| /* |
| * 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/GrGSCoverageProcessor.h" |
| |
| #include "src/gpu/GrMesh.h" |
| #include "src/gpu/glsl/GrGLSLFragmentShaderBuilder.h" |
| #include "src/gpu/glsl/GrGLSLVertexGeoBuilder.h" |
| |
| using InputType = GrGLSLGeometryBuilder::InputType; |
| using OutputType = GrGLSLGeometryBuilder::OutputType; |
| |
| /** |
| * This class and its subclasses implement the coverage processor with geometry shaders. |
| */ |
| class GrGSCoverageProcessor::Impl : public GrGLSLGeometryProcessor { |
| protected: |
| Impl(std::unique_ptr<Shader> shader) : fShader(std::move(shader)) {} |
| |
| virtual bool hasCoverage(const GrGSCoverageProcessor& proc) const { return false; } |
| |
| void setData(const GrGLSLProgramDataManager& pdman, const GrPrimitiveProcessor&, |
| const CoordTransformRange& transformRange) final { |
| this->setTransformDataHelper(SkMatrix::I(), pdman, transformRange); |
| } |
| |
| void onEmitCode(EmitArgs& args, GrGPArgs* gpArgs) final { |
| const GrGSCoverageProcessor& proc = args.fGP.cast<GrGSCoverageProcessor>(); |
| |
| // The vertex shader simply forwards transposed x or y values to the geometry shader. |
| SkASSERT(1 == proc.numVertexAttributes()); |
| gpArgs->fPositionVar = proc.fInputXOrYValues.asShaderVar(); |
| |
| // Geometry shader. |
| GrGLSLVaryingHandler* varyingHandler = args.fVaryingHandler; |
| this->emitGeometryShader(proc, varyingHandler, args.fGeomBuilder, args.fRTAdjustName); |
| varyingHandler->emitAttributes(proc); |
| varyingHandler->setNoPerspective(); |
| SkASSERT(!*args.fFPCoordTransformHandler); |
| |
| // Fragment shader. |
| GrGLSLFPFragmentBuilder* f = args.fFragBuilder; |
| f->codeAppendf("half coverage;"); |
| fShader->emitFragmentCoverageCode(f, "coverage"); |
| f->codeAppendf("%s = half4(coverage);", args.fOutputColor); |
| f->codeAppendf("%s = half4(1);", args.fOutputCoverage); |
| } |
| |
| void emitGeometryShader( |
| const GrGSCoverageProcessor& proc, GrGLSLVaryingHandler* varyingHandler, |
| GrGLSLGeometryBuilder* g, const char* rtAdjust) const { |
| int numInputPoints = proc.numInputPoints(); |
| SkASSERT(3 == numInputPoints || 4 == numInputPoints); |
| |
| int inputWidth = (4 == numInputPoints || proc.hasInputWeight()) ? 4 : 3; |
| const char* posValues = (4 == inputWidth) ? "sk_Position" : "sk_Position.xyz"; |
| g->codeAppendf("float%ix2 pts = transpose(float2x%i(sk_in[0].%s, sk_in[1].%s));", |
| inputWidth, inputWidth, posValues, posValues); |
| |
| GrShaderVar wind("wind", kHalf_GrSLType); |
| g->declareGlobal(wind); |
| Shader::CalcWind(proc, g, "pts", wind.c_str()); |
| if (PrimitiveType::kWeightedTriangles == proc.primitiveType()) { |
| SkASSERT(3 == numInputPoints); |
| SkASSERT(kFloat4_GrVertexAttribType == proc.fInputXOrYValues.cpuType()); |
| g->codeAppendf("%s *= half(sk_in[0].sk_Position.w);", wind.c_str()); |
| } |
| |
| SkString emitVertexFn; |
| SkSTArray<3, GrShaderVar> emitArgs; |
| const char* corner = emitArgs.emplace_back("corner", kFloat2_GrSLType).c_str(); |
| const char* bloatdir = emitArgs.emplace_back("bloatdir", kFloat2_GrSLType).c_str(); |
| const char* inputCoverage = nullptr; |
