| /* |
| * Copyright 2019 Google LLC. |
| * |
| * Use of this source code is governed by a BSD-style license that can be |
| * found in the LICENSE file. |
| */ |
| |
| #include "src/gpu/tessellate/GrTessellatePathOp.h" |
| |
| #include "src/gpu/GrEagerVertexAllocator.h" |
| #include "src/gpu/GrGpu.h" |
| #include "src/gpu/GrOpFlushState.h" |
| #include "src/gpu/GrTriangulator.h" |
| #include "src/gpu/tessellate/GrFillPathShader.h" |
| #include "src/gpu/tessellate/GrPathParser.h" |
| #include "src/gpu/tessellate/GrStencilPathShader.h" |
| |
| GrTessellatePathOp::FixedFunctionFlags GrTessellatePathOp::fixedFunctionFlags() const { |
| auto flags = FixedFunctionFlags::kUsesStencil; |
| if (GrAAType::kNone != fAAType) { |
| flags |= FixedFunctionFlags::kUsesHWAA; |
| } |
| return flags; |
| } |
| |
| void GrTessellatePathOp::onPrePrepare(GrRecordingContext*, |
| const GrSurfaceProxyView* writeView, |
| GrAppliedClip*, |
| const GrXferProcessor::DstProxyView&) { |
| } |
| |
| void GrTessellatePathOp::onPrepare(GrOpFlushState* state) { |
| GrEagerDynamicVertexAllocator pathVertexAllocator(state, &fPathVertexBuffer, &fBasePathVertex); |
| GrEagerDynamicVertexAllocator cubicInstanceAllocator(state, &fCubicInstanceBuffer, |
| &fBaseCubicInstance); |
| |
| // First check if the path is large and/or simple enough that we can actually tessellate the |
| // inner polygon(s) on the CPU. This is our fastest approach. It allows us to stencil only the |
| // curves, and then draw the internal polygons directly to the final render target, thus filling |
| // in the majority of pixels in a single render pass. |
| SkScalar scales[2]; |
| SkAssertResult(fViewMatrix.getMinMaxScales(scales)); // Will fail if perspective. |
| const SkRect& bounds = fPath.getBounds(); |
| int numVerbs = fPath.countVerbs(); |
| if (numVerbs <= 0) { |
| return; |
| } |
| float gpuFragmentWork = bounds.height() * scales[0] * bounds.width() * scales[1]; |
| float cpuTessellationWork = (float)numVerbs * SkNextLog2(numVerbs); // N log N. |
| if (cpuTessellationWork * 500 + (256 * 256) < gpuFragmentWork) { // Don't try below 256x256. |
| bool pathIsLinear; |
| // PathToTriangles(..kSimpleInnerPolygon..) will fail if the inner polygon is not simple. |
| if ((fPathVertexCount = GrTriangulator::PathToTriangles( |
| fPath, 0, SkRect::MakeEmpty(), &pathVertexAllocator, |
| GrTriangulator::Mode::kSimpleInnerPolygons, &pathIsLinear))) { |
| if (((Flags::kStencilOnly | Flags::kWireframe) & fFlags) || |
| GrAAType::kCoverage == fAAType || |
| (state->appliedClip() && state->appliedClip()->hasStencilClip())) { |
| // If we have certain flags, mixed samples, or a stencil clip then we unfortunately |
| // can't fill the inner polygon directly. Create a stencil shader here to ensure we |
| // still stencil the entire path. |
| fStencilPathShader = state->allocator()->make<GrStencilTriangleShader>(fViewMatrix); |
| } |
| if (!(Flags::kStencilOnly & fFlags)) { |
| fFillPathShader = state->allocator()->make<GrFillTriangleShader>( |
| fViewMatrix, fColor); |
| } |
| if (!pathIsLinear) { |
| fCubicInstanceCount = GrPathParser::EmitCubicInstances( |
| fPath, &cubicInstanceAllocator); |
| SkASSERT(fCubicInstanceCount); |
| } |
| return; |
| } |
| } |
| |
| // Next see if we can split up inner polygon triangles and curves, and triangulate the inner |
| // polygon(s) more efficiently. This causes greater CPU overhead due to the extra shaders and |
| // draw calls, but the better triangulation can reduce the rasterizer load by a great deal on |
| // complex paths. |
| // NOTE: Raster-edge work is 1-dimensional, so we sum height and width instead of multiplying. |
| float rasterEdgeWork = (bounds.height() + bounds.width()) * scales[1] * fPath.countVerbs(); |
| if (rasterEdgeWork > 1000 * 1000) { |
| if ((fPathVertexCount = |
| GrPathParser::EmitInnerPolygonTriangles(fPath, &pathVertexAllocator))) { |
| fStencilPathShader = state->allocator()->make<GrStencilTriangleShader>(fViewMatrix); |
| } |
| fCubicInstanceCount = GrPathParser::EmitCubicInstances(fPath, &cubicInstanceAllocator); |
