char* Name() { return "Big ol' Key"; }
 
-    header->fPositionAttributeIndex = 0;
+    virtual const GrBackendFragmentProcessorFactory& getFactory() const SK_OVERRIDE {
+        return GrTBackendFragmentProcessorFactory<BigKeyProcessor>::getInstance();
+    }
 
-    // if the effects have used up all off the available attributes,
-    // don't try to use color or coverage attributes as input
-    do {
-        header->fColorInput = static_cast<GrGLProgramDesc::ColorInput>(
-                                     random->nextULessThan(kColorInputCnt));
-    } while ((GrDrawState::kMaxVertexAttribCnt <= currAttribIndex || isPathRendering) &&
-             kAttribute_ColorInput == header->fColorInput);
-    header->fColorAttributeIndex = (header->fColorInput == kAttribute_ColorInput) ?
-                                        currAttribIndex++ :
-                                        -1;
+    typedef GLBigKeyProcessor GLProcessor;
 
-    do {
-        header->fCoverageInput = static_cast<GrGLProgramDesc::ColorInput>(
-                                     random->nextULessThan(kColorInputCnt));
-    } while ((GrDrawState::kMaxVertexAttribCnt <= currAttribIndex || isPathRendering)  &&
-             kAttribute_ColorInput == header->fCoverageInput);
-    header->fCoverageAttributeIndex = (header->fCoverageInput == kAttribute_ColorInput) ?
-                                        currAttribIndex++ :
-                                        -1;
-    bool useGS = random->nextBool();
-#if GR_GL_EXPERIMENTAL_GS
-    header->fExperimentalGS = gpu->caps()->geometryShaderSupport() && useGS;
-#else
-    (void) useGS;
-#endif
+private:
+    BigKeyProcessor() { }
+    virtual bool onIsEqual(const GrProcessor&) const SK_OVERRIDE { return true; }
+    virtual void onComputeInvariantOutput(InvariantOutput* inout) const SK_OVERRIDE { }
 
-    header->fLocalCoordAttributeIndex = useLocalCoords ? currAttribIndex++ : -1;
+    GR_DECLARE_FRAGMENT_PROCESSOR_TEST;
 
-    header->fColorEffectCnt = numColorStages;
-    header->fCoverageEffectCnt = numCoverageStages;
+    typedef GrFragmentProcessor INHERITED;
+};
 
-    if (dstRead) {
-        header->fDstReadKey = SkToU8(GrGLFragmentShaderBuilder::KeyForDstRead(dstCopyTexture,
-                                                                      gpu->glCaps()));
-    } else {
-        header->fDstReadKey = 0;
-    }
-    if (fragPos) {
-        header->fFragPosKey = SkToU8(GrGLFragmentShaderBuilder::KeyForFragmentPosition(dstRenderTarget,
-                                                                               gpu->glCaps()));
-    } else {
-        header->fFragPosKey = 0;
-    }
+GR_DEFINE_FRAGMENT_PROCESSOR_TEST(BigKeyProcessor);
 
-    header->fUseFragShaderOnly = isPathRendering && gpu->glPathRendering()->texturingMode() ==
-                                                    GrGLPathRendering::FixedFunction_TexturingMode;
-    header->fHasGeometryProcessor = vertexShader;
+GrFragmentProcessor* BigKeyProcessor::TestCreate(SkRandom*,
+                                                 GrContext*,
+                                                 const GrDrawTargetCaps&,
+                                                 GrTexture*[]) {
+    return BigKeyProcessor::Create();
+}
 
