Consolidate stroke-rect ops and use GrFillRectOp instead of GrNonAA/AARectOp
Bug: skia:
Change-Id: Iee57bc970a026de2ad5a0758153e9cbb20753fa1
Reviewed-on: https://skia-review.googlesource.com/c/173105
Commit-Queue: Michael Ludwig <michaelludwig@google.com>
Reviewed-by: Brian Salomon <bsalomon@google.com>
diff --git a/src/gpu/ops/GrStrokeRectOp.cpp b/src/gpu/ops/GrStrokeRectOp.cpp
new file mode 100644
index 0000000..98b3b67
--- /dev/null
+++ b/src/gpu/ops/GrStrokeRectOp.cpp
@@ -0,0 +1,804 @@
+/*
+ * Copyright 2018 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#include "GrStrokeRectOp.h"
+
+#include "GrColor.h"
+#include "GrDefaultGeoProcFactory.h"
+#include "GrDrawOpTest.h"
+#include "GrMeshDrawOp.h"
+#include "GrOpFlushState.h"
+#include "GrResourceKey.h"
+#include "GrResourceProvider.h"
+#include "GrSimpleMeshDrawOpHelper.h"
+#include "GrVertexWriter.h"
+#include "ops/GrFillRectOp.h"
+#include "SkRandom.h"
+#include "SkStrokeRec.h"
+
+namespace {
+
+// We support all hairlines, bevels, and miters, but not round joins. Also, check whether the miter
+// limit makes a miter join effectively beveled. If the miter is effectively beveled, it is only
+// supported when using an AA stroke.
+inline static bool allowed_stroke(const SkStrokeRec& stroke, GrAA aa, bool* isMiter) {
+ SkASSERT(stroke.getStyle() == SkStrokeRec::kStroke_Style ||
+ stroke.getStyle() == SkStrokeRec::kHairline_Style);
+ // For hairlines, make bevel and round joins appear the same as mitered ones.
+ if (!stroke.getWidth()) {
+ *isMiter = true;
+ return true;
+ }
+ if (stroke.getJoin() == SkPaint::kBevel_Join) {
+ *isMiter = false;
+ return aa == GrAA::kYes; // bevel only supported with AA
+ }
+ if (stroke.getJoin() == SkPaint::kMiter_Join) {
+ *isMiter = stroke.getMiter() >= SK_ScalarSqrt2;
+ // Supported under non-AA only if it remains mitered
+ return aa == GrAA::kYes || *isMiter;
+ }
+ return false;
+}
+
+
+///////////////////////////////////////////////////////////////////////////////////////////////////
+// Non-AA Stroking
+///////////////////////////////////////////////////////////////////////////////////////////////////
+
+/* create a triangle strip that strokes the specified rect. There are 8
+ unique vertices, but we repeat the last 2 to close up. Alternatively we
+ could use an indices array, and then only send 8 verts, but not sure that
+ would be faster.
+ */
+static void init_nonaa_stroke_rect_strip(SkPoint verts[10], const SkRect& rect, SkScalar width) {
+ const SkScalar rad = SkScalarHalf(width);
+
+ verts[0].set(rect.fLeft + rad, rect.fTop + rad);
+ verts[1].set(rect.fLeft - rad, rect.fTop - rad);
+ verts[2].set(rect.fRight - rad, rect.fTop + rad);
+ verts[3].set(rect.fRight + rad, rect.fTop - rad);
+ verts[4].set(rect.fRight - rad, rect.fBottom - rad);
+ verts[5].set(rect.fRight + rad, rect.fBottom + rad);
+ verts[6].set(rect.fLeft + rad, rect.fBottom - rad);
+ verts[7].set(rect.fLeft - rad, rect.fBottom + rad);
+ verts[8] = verts[0];
+ verts[9] = verts[1];
+
+ // TODO: we should be catching this higher up the call stack and just draw a single
+ // non-AA rect
+ if (2*rad >= rect.width()) {
+ verts[0].fX = verts[2].fX = verts[4].fX = verts[6].fX = verts[8].fX = rect.centerX();
+ }
+ if (2*rad >= rect.height()) {
+ verts[0].fY = verts[2].fY = verts[4].fY = verts[6].fY = verts[8].fY = rect.centerY();
+ }
+}
+
+class NonAAStrokeRectOp final : public GrMeshDrawOp {
+private:
+ using Helper = GrSimpleMeshDrawOpHelper;
+
+public:
+ DEFINE_OP_CLASS_ID
+
+ const char* name() const override { return "NonAAStrokeRectOp"; }
+
+ void visitProxies(const VisitProxyFunc& func, VisitorType) const override {
+ fHelper.visitProxies(func);
+ }
+
+#ifdef SK_DEBUG
+ SkString dumpInfo() const override {
+ SkString string;
+ string.appendf(
+ "Color: 0x%08x, Rect [L: %.2f, T: %.2f, R: %.2f, B: %.2f], "
+ "StrokeWidth: %.2f\n",
+ fColor.toBytes_RGBA(), fRect.fLeft, fRect.fTop, fRect.fRight, fRect.fBottom,
+ fStrokeWidth);
+ string += fHelper.dumpInfo();
+ string += INHERITED::dumpInfo();
+ return string;
+ }
+#endif
+
+ static std::unique_ptr<GrDrawOp> Make(GrContext* context,
+ GrPaint&& paint,
+ const SkMatrix& viewMatrix,
+ const SkRect& rect,
+ const SkStrokeRec& stroke,
+ GrAAType aaType) {
+ bool isMiter;
+ if (!allowed_stroke(stroke, GrAA::kNo, &isMiter)) {
+ return nullptr;
+ }
+ Helper::Flags flags = Helper::Flags::kNone;
+ // Depending on sub-pixel coordinates and the particular GPU, we may lose a corner of
+ // hairline rects. We jam all the vertices to pixel centers to avoid this, but not
+ // when MSAA is enabled because it can cause ugly artifacts.
