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1 /*
2  * Copyright 2018 Google Inc.
3  *
4  * Use of this source code is governed by a BSD-style license that can be
5  * found in the LICENSE file.
6  */
7 
8 #include "src/gpu/ops/GrStrokeRectOp.h"
9 
10 #include "include/core/SkStrokeRec.h"
11 #include "include/private/GrResourceKey.h"
12 #include "include/utils/SkRandom.h"
13 #include "src/gpu/GrCaps.h"
14 #include "src/gpu/GrColor.h"
15 #include "src/gpu/GrDefaultGeoProcFactory.h"
16 #include "src/gpu/GrDrawOpTest.h"
17 #include "src/gpu/GrOpFlushState.h"
18 #include "src/gpu/GrResourceProvider.h"
19 #include "src/gpu/GrVertexWriter.h"
20 #include "src/gpu/ops/GrFillRectOp.h"
21 #include "src/gpu/ops/GrMeshDrawOp.h"
22 #include "src/gpu/ops/GrSimpleMeshDrawOpHelper.h"
23 
24 namespace {
25 
26 // We support all hairlines, bevels, and miters, but not round joins. Also, check whether the miter
27 // limit makes a miter join effectively beveled. If the miter is effectively beveled, it is only
28 // supported when using an AA stroke.
allowed_stroke(const SkStrokeRec & stroke,GrAA aa,bool * isMiter)29 inline static bool allowed_stroke(const SkStrokeRec& stroke, GrAA aa, bool* isMiter) {
30     SkASSERT(stroke.getStyle() == SkStrokeRec::kStroke_Style ||
31              stroke.getStyle() == SkStrokeRec::kHairline_Style);
32     // For hairlines, make bevel and round joins appear the same as mitered ones.
33     if (!stroke.getWidth()) {
34         *isMiter = true;
35         return true;
36     }
37     if (stroke.getJoin() == SkPaint::kBevel_Join) {
38         *isMiter = false;
39         return aa == GrAA::kYes; // bevel only supported with AA
40     }
41     if (stroke.getJoin() == SkPaint::kMiter_Join) {
42         *isMiter = stroke.getMiter() >= SK_ScalarSqrt2;
43         // Supported under non-AA only if it remains mitered
44         return aa == GrAA::kYes || *isMiter;
45     }
46     return false;
47 }
48 
49 
50 ///////////////////////////////////////////////////////////////////////////////////////////////////
51 // Non-AA Stroking
52 ///////////////////////////////////////////////////////////////////////////////////////////////////
53 
54 /*  create a triangle strip that strokes the specified rect. There are 8
55     unique vertices, but we repeat the last 2 to close up. Alternatively we
56     could use an indices array, and then only send 8 verts, but not sure that
57     would be faster.
58     */
init_nonaa_stroke_rect_strip(SkPoint verts[10],const SkRect & rect,SkScalar width)59 static void init_nonaa_stroke_rect_strip(SkPoint verts[10], const SkRect& rect, SkScalar width) {
60     const SkScalar rad = SkScalarHalf(width);
61 
62     verts[0].set(rect.fLeft + rad, rect.fTop + rad);
63     verts[1].set(rect.fLeft - rad, rect.fTop - rad);
64     verts[2].set(rect.fRight - rad, rect.fTop + rad);
65     verts[3].set(rect.fRight + rad, rect.fTop - rad);
66     verts[4].set(rect.fRight - rad, rect.fBottom - rad);
67     verts[5].set(rect.fRight + rad, rect.fBottom + rad);
68     verts[6].set(rect.fLeft + rad, rect.fBottom - rad);
69     verts[7].set(rect.fLeft - rad, rect.fBottom + rad);
70     verts[8] = verts[0];
71     verts[9] = verts[1];
72 
73     // TODO: we should be catching this higher up the call stack and just draw a single
74     // non-AA rect
75     if (2*rad >= rect.width()) {
76         verts[0].fX = verts[2].fX = verts[4].fX = verts[6].fX = verts[8].fX = rect.centerX();
77     }
78     if (2*rad >= rect.height()) {
79         verts[0].fY = verts[2].fY = verts[4].fY = verts[6].fY = verts[8].fY = rect.centerY();
80     }
81 }
82 
83 class NonAAStrokeRectOp final : public GrMeshDrawOp {
84 private:
85     using Helper = GrSimpleMeshDrawOpHelper;
86 
87 public:
88     DEFINE_OP_CLASS_ID
89 
name() const90     const char* name() const override { return "NonAAStrokeRectOp"; }
91 
visitProxies(const VisitProxyFunc & func) const92     void visitProxies(const VisitProxyFunc& func) const override {
93         fHelper.visitProxies(func);
94     }
95 
96 #ifdef SK_DEBUG
dumpInfo() const97     SkString dumpInfo() const override {
98         SkString string;
99         string.appendf(
100                 "Color: 0x%08x, Rect [L: %.2f, T: %.2f, R: %.2f, B: %.2f], "
