Added GrAAFlatteningConvexPathRenderer

src/gpu/GrAALinearizingConvexPathRenderer.cpp

Index: src/gpu/GrAALinearizingConvexPathRenderer.cpp
diff --git a/src/gpu/GrAALinearizingConvexPathRenderer.cpp b/src/gpu/GrAALinearizingConvexPathRenderer.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..e03df81def198f76d4bdc09349f726cc7cf4537e
--- /dev/null
+++ b/src/gpu/GrAALinearizingConvexPathRenderer.cpp
@@ -0,0 +1,320 @@
+
+/*
+ * Copyright 2015 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#include "GrAALinearizingConvexPathRenderer.h"
+
+#include "GrAAConvexTessellator.h"
+#include "GrBatch.h"
+#include "GrBatchTarget.h"
+#include "GrBatchTest.h"
+#include "GrContext.h"
+#include "GrDefaultGeoProcFactory.h"
+#include "GrGeometryProcessor.h"
+#include "GrInvariantOutput.h"
+#include "GrPathUtils.h"
+#include "GrProcessor.h"
+#include "GrPipelineBuilder.h"
+#include "GrStrokeInfo.h"
+#include "SkGeometry.h"
+#include "SkString.h"
+#include "SkTraceEvent.h"
+#include "gl/GrGLProcessor.h"
+#include "gl/GrGLSL.h"
+#include "gl/GrGLGeometryProcessor.h"
+#include "gl/builders/GrGLProgramBuilder.h"
+
+#define DEFAULT_BUFFER_SIZE 100
+
+GrAALinearizingConvexPathRenderer::GrAALinearizingConvexPathRenderer() {
+}
+
+///////////////////////////////////////////////////////////////////////////////
+
+bool GrAALinearizingConvexPathRenderer::canDrawPath(const GrDrawTarget* target,
+                                                    const GrPipelineBuilder*,
+                                                    const SkMatrix& viewMatrix,
+                                                    const SkPath& path,
+                                                    const GrStrokeInfo& stroke,
+                                                    bool antiAlias) const {
+    return (antiAlias && stroke.isFillStyle() && !path.isInverseFillType() && path.isConvex());
+}
+
+// extract the result vertices and indices from the GrAAConvexTessellator
+static void extract_verts(const GrAAConvexTessellator& tess,
+                          void* vertices,
+                          size_t vertexStride,
+                          GrColor color,
+                          uint16_t firstIndex,
+                          uint16_t* idxs,
+                          bool tweakAlphaForCoverage) {
+    intptr_t verts = reinterpret_cast<intptr_t>(vertices);
+
+    for (int i = 0; i < tess.numPts(); ++i) {
+        *((SkPoint*)((intptr_t)verts + i * vertexStride)) = tess.point(i);
+    }
+
+    // Make 'verts' point to the colors
+    verts += sizeof(SkPoint);
+    for (int i = 0; i < tess.numPts(); ++i) {
+        SkASSERT(tess.depth(i) >= -0.5f && tess.depth(i) <= 0.5f);
+        if (tweakAlphaForCoverage) {
+            SkASSERT(SkScalarRoundToInt(255.0f * (tess.depth(i) + 0.5f)) <= 255);
+            unsigned scale = SkScalarRoundToInt(255.0f * (tess.depth(i) + 0.5f));
+            GrColor scaledColor = (0xff == scale) ? color : SkAlphaMulQ(color, scale);
+            *reinterpret_cast<GrColor*>(verts + i * vertexStride) = scaledColor;
+        } else {
+            *reinterpret_cast<GrColor*>(verts + i * vertexStride) = color;
+            *reinterpret_cast<float*>(verts + i * vertexStride + sizeof(GrColor)) = 
+                                                                    tess.depth(i) + 0.5f;
+        }
+    }
+
+    for (int i = 0; i < tess.numIndices(); ++i) {
+        idxs[i] = tess.index(i) + firstIndex;
+    }
+}
+
+static const GrGeometryProcessor* create_fill_gp(bool tweakAlphaForCoverage,
+                                                 const SkMatrix& localMatrix,
+                                                 bool usesLocalCoords,
+                                                 bool coverageIgnored) {
+    uint32_t flags = GrDefaultGeoProcFactory::kColor_GPType;
+    if (!tweakAlphaForCoverage) {
+        flags |= GrDefaultGeoProcFactory::kCoverage_GPType;
+    }
+
+    return GrDefaultGeoProcFactory::Create(flags, GrColor_WHITE, usesLocalCoords, coverageIgnored,
+                                           SkMatrix::I(), localMatrix);
+}
+
+class AAFlatteningConvexPathBatch : public GrBatch {
+public:
+    struct Geometry {
+        GrColor fColor;
+        SkMatrix fViewMatrix;
+        SkPath fPath;
+    };
+
+    static GrBatch* Create(const Geometry& geometry) {
+        return SkNEW_ARGS(AAFlatteningConvexPathBatch, (geometry));