-    GrOptDrawState::PrimaryOutputType primaryOutput;
-    GrOptDrawState::SecondaryOutputType secondaryOutput;
-    if (!dstRead) {
-        primaryOutput = GrOptDrawState::kModulate_PrimaryOutputType;
-    } else {
-        primaryOutput = static_cast<GrOptDrawState::PrimaryOutputType>(
-            random->nextULessThan(GrOptDrawState::kPrimaryOutputTypeCnt));
+class GLBigKeyProcessor : public GrGLFragmentProcessor {
+public:
+    GLBigKeyProcessor(const GrBackendProcessorFactory& factory, const GrProcessor&)
+        : INHERITED(factory) {}
+
+    virtual void emitCode(GrGLProgramBuilder* builder,
+                          const GrFragmentProcessor& fp,
+                          const GrProcessorKey& key,
+                          const char* outputColor,
+                          const char* inputColor,
+                          const TransformedCoordsArray&,
+                          const TextureSamplerArray&) {
+        for (uint32_t i = 0; i < kMaxKeySize; i++) {
+            SkASSERT(key.get32(i) == i);
+        }
     }
 
-    if (GrOptDrawState::kCombineWithDst_PrimaryOutputType == primaryOutput ||
-        !gpu->caps()->dualSourceBlendingSupport()) {
-        secondaryOutput = GrOptDrawState::kNone_SecondaryOutputType;
-    } else {
-        secondaryOutput = static_cast<GrOptDrawState::SecondaryOutputType>(
-            random->nextULessThan(GrOptDrawState::kSecondaryOutputTypeCnt));
+    static void GenKey(const GrProcessor& processor, const GrGLCaps&, GrProcessorKeyBuilder* b) {
+        for (uint32_t i = 0; i < kMaxKeySize; i++) {
+            b->add32(i);
+        }
     }
 
-    header->fPrimaryOutputType = primaryOutput;
-    header->fSecondaryOutputType = secondaryOutput;
+private:
+    typedef GrGLFragmentProcessor INHERITED;
+};
 
-    this->finalize();
-    return true;
+/*
+ * Begin test code
+ */
+static const int kRenderTargetHeight = 1;
+static const int kRenderTargetWidth = 1;
+
+static GrRenderTarget* random_render_target(GrGpuGL* gpu,
+                                            const GrCacheID& cacheId,
+                                            SkRandom* random) {
+    // setup render target
+    GrTextureParams params;
+    GrTextureDesc texDesc;
+    texDesc.fWidth = kRenderTargetWidth;
+    texDesc.fHeight = kRenderTargetHeight;
+    texDesc.fFlags = kRenderTarget_GrTextureFlagBit;
+    texDesc.fConfig = kRGBA_8888_GrPixelConfig;
+    texDesc.fOrigin = random->nextBool() == true ? kTopLeft_GrSurfaceOrigin :
+                                                   kBottomLeft_GrSurfaceOrigin;
+
+    GrTexture* texture = gpu->getContext()->findAndRefTexture(texDesc, cacheId, &params);
+    if (NULL == texture) {
+        texture = gpu->getContext()->createTexture(&params, texDesc, cacheId, 0, 0);
+        if (NULL == texture) {
+            return NULL;
+        }
+    }
+    return texture->asRenderTarget();
 }
 
 // TODO clean this up, we have to do this to test geometry processors but there has got to be
 // a better way.  In the mean time, we actually fill out these generic vertex attribs below with
 // the correct vertex attribs from the GP.  We have to ensure, however, we don't try to add more
-// than two attributes.
-GrVertexAttrib genericVertexAttribs[] = {
+// than two attributes.  In addition, we 'pad' the below array with GPs up to 6 entries, 4 fixed
+// function vertex attributes and 2 GP custom attributes.
+GrVertexAttrib kGenericVertexAttribs[] = {
     { kVec2f_GrVertexAttribType, 0,   kPosition_GrVertexAttribBinding },
     { kVec2f_GrVertexAttribType, 0,   kGeometryProcessor_GrVertexAttribBinding },
+    { kVec2f_GrVertexAttribType, 0,   kGeometryProcessor_GrVertexAttribBinding },
+    { kVec2f_GrVertexAttribType, 0,   kGeometryProcessor_GrVertexAttribBinding },
+    { kVec2f_GrVertexAttribType, 0,   kGeometryProcessor_GrVertexAttribBinding },
     { kVec2f_GrVertexAttribType, 0,   kGeometryProcessor_GrVertexAttribBinding }
 };
 