+ if (stroke.getStyle() == SkStrokeRec::kHairline_Style && aaType != GrAAType::kMSAA) {
+ flags |= Helper::Flags::kSnapVerticesToPixelCenters;
+ }
+ return Helper::FactoryHelper<NonAAStrokeRectOp>(context, std::move(paint), flags,
+ viewMatrix, rect,
+ stroke, aaType);
+ }
+
+ NonAAStrokeRectOp(const Helper::MakeArgs& helperArgs, const SkPMColor4f& color,
+ Helper::Flags flags, const SkMatrix& viewMatrix, const SkRect& rect,
+ const SkStrokeRec& stroke, GrAAType aaType)
+ : INHERITED(ClassID()), fHelper(helperArgs, aaType, flags) {
+ fColor = color;
+ fViewMatrix = viewMatrix;
+ fRect = rect;
+ // Sort the rect for hairlines
+ fRect.sort();
+ fStrokeWidth = stroke.getWidth();
+
+ SkScalar rad = SkScalarHalf(fStrokeWidth);
+ SkRect bounds = rect;
+ bounds.outset(rad, rad);
+
+ // If our caller snaps to pixel centers then we have to round out the bounds
+ if (flags & Helper::Flags::kSnapVerticesToPixelCenters) {
+ viewMatrix.mapRect(&bounds);
+ // We want to be consistent with how we snap non-aa lines. To match what we do in
+ // GrGLSLVertexShaderBuilder, we first floor all the vertex values and then add half a
+ // pixel to force us to pixel centers.
+ bounds.set(SkScalarFloorToScalar(bounds.fLeft),
+ SkScalarFloorToScalar(bounds.fTop),
+ SkScalarFloorToScalar(bounds.fRight),
+ SkScalarFloorToScalar(bounds.fBottom));
+ bounds.offset(0.5f, 0.5f);
+ this->setBounds(bounds, HasAABloat::kNo, IsZeroArea::kNo);
+ } else {
+ this->setTransformedBounds(bounds, fViewMatrix, HasAABloat::kNo, IsZeroArea::kNo);
+ }
+ }
+
+ FixedFunctionFlags fixedFunctionFlags() const override { return fHelper.fixedFunctionFlags(); }
+
+ RequiresDstTexture finalize(const GrCaps& caps, const GrAppliedClip* clip) override {
+ return fHelper.xpRequiresDstTexture(caps, clip, GrProcessorAnalysisCoverage::kNone,
+ &fColor);
+ }
+
+private:
+ void onPrepareDraws(Target* target) override {
+ sk_sp<GrGeometryProcessor> gp;
+ {
+ using namespace GrDefaultGeoProcFactory;
+ Color color(fColor);
+ LocalCoords::Type localCoordsType = fHelper.usesLocalCoords()
+ ? LocalCoords::kUsePosition_Type
+ : LocalCoords::kUnused_Type;
+ gp = GrDefaultGeoProcFactory::Make(target->caps().shaderCaps(), color,
+ Coverage::kSolid_Type, localCoordsType,
+ fViewMatrix);
+ }
+
+ size_t kVertexStride = gp->vertexStride();
+ int vertexCount = kVertsPerHairlineRect;
+ if (fStrokeWidth > 0) {
+ vertexCount = kVertsPerStrokeRect;
+ }
+
+ const GrBuffer* vertexBuffer;
+ int firstVertex;
+
+ void* verts =
+ target->makeVertexSpace(kVertexStride, vertexCount, &vertexBuffer, &firstVertex);
+
+ if (!verts) {
+ SkDebugf("Could not allocate vertices\n");
+ return;
+ }
+
+ SkPoint* vertex = reinterpret_cast<SkPoint*>(verts);
+
+ GrPrimitiveType primType;
+ if (fStrokeWidth > 0) {
+ primType = GrPrimitiveType::kTriangleStrip;