| if (this->hasCoverage(proc)) { |
| inputCoverage = emitArgs.emplace_back("coverage", kHalf_GrSLType).c_str(); |
| } |
| const char* cornerCoverage = nullptr; |
| if (Subpass::kCorners == proc.fSubpass) { |
| cornerCoverage = emitArgs.emplace_back("corner_coverage", kHalf2_GrSLType).c_str(); |
| } |
| g->emitFunction(kVoid_GrSLType, "emitVertex", emitArgs.count(), emitArgs.begin(), [&]() { |
| SkString fnBody; |
| fnBody.appendf("float2 vertexpos = fma(%s, float2(bloat), %s);", bloatdir, corner); |
| const char* coverage = inputCoverage; |
| if (!coverage) { |
| if (!fShader->calculatesOwnEdgeCoverage()) { |
| // Flat edge opposite the curve. Coverages need full precision since distance |
| // to the opposite edge can be large. |
| fnBody.appendf("float coverage = dot(float3(vertexpos, 1), %s);", |
| fEdgeDistanceEquation.c_str()); |
| } else { |
| // The "coverage" param should hold only the signed winding value. |
| fnBody.appendf("float coverage = 1;"); |
| } |
| coverage = "coverage"; |
| } |
| fnBody.appendf("%s *= %s;", coverage, wind.c_str()); |
| if (cornerCoverage) { |
| fnBody.appendf("%s.x *= %s;", cornerCoverage, wind.c_str()); |
| } |
| fShader->emitVaryings(varyingHandler, GrGLSLVarying::Scope::kGeoToFrag, &fnBody, |
| "vertexpos", coverage, cornerCoverage, wind.c_str()); |
| g->emitVertex(&fnBody, "vertexpos", rtAdjust); |
| return fnBody; |
| }().c_str(), &emitVertexFn); |
| |
| float bloat = kAABloatRadius; |
| #ifdef SK_DEBUG |
| if (proc.debugBloatEnabled()) { |
| bloat *= proc.debugBloat(); |
| } |
| #endif |
| g->defineConstant("bloat", bloat); |
| |
| if (!this->hasCoverage(proc) && !fShader->calculatesOwnEdgeCoverage()) { |
| // Determine the amount of coverage to subtract out for the flat edge of the curve. |
| g->declareGlobal(fEdgeDistanceEquation); |
| g->codeAppendf("float2 p0 = pts[0], p1 = pts[%i];", numInputPoints - 1); |
| g->codeAppendf("float2 n = float2(p0.y - p1.y, p1.x - p0.x);"); |
| g->codeAppend ("float nwidth = bloat*2 * (abs(n.x) + abs(n.y));"); |
| // When nwidth=0, wind must also be 0 (and coverage * wind = 0). So it doesn't matter |
| // what we come up with here as long as it isn't NaN or Inf. |
| g->codeAppend ("n /= (0 != nwidth) ? nwidth : 1;"); |
| g->codeAppendf("%s = float3(-n, dot(n, p0) - .5*sign(%s));", |
| fEdgeDistanceEquation.c_str(), wind.c_str()); |
| } |
| |
| this->onEmitGeometryShader(proc, g, wind, emitVertexFn.c_str()); |
| } |
| |
| virtual void onEmitGeometryShader(const GrGSCoverageProcessor&, GrGLSLGeometryBuilder*, |
| const GrShaderVar& wind, const char* emitVertexFn) const = 0; |
| |
| const std::unique_ptr<Shader> fShader; |
| const GrShaderVar fEdgeDistanceEquation{"edge_distance_equation", kFloat3_GrSLType}; |
| |
| typedef GrGLSLGeometryProcessor INHERITED; |
| }; |
| |
| /** |
| * Generates conservative rasters around a triangle and its edges, and calculates coverage ramps. |
| * |
| * Triangle rough outlines are drawn in two steps: (1) draw a conservative raster of the entire |
| * triangle, with a coverage of +1, and (2) draw conservative rasters around each edge, with a |
| * coverage ramp from -1 to 0. These edge coverage values convert jagged conservative raster edges |