101                 "StrokeWidth: %.2f\n",
102                 fColor.toBytes_RGBA(), fRect.fLeft, fRect.fTop, fRect.fRight, fRect.fBottom,
103                 fStrokeWidth);
104         string += fHelper.dumpInfo();
105         string += INHERITED::dumpInfo();
106         return string;
107     }
108 #endif
109 
Make(GrRecordingContext * context,GrPaint && paint,const SkMatrix & viewMatrix,const SkRect & rect,const SkStrokeRec & stroke,GrAAType aaType)110     static std::unique_ptr<GrDrawOp> Make(GrRecordingContext* context,
111                                           GrPaint&& paint,
112                                           const SkMatrix& viewMatrix,
113                                           const SkRect& rect,
114                                           const SkStrokeRec& stroke,
115                                           GrAAType aaType) {
116         bool isMiter;
117         if (!allowed_stroke(stroke, GrAA::kNo, &isMiter)) {
118             return nullptr;
119         }
120         Helper::InputFlags inputFlags = Helper::InputFlags::kNone;
121         // Depending on sub-pixel coordinates and the particular GPU, we may lose a corner of
122         // hairline rects. We jam all the vertices to pixel centers to avoid this, but not
123         // when MSAA is enabled because it can cause ugly artifacts.
124         if (stroke.getStyle() == SkStrokeRec::kHairline_Style && aaType != GrAAType::kMSAA) {
125             inputFlags |= Helper::InputFlags::kSnapVerticesToPixelCenters;
126         }
127         return Helper::FactoryHelper<NonAAStrokeRectOp>(context, std::move(paint), inputFlags,
128                                                         viewMatrix, rect,
129                                                         stroke, aaType);
130     }
131 
NonAAStrokeRectOp(const Helper::MakeArgs & helperArgs,const SkPMColor4f & color,Helper::InputFlags inputFlags,const SkMatrix & viewMatrix,const SkRect & rect,const SkStrokeRec & stroke,GrAAType aaType)132     NonAAStrokeRectOp(const Helper::MakeArgs& helperArgs, const SkPMColor4f& color,
133                       Helper::InputFlags inputFlags, const SkMatrix& viewMatrix, const SkRect& rect,
134                       const SkStrokeRec& stroke, GrAAType aaType)
135             : INHERITED(ClassID()), fHelper(helperArgs, aaType, inputFlags) {
136         fColor = color;
137         fViewMatrix = viewMatrix;
138         fRect = rect;
139         // Sort the rect for hairlines
140         fRect.sort();
141         fStrokeWidth = stroke.getWidth();
142 
143         SkScalar rad = SkScalarHalf(fStrokeWidth);
144         SkRect bounds = rect;
145         bounds.outset(rad, rad);
146 
147         // If our caller snaps to pixel centers then we have to round out the bounds
148         if (inputFlags & Helper::InputFlags::kSnapVerticesToPixelCenters) {
149             viewMatrix.mapRect(&bounds);
150             // We want to be consistent with how we snap non-aa lines. To match what we do in
151             // GrGLSLVertexShaderBuilder, we first floor all the vertex values and then add half a
152             // pixel to force us to pixel centers.
153             bounds.set(SkScalarFloorToScalar(bounds.fLeft),
154                        SkScalarFloorToScalar(bounds.fTop),
155                        SkScalarFloorToScalar(bounds.fRight),
156                        SkScalarFloorToScalar(bounds.fBottom));
157             bounds.offset(0.5f, 0.5f);
158             this->setBounds(bounds, HasAABloat::kNo, IsZeroArea::kNo);
159         } else {
160             this->setTransformedBounds(bounds, fViewMatrix, HasAABloat::kNo, IsZeroArea::kNo);
161         }
162     }
163 
fixedFunctionFlags() const164     FixedFunctionFlags fixedFunctionFlags() const override { return fHelper.fixedFunctionFlags(); }
165 
finalize(const GrCaps & caps,const GrAppliedClip * clip,bool hasMixedSampledCoverage,GrClampType clampType)166     GrProcessorSet::Analysis finalize(
167             const GrCaps& caps, const GrAppliedClip* clip, bool hasMixedSampledCoverage,
168             GrClampType clampType) override {
169         // This Op uses uniform (not vertex) color, so doesn't need to track wide color.