+ init_nonaa_stroke_rect_strip(vertex, fRect, fStrokeWidth);
+ } else {
+ // hairline
+ primType = GrPrimitiveType::kLineStrip;
+ vertex[0].set(fRect.fLeft, fRect.fTop);
+ vertex[1].set(fRect.fRight, fRect.fTop);
+ vertex[2].set(fRect.fRight, fRect.fBottom);
+ vertex[3].set(fRect.fLeft, fRect.fBottom);
+ vertex[4].set(fRect.fLeft, fRect.fTop);
+ }
+
+ GrMesh* mesh = target->allocMesh(primType);
+ mesh->setNonIndexedNonInstanced(vertexCount);
+ mesh->setVertexData(vertexBuffer, firstVertex);
+ auto pipe = fHelper.makePipeline(target);
+ target->draw(std::move(gp), pipe.fPipeline, pipe.fFixedDynamicState, mesh);
+ }
+
+ // TODO: override onCombineIfPossible
+
+ Helper fHelper;
+ SkPMColor4f fColor;
+ SkMatrix fViewMatrix;
+ SkRect fRect;
+ SkScalar fStrokeWidth;
+
+ const static int kVertsPerHairlineRect = 5;
+ const static int kVertsPerStrokeRect = 10;
+
+ typedef GrMeshDrawOp INHERITED;
+};
+
+///////////////////////////////////////////////////////////////////////////////////////////////////
+// AA Stroking
+///////////////////////////////////////////////////////////////////////////////////////////////////
+
+GR_DECLARE_STATIC_UNIQUE_KEY(gMiterIndexBufferKey);
+GR_DECLARE_STATIC_UNIQUE_KEY(gBevelIndexBufferKey);
+
+static void compute_aa_rects(SkRect* devOutside, SkRect* devOutsideAssist, SkRect* devInside,
+ bool* isDegenerate, const SkMatrix& viewMatrix, const SkRect& rect,
+ SkScalar strokeWidth, bool miterStroke) {
+ SkRect devRect;
+ viewMatrix.mapRect(&devRect, rect);
+
+ SkVector devStrokeSize;
+ if (strokeWidth > 0) {
+ devStrokeSize.set(strokeWidth, strokeWidth);
+ viewMatrix.mapVectors(&devStrokeSize, 1);
+ devStrokeSize.setAbs(devStrokeSize);
+ } else {
+ devStrokeSize.set(SK_Scalar1, SK_Scalar1);
+ }
+
+ const SkScalar dx = devStrokeSize.fX;
+ const SkScalar dy = devStrokeSize.fY;
+ const SkScalar rx = SkScalarHalf(dx);
+ const SkScalar ry = SkScalarHalf(dy);
+
+ *devOutside = devRect;
+ *devOutsideAssist = devRect;
+ *devInside = devRect;
+
+ devOutside->outset(rx, ry);
+ devInside->inset(rx, ry);
+
+ // If we have a degenerate stroking rect(ie the stroke is larger than inner rect) then we
+ // make a degenerate inside rect to avoid double hitting. We will also jam all of the points
+ // together when we render these rects.
+ SkScalar spare;
+ {
+ SkScalar w = devRect.width() - dx;
+ SkScalar h = devRect.height() - dy;
+ spare = SkTMin(w, h);
+ }
+
+ *isDegenerate = spare <= 0;
+ if (*isDegenerate) {
+ devInside->fLeft = devInside->fRight = devRect.centerX();
+ devInside->fTop = devInside->fBottom = devRect.centerY();
+ }
+
+ // For bevel-stroke, use 2 SkRect instances(devOutside and devOutsideAssist)
+ // to draw the outside of the octagon. Because there are 8 vertices on the outer
+ // edge, while vertex number of inner edge is 4, the same as miter-stroke.