| * into smooth, antialiased ones. |
| * |
| * The final corners get touched up in a later step by TriangleCornerImpl. |
| */ |
| class GrGSCoverageProcessor::TriangleHullImpl : public GrGSCoverageProcessor::Impl { |
| public: |
| TriangleHullImpl(std::unique_ptr<Shader> shader) : Impl(std::move(shader)) {} |
| |
| bool hasCoverage(const GrGSCoverageProcessor& proc) const override { return true; } |
| |
| void onEmitGeometryShader(const GrGSCoverageProcessor&, GrGLSLGeometryBuilder* g, |
| const GrShaderVar& wind, const char* emitVertexFn) const override { |
| fShader->emitSetupCode(g, "pts"); |
| |
| // Visualize the input triangle as upright and equilateral, with a flat base. Paying special |
| // attention to wind, we can identify the points as top, bottom-left, and bottom-right. |
| // |
| // NOTE: We generate the rasters in 5 independent invocations, so each invocation designates |
| // the corner it will begin with as the top. |
| g->codeAppendf("int i = (%s > 0 ? sk_InvocationID : 4 - sk_InvocationID) %% 3;", |
| wind.c_str()); |
| g->codeAppend ("float2 top = pts[i];"); |
| g->codeAppendf("float2 right = pts[(i + (%s > 0 ? 1 : 2)) %% 3];", wind.c_str()); |
| g->codeAppendf("float2 left = pts[(i + (%s > 0 ? 2 : 1)) %% 3];", wind.c_str()); |
| |
| // Determine which direction to outset the conservative raster from each of the three edges. |
| g->codeAppend ("float2 leftbloat = sign(top - left);"); |
| g->codeAppend ("leftbloat = float2(0 != leftbloat.y ? leftbloat.y : leftbloat.x, " |
| "0 != leftbloat.x ? -leftbloat.x : -leftbloat.y);"); |
| |
| g->codeAppend ("float2 rightbloat = sign(right - top);"); |
| g->codeAppend ("rightbloat = float2(0 != rightbloat.y ? rightbloat.y : rightbloat.x, " |
| "0 != rightbloat.x ? -rightbloat.x : -rightbloat.y);"); |
| |
| g->codeAppend ("float2 downbloat = sign(left - right);"); |
| g->codeAppend ("downbloat = float2(0 != downbloat.y ? downbloat.y : downbloat.x, " |
| "0 != downbloat.x ? -downbloat.x : -downbloat.y);"); |
| |
| // The triangle's conservative raster has a coverage of +1 all around. |
| g->codeAppend ("half4 coverages = half4(+1);"); |
| |
| // Edges have coverage ramps. |
| g->codeAppend ("if (sk_InvocationID >= 2) {"); // Are we an edge? |
| Shader::CalcEdgeCoverageAtBloatVertex(g, "top", "right", |
| "float2(+rightbloat.y, -rightbloat.x)", |
| "coverages[0]"); |
| g->codeAppend ( "coverages.yzw = half3(-1, 0, -1 - coverages[0]);"); |
| // Reassign bloats to characterize a conservative raster around a single edge, rather than |
| // the entire triangle. |
| g->codeAppend ( "leftbloat = downbloat = -rightbloat;"); |
| g->codeAppend ("}"); |
| |
| // Here we generate the conservative raster geometry. The triangle's conservative raster is |
| // the convex hull of 3 pixel-size boxes centered on the input points. This translates to a |
| // convex polygon with either one, two, or three vertices at each input point (depending on |
| // how sharp the corner is) that we split between two invocations. Edge conservative rasters |
| // are convex hulls of 2 pixel-size boxes, one at each endpoint. For more details on |
| // conservative raster, see: |