170         return fHelper.finalizeProcessors(caps, clip, hasMixedSampledCoverage, clampType,
171                                           GrProcessorAnalysisCoverage::kNone, &fColor, nullptr);
172     }
173 
174 private:
onPrepareDraws(Target * target)175     void onPrepareDraws(Target* target) override {
176         sk_sp<GrGeometryProcessor> gp;
177         {
178             using namespace GrDefaultGeoProcFactory;
179             Color color(fColor);
180             LocalCoords::Type localCoordsType = fHelper.usesLocalCoords()
181                                                         ? LocalCoords::kUsePosition_Type
182                                                         : LocalCoords::kUnused_Type;
183             gp = GrDefaultGeoProcFactory::Make(target->caps().shaderCaps(), color,
184                                                Coverage::kSolid_Type, localCoordsType,
185                                                fViewMatrix);
186         }
187 
188         size_t kVertexStride = gp->vertexStride();
189         int vertexCount = kVertsPerHairlineRect;
190         if (fStrokeWidth > 0) {
191             vertexCount = kVertsPerStrokeRect;
192         }
193 
194         sk_sp<const GrBuffer> vertexBuffer;
195         int firstVertex;
196 
197         void* verts =
198                 target->makeVertexSpace(kVertexStride, vertexCount, &vertexBuffer, &firstVertex);
199 
200         if (!verts) {
201             SkDebugf("Could not allocate vertices\n");
202             return;
203         }
204 
205         SkPoint* vertex = reinterpret_cast<SkPoint*>(verts);
206 
207         GrPrimitiveType primType;
208         if (fStrokeWidth > 0) {
209             primType = GrPrimitiveType::kTriangleStrip;
210             init_nonaa_stroke_rect_strip(vertex, fRect, fStrokeWidth);
211         } else {
212             // hairline
213             primType = GrPrimitiveType::kLineStrip;
214             vertex[0].set(fRect.fLeft, fRect.fTop);
215             vertex[1].set(fRect.fRight, fRect.fTop);
216             vertex[2].set(fRect.fRight, fRect.fBottom);
217             vertex[3].set(fRect.fLeft, fRect.fBottom);
218             vertex[4].set(fRect.fLeft, fRect.fTop);
219         }
220 
221         GrMesh* mesh = target->allocMesh(primType);
222         mesh->setNonIndexedNonInstanced(vertexCount);
223         mesh->setVertexData(std::move(vertexBuffer), firstVertex);
224         target->recordDraw(std::move(gp), mesh);
225     }
226 
onExecute(GrOpFlushState * flushState,const SkRect & chainBounds)227     void onExecute(GrOpFlushState* flushState, const SkRect& chainBounds) override {
228         fHelper.executeDrawsAndUploads(this, flushState, chainBounds);
229     }
230 
231     // TODO: override onCombineIfPossible
232 
233     Helper fHelper;
234     SkPMColor4f fColor;
235     SkMatrix fViewMatrix;
236     SkRect fRect;
237     SkScalar fStrokeWidth;
238 
239     const static int kVertsPerHairlineRect = 5;
240     const static int kVertsPerStrokeRect = 10;
241 
242     typedef GrMeshDrawOp INHERITED;
243 };
244 
245 ///////////////////////////////////////////////////////////////////////////////////////////////////
246 // AA Stroking
247 ///////////////////////////////////////////////////////////////////////////////////////////////////
248 
249 GR_DECLARE_STATIC_UNIQUE_KEY(gMiterIndexBufferKey);
250 GR_DECLARE_STATIC_UNIQUE_KEY(gBevelIndexBufferKey);
251 
compute_aa_rects(SkRect * devOutside,SkRect * devOutsideAssist,SkRect * devInside,bool * isDegenerate,const SkMatrix & viewMatrix,const SkRect & rect,SkScalar strokeWidth,bool miterStroke)252 static void compute_aa_rects(SkRect* devOutside, SkRect* devOutsideAssist, SkRect* devInside,
253                              bool* isDegenerate, const SkMatrix& viewMatrix, const SkRect& rect,
254                              SkScalar strokeWidth, bool miterStroke) {
255     SkRect devRect;
256     viewMatrix.mapRect(&devRect, rect);
257 
258     SkVector devStrokeSize;
259     if (strokeWidth > 0) {
260         devStrokeSize.set(strokeWidth, strokeWidth);
261         viewMatrix.mapVectors(&devStrokeSize, 1);
262         devStrokeSize.setAbs(devStrokeSize);
263     } else {
264         devStrokeSize.set(SK_Scalar1, SK_Scalar1);
265     }
266 
267     const SkScalar dx = devStrokeSize.fX;
268     const SkScalar dy = devStrokeSize.fY;
269     const SkScalar rx = SkScalarHalf(dx);
270     const SkScalar ry = SkScalarHalf(dy);
271 
272     *devOutside = devRect;
273     *devOutsideAssist = devRect;
274     *devInside = devRect;
275 
276     devOutside->outset(rx, ry);
277     devInside->inset(rx, ry);
278 
279     // If we have a degenerate stroking rect(ie the stroke is larger than inner rect) then we
280     // make a degenerate inside rect to avoid double hitting.  We will also jam all of the points
281     // together when we render these rects.