 /*
  * convert sl type to vertexattrib type, not a complete implementation, only use for debugging
  */
-GrVertexAttribType convert_sltype_to_attribtype(GrSLType type) {
+static GrVertexAttribType convert_sltype_to_attribtype(GrSLType type) {
     switch (type) {
         case kFloat_GrSLType:
             return kFloat_GrVertexAttribType;
@@ -211,11 +153,227 @@ GrVertexAttribType convert_sltype_to_attribtype(GrSLType type) {
             return kFloat_GrVertexAttribType;
     }
 }
-// TODO end test hack
+// end test hack
+
+static void setup_random_ff_attribute(GrVertexAttribBinding binding, GrVertexAttribType type,
+                                      SkRandom* random, int* attribIndex, int* runningStride) {
+    if (random->nextBool()) {
+        kGenericVertexAttribs[*attribIndex].fType = type;
+        kGenericVertexAttribs[*attribIndex].fOffset = *runningStride;
+        kGenericVertexAttribs[*attribIndex].fBinding = binding;
+        *runningStride += GrVertexAttribTypeSize(kGenericVertexAttribs[(*attribIndex)++].fType);
+    }
+}
 
+static void set_random_gp(GrGpuGL* gpu, SkRandom* random, GrTexture* dummyTextures[]) {
+    GrProgramElementRef<const GrGeometryProcessor> gp(
+            GrProcessorTestFactory<GrGeometryProcessor>::CreateStage(random,
+                                                                     gpu->getContext(),
+                                                                     *gpu->caps(),
+                                                                     dummyTextures));
+    SkASSERT(gp);
+
+    // we have to set dummy vertex attributes, first we setup the fixed function attributes
+    // always leave the position attribute untouched in the array
+    int attribIndex = 1;
+    int runningStride = GrVertexAttribTypeSize(kGenericVertexAttribs[0].fType);
+
+    // local coords
+    setup_random_ff_attribute(kLocalCoord_GrVertexAttribBinding, kVec2f_GrVertexAttribType,
+                              random, &attribIndex, &runningStride);
+
+    // color
+    setup_random_ff_attribute(kColor_GrVertexAttribBinding, kVec4f_GrVertexAttribType,
+                              random, &attribIndex, &runningStride);
+
+    // coverage
+    setup_random_ff_attribute(kCoverage_GrVertexAttribBinding, kVec4f_GrVertexAttribType,
+                              random, &attribIndex, &runningStride);
+
+    // Update the geometry processor attributes
+    const GrGeometryProcessor::VertexAttribArray& v = gp->getVertexAttribs();
+    int numGPAttribs = v.count();
+    SkASSERT(numGPAttribs <= GrGeometryProcessor::kMaxVertexAttribs &&
+             GrGeometryProcessor::kMaxVertexAttribs == 2);
+
+    // we actually can't overflow if kMaxVertexAttribs == 2, but GCC 4.8 wants more proof
+    int maxIndex = SK_ARRAY_COUNT(kGenericVertexAttribs);
+    for (int i = 0; i < numGPAttribs && i + attribIndex < maxIndex; i++) {
+        kGenericVertexAttribs[i + attribIndex].fType =
+                convert_sltype_to_attribtype(v[i].getType());
+        kGenericVertexAttribs[i + attribIndex].fOffset = runningStride;
+        kGenericVertexAttribs[i + attribIndex].fBinding = kGeometryProcessor_GrVertexAttribBinding;
+        runningStride += GrVertexAttribTypeSize(kGenericVertexAttribs[i + attribIndex].fType);
+    }
 