| // https://developer.nvidia.com/gpugems/GPUGems2/gpugems2_chapter42.html |
| g->codeAppendf("bool2 left_right_notequal = notEqual(leftbloat, rightbloat);"); |
| g->codeAppend ("if (all(left_right_notequal)) {"); |
| // The top corner will have three conservative raster vertices. Emit the |
| // middle one first to the triangle strip. |
| g->codeAppendf( "%s(top, float2(-leftbloat.y, +leftbloat.x), coverages[0]);", |
| emitVertexFn); |
| g->codeAppend ("}"); |
| g->codeAppend ("if (any(left_right_notequal)) {"); |
| // Second conservative raster vertex for the top corner. |
| g->codeAppendf( "%s(top, rightbloat, coverages[1]);", emitVertexFn); |
| g->codeAppend ("}"); |
| |
| // Main interior body. |
| g->codeAppendf("%s(top, leftbloat, coverages[2]);", emitVertexFn); |
| g->codeAppendf("%s(right, rightbloat, coverages[1]);", emitVertexFn); |
| |
| // Here the invocations diverge slightly. We can't symmetrically divide three triangle |
| // points between two invocations, so each does the following: |
| // |
| // sk_InvocationID=0: Finishes the main interior body of the triangle hull. |
| // sk_InvocationID=1: Remaining two conservative raster vertices for the third hull corner. |
| // sk_InvocationID=2..4: Finish the opposite endpoint of their corresponding edge. |
| g->codeAppendf("bool2 right_down_notequal = notEqual(rightbloat, downbloat);"); |
| g->codeAppend ("if (any(right_down_notequal) || 0 == sk_InvocationID) {"); |
| g->codeAppendf( "%s((0 == sk_InvocationID) ? left : right, " |
| "(0 == sk_InvocationID) ? leftbloat : downbloat, " |
| "coverages[2]);", emitVertexFn); |
| g->codeAppend ("}"); |
| g->codeAppend ("if (all(right_down_notequal) && 0 != sk_InvocationID) {"); |
| g->codeAppendf( "%s(right, float2(-rightbloat.y, +rightbloat.x), coverages[3]);", |
| emitVertexFn); |
| g->codeAppend ("}"); |
| |
| // 5 invocations: 2 triangle hull invocations and 3 edges. |
| g->configure(InputType::kLines, OutputType::kTriangleStrip, 6, 5); |
| } |
| }; |
| |
| /** |
| * Generates a conservative raster around a convex quadrilateral that encloses a cubic or quadratic. |
| */ |
| class GrGSCoverageProcessor::CurveHullImpl : public GrGSCoverageProcessor::Impl { |
| public: |
| CurveHullImpl(std::unique_ptr<Shader> shader) : Impl(std::move(shader)) {} |
| |
| void onEmitGeometryShader(const GrGSCoverageProcessor&, GrGLSLGeometryBuilder* g, |
| const GrShaderVar& wind, const char* emitVertexFn) const override { |
| const char* hullPts = "pts"; |
| fShader->emitSetupCode(g, "pts", &hullPts); |
| |
| // Visualize the input (convex) quadrilateral as a square. Paying special attention to wind, |
| // we can identify the points by their corresponding corner. |
| // |
| // NOTE: We split the square down the diagonal from top-right to bottom-left, and generate |
| // the hull in two independent invocations. Each invocation designates the corner it will |
| // begin with as top-left. |
| g->codeAppend ("int i = sk_InvocationID * 2;"); |
| g->codeAppendf("float2 topleft = %s[i];", hullPts); |
| g->codeAppendf("float2 topright = %s[%s > 0 ? i + 1 : 3 - i];", hullPts, wind.c_str()); |
| g->codeAppendf("float2 bottomleft = %s[%s > 0 ? 3 - i : i + 1];", hullPts, wind.c_str()); |