282     SkScalar spare;
283     {
284         SkScalar w = devRect.width() - dx;
285         SkScalar h = devRect.height() - dy;
286         spare = SkTMin(w, h);
287     }
288 
289     *isDegenerate = spare <= 0;
290     if (*isDegenerate) {
291         devInside->fLeft = devInside->fRight = devRect.centerX();
292         devInside->fTop = devInside->fBottom = devRect.centerY();
293     }
294 
295     // For bevel-stroke, use 2 SkRect instances(devOutside and devOutsideAssist)
296     // to draw the outside of the octagon. Because there are 8 vertices on the outer
297     // edge, while vertex number of inner edge is 4, the same as miter-stroke.
298     if (!miterStroke) {
299         devOutside->inset(0, ry);
300         devOutsideAssist->outset(0, ry);
301     }
302 }
303 
create_aa_stroke_rect_gp(const GrShaderCaps * shaderCaps,bool tweakAlphaForCoverage,const SkMatrix & viewMatrix,bool usesLocalCoords,bool wideColor)304 static sk_sp<GrGeometryProcessor> create_aa_stroke_rect_gp(const GrShaderCaps* shaderCaps,
305                                                            bool tweakAlphaForCoverage,
306                                                            const SkMatrix& viewMatrix,
307                                                            bool usesLocalCoords,
308                                                            bool wideColor) {
309     using namespace GrDefaultGeoProcFactory;
310 
311     Coverage::Type coverageType =
312         tweakAlphaForCoverage ? Coverage::kSolid_Type : Coverage::kAttribute_Type;
313     LocalCoords::Type localCoordsType =
314         usesLocalCoords ? LocalCoords::kUsePosition_Type : LocalCoords::kUnused_Type;
315     Color::Type colorType =
316         wideColor ? Color::kPremulWideColorAttribute_Type: Color::kPremulGrColorAttribute_Type;
317 
318     return MakeForDeviceSpace(shaderCaps, colorType, coverageType, localCoordsType, viewMatrix);
319 }
320 
321 class AAStrokeRectOp final : public GrMeshDrawOp {
322 private:
323     using Helper = GrSimpleMeshDrawOpHelper;
324 
325 public:
326     DEFINE_OP_CLASS_ID
327 
Make(GrRecordingContext * context,GrPaint && paint,const SkMatrix & viewMatrix,const SkRect & devOutside,const SkRect & devInside)328     static std::unique_ptr<GrDrawOp> Make(GrRecordingContext* context,
329                                           GrPaint&& paint,
330                                           const SkMatrix& viewMatrix,
331                                           const SkRect& devOutside,
332                                           const SkRect& devInside) {
333         return Helper::FactoryHelper<AAStrokeRectOp>(context, std::move(paint), viewMatrix,
334                                                      devOutside, devInside);
335     }
336 
AAStrokeRectOp(const Helper::MakeArgs & helperArgs,const SkPMColor4f & color,const SkMatrix & viewMatrix,const SkRect & devOutside,const SkRect & devInside)337     AAStrokeRectOp(const Helper::MakeArgs& helperArgs, const SkPMColor4f& color,
338                    const SkMatrix& viewMatrix, const SkRect& devOutside, const SkRect& devInside)
339             : INHERITED(ClassID())
340             , fHelper(helperArgs, GrAAType::kCoverage)
341             , fViewMatrix(viewMatrix) {
342         SkASSERT(!devOutside.isEmpty());
343         SkASSERT(!devInside.isEmpty());
344 
345         fRects.emplace_back(RectInfo{color, devOutside, devOutside, devInside, false});
346         this->setBounds(devOutside, HasAABloat::kYes, IsZeroArea::kNo);
347         fMiterStroke = true;
348     }
349 
Make(GrRecordingContext * context,GrPaint && paint,const SkMatrix & viewMatrix,const SkRect & rect,const SkStrokeRec & stroke)350     static std::unique_ptr<GrDrawOp> Make(GrRecordingContext* context,
351                                           GrPaint&& paint,
352                                           const SkMatrix& viewMatrix,
353                                           const SkRect& rect,
354                                           const SkStrokeRec& stroke) {
355         bool isMiter;
356         if (!allowed_stroke(stroke, GrAA::kYes, &isMiter)) {