+ if (!miterStroke) {
+ devOutside->inset(0, ry);
+ devOutsideAssist->outset(0, ry);
+ }
+}
+
+static sk_sp<GrGeometryProcessor> create_aa_stroke_rect_gp(const GrShaderCaps* shaderCaps,
+ bool tweakAlphaForCoverage,
+ const SkMatrix& viewMatrix,
+ bool usesLocalCoords) {
+ using namespace GrDefaultGeoProcFactory;
+
+ Coverage::Type coverageType;
+ if (tweakAlphaForCoverage) {
+ coverageType = Coverage::kSolid_Type;
+ } else {
+ coverageType = Coverage::kAttribute_Type;
+ }
+ LocalCoords::Type localCoordsType =
+ usesLocalCoords ? LocalCoords::kUsePosition_Type : LocalCoords::kUnused_Type;
+ return MakeForDeviceSpace(shaderCaps,
+ Color::kPremulGrColorAttribute_Type,
+ coverageType,
+ localCoordsType,
+ viewMatrix);
+}
+
+class AAStrokeRectOp final : public GrMeshDrawOp {
+private:
+ using Helper = GrSimpleMeshDrawOpHelper;
+
+public:
+ DEFINE_OP_CLASS_ID
+
+ static std::unique_ptr<GrDrawOp> Make(GrContext* context,
+ GrPaint&& paint,
+ const SkMatrix& viewMatrix,
+ const SkRect& devOutside,
+ const SkRect& devInside) {
+ return Helper::FactoryHelper<AAStrokeRectOp>(context, std::move(paint), viewMatrix,
+ devOutside, devInside);
+ }
+
+ AAStrokeRectOp(const Helper::MakeArgs& helperArgs, const SkPMColor4f& color,
+ const SkMatrix& viewMatrix, const SkRect& devOutside, const SkRect& devInside)
+ : INHERITED(ClassID())
+ , fHelper(helperArgs, GrAAType::kCoverage)
+ , fViewMatrix(viewMatrix) {
+ SkASSERT(!devOutside.isEmpty());
+ SkASSERT(!devInside.isEmpty());
+
+ fRects.emplace_back(RectInfo{color, devOutside, devOutside, devInside, false});
+ this->setBounds(devOutside, HasAABloat::kYes, IsZeroArea::kNo);
+ fMiterStroke = true;
+ }
+
+ static std::unique_ptr<GrDrawOp> Make(GrContext* context,
+ GrPaint&& paint,
+ const SkMatrix& viewMatrix,
+ const SkRect& rect,
+ const SkStrokeRec& stroke) {
+ bool isMiter;
+ if (!allowed_stroke(stroke, GrAA::kYes, &isMiter)) {
+ return nullptr;
+ }
+ return Helper::FactoryHelper<AAStrokeRectOp>(context, std::move(paint), viewMatrix, rect,
+ stroke, isMiter);
+ }
+
+ AAStrokeRectOp(const Helper::MakeArgs& helperArgs, const SkPMColor4f& color,
+ const SkMatrix& viewMatrix, const SkRect& rect, const SkStrokeRec& stroke,
+ bool isMiter)
+ : INHERITED(ClassID())
+ , fHelper(helperArgs, GrAAType::kCoverage)
+ , fViewMatrix(viewMatrix) {
+ fMiterStroke = isMiter;
+ RectInfo& info = fRects.push_back();
+ compute_aa_rects(&info.fDevOutside, &info.fDevOutsideAssist, &info.fDevInside,
+ &info.fDegenerate, viewMatrix, rect, stroke.getWidth(), isMiter);
+ info.fColor = color;
+ if (isMiter) {
+ this->setBounds(info.fDevOutside, HasAABloat::kYes, IsZeroArea::kNo);
+ } else {
+ // The outer polygon of the bevel stroke is an octagon specified by the points of a
+ // pair of overlapping rectangles where one is wide and the other is narrow.
+ SkRect bounds = info.fDevOutside;
+ bounds.joinPossiblyEmptyRect(info.fDevOutsideAssist);
+ this->setBounds(bounds, HasAABloat::kYes, IsZeroArea::kNo);
+ }
+ }
+
+ const char* name() const override { return "AAStrokeRect"; }
+
+ void visitProxies(const VisitProxyFunc& func, VisitorType) const override {
+ fHelper.visitProxies(func);
+ }
+
+#ifdef SK_DEBUG
+ SkString dumpInfo() const override {
+ SkString string;
+ for (const auto& info : fRects) {
+ string.appendf(
+ "Color: 0x%08x, ORect [L: %.2f, T: %.2f, R: %.2f, B: %.2f], "
+ "AssistORect [L: %.2f, T: %.2f, R: %.2f, B: %.2f], "
+ "IRect [L: %.2f, T: %.2f, R: %.2f, B: %.2f], Degen: %d",
+ info.fColor.toBytes_RGBA(), info.fDevOutside.fLeft, info.fDevOutside.fTop,
+ info.fDevOutside.fRight, info.fDevOutside.fBottom, info.fDevOutsideAssist.fLeft,