| g->codeAppendf("float2 bottomright = %s[2 - i];", hullPts); |
| |
| // Determine how much to outset the conservative raster hull from the relevant edges. |
| g->codeAppend ("float2 leftbloat = float2(topleft.y > bottomleft.y ? +1 : -1, " |
| "topleft.x > bottomleft.x ? -1 : +1);"); |
| g->codeAppend ("float2 upbloat = float2(topright.y > topleft.y ? +1 : -1, " |
| "topright.x > topleft.x ? -1 : +1);"); |
| g->codeAppend ("float2 rightbloat = float2(bottomright.y > topright.y ? +1 : -1, " |
| "bottomright.x > topright.x ? -1 : +1);"); |
| |
| // Here we generate the conservative raster geometry. It is the convex hull of 4 pixel-size |
| // boxes centered on the input points, split evenly between two invocations. This translates |
| // to a polygon with either one, two, or three vertices at each input point, depending on |
| // how sharp the corner is. For more details on conservative raster, see: |
| // https://developer.nvidia.com/gpugems/GPUGems2/gpugems2_chapter42.html |
| g->codeAppendf("bool2 left_up_notequal = notEqual(leftbloat, upbloat);"); |
| g->codeAppend ("if (all(left_up_notequal)) {"); |
| // The top-left corner will have three conservative raster vertices. |
| // Emit the middle one first to the triangle strip. |
| g->codeAppendf( "%s(topleft, float2(-leftbloat.y, leftbloat.x));", emitVertexFn); |
| g->codeAppend ("}"); |
| g->codeAppend ("if (any(left_up_notequal)) {"); |
| // Second conservative raster vertex for the top-left corner. |
| g->codeAppendf( "%s(topleft, leftbloat);", emitVertexFn); |
| g->codeAppend ("}"); |
| |
| // Main interior body of this invocation's half of the hull. |
| g->codeAppendf("%s(topleft, upbloat);", emitVertexFn); |
| g->codeAppendf("%s(bottomleft, leftbloat);", emitVertexFn); |
| g->codeAppendf("%s(topright, upbloat);", emitVertexFn); |
| |
| // Remaining two conservative raster vertices for the top-right corner. |
| g->codeAppendf("bool2 up_right_notequal = notEqual(upbloat, rightbloat);"); |
| g->codeAppend ("if (any(up_right_notequal)) {"); |
| g->codeAppendf( "%s(topright, rightbloat);", emitVertexFn); |
| g->codeAppend ("}"); |
| g->codeAppend ("if (all(up_right_notequal)) {"); |
| g->codeAppendf( "%s(topright, float2(-upbloat.y, upbloat.x));", emitVertexFn); |
| g->codeAppend ("}"); |
| |
| g->configure(InputType::kLines, OutputType::kTriangleStrip, 7, 2); |
| } |
| }; |
| |
| /** |
| * Generates conservative rasters around corners (aka pixel-size boxes) and calculates |
| * coverage and attenuation ramps to fix up the coverage values written by the hulls. |
| */ |
| class GrGSCoverageProcessor::CornerImpl : public GrGSCoverageProcessor::Impl { |
| public: |
| CornerImpl(std::unique_ptr<Shader> shader) : Impl(std::move(shader)) {} |
| |
| bool hasCoverage(const GrGSCoverageProcessor& proc) const override { |
| return proc.isTriangles(); |
| } |
| |
| void onEmitGeometryShader(const GrGSCoverageProcessor& proc, GrGLSLGeometryBuilder* g, |
| const GrShaderVar& wind, const char* emitVertexFn) const override { |
| fShader->emitSetupCode(g, "pts"); |
| |
| g->codeAppendf("int corneridx = sk_InvocationID;"); |
| if (!proc.isTriangles()) { |
