/* * Copyright 2017 Google Inc. * * Use of this source code is governed by a BSD-style license that can be * found in the LICENSE file. */ #include "GrCCPRPathProcessor.h" #include "GrOnFlushResourceProvider.h" #include "GrTexture.h" #include "glsl/GrGLSLFragmentShaderBuilder.h" #include "glsl/GrGLSLGeometryProcessor.h" #include "glsl/GrGLSLProgramBuilder.h" #include "glsl/GrGLSLVarying.h" // Slightly undershoot an AA bloat radius of 0.5 so vertices that fall on integer boundaries don't // accidentally reach into neighboring path masks within the atlas. constexpr float kAABloatRadius = 0.491111f; // Paths are drawn as octagons. Each point on the octagon is the intersection of two lines: one edge // from the path's bounding box and one edge from its 45-degree bounding box. The below inputs // define a vertex by the two edges that need to be intersected. Normals point out of the octagon, // and the bounding boxes are sent in as instance attribs. static constexpr float kOctoEdgeNorms[8 * 4] = { // bbox // bbox45 -1, 0, -1,+1, -1, 0, -1,-1, 0,-1, -1,-1, 0,-1, +1,-1, +1, 0, +1,-1, +1, 0, +1,+1, 0,+1, +1,+1, 0,+1, -1,+1, }; GR_DECLARE_STATIC_UNIQUE_KEY(gVertexBufferKey); sk_sp GrCCPRPathProcessor::FindVertexBuffer(GrOnFlushResourceProvider* onFlushRP) { GR_DEFINE_STATIC_UNIQUE_KEY(gVertexBufferKey); return onFlushRP->findOrMakeStaticBuffer(kVertex_GrBufferType, sizeof(kOctoEdgeNorms), kOctoEdgeNorms, gVertexBufferKey); } // Index buffer for the octagon defined above. static uint16_t kOctoIndices[GrCCPRPathProcessor::kPerInstanceIndexCount] = { 0, 4, 2, 0, 6, 4, 0, 2, 1, 2, 4, 3, 4, 6, 5, 6, 0, 7, }; GR_DECLARE_STATIC_UNIQUE_KEY(gIndexBufferKey); sk_sp GrCCPRPathProcessor::FindIndexBuffer(GrOnFlushResourceProvider* onFlushRP) { GR_DEFINE_STATIC_UNIQUE_KEY(gIndexBufferKey); return onFlushRP->findOrMakeStaticBuffer(kIndex_GrBufferType, sizeof(kOctoIndices), kOctoIndices, gIndexBufferKey); } GrCCPRPathProcessor::GrCCPRPathProcessor(GrResourceProvider* rp, sk_sp atlas, SkPath::FillType fillType, const GrShaderCaps& shaderCaps) : INHERITED(kGrCCPRPathProcessor_ClassID) , fFillType(fillType) , fAtlasAccess(std::move(atlas), GrSamplerState::Filter::kNearest, GrSamplerState::WrapMode::kClamp, kFragment_GrShaderFlag) { this->addInstanceAttrib("devbounds", kFloat4_GrVertexAttribType); this->addInstanceAttrib("devbounds45", kFloat4_GrVertexAttribType); this->addInstanceAttrib("view_matrix", kFloat4_GrVertexAttribType); this->addInstanceAttrib("view_translate", kFloat2_GrVertexAttribType); this->addInstanceAttrib("atlas_offset", kShort2_GrVertexAttribType); this->addInstanceAttrib("color", kUByte4_norm_GrVertexAttribType); SkASSERT(offsetof(Instance, fDevBounds) == this->getInstanceAttrib(InstanceAttribs::kDevBounds).fOffsetInRecord); SkASSERT(offsetof(Instance, fDevBounds45) == this->getInstanceAttrib(InstanceAttribs::kDevBounds45).fOffsetInRecord); SkASSERT(offsetof(Instance, fViewMatrix) == this->getInstanceAttrib(InstanceAttribs::kViewMatrix).fOffsetInRecord); SkASSERT(offsetof(Instance, fViewTranslate) == this->getInstanceAttrib(InstanceAttribs::kViewTranslate).fOffsetInRecord); SkASSERT(offsetof(Instance, fAtlasOffset) == this->getInstanceAttrib(InstanceAttribs::kAtlasOffset).fOffsetInRecord); SkASSERT(offsetof(Instance, fColor) == this->getInstanceAttrib(InstanceAttribs::kColor).fOffsetInRecord); SkASSERT(sizeof(Instance) == this->getInstanceStride()); GR_STATIC_ASSERT(6 == kNumInstanceAttribs); this->addVertexAttrib("edge_norms", kFloat4_GrVertexAttribType); fAtlasAccess.instantiate(rp); this->addTextureSampler(&fAtlasAccess); } void GrCCPRPathProcessor::getGLSLProcessorKey(const GrShaderCaps&, GrProcessorKeyBuilder* b) const { b->add32((fFillType << 16) | this->atlasProxy()->origin()); } class GLSLPathProcessor : public GrGLSLGeometryProcessor { public: void onEmitCode(EmitArgs& args, GrGPArgs* gpArgs) override; private: void setData(const GrGLSLProgramDataManager& pdman, const GrPrimitiveProcessor& primProc, FPCoordTransformIter&& transformIter) override { const GrCCPRPathProcessor& proc = primProc.cast(); pdman.set2f(fAtlasAdjustUniform, 1.0f / proc.atlas()->width(), 1.0f / proc.atlas()->height()); this->setTransformDataHelper(SkMatrix::I(), pdman, &transformIter); } GrGLSLUniformHandler::UniformHandle fAtlasAdjustUniform; typedef GrGLSLGeometryProcessor INHERITED; }; GrGLSLPrimitiveProcessor* GrCCPRPathProcessor::createGLSLInstance(const GrShaderCaps&) const { return new GLSLPathProcessor(); } void GLSLPathProcessor::onEmitCode(EmitArgs& args, GrGPArgs* gpArgs) { using InstanceAttribs = GrCCPRPathProcessor::InstanceAttribs; const GrCCPRPathProcessor& proc = args.fGP.cast(); GrGLSLUniformHandler* uniHandler = args.fUniformHandler; GrGLSLVaryingHandler* varyingHandler = args.fVaryingHandler; const char* atlasAdjust; fAtlasAdjustUniform = uniHandler->addUniform( kVertex_GrShaderFlag, kFloat2_GrSLType, "atlas_adjust", &atlasAdjust); varyingHandler->emitAttributes(proc); GrGLSLVarying texcoord(kFloat2_GrSLType); GrGLSLVarying color(kHalf4_GrSLType); varyingHandler->addVarying("texcoord", &texcoord); varyingHandler->addFlatPassThroughAttribute(&proc.getInstanceAttrib(InstanceAttribs::kColor), args.fOutputColor); // Vertex shader. GrGLSLVertexBuilder* v = args.fVertBuilder; // Find the intersections of (bloated) devBounds and devBounds45 in order to come up with an // octagon that circumscribes the (bloated) path. A vertex is the intersection of two lines: // one edge from the path's bounding box and one edge from its 45-degree bounding box. v->codeAppendf("float2x2 N = float2x2(%s);", proc.getEdgeNormsAttrib().fName); // N[0] is the normal for the edge we are intersecting from the regular bounding box, pointing // out of the octagon. v->codeAppendf("float2 refpt = (min(N[0].x, N[0].y) < 0) ? %s.xy : %s.zw;", proc.getInstanceAttrib(InstanceAttribs::kDevBounds).fName, proc.getInstanceAttrib(InstanceAttribs::kDevBounds).fName); v->codeAppendf("refpt += N[0] * %f;", kAABloatRadius); // bloat for AA. // N[1] is the normal for the edge we are intersecting from the 45-degree bounding box, pointing // out of the octagon. v->codeAppendf("float2 refpt45 = (N[1].x < 0) ? %s.xy : %s.zw;", proc.getInstanceAttrib(InstanceAttribs::kDevBounds45).fName, proc.getInstanceAttrib(InstanceAttribs::kDevBounds45).fName); v->codeAppendf("refpt45 *= float2x2(.5,.5,-.5,.5);"); // transform back to device space. v->codeAppendf("refpt45 += N[1] * %f;", kAABloatRadius); // bloat for AA. v->codeAppend ("float2 K = float2(dot(N[0], refpt), dot(N[1], refpt45));"); v->codeAppendf("float2 octocoord = K * inverse(N);"); gpArgs->fPositionVar.set(kFloat2_GrSLType, "octocoord"); // Convert to atlas coordinates in order to do our texture lookup. v->codeAppendf("float2 atlascoord = octocoord + float2(%s);", proc.getInstanceAttrib(InstanceAttribs::kAtlasOffset).fName); if (kTopLeft_GrSurfaceOrigin == proc.atlasProxy()->origin()) { v->codeAppendf("%s = atlascoord * %s;", texcoord.vsOut(), atlasAdjust); } else { SkASSERT(kBottomLeft_GrSurfaceOrigin == proc.atlasProxy()->origin()); v->codeAppendf("%s = float2(atlascoord.x * %s.x, 1 - atlascoord.y * %s.y);", texcoord.vsOut(), atlasAdjust, atlasAdjust); } // Convert to (local) path cordinates. v->codeAppendf("float2 pathcoord = inverse(float2x2(%s)) * (octocoord - %s);", proc.getInstanceAttrib(InstanceAttribs::kViewMatrix).fName, proc.getInstanceAttrib(InstanceAttribs::kViewTranslate).fName); this->emitTransforms(v, varyingHandler, uniHandler, GrShaderVar("pathcoord", kFloat2_GrSLType), args.fFPCoordTransformHandler); // Fragment shader. GrGLSLPPFragmentBuilder* f = args.fFragBuilder; f->codeAppend ("half coverage_count = "); f->appendTextureLookup(args.fTexSamplers[0], texcoord.fsIn(), kFloat2_GrSLType); f->codeAppend (".a;"); if (SkPath::kWinding_FillType == proc.fillType()) { f->codeAppendf("%s = half4(min(abs(coverage_count), 1));", args.fOutputCoverage); } else { SkASSERT(SkPath::kEvenOdd_FillType == proc.fillType()); f->codeAppend ("half t = mod(abs(coverage_count), 2);"); f->codeAppendf("%s = half4(1 - abs(t - 1));", args.fOutputCoverage); } }