357             return nullptr;
358         }
359         return Helper::FactoryHelper<AAStrokeRectOp>(context, std::move(paint), viewMatrix, rect,
360                                                      stroke, isMiter);
361     }
362 
AAStrokeRectOp(const Helper::MakeArgs & helperArgs,const SkPMColor4f & color,const SkMatrix & viewMatrix,const SkRect & rect,const SkStrokeRec & stroke,bool isMiter)363     AAStrokeRectOp(const Helper::MakeArgs& helperArgs, const SkPMColor4f& color,
364                    const SkMatrix& viewMatrix, const SkRect& rect, const SkStrokeRec& stroke,
365                    bool isMiter)
366             : INHERITED(ClassID())
367             , fHelper(helperArgs, GrAAType::kCoverage)
368             , fViewMatrix(viewMatrix) {
369         fMiterStroke = isMiter;
370         RectInfo& info = fRects.push_back();
371         compute_aa_rects(&info.fDevOutside, &info.fDevOutsideAssist, &info.fDevInside,
372                          &info.fDegenerate, viewMatrix, rect, stroke.getWidth(), isMiter);
373         info.fColor = color;
374         if (isMiter) {
375             this->setBounds(info.fDevOutside, HasAABloat::kYes, IsZeroArea::kNo);
376         } else {
377             // The outer polygon of the bevel stroke is an octagon specified by the points of a
378             // pair of overlapping rectangles where one is wide and the other is narrow.
379             SkRect bounds = info.fDevOutside;
380             bounds.joinPossiblyEmptyRect(info.fDevOutsideAssist);
381             this->setBounds(bounds, HasAABloat::kYes, IsZeroArea::kNo);
382         }
383     }
384 
name() const385     const char* name() const override { return "AAStrokeRect"; }
386 
visitProxies(const VisitProxyFunc & func) const387     void visitProxies(const VisitProxyFunc& func) const override {
388         fHelper.visitProxies(func);
389     }
390 
391 #ifdef SK_DEBUG
dumpInfo() const392     SkString dumpInfo() const override {
393         SkString string;
394         for (const auto& info : fRects) {
395             string.appendf(
396                     "Color: 0x%08x, ORect [L: %.2f, T: %.2f, R: %.2f, B: %.2f], "
397                     "AssistORect [L: %.2f, T: %.2f, R: %.2f, B: %.2f], "
398                     "IRect [L: %.2f, T: %.2f, R: %.2f, B: %.2f], Degen: %d",
399                     info.fColor.toBytes_RGBA(), info.fDevOutside.fLeft, info.fDevOutside.fTop,
400                     info.fDevOutside.fRight, info.fDevOutside.fBottom, info.fDevOutsideAssist.fLeft,
401                     info.fDevOutsideAssist.fTop, info.fDevOutsideAssist.fRight,
402                     info.fDevOutsideAssist.fBottom, info.fDevInside.fLeft, info.fDevInside.fTop,
403                     info.fDevInside.fRight, info.fDevInside.fBottom, info.fDegenerate);
404         }
405         string += fHelper.dumpInfo();
406         string += INHERITED::dumpInfo();
407         return string;
408     }
409 #endif
410 
fixedFunctionFlags() const411     FixedFunctionFlags fixedFunctionFlags() const override { return fHelper.fixedFunctionFlags(); }
412 
finalize(const GrCaps & caps,const GrAppliedClip * clip,bool hasMixedSampledCoverage,GrClampType clampType)413     GrProcessorSet::Analysis finalize(
414             const GrCaps& caps, const GrAppliedClip* clip, bool hasMixedSampledCoverage,
415             GrClampType clampType) override {
416         return fHelper.finalizeProcessors(
417                 caps, clip, hasMixedSampledCoverage, clampType,
418                 GrProcessorAnalysisCoverage::kSingleChannel, &fRects.back().fColor, &fWideColor);
419     }
420 
421 private:
422     void onPrepareDraws(Target*) override;
423     void onExecute(GrOpFlushState*, const SkRect& chainBounds) override;
424 
425     static const int kMiterIndexCnt = 3 * 24;
426     static const int kMiterVertexCnt = 16;
427     static const int kNumMiterRectsInIndexBuffer = 256;
428 
429     static const int kBevelIndexCnt = 48 + 36 + 24;
430     static const int kBevelVertexCnt = 24;
431     static const int kNumBevelRectsInIndexBuffer = 256;
432 
433     static sk_sp<const GrGpuBuffer> GetIndexBuffer(GrResourceProvider*, bool miterStroke);