-bool GrGpuGL::programUnitTest(int maxStages) {
+    // update the vertex attributes with the ds
+    GrDrawState* ds = gpu->drawState();
+    ds->setVertexAttribs<kGenericVertexAttribs>(attribIndex + numGPAttribs, runningStride);
+    ds->setGeometryProcessor(gp);
+}
+
+static void set_random_color_coverage_stages(GrGpuGL* gpu,
+                                             int maxStages,
+                                             bool usePathRendering,
+                                             SkRandom* random,
+                                             GrTexture* dummyTextures[]) {
+    int numProcs = random->nextULessThan(maxStages + 1);
+    int numColorProcs = random->nextULessThan(numProcs + 1);
+
+    int currTextureCoordSet = 0;
+    for (int s = 0; s < numProcs;) {
+        GrProgramElementRef<GrFragmentProcessor> fp(
+                GrProcessorTestFactory<GrFragmentProcessor>::CreateStage(random,
+                                                                         gpu->getContext(),
+                                                                         *gpu->caps(),
+                                                                         dummyTextures));
+        SkASSERT(fp);
+
+        // don't add dst color reads to coverage stage
+        if (s >= numColorProcs && fp->willReadDstColor()) {
+            continue;
+        }
+
+        // If adding this effect would exceed the max texture coord set count then generate a
+        // new random effect.
+        if (usePathRendering && gpu->glPathRendering()->texturingMode() ==
+                                GrGLPathRendering::FixedFunction_TexturingMode) {;
+            int numTransforms = fp->numTransforms();
+            if (currTextureCoordSet + numTransforms >
+                gpu->glCaps().maxFixedFunctionTextureCoords()) {
+                continue;
+            }
+            currTextureCoordSet += numTransforms;
+        }
+
+        // finally add the stage to the correct pipeline in the drawstate
+        GrDrawState* ds = gpu->drawState();
+        if (s < numColorProcs) {
+            ds->addColorProcessor(fp);
+        } else {
+            ds->addCoverageProcessor(fp);
+        }
+        ++s;
+    }
+}
+
+// There are only a few cases of random colors which interest us
+enum ColorMode {
+    kAllOnes_ColorMode,
+    kAllZeros_ColorMode,
+    kAlphaOne_ColorMode,
+    kRandom_ColorMode,
+    kLast_ColorMode = kRandom_ColorMode
+};
+
+static void set_random_color(GrGpuGL* gpu, SkRandom* random) {
+    ColorMode colorMode = ColorMode(random->nextULessThan(kLast_ColorMode + 1));
+    GrColor color;
+    switch (colorMode) {
+        case kAllOnes_ColorMode:
+            color = GrColorPackRGBA(0xFF, 0xFF, 0xFF, 0xFF);
+            break;
+        case kAllZeros_ColorMode:
+            color = GrColorPackRGBA(0, 0, 0, 0);
+            break;
+        case kAlphaOne_ColorMode:
+            color = GrColorPackRGBA(random->nextULessThan(256),
+                                    random->nextULessThan(256),
+                                    random->nextULessThan(256),
+                                    0xFF);
+            break;
+        case kRandom_ColorMode:
+            uint8_t alpha = random->nextULessThan(256);
+            color = GrColorPackRGBA(random->nextRangeU(0, alpha),
+                                    random->nextRangeU(0, alpha),
+                                    random->nextRangeU(0, alpha),
+                                    alpha);
+            break;
+    }
+    GrColorIsPMAssert(color);
+    gpu->drawState()->setColor(color);
+}
+
+// There are only a few cases of random coverages which interest us
+enum CoverageMode {
+    kZero_CoverageMode,
+    kFF_CoverageMode,
+    kRandom_CoverageMode,
+    kLast_CoverageMode = kRandom_CoverageMode
+};
+
+static void set_random_coverage(GrGpuGL* gpu, SkRandom* random) {
+    CoverageMode coverageMode = CoverageMode(random->nextULessThan(kLast_CoverageMode + 1));
+    uint8_t coverage;
+    switch (coverageMode) {
+        case kZero_CoverageMode:
+            coverage = 0;
+            break;
+        case kFF_CoverageMode:
+            coverage = 0xFF;
+            break;
+        case kRandom_CoverageMode:
+            coverage = uint8_t(random->nextU());
+            break;
+    }
+    gpu->drawState()->setCoverage(coverage);
+}
+
+static void set_random_hints(GrGpuGL* gpu, SkRandom* random) {
+    for (int i = 1; i <= GrDrawState::kLast_Hint; i <<= 1) {
+        gpu->drawState()->setHint(GrDrawState::Hints(i), random->nextBool());
+    }
+}
+
+static void set_random_state(GrGpuGL* gpu, SkRandom* random) {
+    int state = 0;
+    for (int i = 1; i <= GrDrawState::kLastPublicStateBit; i <<= 1) {
+        state |= random->nextBool() * i;
+    }
+    gpu->drawState()->enableState(state);
+}
+
+// this function will randomly pick non-self referencing blend modes
+static void set_random_blend_func(GrGpuGL* gpu, SkRandom* random) {
+    GrBlendCoeff src;
+    do {
+        src = GrBlendCoeff(random->nextRangeU(kFirstPublicGrBlendCoeff, kLastPublicGrBlendCoeff));
+    } while (GrBlendCoeffRefsSrc(src));
 