+ info.fDevOutsideAssist.fTop, info.fDevOutsideAssist.fRight,
+ info.fDevOutsideAssist.fBottom, info.fDevInside.fLeft, info.fDevInside.fTop,
+ info.fDevInside.fRight, info.fDevInside.fBottom, info.fDegenerate);
+ }
+ string += fHelper.dumpInfo();
+ string += INHERITED::dumpInfo();
+ return string;
+ }
+#endif
+
+ FixedFunctionFlags fixedFunctionFlags() const override { return fHelper.fixedFunctionFlags(); }
+
+ RequiresDstTexture finalize(const GrCaps& caps, const GrAppliedClip* clip) override {
+ return fHelper.xpRequiresDstTexture(caps, clip, GrProcessorAnalysisCoverage::kSingleChannel,
+ &fRects.back().fColor);
+ }
+
+private:
+ void onPrepareDraws(Target*) override;
+
+ static const int kMiterIndexCnt = 3 * 24;
+ static const int kMiterVertexCnt = 16;
+ static const int kNumMiterRectsInIndexBuffer = 256;
+
+ static const int kBevelIndexCnt = 48 + 36 + 24;
+ static const int kBevelVertexCnt = 24;
+ static const int kNumBevelRectsInIndexBuffer = 256;
+
+ static sk_sp<const GrBuffer> GetIndexBuffer(GrResourceProvider*, bool miterStroke);
+
+ const SkMatrix& viewMatrix() const { return fViewMatrix; }
+ bool miterStroke() const { return fMiterStroke; }
+
+ CombineResult onCombineIfPossible(GrOp* t, const GrCaps&) override;
+
+ void generateAAStrokeRectGeometry(GrVertexWriter& vertices,
+ GrColor color,
+ const SkRect& devOutside,
+ const SkRect& devOutsideAssist,
+ const SkRect& devInside,
+ bool miterStroke,
+ bool degenerate,
+ bool tweakAlphaForCoverage) const;
+
+ // TODO support AA rotated stroke rects by copying around view matrices
+ struct RectInfo {
+ SkPMColor4f fColor;
+ SkRect fDevOutside;
+ SkRect fDevOutsideAssist;
+ SkRect fDevInside;
+ bool fDegenerate;
+ };
+
+ Helper fHelper;
+ SkSTArray<1, RectInfo, true> fRects;
+ SkMatrix fViewMatrix;
+ bool fMiterStroke;
+
+ typedef GrMeshDrawOp INHERITED;
+};
+
+void AAStrokeRectOp::onPrepareDraws(Target* target) {
+ sk_sp<GrGeometryProcessor> gp(create_aa_stroke_rect_gp(target->caps().shaderCaps(),
+ fHelper.compatibleWithAlphaAsCoverage(),
+ this->viewMatrix(),
+ fHelper.usesLocalCoords()));
+ if (!gp) {
+ SkDebugf("Couldn't create GrGeometryProcessor\n");
+ return;
+ }
+
+ int innerVertexNum = 4;
+ int outerVertexNum = this->miterStroke() ? 4 : 8;
+ int verticesPerInstance = (outerVertexNum + innerVertexNum) * 2;
+ int indicesPerInstance = this->miterStroke() ? kMiterIndexCnt : kBevelIndexCnt;
+ int instanceCount = fRects.count();
+
+ sk_sp<const GrBuffer> indexBuffer =
+ GetIndexBuffer(target->resourceProvider(), this->miterStroke());
+ PatternHelper helper(target, GrPrimitiveType::kTriangles, gp->vertexStride(), indexBuffer.get(),
+ verticesPerInstance, indicesPerInstance, instanceCount);
+ GrVertexWriter vertices{ helper.vertices() };
+ if (!vertices.fPtr || !indexBuffer) {
+ SkDebugf("Could not allocate vertices\n");
+ return;
+ }
+
+ for (int i = 0; i < instanceCount; i++) {
+ const RectInfo& info = fRects[i];
+ this->generateAAStrokeRectGeometry(vertices,
+ info.fColor.toBytes_RGBA(), // TODO4F
+ info.fDevOutside,
+ info.fDevOutsideAssist,
+ info.fDevInside,
+ fMiterStroke,
+ info.fDegenerate,
+ fHelper.compatibleWithAlphaAsCoverage());
+ }
+ auto pipe = fHelper.makePipeline(target);
+ helper.recordDraw(target, std::move(gp), pipe.fPipeline, pipe.fFixedDynamicState);
+}
+
+sk_sp<const GrBuffer> AAStrokeRectOp::GetIndexBuffer(GrResourceProvider* resourceProvider,
+ bool miterStroke) {
+ if (miterStroke) {
+ // clang-format off
+ static const uint16_t gMiterIndices[] = {
+ 0 + 0, 1 + 0, 5 + 0, 5 + 0, 4 + 0, 0 + 0,
+ 1 + 0, 2 + 0, 6 + 0, 6 + 0, 5 + 0, 1 + 0,