434 
viewMatrix() const435     const SkMatrix& viewMatrix() const { return fViewMatrix; }
miterStroke() const436     bool miterStroke() const { return fMiterStroke; }
437 
438     CombineResult onCombineIfPossible(GrOp* t, const GrCaps&) override;
439 
440     void generateAAStrokeRectGeometry(GrVertexWriter& vertices,
441                                       const SkPMColor4f& color,
442                                       bool wideColor,
443                                       const SkRect& devOutside,
444                                       const SkRect& devOutsideAssist,
445                                       const SkRect& devInside,
446                                       bool miterStroke,
447                                       bool degenerate,
448                                       bool tweakAlphaForCoverage) const;
449 
450     // TODO support AA rotated stroke rects by copying around view matrices
451     struct RectInfo {
452         SkPMColor4f fColor;
453         SkRect fDevOutside;
454         SkRect fDevOutsideAssist;
455         SkRect fDevInside;
456         bool fDegenerate;
457     };
458 
459     Helper fHelper;
460     SkSTArray<1, RectInfo, true> fRects;
461     SkMatrix fViewMatrix;
462     bool fMiterStroke;
463     bool fWideColor;
464 
465     typedef GrMeshDrawOp INHERITED;
466 };
467 
onPrepareDraws(Target * target)468 void AAStrokeRectOp::onPrepareDraws(Target* target) {
469     sk_sp<GrGeometryProcessor> gp(create_aa_stroke_rect_gp(target->caps().shaderCaps(),
470                                                            fHelper.compatibleWithCoverageAsAlpha(),
471                                                            this->viewMatrix(),
472                                                            fHelper.usesLocalCoords(),
473                                                            fWideColor));
474     if (!gp) {
475         SkDebugf("Couldn't create GrGeometryProcessor\n");
476         return;
477     }
478 
479     int innerVertexNum = 4;
480     int outerVertexNum = this->miterStroke() ? 4 : 8;
481     int verticesPerInstance = (outerVertexNum + innerVertexNum) * 2;
482     int indicesPerInstance = this->miterStroke() ? kMiterIndexCnt : kBevelIndexCnt;
483     int instanceCount = fRects.count();
484 
485     sk_sp<const GrGpuBuffer> indexBuffer =
486             GetIndexBuffer(target->resourceProvider(), this->miterStroke());
487     if (!indexBuffer) {
488         SkDebugf("Could not allocate indices\n");
489         return;
490     }
491     PatternHelper helper(target, GrPrimitiveType::kTriangles, gp->vertexStride(),
492                          std::move(indexBuffer), verticesPerInstance, indicesPerInstance,
493                          instanceCount);
494     GrVertexWriter vertices{ helper.vertices() };
495     if (!vertices.fPtr) {
496         SkDebugf("Could not allocate vertices\n");
497         return;
498     }
499 
500     for (int i = 0; i < instanceCount; i++) {
501         const RectInfo& info = fRects[i];
502         this->generateAAStrokeRectGeometry(vertices,
503                                            info.fColor,
504                                            fWideColor,
505                                            info.fDevOutside,
506                                            info.fDevOutsideAssist,
507                                            info.fDevInside,
508                                            fMiterStroke,
509                                            info.fDegenerate,
510                                            fHelper.compatibleWithCoverageAsAlpha());
511     }
512     helper.recordDraw(target, std::move(gp));
513 }
514 
onExecute(GrOpFlushState * flushState,const SkRect & chainBounds)515 void AAStrokeRectOp::onExecute(GrOpFlushState* flushState, const SkRect& chainBounds) {
516     fHelper.executeDrawsAndUploads(this, flushState, chainBounds);
517 }
518 
GetIndexBuffer(GrResourceProvider * resourceProvider,bool miterStroke)519 sk_sp<const GrGpuBuffer> AAStrokeRectOp::GetIndexBuffer(GrResourceProvider* resourceProvider,