+    GrBlendCoeff dst;
+    do {
+        dst = GrBlendCoeff(random->nextRangeU(kFirstPublicGrBlendCoeff, kLastPublicGrBlendCoeff));
+    } while (GrBlendCoeffRefsDst(dst));
+
+    gpu->drawState()->setBlendFunc(src, dst);
+}
+
+// right now, the only thing we seem to care about in drawState's stencil is 'doesWrite()'
+static void set_random_stencil(GrGpuGL* gpu, SkRandom* random) {
+    GR_STATIC_CONST_SAME_STENCIL(kDoesWriteStencil,
+                                 kReplace_StencilOp,
+                                 kReplace_StencilOp,
+                                 kAlways_StencilFunc,
+                                 0xffff,
+                                 0xffff,
+                                 0xffff);
+    GR_STATIC_CONST_SAME_STENCIL(kDoesNotWriteStencil,
+                                 kKeep_StencilOp,
+                                 kKeep_StencilOp,
+                                 kNever_StencilFunc,
+                                 0xffff,
+                                 0xffff,
+                                 0xffff);
+
+    if (random->nextBool()) {
+        gpu->drawState()->setStencil(kDoesWriteStencil);
+    } else {
+        gpu->drawState()->setStencil(kDoesNotWriteStencil);
+    }
+}
+
+bool GrGpuGL::programUnitTest(int maxStages) {
+    // setup dummy textures
     GrTextureDesc dummyDesc;
     dummyDesc.fFlags = kRenderTarget_GrTextureFlagBit;
     dummyDesc.fConfig = kSkia8888_GrPixelConfig;
@@ -229,130 +387,116 @@ bool GrGpuGL::programUnitTest(int maxStages) {
     SkAutoTUnref<GrTexture> dummyTexture2(this->createTexture(dummyDesc, NULL, 0));
 
     if (!dummyTexture1 || ! dummyTexture2) {
+        SkDebugf("Could not allocate dummy textures");
         return false;
     }
 
-    static const int NUM_TESTS = 512;
+    GrTexture* dummyTextures[] = {dummyTexture1.get(), dummyTexture2.get()};
 
-    SkRandom random;
-    for (int t = 0; t < NUM_TESTS; ++t) {
+    // Setup texture cache id key
+    const GrCacheID::Domain glProgramsDomain = GrCacheID::GenerateDomain();
+    GrCacheID::Key key;
+    memset(&key, 0, sizeof(key));
+    key.fData32[0] = kRenderTargetWidth;
+    key.fData32[1] = kRenderTargetHeight;
+    GrCacheID glProgramsCacheID(glProgramsDomain, key);
 
-#if 0
-        GrPrintf("\nTest Program %d\n-------------\n", t);
-        static const int stop = -1;
-        if (t == stop) {
-            int breakpointhere = 9;
-        }
-#endif
+    // setup clip
+    SkRect screen =
+            SkRect::MakeWH(SkIntToScalar(kRenderTargetWidth), SkIntToScalar(kRenderTargetHeight));
 
