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- /*
- * 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 "src/gpu/ccpr/GrCCPathProcessor.h"
- #include "include/gpu/GrTexture.h"
- #include "src/gpu/GrGpuCommandBuffer.h"
- #include "src/gpu/GrOnFlushResourceProvider.h"
- #include "src/gpu/GrTexturePriv.h"
- #include "src/gpu/ccpr/GrCCPerFlushResources.h"
- #include "src/gpu/glsl/GrGLSLFragmentShaderBuilder.h"
- #include "src/gpu/glsl/GrGLSLGeometryProcessor.h"
- #include "src/gpu/glsl/GrGLSLProgramBuilder.h"
- #include "src/gpu/glsl/GrGLSLVarying.h"
- // 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 selectors
- // below indicate one corner from the bounding box, paired with a corner from the 45-degree bounding
- // box. The octagon vertex is the point that lies between these two corners, found by intersecting
- // their edges.
- static constexpr float kOctoEdgeNorms[8*4] = {
- // bbox // bbox45
- 0,0, 0,0,
- 0,0, 1,0,
- 1,0, 1,0,
- 1,0, 1,1,
- 1,1, 1,1,
- 1,1, 0,1,
- 0,1, 0,1,
- 0,1, 0,0,
- };
- GR_DECLARE_STATIC_UNIQUE_KEY(gVertexBufferKey);
- sk_sp<const GrGpuBuffer> GrCCPathProcessor::FindVertexBuffer(GrOnFlushResourceProvider* onFlushRP) {
- GR_DEFINE_STATIC_UNIQUE_KEY(gVertexBufferKey);
- return onFlushRP->findOrMakeStaticBuffer(GrGpuBufferType::kVertex, sizeof(kOctoEdgeNorms),
- kOctoEdgeNorms, gVertexBufferKey);
- }
- static constexpr uint16_t kRestartStrip = 0xffff;
- static constexpr uint16_t kOctoIndicesAsStrips[] = {
- 3, 4, 2, 0, 1, kRestartStrip, // First half.
- 7, 0, 6, 4, 5 // Second half.
- };
- static constexpr uint16_t kOctoIndicesAsTris[] = {
- // First half.
- 3, 4, 2,
- 4, 0, 2,
- 2, 0, 1,
- // Second half.
- 7, 0, 6,
- 0, 4, 6,
- 6, 4, 5,
- };
- GR_DECLARE_STATIC_UNIQUE_KEY(gIndexBufferKey);
- constexpr GrPrimitiveProcessor::Attribute GrCCPathProcessor::kInstanceAttribs[];
- constexpr GrPrimitiveProcessor::Attribute GrCCPathProcessor::kCornersAttrib;
- sk_sp<const GrGpuBuffer> GrCCPathProcessor::FindIndexBuffer(GrOnFlushResourceProvider* onFlushRP) {
- GR_DEFINE_STATIC_UNIQUE_KEY(gIndexBufferKey);
- if (onFlushRP->caps()->usePrimitiveRestart()) {
- return onFlushRP->findOrMakeStaticBuffer(GrGpuBufferType::kIndex,
- sizeof(kOctoIndicesAsStrips), kOctoIndicesAsStrips,
- gIndexBufferKey);
- } else {
- return onFlushRP->findOrMakeStaticBuffer(GrGpuBufferType::kIndex,
- sizeof(kOctoIndicesAsTris), kOctoIndicesAsTris,
- gIndexBufferKey);
- }
- }
- GrCCPathProcessor::GrCCPathProcessor(CoverageMode coverageMode, const GrTexture* atlasTexture,
- const GrSwizzle& swizzle, GrSurfaceOrigin atlasOrigin,
- const SkMatrix& viewMatrixIfUsingLocalCoords)
- : INHERITED(kGrCCPathProcessor_ClassID)
- , fCoverageMode(coverageMode)
- , fAtlasAccess(atlasTexture->texturePriv().textureType(), atlasTexture->config(),
- GrSamplerState::Filter::kNearest, GrSamplerState::WrapMode::kClamp, swizzle)
- , fAtlasSize(SkISize::Make(atlasTexture->width(), atlasTexture->height()))
- , fAtlasOrigin(atlasOrigin) {
- // TODO: Can we just assert that atlas has GrCCAtlas::kTextureOrigin and remove fAtlasOrigin?