| return; |
| } |
| |
| // Fastest CPU approach: emit one cubic wedge per verb, fanning out from the center. |
| if ((fPathVertexCount = GrPathParser::EmitCenterWedgePatches(fPath, &pathVertexAllocator))) { |
| fStencilPathShader = state->allocator()->make<GrStencilWedgeShader>(fViewMatrix); |
| } |
| } |
| |
| void GrTessellatePathOp::onExecute(GrOpFlushState* state, const SkRect& chainBounds) { |
| this->drawStencilPass(state); |
| if (!(Flags::kStencilOnly & fFlags)) { |
| this->drawCoverPass(state); |
| } |
| } |
| |
| void GrTessellatePathOp::drawStencilPass(GrOpFlushState* state) { |
| // Increments clockwise triangles and decrements counterclockwise. Used for "winding" fill. |
| constexpr static GrUserStencilSettings kIncrDecrStencil( |
| GrUserStencilSettings::StaticInitSeparate< |
| 0x0000, 0x0000, |
| GrUserStencilTest::kAlwaysIfInClip, GrUserStencilTest::kAlwaysIfInClip, |
| 0xffff, 0xffff, |
| GrUserStencilOp::kIncWrap, GrUserStencilOp::kDecWrap, |
| GrUserStencilOp::kKeep, GrUserStencilOp::kKeep, |
| 0xffff, 0xffff>()); |
| |
| // Inverts the bottom stencil bit. Used for "even/odd" fill. |
| constexpr static GrUserStencilSettings kInvertStencil( |
| GrUserStencilSettings::StaticInit< |
| 0x0000, |
| GrUserStencilTest::kAlwaysIfInClip, |
| 0xffff, |
| GrUserStencilOp::kInvert, |
| GrUserStencilOp::kKeep, |
| 0x0001>()); |
| |
| GrPipeline::InitArgs initArgs; |
| if (GrAAType::kNone != fAAType) { |
| initArgs.fInputFlags |= GrPipeline::InputFlags::kHWAntialias; |
| } |
| if (state->caps().wireframeSupport() && (Flags::kWireframe & fFlags)) { |
| initArgs.fInputFlags |= GrPipeline::InputFlags::kWireframe; |
| } |
| SkASSERT(SkPathFillType::kWinding == fPath.getFillType() || |
| SkPathFillType::kEvenOdd == fPath.getFillType()); |
| initArgs.fUserStencil = (SkPathFillType::kWinding == fPath.getFillType()) ? |
| &kIncrDecrStencil : &kInvertStencil; |
| initArgs.fCaps = &state->caps(); |
| GrPipeline pipeline(initArgs, GrDisableColorXPFactory::MakeXferProcessor(), |
| state->appliedHardClip()); |
| |
| if (fStencilPathShader) { |
| SkASSERT(fPathVertexBuffer); |
| GrPathShader::ProgramInfo programInfo(state->writeView(), &pipeline, fStencilPathShader); |
| state->bindPipelineAndScissorClip(programInfo, this->bounds()); |
| state->bindBuffers(nullptr, nullptr, fPathVertexBuffer.get()); |
| state->draw(fPathVertexCount, fBasePathVertex); |
| } |
| |
| if (fCubicInstanceBuffer) { |
| // Here we treat the cubic instance buffer as tessellation patches to stencil the curves. |
| GrStencilCubicShader shader(fViewMatrix); |
| GrPathShader::ProgramInfo programInfo(state->writeView(), &pipeline, &shader); |
| state->bindPipelineAndScissorClip(programInfo, this->bounds()); |
| // Bind instancedBuff as vertex. |
| state->bindBuffers(nullptr, nullptr, fCubicInstanceBuffer.get()); |
| state->draw(fCubicInstanceCount * 4, fBaseCubicInstance * 4); |
| } |
| |
| // http://skbug.com/9739 |
| if (state->caps().requiresManualFBBarrierAfterTessellatedStencilDraw()) { |
| state->gpu()->insertManualFramebufferBarrier(); |
| } |
| } |
| |
| void GrTessellatePathOp::drawCoverPass(GrOpFlushState* state) { |
| // Allows non-zero stencil values to pass and write a color, and resets the stencil value back |
| // to zero; discards immediately on stencil values of zero. |
| // NOTE: It's ok to not check the clip here because the previous stencil pass only wrote to |
| // samples already inside the clip. |
| constexpr static GrUserStencilSettings kTestAndResetStencil( |
| GrUserStencilSettings::StaticInit< |
| 0x0000, |
| GrUserStencilTest::kNotEqual, |
| 0xffff, |
| GrUserStencilOp::kZero, |
| GrUserStencilOp::kKeep, |
| 0xffff>()); |
| |
| GrPipeline::InitArgs initArgs; |
| if (GrAAType::kNone != fAAType) { |
| initArgs.fInputFlags |= GrPipeline::InputFlags::kHWAntialias; |
| if (1 == state->proxy()->numSamples()) { |
| SkASSERT(GrAAType::kCoverage == fAAType); |
| // We are mixed sampled. Use conservative raster to make the sample coverage mask 100% |
| // at every fragment. This way we will still get a double hit on shared edges, but |