-        GrGLProgramDesc pdesc;
+    SkClipStack stack;
+    stack.clipDevRect(screen, SkRegion::kReplace_Op, false);
 
-        int currAttribIndex = 1;  // we need to always leave room for position
-        int currTextureCoordSet = 0;
-        GrTexture* dummyTextures[] = {dummyTexture1.get(), dummyTexture2.get()};
+    // wrap the SkClipStack in a GrClipData
+    GrClipData clipData;
+    clipData.fClipStack = &stack;
+    this->setClip(&clipData);
 
-        int numStages = random.nextULessThan(maxStages + 1);
-        int numColorStages = random.nextULessThan(numStages + 1);
-        int numCoverageStages = numStages - numColorStages;
+    SkRandom random;
+    static const int NUM_TESTS = 512;
+    for (int t = 0; t < NUM_TESTS;) {
+        // setup random render target(can fail)
+        GrRenderTarget* rtPtr = random_render_target(this, glProgramsCacheID, &random);
+        if (!rtPtr) {
+            SkDebugf("Could not allocate render target");
+            return false;
+        }
+        GrTGpuResourceRef<GrRenderTarget> rt(SkRef(rtPtr), kWrite_GrIOType);
 
-        SkAutoSTMalloc<8, const GrFragmentStage*> stages(numStages);
+        GrDrawState* ds = this->drawState();
+        ds->setRenderTarget(rt.get());
 
+        // if path rendering we have to setup a couple of things like the draw type
         bool usePathRendering = this->glCaps().pathRenderingSupport() && random.nextBool();
 
         GrGpu::DrawType drawType = usePathRendering ? GrGpu::kDrawPath_DrawType :
                                                       GrGpu::kDrawPoints_DrawType;
 