+ 2 + 0, 3 + 0, 7 + 0, 7 + 0, 6 + 0, 2 + 0,
+ 3 + 0, 0 + 0, 4 + 0, 4 + 0, 7 + 0, 3 + 0,
+
+ 0 + 4, 1 + 4, 5 + 4, 5 + 4, 4 + 4, 0 + 4,
+ 1 + 4, 2 + 4, 6 + 4, 6 + 4, 5 + 4, 1 + 4,
+ 2 + 4, 3 + 4, 7 + 4, 7 + 4, 6 + 4, 2 + 4,
+ 3 + 4, 0 + 4, 4 + 4, 4 + 4, 7 + 4, 3 + 4,
+
+ 0 + 8, 1 + 8, 5 + 8, 5 + 8, 4 + 8, 0 + 8,
+ 1 + 8, 2 + 8, 6 + 8, 6 + 8, 5 + 8, 1 + 8,
+ 2 + 8, 3 + 8, 7 + 8, 7 + 8, 6 + 8, 2 + 8,
+ 3 + 8, 0 + 8, 4 + 8, 4 + 8, 7 + 8, 3 + 8,
+ };
+ // clang-format on
+ GR_STATIC_ASSERT(SK_ARRAY_COUNT(gMiterIndices) == kMiterIndexCnt);
+ GR_DEFINE_STATIC_UNIQUE_KEY(gMiterIndexBufferKey);
+ return resourceProvider->findOrCreatePatternedIndexBuffer(
+ gMiterIndices, kMiterIndexCnt, kNumMiterRectsInIndexBuffer, kMiterVertexCnt,
+ gMiterIndexBufferKey);
+ } else {
+ /**
+ * As in miter-stroke, index = a + b, and a is the current index, b is the shift
+ * from the first index. The index layout:
+ * outer AA line: 0~3, 4~7
+ * outer edge: 8~11, 12~15
+ * inner edge: 16~19
+ * inner AA line: 20~23
+ * Following comes a bevel-stroke rect and its indices:
+ *
+ * 4 7
+ * *********************************
+ * * ______________________________ *
+ * * / 12 15 \ *
+ * * / \ *
+ * 0 * |8 16_____________________19 11 | * 3
+ * * | | | | *
+ * * | | **************** | | *
+ * * | | * 20 23 * | | *
+ * * | | * * | | *
+ * * | | * 21 22 * | | *
+ * * | | **************** | | *
+ * * | |____________________| | *
+ * 1 * |9 17 18 10| * 2
+ * * \ / *
+ * * \13 __________________________14/ *
+ * * *
+ * **********************************
+ * 5 6
+ */
+ // clang-format off
+ static const uint16_t gBevelIndices[] = {
+ // Draw outer AA, from outer AA line to outer edge, shift is 0.
+ 0 + 0, 1 + 0, 9 + 0, 9 + 0, 8 + 0, 0 + 0,
+ 1 + 0, 5 + 0, 13 + 0, 13 + 0, 9 + 0, 1 + 0,
+ 5 + 0, 6 + 0, 14 + 0, 14 + 0, 13 + 0, 5 + 0,
+ 6 + 0, 2 + 0, 10 + 0, 10 + 0, 14 + 0, 6 + 0,
+ 2 + 0, 3 + 0, 11 + 0, 11 + 0, 10 + 0, 2 + 0,
+ 3 + 0, 7 + 0, 15 + 0, 15 + 0, 11 + 0, 3 + 0,
+ 7 + 0, 4 + 0, 12 + 0, 12 + 0, 15 + 0, 7 + 0,
+ 4 + 0, 0 + 0, 8 + 0, 8 + 0, 12 + 0, 4 + 0,
+
+ // Draw the stroke, from outer edge to inner edge, shift is 8.
+ 0 + 8, 1 + 8, 9 + 8, 9 + 8, 8 + 8, 0 + 8,
+ 1 + 8, 5 + 8, 9 + 8,
+ 5 + 8, 6 + 8, 10 + 8, 10 + 8, 9 + 8, 5 + 8,
+ 6 + 8, 2 + 8, 10 + 8,
+ 2 + 8, 3 + 8, 11 + 8, 11 + 8, 10 + 8, 2 + 8,
+ 3 + 8, 7 + 8, 11 + 8,
+ 7 + 8, 4 + 8, 8 + 8, 8 + 8, 11 + 8, 7 + 8,
+ 4 + 8, 0 + 8, 8 + 8,
+
+ // Draw the inner AA, from inner edge to inner AA line, shift is 16.
+ 0 + 16, 1 + 16, 5 + 16, 5 + 16, 4 + 16, 0 + 16,
+ 1 + 16, 2 + 16, 6 + 16, 6 + 16, 5 + 16, 1 + 16,
+ 2 + 16, 3 + 16, 7 + 16, 7 + 16, 6 + 16, 2 + 16,
+ 3 + 16, 0 + 16, 4 + 16, 4 + 16, 7 + 16, 3 + 16,
+ };
+ // clang-format on
+ GR_STATIC_ASSERT(SK_ARRAY_COUNT(gBevelIndices) == kBevelIndexCnt);
+
+ GR_DEFINE_STATIC_UNIQUE_KEY(gBevelIndexBufferKey);
+ return resourceProvider->findOrCreatePatternedIndexBuffer(
+ gBevelIndices, kBevelIndexCnt, kNumBevelRectsInIndexBuffer, kBevelVertexCnt,
+ gBevelIndexBufferKey);
+ }
+}
+
+GrOp::CombineResult AAStrokeRectOp::onCombineIfPossible(GrOp* t, const GrCaps& caps) {
+ AAStrokeRectOp* that = t->cast<AAStrokeRectOp>();
+
+ if (!fHelper.isCompatible(that->fHelper, caps, this->bounds(), that->bounds())) {
+ return CombineResult::kCannotCombine;
+ }
+
+ // TODO combine across miterstroke changes
+ if (this->miterStroke() != that->miterStroke()) {
+ return CombineResult::kCannotCombine;
+ }
+
+ // We apply the viewmatrix to the rect points on the cpu. However, if the pipeline uses
+ // local coords then we won't be able to combine. TODO: Upload local coords as an attribute.
