| /* |
| * Copyright 2017 Google Inc. |
| * |
| * Use of this source code is governed by a BSD-style license that can be |
| * found in the LICENSE file. |
| */ |
| |
| #ifndef GrCCPRQuadraticProcessor_DEFINED |
| #define GrCCPRQuadraticProcessor_DEFINED |
| |
| #include "ccpr/GrCCPRCoverageProcessor.h" |
| |
| /** |
| * This class renders the coverage of closed quadratic curves using the techniques outlined in |
| * "Resolution Independent Curve Rendering using Programmable Graphics Hardware" by Charles Loop and |
| * Jim Blinn: |
| * |
| * https://www.microsoft.com/en-us/research/wp-content/uploads/2005/01/p1000-loop.pdf |
| * |
| * The provided curves must be monotonic with respect to the vector of their closing edge [P2 - P0]. |
| * (Use GrCCPRGeometry.) |
| */ |
| class GrCCPRQuadraticProcessor : public GrCCPRCoverageProcessor::PrimitiveProcessor { |
| public: |
| GrCCPRQuadraticProcessor() |
| : INHERITED(CoverageType::kShader) |
| , fCanonicalMatrix("canonical_matrix", kMat33f_GrSLType, GrShaderVar::kNonArray, |
| kHigh_GrSLPrecision) |
| , fCanonicalDerivatives("canonical_derivatives", kMat22f_GrSLType, |
| GrShaderVar::kNonArray, kHigh_GrSLPrecision) |
| , fEdgeDistanceEquation("edge_distance_equation", kVec3f_GrSLType, |
| GrShaderVar::kNonArray, kHigh_GrSLPrecision) |
| , fXYD(kVec3f_GrSLType) {} |
| |
| void resetVaryings(GrGLSLVaryingHandler* varyingHandler) override { |
| varyingHandler->addVarying("xyd", &fXYD, kHigh_GrSLPrecision); |
| } |
| |
| void onEmitVertexShader(const GrCCPRCoverageProcessor&, GrGLSLVertexBuilder*, |
| const TexelBufferHandle& pointsBuffer, const char* atlasOffset, |
| const char* rtAdjust, GrGPArgs*) const override; |
| void emitWind(GrGLSLGeometryBuilder*, const char* rtAdjust, const char* outputWind) const final; |
| void onEmitGeometryShader(GrGLSLGeometryBuilder*, const char* emitVertexFn, const char* wind, |
| const char* rtAdjust) const final; |
| void emitPerVertexGeometryCode(SkString* fnBody, const char* position, const char* coverage, |
| const char* wind) const final; |
| |
| protected: |
| virtual void emitQuadraticGeometry(GrGLSLGeometryBuilder*, const char* emitVertexFn, |
| const char* rtAdjust) const = 0; |
| virtual void onEmitPerVertexGeometryCode(SkString* fnBody) const = 0; |
| |
| GrShaderVar fCanonicalMatrix; |
| GrShaderVar fCanonicalDerivatives; |
| GrShaderVar fEdgeDistanceEquation; |
| GrGLSLGeoToFrag fXYD; |
| |
| typedef GrCCPRCoverageProcessor::PrimitiveProcessor INHERITED; |
| }; |
| |
| /** |
| * This pass draws a conservative raster hull around the quadratic bezier curve, computes the |
| * curve's coverage using the gradient-based AA technique outlined in the Loop/Blinn paper, and |
| * uses simple distance-to-edge to subtract out coverage for the flat closing edge [P2 -> P0]. Since |
| * the provided curves are monotonic, this will get every pixel right except the two corners. |
| */ |
| class GrCCPRQuadraticHullProcessor : public GrCCPRQuadraticProcessor { |
| public: |
| GrCCPRQuadraticHullProcessor() |
| : fGradXY(kVec2f_GrSLType) {} |
| |
| void resetVaryings(GrGLSLVaryingHandler* varyingHandler) override { |
| this->INHERITED::resetVaryings(varyingHandler); |
| varyingHandler->addVarying("grad_xy", &fGradXY, kHigh_GrSLPrecision); |
| } |
| |
| void emitQuadraticGeometry(GrGLSLGeometryBuilder*, const char* emitVertexFn, |
| const char* rtAdjust) const override; |
| void onEmitPerVertexGeometryCode(SkString* fnBody) const override; |
| void emitShaderCoverage(GrGLSLFragmentBuilder* f, const char* outputCoverage) const override; |
| |
| private: |
| GrGLSLGeoToFrag fGradXY; |
| |
| typedef GrCCPRQuadraticProcessor INHERITED; |
| }; |
| |
| /** |
| * This pass fixes the corners of a closed quadratic segment with soft MSAA. |
| */ |
| class GrCCPRQuadraticCornerProcessor : public GrCCPRQuadraticProcessor { |
| public: |
| GrCCPRQuadraticCornerProcessor() |
| : fEdgeDistanceDerivatives("edge_distance_derivatives", kVec2f_GrSLType, |
| GrShaderVar::kNonArray, kHigh_GrSLPrecision) |
| , fdXYDdx(kVec3f_GrSLType) |
| , fdXYDdy(kVec3f_GrSLType) {} |
| |
| void resetVaryings(GrGLSLVaryingHandler* varyingHandler) override { |
| this->INHERITED::resetVaryings(varyingHandler); |
| varyingHandler->addFlatVarying("dXYDdx", &fdXYDdx, kHigh_GrSLPrecision); |
| varyingHandler->addFlatVarying("dXYDdy", &fdXYDdy, kHigh_GrSLPrecision); |
| } |
| |
| void emitQuadraticGeometry(GrGLSLGeometryBuilder*, const char* emitVertexFn, |
| const char* rtAdjust) const override; |
| void onEmitPerVertexGeometryCode(SkString* fnBody) const override; |
| void emitShaderCoverage(GrGLSLFragmentBuilder*, const char* outputCoverage) const override; |
| |
| private: |
| GrShaderVar fEdgeDistanceDerivatives; |
| GrGLSLGeoToFrag fdXYDdx; |
| GrGLSLGeoToFrag fdXYDdy; |
| |
| typedef GrCCPRQuadraticProcessor INHERITED; |
| }; |
| |
| #endif |