| // whichever side comes first will cover every sample and will clear the stencil. The |
| // other side will then be discarded and not cause a double blend. |
| initArgs.fInputFlags |= GrPipeline::InputFlags::kConservativeRaster; |
| } |
| } |
| initArgs.fCaps = &state->caps(); |
| initArgs.fDstProxyView = state->drawOpArgs().dstProxyView(); |
| initArgs.fWriteSwizzle = state->drawOpArgs().writeSwizzle(); |
| GrPipeline pipeline(initArgs, std::move(fProcessors), state->detachAppliedClip()); |
| |
| if (fFillPathShader) { |
| SkASSERT(fPathVertexBuffer); |
| |
| // These are a twist on the standard red book stencil settings that allow us to draw the |
| // inner polygon directly to the final render target. At this point, the curves are already |
| // stencilled in. So if the stencil value is zero, then it means the path at our sample is |
| // not affected by any curves and we fill the path in directly. If the stencil value is |
| // nonzero, then we don't fill and instead continue the standard red book stencil process. |
| // |
| // NOTE: These settings are currently incompatible with a stencil clip. |
| constexpr static GrUserStencilSettings kFillOrIncrDecrStencil( |
| GrUserStencilSettings::StaticInitSeparate< |
| 0x0000, 0x0000, |
| GrUserStencilTest::kEqual, GrUserStencilTest::kEqual, |
| 0xffff, 0xffff, |
| GrUserStencilOp::kKeep, GrUserStencilOp::kKeep, |
| GrUserStencilOp::kIncWrap, GrUserStencilOp::kDecWrap, |
| 0xffff, 0xffff>()); |
| |
| constexpr static GrUserStencilSettings kFillOrInvertStencil( |
| GrUserStencilSettings::StaticInit< |
| 0x0000, |
| GrUserStencilTest::kEqual, |
| 0xffff, |
| GrUserStencilOp::kKeep, |
| GrUserStencilOp::kZero, |
| 0xffff>()); |
| |
| if (fStencilPathShader) { |
| // The path was already stencilled. Here we just need to do a cover pass. |
| pipeline.setUserStencil(&kTestAndResetStencil); |
| } else if (!fCubicInstanceBuffer) { |
| // There are no curves, so we can just ignore stencil and fill the path directly. |
| pipeline.setUserStencil(&GrUserStencilSettings::kUnused); |
| } else if (SkPathFillType::kWinding == fPath.getFillType()) { |
| // Fill in the path pixels not touched by curves, incr/decr stencil otherwise. |
| SkASSERT(!pipeline.hasStencilClip()); |
| pipeline.setUserStencil(&kFillOrIncrDecrStencil); |
| } else { |
| // Fill in the path pixels not touched by curves, invert stencil otherwise. |
| SkASSERT(!pipeline.hasStencilClip()); |
| pipeline.setUserStencil(&kFillOrInvertStencil); |
| } |
| GrPathShader::ProgramInfo programInfo(state->writeView(), &pipeline, fFillPathShader); |
| state->bindPipelineAndScissorClip(programInfo, this->bounds()); |
| state->bindTextures(*fFillPathShader, nullptr, pipeline); |
| state->bindBuffers(nullptr, nullptr, fPathVertexBuffer.get()); |
| state->draw(fPathVertexCount, fBasePathVertex); |
| |
| if (fCubicInstanceBuffer) { |
| // At this point, every pixel is filled in except the ones touched by curves. Issue a |
| // final cover pass over the curves by drawing their convex hulls. This will fill in any |
| // remaining samples and reset the stencil buffer. |
| pipeline.setUserStencil(&kTestAndResetStencil); |
| GrFillCubicHullShader shader(fViewMatrix, fColor); |
| GrPathShader::ProgramInfo programInfo(state->writeView(), &pipeline, &shader); |
| state->bindPipelineAndScissorClip(programInfo, this->bounds()); |
| state->bindTextures(shader, nullptr, pipeline); |
| state->bindBuffers(nullptr, fCubicInstanceBuffer.get(), nullptr); |
| state->drawInstanced(fCubicInstanceCount, fBaseCubicInstance, 4, 0); |
| } |
| } else { |
| // There is not a fill shader for the path. Just draw a bounding box. |
| pipeline.setUserStencil(&kTestAndResetStencil); |
| GrFillBoundingBoxShader shader(fViewMatrix, fColor, fPath.getBounds()); |
| GrPathShader::ProgramInfo programInfo(state->writeView(), &pipeline, &shader); |
| state->bindPipelineAndScissorClip(programInfo, this->bounds()); |
| state->bindTextures(shader, nullptr, pipeline); |
| state->bindBuffers(nullptr, nullptr, nullptr); |
| state->draw(4, 0); |
| } |
| } |