+ if (fHelper.usesLocalCoords() && !this->viewMatrix().cheapEqualTo(that->viewMatrix())) {
+ return CombineResult::kCannotCombine;
+ }
+
+ fRects.push_back_n(that->fRects.count(), that->fRects.begin());
+ return CombineResult::kMerged;
+}
+
+static void setup_scale(int* scale, SkScalar inset) {
+ if (inset < SK_ScalarHalf) {
+ *scale = SkScalarFloorToInt(512.0f * inset / (inset + SK_ScalarHalf));
+ SkASSERT(*scale >= 0 && *scale <= 255);
+ } else {
+ *scale = 0xff;
+ }
+}
+
+void AAStrokeRectOp::generateAAStrokeRectGeometry(GrVertexWriter& vertices,
+ GrColor color,
+ const SkRect& devOutside,
+ const SkRect& devOutsideAssist,
+ const SkRect& devInside,
+ bool miterStroke,
+ bool degenerate,
+ bool tweakAlphaForCoverage) const {
+ // We create vertices for four nested rectangles. There are two ramps from 0 to full
+ // coverage, one on the exterior of the stroke and the other on the interior.
+
+ // TODO: this only really works if the X & Y margins are the same all around
+ // the rect (or if they are all >= 1.0).
+ SkScalar inset;
+ if (!degenerate) {
+ inset = SkMinScalar(SK_Scalar1, devOutside.fRight - devInside.fRight);
+ inset = SkMinScalar(inset, devInside.fLeft - devOutside.fLeft);
+ inset = SkMinScalar(inset, devInside.fTop - devOutside.fTop);
+ if (miterStroke) {
+ inset = SK_ScalarHalf * SkMinScalar(inset, devOutside.fBottom - devInside.fBottom);
+ } else {
+ inset = SK_ScalarHalf *
+ SkMinScalar(inset, devOutsideAssist.fBottom - devInside.fBottom);
+ }
+ SkASSERT(inset >= 0);
+ } else {
+ // TODO use real devRect here
+ inset = SkMinScalar(devOutside.width(), SK_Scalar1);
+ inset = SK_ScalarHalf *
+ SkMinScalar(inset, SkTMax(devOutside.height(), devOutsideAssist.height()));
+ }
+
+ auto inset_fan = [](const SkRect& r, SkScalar dx, SkScalar dy) {
+ return GrVertexWriter::TriFanFromRect(r.makeInset(dx, dy));
+ };
+
+ auto maybe_coverage = [tweakAlphaForCoverage](float coverage) {
+ return GrVertexWriter::If(!tweakAlphaForCoverage, coverage);
+ };
+
+ GrColor outerColor = tweakAlphaForCoverage ? 0 : color;
+
+ // Outermost rect
+ vertices.writeQuad(inset_fan(devOutside, -SK_ScalarHalf, -SK_ScalarHalf),
+ outerColor,
+ maybe_coverage(0.0f));
+
+ if (!miterStroke) {
+ // Second outermost
+ vertices.writeQuad(inset_fan(devOutsideAssist, -SK_ScalarHalf, -SK_ScalarHalf),
+ outerColor,
+ maybe_coverage(0.0f));
+ }
+
+ // scale is the coverage for the the inner two rects.
+ int scale;
+ setup_scale(&scale, inset);
+
+ float innerCoverage = GrNormalizeByteToFloat(scale);
+ GrColor scaledColor = (0xff == scale) ? color : SkAlphaMulQ(color, scale);
+ GrColor innerColor = tweakAlphaForCoverage ? scaledColor : color;
+
+ // Inner rect
+ vertices.writeQuad(inset_fan(devOutside, inset, inset),
+ innerColor,
+ maybe_coverage(innerCoverage));
+
+ if (!miterStroke) {
+ // Second inner
+ vertices.writeQuad(inset_fan(devOutsideAssist, inset, inset),
+ innerColor,
+ maybe_coverage(innerCoverage));
+ }
+
+ if (!degenerate) {
+ vertices.writeQuad(inset_fan(devInside, -inset, -inset),
+ innerColor,
+ maybe_coverage(innerCoverage));
+
+ // The innermost rect has 0 coverage...