520                                                         bool miterStroke) {
521     if (miterStroke) {
522         // clang-format off
523         static const uint16_t gMiterIndices[] = {
524             0 + 0, 1 + 0, 5 + 0, 5 + 0, 4 + 0, 0 + 0,
525             1 + 0, 2 + 0, 6 + 0, 6 + 0, 5 + 0, 1 + 0,
526             2 + 0, 3 + 0, 7 + 0, 7 + 0, 6 + 0, 2 + 0,
527             3 + 0, 0 + 0, 4 + 0, 4 + 0, 7 + 0, 3 + 0,
528 
529             0 + 4, 1 + 4, 5 + 4, 5 + 4, 4 + 4, 0 + 4,
530             1 + 4, 2 + 4, 6 + 4, 6 + 4, 5 + 4, 1 + 4,
531             2 + 4, 3 + 4, 7 + 4, 7 + 4, 6 + 4, 2 + 4,
532             3 + 4, 0 + 4, 4 + 4, 4 + 4, 7 + 4, 3 + 4,
533 
534             0 + 8, 1 + 8, 5 + 8, 5 + 8, 4 + 8, 0 + 8,
535             1 + 8, 2 + 8, 6 + 8, 6 + 8, 5 + 8, 1 + 8,
536             2 + 8, 3 + 8, 7 + 8, 7 + 8, 6 + 8, 2 + 8,
537             3 + 8, 0 + 8, 4 + 8, 4 + 8, 7 + 8, 3 + 8,
538         };
539         // clang-format on
540         GR_STATIC_ASSERT(SK_ARRAY_COUNT(gMiterIndices) == kMiterIndexCnt);
541         GR_DEFINE_STATIC_UNIQUE_KEY(gMiterIndexBufferKey);
542         return resourceProvider->findOrCreatePatternedIndexBuffer(
543                 gMiterIndices, kMiterIndexCnt, kNumMiterRectsInIndexBuffer, kMiterVertexCnt,
544                 gMiterIndexBufferKey);
545     } else {
546         /**
547          * As in miter-stroke, index = a + b, and a is the current index, b is the shift
548          * from the first index. The index layout:
549          * outer AA line: 0~3, 4~7
550          * outer edge:    8~11, 12~15
551          * inner edge:    16~19
552          * inner AA line: 20~23
553          * Following comes a bevel-stroke rect and its indices:
554          *
555          *           4                                 7
556          *            *********************************
557          *          *   ______________________________  *
558          *         *  / 12                          15 \  *
559          *        *  /                                  \  *
560          *     0 *  |8     16_____________________19  11 |  * 3
561          *       *  |       |                    |       |  *
562          *       *  |       |  ****************  |       |  *
563          *       *  |       |  * 20        23 *  |       |  *
564          *       *  |       |  *              *  |       |  *
565          *       *  |       |  * 21        22 *  |       |  *
566          *       *  |       |  ****************  |       |  *
567          *       *  |       |____________________|       |  *
568          *     1 *  |9    17                      18   10|  * 2
569          *        *  \                                  /  *
570          *         *  \13 __________________________14/  *
571          *          *                                   *
572          *           **********************************
573          *          5                                  6
574          */
575         // clang-format off
576         static const uint16_t gBevelIndices[] = {
577             // Draw outer AA, from outer AA line to outer edge, shift is 0.
578             0 + 0, 1 + 0,  9 + 0,  9 + 0,  8 + 0, 0 + 0,
579             1 + 0, 5 + 0, 13 + 0, 13 + 0,  9 + 0, 1 + 0,
580             5 + 0, 6 + 0, 14 + 0, 14 + 0, 13 + 0, 5 + 0,
581             6 + 0, 2 + 0, 10 + 0, 10 + 0, 14 + 0, 6 + 0,
582             2 + 0, 3 + 0, 11 + 0, 11 + 0, 10 + 0, 2 + 0,
583             3 + 0, 7 + 0, 15 + 0, 15 + 0, 11 + 0, 3 + 0,
584             7 + 0, 4 + 0, 12 + 0, 12 + 0, 15 + 0, 7 + 0,
585             4 + 0, 0 + 0,  8 + 0,  8 + 0, 12 + 0, 4 + 0,
586 
587             // Draw the stroke, from outer edge to inner edge, shift is 8.
588             0 + 8, 1 + 8, 9 + 8, 9 + 8, 8 + 8, 0 + 8,
589             1 + 8, 5 + 8, 9 + 8,
590             5 + 8, 6 + 8, 10 + 8, 10 + 8, 9 + 8, 5 + 8,
591             6 + 8, 2 + 8, 10 + 8,
592             2 + 8, 3 + 8, 11 + 8, 11 + 8, 10 + 8, 2 + 8,
593             3 + 8, 7 + 8, 11 + 8,
594             7 + 8, 4 + 8, 8 + 8, 8 + 8, 11 + 8, 7 + 8,
595             4 + 8, 0 + 8, 8 + 8,
596 
597             // Draw the inner AA, from inner edge to inner AA line, shift is 16.