- this->setInstanceAttributes(kInstanceAttribs, SK_ARRAY_COUNT(kInstanceAttribs));
- SkASSERT(this->instanceStride() == sizeof(Instance));
- this->setVertexAttributes(&kCornersAttrib, 1);
- this->setTextureSamplerCnt(1);
- if (!viewMatrixIfUsingLocalCoords.invert(&fLocalMatrix)) {
- fLocalMatrix.setIdentity();
- }
- }
- class GrCCPathProcessor::Impl : public GrGLSLGeometryProcessor {
- public:
- void onEmitCode(EmitArgs& args, GrGPArgs* gpArgs) override;
- private:
- void setData(const GrGLSLProgramDataManager& pdman, const GrPrimitiveProcessor& primProc,
- FPCoordTransformIter&& transformIter) override {
- const auto& proc = primProc.cast<GrCCPathProcessor>();
- pdman.set2f(
- fAtlasAdjustUniform, 1.0f / proc.fAtlasSize.fWidth, 1.0f / proc.fAtlasSize.fHeight);
- this->setTransformDataHelper(proc.fLocalMatrix, pdman, &transformIter);
- }
- GrGLSLUniformHandler::UniformHandle fAtlasAdjustUniform;
- typedef GrGLSLGeometryProcessor INHERITED;
- };
- GrGLSLPrimitiveProcessor* GrCCPathProcessor::createGLSLInstance(const GrShaderCaps&) const {
- return new Impl();
- }
- void GrCCPathProcessor::drawPaths(GrOpFlushState* flushState, const GrPipeline& pipeline,
- const GrPipeline::FixedDynamicState* fixedDynamicState,
- const GrCCPerFlushResources& resources, int baseInstance,
- int endInstance, const SkRect& bounds) const {
- const GrCaps& caps = flushState->caps();
- GrPrimitiveType primitiveType = caps.usePrimitiveRestart()
- ? GrPrimitiveType::kTriangleStrip
- : GrPrimitiveType::kTriangles;
- int numIndicesPerInstance = caps.usePrimitiveRestart()
- ? SK_ARRAY_COUNT(kOctoIndicesAsStrips)
- : SK_ARRAY_COUNT(kOctoIndicesAsTris);
- GrMesh mesh(primitiveType);
- auto enablePrimitiveRestart = GrPrimitiveRestart(flushState->caps().usePrimitiveRestart());
- mesh.setIndexedInstanced(resources.refIndexBuffer(), numIndicesPerInstance,
- resources.refInstanceBuffer(), endInstance - baseInstance,
- baseInstance, enablePrimitiveRestart);
- mesh.setVertexData(resources.refVertexBuffer());
- flushState->rtCommandBuffer()->draw(*this, pipeline, fixedDynamicState, nullptr, &mesh, 1,
- bounds);
- }
- void GrCCPathProcessor::Impl::onEmitCode(EmitArgs& args, GrGPArgs* gpArgs) {
- using Interpolation = GrGLSLVaryingHandler::Interpolation;
- const GrCCPathProcessor& proc = args.fGP.cast<GrCCPathProcessor>();
- GrGLSLUniformHandler* uniHandler = args.fUniformHandler;
- GrGLSLVaryingHandler* varyingHandler = args.fVaryingHandler;
- bool isCoverageCount = (CoverageMode::kCoverageCount == proc.fCoverageMode);
- const char* atlasAdjust;
- fAtlasAdjustUniform = uniHandler->addUniform(
- kVertex_GrShaderFlag, kFloat2_GrSLType, "atlas_adjust", &atlasAdjust);
- varyingHandler->emitAttributes(proc);
- GrGLSLVarying texcoord((isCoverageCount) ? kFloat3_GrSLType : kFloat2_GrSLType);
- varyingHandler->addVarying("texcoord", &texcoord);
- GrGLSLVarying color(kHalf4_GrSLType);
- varyingHandler->addPassThroughAttribute(
- kInstanceAttribs[kColorAttribIdx], args.fOutputColor, Interpolation::kCanBeFlat);
- // The vertex shader bloats and intersects the devBounds and devBounds45 rectangles, in order to
- // find an octagon that circumscribes the (bloated) path.