| g->codeAppendf("corneridx *= %i;", proc.numInputPoints() - 1); |
| } |
| |
| g->codeAppendf("float2 corner = pts[corneridx];"); |
| g->codeAppendf("float2 left = pts[(corneridx + (%s > 0 ? %i : 1)) %% %i];", |
| wind.c_str(), proc.numInputPoints() - 1, proc.numInputPoints()); |
| g->codeAppendf("float2 right = pts[(corneridx + (%s > 0 ? 1 : %i)) %% %i];", |
| wind.c_str(), proc.numInputPoints() - 1, proc.numInputPoints()); |
| |
| g->codeAppend ("float2 leftdir = corner - left;"); |
| g->codeAppend ("leftdir = (float2(0) != leftdir) ? normalize(leftdir) : float2(1, 0);"); |
| |
| g->codeAppend ("float2 rightdir = right - corner;"); |
| g->codeAppend ("rightdir = (float2(0) != rightdir) ? normalize(rightdir) : float2(1, 0);"); |
| |
| // Find "outbloat" and "crossbloat" at our corner. The outbloat points diagonally out of the |
| // triangle, in the direction that should ramp to zero coverage with attenuation. The |
| // crossbloat runs perpindicular to outbloat. |
| g->codeAppend ("float2 outbloat = float2(leftdir.x > rightdir.x ? +1 : -1, " |
| "leftdir.y > rightdir.y ? +1 : -1);"); |
| g->codeAppend ("float2 crossbloat = float2(-outbloat.y, +outbloat.x);"); |
| |
| g->codeAppend ("half attenuation; {"); |
| Shader::CalcCornerAttenuation(g, "leftdir", "rightdir", "attenuation"); |
| g->codeAppend ("}"); |
| |
| if (proc.isTriangles()) { |
| g->codeAppend ("half2 left_coverages; {"); |
| Shader::CalcEdgeCoveragesAtBloatVertices(g, "left", "corner", "-outbloat", |
| "-crossbloat", "left_coverages"); |
| g->codeAppend ("}"); |
| |
| g->codeAppend ("half2 right_coverages; {"); |
| Shader::CalcEdgeCoveragesAtBloatVertices(g, "corner", "right", "-outbloat", |
| "crossbloat", "right_coverages"); |
| g->codeAppend ("}"); |
| |
| // Emit a corner box. The first coverage argument erases the values that were written |
| // previously by the hull and edge geometry. The second pair are multiplied together by |
| // the fragment shader. They ramp to 0 with attenuation in the direction of outbloat, |
| // and linearly from left-edge coverage to right-edge coverage in the direction of |
| // crossbloat. |
| // |
| // NOTE: Since this is not a linear mapping, it is important that the box's diagonal |
| // shared edge points in the direction of outbloat. |
| g->codeAppendf("%s(corner, -crossbloat, right_coverages[1] - left_coverages[1]," |
| "half2(1 + left_coverages[1], 1));", |
| emitVertexFn); |
| |
| g->codeAppendf("%s(corner, outbloat, 1 + left_coverages[0] + right_coverages[0], " |
| "half2(0, attenuation));", |
| emitVertexFn); |
| |
| g->codeAppendf("%s(corner, -outbloat, -1 - left_coverages[0] - right_coverages[0], " |
| "half2(1 + left_coverages[0] + right_coverages[0], 1));", |
| emitVertexFn); |
| |
| g->codeAppendf("%s(corner, crossbloat, left_coverages[1] - right_coverages[1]," |
| "half2(1 + right_coverages[1], 1));", |
| emitVertexFn); |
| } else { |
| // Curves are simpler. Setting "wind = -wind" causes the Shader to erase what it had |
| // written in the previous pass hull. Then, at each vertex of the corner box, the Shader |
| // will calculate the curve's local coverage value, interpolate it alongside our |