-        SkAutoTDelete<GrGeometryStage> geometryProcessor;
+        // twiddle drawstate knobs randomly
         bool hasGeometryProcessor = usePathRendering ? false : random.nextBool();
         if (hasGeometryProcessor) {
-            while (true) {
-                SkAutoTUnref<const GrGeometryProcessor> effect(
-                        GrProcessorTestFactory<GrGeometryProcessor>::CreateStage(&random, this->getContext(), *this->caps(),
-                                                         dummyTextures));
-                SkASSERT(effect);
-                // Only geometryProcessor can use vertex shader
-                GrGeometryStage* stage = SkNEW_ARGS(GrGeometryStage, (effect.get()));
-                geometryProcessor.reset(stage);
-
-                // we have to set dummy vertex attribs
-                const GrGeometryProcessor::VertexAttribArray& v = effect->getVertexAttribs();
-                int numVertexAttribs = v.count();
-
-                SkASSERT(GrGeometryProcessor::kMaxVertexAttribs == 2 &&
-                         GrGeometryProcessor::kMaxVertexAttribs >= numVertexAttribs);
-                size_t runningStride = GrVertexAttribTypeSize(genericVertexAttribs[0].fType);
-                for (int i = 0; i < numVertexAttribs; i++) {
-                    genericVertexAttribs[i + 1].fOffset = runningStride;
-                    genericVertexAttribs[i + 1].fType =
-                            convert_sltype_to_attribtype(v[i].getType());
-                    runningStride += GrVertexAttribTypeSize(genericVertexAttribs[i + 1].fType);
-                }
-
-                // update the vertex attributes with the ds
-                GrDrawState* ds = this->drawState();
-                ds->setVertexAttribs<genericVertexAttribs>(numVertexAttribs + 1, runningStride);
-                currAttribIndex = numVertexAttribs + 1;
-                break;
-            }
+            set_random_gp(this, &random, dummyTextures);
         }
-        for (int s = 0; s < numStages;) {
-            SkAutoTUnref<const GrFragmentProcessor> effect(
-                    GrProcessorTestFactory<GrFragmentProcessor>::CreateStage(
-                                                                            &random,
-                                                                            this->getContext(),
-                                                                            *this->caps(),
-                                                                            dummyTextures));
-            SkASSERT(effect);
-
-            // If adding this effect would exceed the max texture coord set count then generate a
-            // new random effect.
-            if (usePathRendering && this->glPathRendering()->texturingMode() ==
-                                    GrGLPathRendering::FixedFunction_TexturingMode) {;
-                int numTransforms = effect->numTransforms();
-                if (currTextureCoordSet + numTransforms > this->glCaps().maxFixedFunctionTextureCoords()) {
-                    continue;
-                }
-                currTextureCoordSet += numTransforms;
-            }
-            GrFragmentStage* stage = SkNEW_ARGS(GrFragmentStage, (effect.get()));
-
-            stages[s] = stage;
-            ++s;
+        set_random_color_coverage_stages(this, maxStages - hasGeometryProcessor, usePathRendering,
+                                         &random, dummyTextures);
+        set_random_color(this, &random);
+        set_random_coverage(this, &random);
+        set_random_hints(this, &random);
+        set_random_state(this, &random);
+        set_random_blend_func(this, &random);
+        set_random_stencil(this, &random);
+
+        // create optimized draw state, setup readDst texture if required, and build a descriptor
+        // and program.  ODS creation can fail, so we have to check
+        SkAutoTUnref<GrOptDrawState> ods(GrOptDrawState::Create(this->getDrawState(),
+                                                                *this->caps(),
+                                                                drawType));
+        if (!ods.get()) {
+            ds->reset();
+            continue;
         }
-        const GrTexture* dstTexture = random.nextBool() ? dummyTextures[0] : dummyTextures[1];
-        if (!pdesc.setRandom(&random,
-                             this,
-                             dummyTextures[0]->asRenderTarget(),
-                             dstTexture,
-                             geometryProcessor.get(),
-                             stages.get(),
-                             numColorStages,
-                             numCoverageStages,
-                             currAttribIndex,
-                             drawType)) {
+        const GrGeometryStage*                     geometryProcessor = NULL;
+        SkSTArray<8, const GrFragmentStage*, true> colorStages;
+        SkSTArray<8, const GrFragmentStage*, true> coverageStages;
+        GrGLProgramDesc desc;
+        GrDeviceCoordTexture dstCopy;
+
+        if (!this->setupDstReadIfNecessary(&dstCopy, NULL)) {
+            SkDebugf("Couldn't setup dst read texture");
             return false;
         }
-
-        SkAutoTUnref<GrOptDrawState> optState(GrOptDrawState::Create(this->getDrawState(),
-                                                                     *this->caps(),
-                                                                     drawType));
-        SkAutoTUnref<GrGLProgram> program(
-                        GrGLProgramBuilder::CreateProgram(*optState,
-                                                          pdesc,
-                                                          drawType,
-                                                          geometryProcessor,
-                                                          stages,
-                                                          stages + numColorStages,
-                                                          this));
-        for (int s = 0; s < numStages; ++s) {
-            SkDELETE(stages[s]);
+        if (!GrGLProgramDesc::Build(*ods,
+                                    drawType,
+                                    ods->getSrcBlendCoeff(),
+                                    ods->getDstBlendCoeff(),
+                                    this,
+                                    dstCopy.texture() ? &dstCopy : NULL,
+                                    &geometryProcessor,
+                                    &colorStages,
+                                    &coverageStages,
+                                    &desc)) {
+            SkDebugf("Failed to generate GL program descriptor");
+            return false;
         }
+        SkAutoTUnref<GrGLProgram> program(GrGLProgramBuilder::CreateProgram(*ods,
+                                                                            desc,
+                                                                            drawType,
+                                                                            geometryProcessor,
+                                                                            colorStages.begin(),
+                                                                            coverageStages.begin(),
+                                                                            this));
         if (NULL == program.get()) {
+            SkDebugf("Failed to create program!");
             return false;
         }
 
         // We have to reset the drawstate because we might have added a gp
-        this->drawState()->reset();
+        ds->reset();
+
+        // because occasionally optimized drawstate creation will fail for valid reasons, we only
+        // want to increment on success
+        ++t;
     }
     return true;
 }