+ vertices.writeQuad(inset_fan(devInside, SK_ScalarHalf, SK_ScalarHalf),
+ (GrColor)0,
+ maybe_coverage(0.0f));
+ } else {
+ // When the interior rect has become degenerate we smoosh to a single point
+ SkASSERT(devInside.fLeft == devInside.fRight && devInside.fTop == devInside.fBottom);
+
+ vertices.writeQuad(GrVertexWriter::TriFanFromRect(devInside),
+ innerColor,
+ maybe_coverage(innerCoverage));
+
+ // ... unless we are degenerate, in which case we must apply the scaled coverage
+ vertices.writeQuad(GrVertexWriter::TriFanFromRect(devInside),
+ innerColor,
+ maybe_coverage(innerCoverage));
+ }
+}
+
+} // anonymous namespace
+
+namespace GrStrokeRectOp {
+
+std::unique_ptr<GrDrawOp> Make(GrContext* context,
+ GrPaint&& paint,
+ GrAAType aaType,
+ const SkMatrix& viewMatrix,
+ const SkRect& rect,
+ const SkStrokeRec& stroke) {
+ if (aaType == GrAAType::kCoverage) {
+ // The AA op only supports axis-aligned rectangles
+ if (!viewMatrix.rectStaysRect()) {
+ return nullptr;
+ }
+ return AAStrokeRectOp::Make(context, std::move(paint), viewMatrix, rect, stroke);
+ } else {
+ return NonAAStrokeRectOp::Make(context, std::move(paint), viewMatrix, rect, stroke, aaType);
+ }
+}
+
+std::unique_ptr<GrDrawOp> MakeNested(GrContext* context,
+ GrPaint&& paint,
+ const SkMatrix& viewMatrix,
+ const SkRect rects[2]) {
+ SkASSERT(viewMatrix.rectStaysRect());
+ SkASSERT(!rects[0].isEmpty() && !rects[1].isEmpty());
+
+ SkRect devOutside, devInside;
+ viewMatrix.mapRect(&devOutside, rects[0]);
+ viewMatrix.mapRect(&devInside, rects[1]);
+ if (devInside.isEmpty()) {
+ if (devOutside.isEmpty()) {
+ return nullptr;
+ }
+ return GrFillRectOp::Make(context, std::move(paint), GrAAType::kCoverage, viewMatrix,
+ rects[0]);
+ }
+
+ return AAStrokeRectOp::Make(context, std::move(paint), viewMatrix, devOutside, devInside);
+}
+
+} // namespace GrStrokeRectOp
+
+#if GR_TEST_UTILS
+
+#include "GrDrawOpTest.h"
+
+GR_DRAW_OP_TEST_DEFINE(NonAAStrokeRectOp) {
+ SkMatrix viewMatrix = GrTest::TestMatrix(random);
+ SkRect rect = GrTest::TestRect(random);
+ SkScalar strokeWidth = random->nextBool() ? 0.0f : 2.0f;
+ SkPaint strokePaint;
+ strokePaint.setStrokeWidth(strokeWidth);
+ strokePaint.setStyle(SkPaint::kStroke_Style);
+ strokePaint.setStrokeJoin(SkPaint::kMiter_Join);
+ SkStrokeRec strokeRec(strokePaint);
+ GrAAType aaType = GrAAType::kNone;
+ if (fsaaType == GrFSAAType::kUnifiedMSAA) {
+ aaType = random->nextBool() ? GrAAType::kMSAA : GrAAType::kNone;
+ }
+ return NonAAStrokeRectOp::Make(context, std::move(paint), viewMatrix, rect, strokeRec, aaType);
+}
+
+GR_DRAW_OP_TEST_DEFINE(AAStrokeRectOp) {
+ bool miterStroke = random->nextBool();
+
+ // Create either a empty rect or a non-empty rect.
+ SkRect rect =
+ random->nextBool() ? SkRect::MakeXYWH(10, 10, 50, 40) : SkRect::MakeXYWH(6, 7, 0, 0);
+ SkScalar minDim = SkMinScalar(rect.width(), rect.height());
+ SkScalar strokeWidth = random->nextUScalar1() * minDim;
+
+ SkStrokeRec rec(SkStrokeRec::kFill_InitStyle);
+ rec.setStrokeStyle(strokeWidth);
+ rec.setStrokeParams(SkPaint::kButt_Cap,
+ miterStroke ? SkPaint::kMiter_Join : SkPaint::kBevel_Join, 1.f);
+ SkMatrix matrix = GrTest::TestMatrixRectStaysRect(random);
+ return AAStrokeRectOp::Make(context, std::move(paint), matrix, rect, rec);
+}
+
+#endif