+    }
+
+    const char* name() const override { return "AAConvexBatch"; }
+
+    void getInvariantOutputColor(GrInitInvariantOutput* out) const override {
+        // When this is called on a batch, there is only one geometry bundle
+        out->setKnownFourComponents(fGeoData[0].fColor);
+    }
+    void getInvariantOutputCoverage(GrInitInvariantOutput* out) const override {
+        out->setUnknownSingleComponent();
+    }
+
+    void initBatchTracker(const GrPipelineInfo& init) override {
+        // Handle any color overrides
+        if (init.fColorIgnored) {
+            fGeoData[0].fColor = GrColor_ILLEGAL;
+        } else if (GrColor_ILLEGAL != init.fOverrideColor) {
+            fGeoData[0].fColor = init.fOverrideColor;
+        }
+
+        // setup batch properties
+        fBatch.fColorIgnored = init.fColorIgnored;
+        fBatch.fColor = fGeoData[0].fColor;
+        fBatch.fUsesLocalCoords = init.fUsesLocalCoords;
+        fBatch.fCoverageIgnored = init.fCoverageIgnored;
+        fBatch.fLinesOnly = SkPath::kLine_SegmentMask == fGeoData[0].fPath.getSegmentMasks();
+        fBatch.fCanTweakAlphaForCoverage = init.fCanTweakAlphaForCoverage;
+    }
+
+    void draw(GrBatchTarget* batchTarget, const GrPipeline* pipeline, int vertexCount, 
+            size_t vertexStride, void* vertices, int indexCount, uint16_t* indices) {
+        if (vertexCount == 0 || indexCount == 0) {
+            return;
+        }
+        const GrVertexBuffer* vertexBuffer;
+        GrVertices info;
+        int firstVertex;
+        void* verts = batchTarget->makeVertSpace(vertexStride, vertexCount, &vertexBuffer, 
+                &firstVertex);
+        if (!verts) {
+            SkDebugf("Could not allocate vertices\n");
+            return;
+        }
+        memcpy(verts, vertices, vertexCount * vertexStride);
+
+        const GrIndexBuffer* indexBuffer;
+        int firstIndex;
+        uint16_t* idxs = batchTarget->makeIndexSpace(indexCount, &indexBuffer, &firstIndex);
+        if (!idxs) {
+            SkDebugf("Could not allocate indices\n");
+            return;
+        }
+        memcpy(idxs, indices, indexCount * sizeof(uint16_t));
+        info.initIndexed(kTriangles_GrPrimitiveType, vertexBuffer, indexBuffer, firstVertex, 
+                firstIndex, vertexCount, indexCount);
+        batchTarget->draw(info);
+    }
+
+    void generateGeometry(GrBatchTarget* batchTarget, const GrPipeline* pipeline) override {
+        bool canTweakAlphaForCoverage = this->canTweakAlphaForCoverage();
+
+        SkMatrix invert;
+        if (this->usesLocalCoords() && !this->viewMatrix().invert(&invert)) {
+            SkDebugf("Could not invert viewmatrix\n");
+            return;
+        }
+
+        // Setup GrGeometryProcessor
+        SkAutoTUnref<const GrGeometryProcessor> gp(
+                                                create_fill_gp(canTweakAlphaForCoverage, invert,
+                                                               this->usesLocalCoords(),
+                                                               this->coverageIgnored()));
+
+        batchTarget->initDraw(gp, pipeline);
+
+        size_t vertexStride = gp->getVertexStride();
+
+        SkASSERT(canTweakAlphaForCoverage ?
+                 vertexStride == sizeof(GrDefaultGeoProcFactory::PositionColorAttr) :
+                 vertexStride == sizeof(GrDefaultGeoProcFactory::PositionColorCoverageAttr));
+
+        GrAAConvexTessellator tess;
+
+        int instanceCount = fGeoData.count();
+
+        int vertexCount = 0;
+        int indexCount = 0;
+        int maxVertices = DEFAULT_BUFFER_SIZE;
+        int maxIndices = DEFAULT_BUFFER_SIZE;
+        uint8_t* vertices = (uint8_t*) malloc(maxVertices * vertexStride);
+        uint16_t* indices = (uint16_t*) malloc(maxIndices * sizeof(uint16_t));
+        for (int i = 0; i < instanceCount; i++) {
+            tess.rewind();
+
+            Geometry& args = fGeoData[i];
+
+            if (!tess.tessellate(args.fViewMatrix, args.fPath)) {
+                continue;
+            }
+
+            int currentIndices = tess.numIndices();
+            SkASSERT(currentIndices <= UINT16_MAX);
+            if (indexCount + currentIndices > UINT16_MAX) {
+                // if we added the current instance, we would overflow the indices we can store in a 
+                // uint16_t. Draw what we've got so far and reset.