| // attenuation parameter, and multiply the two together for a final coverage value. |
| g->codeAppendf("%s = -%s;", wind.c_str(), wind.c_str()); |
| if (!fShader->calculatesOwnEdgeCoverage()) { |
| g->codeAppendf("%s = -%s;", |
| fEdgeDistanceEquation.c_str(), fEdgeDistanceEquation.c_str()); |
| } |
| g->codeAppendf("%s(corner, -crossbloat, half2(-1, 1));", emitVertexFn); |
| g->codeAppendf("%s(corner, outbloat, half2(0, attenuation));", |
| emitVertexFn); |
| g->codeAppendf("%s(corner, -outbloat, half2(-1, 1));", emitVertexFn); |
| g->codeAppendf("%s(corner, crossbloat, half2(-1, 1));", emitVertexFn); |
| } |
| |
| g->configure(InputType::kLines, OutputType::kTriangleStrip, 4, proc.isTriangles() ? 3 : 2); |
| } |
| }; |
| |
| void GrGSCoverageProcessor::reset(PrimitiveType primitiveType, GrResourceProvider*) { |
| fPrimitiveType = primitiveType; // This will affect the return values for numInputPoints, etc. |
| |
| if (4 == this->numInputPoints() || this->hasInputWeight()) { |
| fInputXOrYValues = |
| {"x_or_y_values", kFloat4_GrVertexAttribType, kFloat4_GrSLType}; |
| static_assert(sizeof(QuadPointInstance) == |
| 2 * GrVertexAttribTypeSize(kFloat4_GrVertexAttribType)); |
| static_assert(offsetof(QuadPointInstance, fY) == |
| GrVertexAttribTypeSize(kFloat4_GrVertexAttribType)); |
| } else { |
| fInputXOrYValues = |
| {"x_or_y_values", kFloat3_GrVertexAttribType, kFloat3_GrSLType}; |
| static_assert(sizeof(TriPointInstance) == |
| 2 * GrVertexAttribTypeSize(kFloat3_GrVertexAttribType)); |
| } |
| |
| this->setVertexAttributes(&fInputXOrYValues, 1); |
| } |
| |
| void GrGSCoverageProcessor::appendMesh(sk_sp<const GrGpuBuffer> instanceBuffer, int instanceCount, |
| int baseInstance, SkTArray<GrMesh>* out) const { |
| // We don't actually make instanced draw calls. Instead, we feed transposed x,y point values to |
| // the GPU in a regular vertex array and draw kLines (see initGS). Then, each vertex invocation |
| // receives either the shape's x or y values as inputs, which it forwards to the geometry |
| // shader. |
| GrMesh& mesh = out->push_back(); |
| mesh.setNonIndexedNonInstanced(instanceCount * 2); |
| mesh.setVertexData(std::move(instanceBuffer), baseInstance * 2); |
| } |
| |
| void GrGSCoverageProcessor::draw( |
| GrOpFlushState* flushState, const GrPipeline& pipeline, const SkIRect scissorRects[], |
| const GrMesh meshes[], int meshCount, const SkRect& drawBounds) const { |
| // The geometry shader impl draws primitives in two subpasses: The first pass fills the interior |
| // and does edge AA. The second pass does touch up on corner pixels. |
| for (int i = 0; i < 2; ++i) { |
| fSubpass = (Subpass) i; |
| INHERITED::draw(flushState, pipeline, scissorRects, meshes, meshCount, drawBounds); |
| } |
| } |
| |
| GrGLSLPrimitiveProcessor* GrGSCoverageProcessor::onCreateGLSLInstance( |
| std::unique_ptr<Shader> shader) const { |
| if (Subpass::kHulls == fSubpass) { |
| return this->isTriangles() |
| ? (Impl*) new TriangleHullImpl(std::move(shader)) |
| : (Impl*) new CurveHullImpl(std::move(shader)); |
| } |
| SkASSERT(Subpass::kCorners == fSubpass); |
| return new CornerImpl(std::move(shader)); |
| } |