- GrGLSLVertexBuilder* v = args.fVertBuilder;
- // Are we clockwise? (Positive wind => nonzero fill rule.)
- // Or counter-clockwise? (negative wind => even/odd fill rule.)
- v->codeAppendf("float wind = sign(devbounds.z - devbounds.x);");
- // Find our reference corner from the device-space bounding box.
- v->codeAppendf("float2 refpt = mix(devbounds.xy, devbounds.zw, corners.xy);");
- // Find our reference corner from the 45-degree bounding box.
- v->codeAppendf("float2 refpt45 = mix(devbounds45.xy, devbounds45.zw, corners.zw);");
- // Transform back to device space.
- v->codeAppendf("refpt45 *= float2x2(+1, +1, -wind, +wind) * .5;");
- // Find the normals to each edge, then intersect them to find our octagon vertex.
- v->codeAppendf("float2x2 N = float2x2("
- "corners.z + corners.w - 1, corners.w - corners.z, "
- "corners.xy*2 - 1);");
- v->codeAppendf("N = float2x2(wind, 0, 0, 1) * N;");
- v->codeAppendf("float2 K = float2(dot(N[0], refpt), dot(N[1], refpt45));");
- v->codeAppendf("float2 octocoord = K * inverse(N);");
- // Round the octagon out to ensure we rasterize every pixel the path might touch. (Positive
- // bloatdir means we should take the "ceil" and negative means to take the "floor".)
- //
- // NOTE: If we were just drawing a rect, ceil/floor would be enough. But since there are also
- // diagonals in the octagon that cross through pixel centers, we need to outset by another
- // quarter px to ensure those pixels get rasterized.
- v->codeAppendf("float2 bloatdir = (0 != N[0].x) "
- "? float2(N[0].x, N[1].y)"
- ": float2(N[1].x, N[0].y);");
- v->codeAppendf("octocoord = (ceil(octocoord * bloatdir - 1e-4) + 0.25) * bloatdir;");
- v->codeAppendf("float2 atlascoord = octocoord + float2(dev_to_atlas_offset);");
- // Convert to atlas coordinates in order to do our texture lookup.
- if (kTopLeft_GrSurfaceOrigin == proc.fAtlasOrigin) {
- v->codeAppendf("%s.xy = atlascoord * %s;", texcoord.vsOut(), atlasAdjust);
- } else {
- SkASSERT(kBottomLeft_GrSurfaceOrigin == proc.fAtlasOrigin);
- v->codeAppendf("%s.xy = float2(atlascoord.x * %s.x, 1 - atlascoord.y * %s.y);",
- texcoord.vsOut(), atlasAdjust, atlasAdjust);
- }
- if (isCoverageCount) {
- v->codeAppendf("%s.z = wind * .5;", texcoord.vsOut());
- }
- gpArgs->fPositionVar.set(kFloat2_GrSLType, "octocoord");
- this->emitTransforms(v, varyingHandler, uniHandler, gpArgs->fPositionVar, proc.fLocalMatrix,
- args.fFPCoordTransformHandler);
- // Fragment shader.
- GrGLSLFPFragmentBuilder* f = args.fFragBuilder;
- // Look up coverage in the atlas.
- f->codeAppendf("half coverage = ");
- f->appendTextureLookup(args.fTexSamplers[0], SkStringPrintf("%s.xy", texcoord.fsIn()).c_str(),
- kFloat2_GrSLType);
- f->codeAppendf(".a;");
- if (isCoverageCount) {
- f->codeAppendf("coverage = abs(coverage);");
- // Scale coverage count by .5. Make it negative for even-odd paths and positive for
- // winding ones. Clamp winding coverage counts at 1.0 (i.e. min(coverage/2, .5)).
- f->codeAppendf("coverage = min(abs(coverage) * half(%s.z), .5);", texcoord.fsIn());
- // For negative values, this finishes the even-odd sawtooth function. Since positive
- // (winding) values were clamped at "coverage/2 = .5", this only undoes the previous
- // multiply by .5.
- f->codeAppend ("coverage = 1 - abs(fract(coverage) * 2 - 1);");
- }
- f->codeAppendf("%s = half4(coverage);", args.fOutputCoverage);
- }
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