+                draw(batchTarget, pipeline, vertexCount, vertexStride, vertices, indexCount, 
+                        indices);
+                vertexCount = 0;
+                indexCount = 0;
+            }
+            int currentVertices = tess.numPts();
+            if (vertexCount + currentVertices > maxVertices) {
+                maxVertices = SkTMax(vertexCount + currentVertices, maxVertices * 2);
+                vertices = (uint8_t*) realloc(vertices, maxVertices * vertexStride);
+            }
+            if (indexCount + currentIndices > maxIndices) {
+                maxIndices = SkTMax(indexCount + currentIndices, maxIndices * 2);
+                indices = (uint16_t*) realloc(indices, maxIndices * sizeof(uint16_t));
+            }
+
+            extract_verts(tess, vertices + vertexStride * vertexCount, vertexStride, args.fColor, 
+                    vertexCount, indices + indexCount, canTweakAlphaForCoverage);
+            vertexCount += currentVertices;
+            indexCount += currentIndices;
+        }
+        draw(batchTarget, pipeline, vertexCount, vertexStride, vertices, indexCount, indices);
+        free(vertices);
+        free(indices);
+    }
+
+    SkSTArray<1, Geometry, true>* geoData() { return &fGeoData; }
+
+private:
+    AAFlatteningConvexPathBatch(const Geometry& geometry) {
+        this->initClassID<AAFlatteningConvexPathBatch>();
+        fGeoData.push_back(geometry);
+
+        // compute bounds
+        fBounds = geometry.fPath.getBounds();
+        geometry.fViewMatrix.mapRect(&fBounds);
+    }
+
+    bool onCombineIfPossible(GrBatch* t) override {
+        AAFlatteningConvexPathBatch* that = t->cast<AAFlatteningConvexPathBatch>();
+
+        SkASSERT(this->usesLocalCoords() == that->usesLocalCoords());
+        if (this->usesLocalCoords() && !this->viewMatrix().cheapEqualTo(that->viewMatrix())) {
+            return false;
+        }
+
+        // In the event of two batches, one who can tweak, one who cannot, we just fall back to
+        // not tweaking
+        if (this->canTweakAlphaForCoverage() != that->canTweakAlphaForCoverage()) {
+            fBatch.fCanTweakAlphaForCoverage = false;
+        }
+
+        fGeoData.push_back_n(that->geoData()->count(), that->geoData()->begin());
+        this->joinBounds(that->bounds());
+        return true;
+    }
+
+    GrColor color() const { return fBatch.fColor; }
+    bool linesOnly() const { return fBatch.fLinesOnly; }
+    bool usesLocalCoords() const { return fBatch.fUsesLocalCoords; }
+    bool canTweakAlphaForCoverage() const { return fBatch.fCanTweakAlphaForCoverage; }
+    const SkMatrix& viewMatrix() const { return fGeoData[0].fViewMatrix; }
+    bool coverageIgnored() const { return fBatch.fCoverageIgnored; }
+
+    struct BatchTracker {
+        GrColor fColor;
+        bool fUsesLocalCoords;
+        bool fColorIgnored;
+        bool fCoverageIgnored;
+        bool fLinesOnly;
+        bool fCanTweakAlphaForCoverage;
+    };
+
+    BatchTracker fBatch;
+    SkSTArray<1, Geometry, true> fGeoData;
+};
+
+bool GrAALinearizingConvexPathRenderer::onDrawPath(GrDrawTarget* target,
+                                                   GrPipelineBuilder* pipelineBuilder,
+                                                   GrColor color,
+                                                   const SkMatrix& vm,
+                                                   const SkPath& path,
+                                                   const GrStrokeInfo&,
+                                                   bool antiAlias) {
+    if (path.isEmpty()) {
+        return true;
+    }
+    AAFlatteningConvexPathBatch::Geometry geometry;
+    geometry.fColor = color;
+    geometry.fViewMatrix = vm;
+    geometry.fPath = path;
+
+    SkAutoTUnref<GrBatch> batch(AAFlatteningConvexPathBatch::Create(geometry));
+    target->drawBatch(pipelineBuilder, batch);
+
+    return true;
+}
+
+///////////////////////////////////////////////////////////////////////////////////////////////////
+
+#ifdef GR_TEST_UTILS
+
+BATCH_TEST_DEFINE(AAFlatteningConvexPathBatch) {
+    AAFlatteningConvexPathBatch::Geometry geometry;
+    geometry.fColor = GrRandomColor(random);
+    geometry.fViewMatrix = GrTest::TestMatrixInvertible(random);
+    geometry.fPath = GrTest::TestPathConvex(random);
+
+    return AAFlatteningConvexPathBatch::Create(geometry);
+}
+
+#endif