598             0 + 16, 1 + 16, 5 + 16, 5 + 16, 4 + 16, 0 + 16,
599             1 + 16, 2 + 16, 6 + 16, 6 + 16, 5 + 16, 1 + 16,
600             2 + 16, 3 + 16, 7 + 16, 7 + 16, 6 + 16, 2 + 16,
601             3 + 16, 0 + 16, 4 + 16, 4 + 16, 7 + 16, 3 + 16,
602         };
603         // clang-format on
604         GR_STATIC_ASSERT(SK_ARRAY_COUNT(gBevelIndices) == kBevelIndexCnt);
605 
606         GR_DEFINE_STATIC_UNIQUE_KEY(gBevelIndexBufferKey);
607         return resourceProvider->findOrCreatePatternedIndexBuffer(
608                 gBevelIndices, kBevelIndexCnt, kNumBevelRectsInIndexBuffer, kBevelVertexCnt,
609                 gBevelIndexBufferKey);
610     }
611 }
612 
onCombineIfPossible(GrOp * t,const GrCaps & caps)613 GrOp::CombineResult AAStrokeRectOp::onCombineIfPossible(GrOp* t, const GrCaps& caps) {
614     AAStrokeRectOp* that = t->cast<AAStrokeRectOp>();
615 
616     if (!fHelper.isCompatible(that->fHelper, caps, this->bounds(), that->bounds())) {
617         return CombineResult::kCannotCombine;
618     }
619 
620     // TODO combine across miterstroke changes
621     if (this->miterStroke() != that->miterStroke()) {
622         return CombineResult::kCannotCombine;
623     }
624 
625     // We apply the viewmatrix to the rect points on the cpu.  However, if the pipeline uses
626     // local coords then we won't be able to combine. TODO: Upload local coords as an attribute.
627     if (fHelper.usesLocalCoords() && !this->viewMatrix().cheapEqualTo(that->viewMatrix())) {
628         return CombineResult::kCannotCombine;
629     }
630 
631     fRects.push_back_n(that->fRects.count(), that->fRects.begin());
632     fWideColor |= that->fWideColor;
633     return CombineResult::kMerged;
634 }
635 
setup_scale(int * scale,SkScalar inset)636 static void setup_scale(int* scale, SkScalar inset) {
637     if (inset < SK_ScalarHalf) {
638         *scale = SkScalarFloorToInt(512.0f * inset / (inset + SK_ScalarHalf));
639         SkASSERT(*scale >= 0 && *scale <= 255);
640     } else {
641         *scale = 0xff;
642     }
643 }
644 
generateAAStrokeRectGeometry(GrVertexWriter & vertices,const SkPMColor4f & color,bool wideColor,const SkRect & devOutside,const SkRect & devOutsideAssist,const SkRect & devInside,bool miterStroke,bool degenerate,bool tweakAlphaForCoverage) const645 void AAStrokeRectOp::generateAAStrokeRectGeometry(GrVertexWriter& vertices,
646                                                   const SkPMColor4f& color,
647                                                   bool wideColor,
648                                                   const SkRect& devOutside,
649                                                   const SkRect& devOutsideAssist,
650                                                   const SkRect& devInside,
651                                                   bool miterStroke,
652                                                   bool degenerate,
653                                                   bool tweakAlphaForCoverage) const {
654     // We create vertices for four nested rectangles. There are two ramps from 0 to full
655     // coverage, one on the exterior of the stroke and the other on the interior.
656 
657     // TODO: this only really works if the X & Y margins are the same all around
658     // the rect (or if they are all >= 1.0).
659     SkScalar inset;
660     if (!degenerate) {
661         inset = SkMinScalar(SK_Scalar1, devOutside.fRight - devInside.fRight);
662         inset = SkMinScalar(inset, devInside.fLeft - devOutside.fLeft);
663         inset = SkMinScalar(inset, devInside.fTop - devOutside.fTop);
664         if (miterStroke) {
665             inset = SK_ScalarHalf * SkMinScalar(inset, devOutside.fBottom - devInside.fBottom);
666         } else {
667             inset = SK_ScalarHalf *
668                     SkMinScalar(inset, devOutsideAssist.fBottom - devInside.fBottom);
669         }
670         SkASSERT(inset >= 0);
671     } else {
672         // TODO use real devRect here
673         inset = SkMinScalar(devOutside.width(), SK_Scalar1);
674         inset = SK_ScalarHalf *
675                 SkMinScalar(inset, SkTMax(devOutside.height(), devOutsideAssist.height()));
676     }
677 
678     auto inset_fan = [](const SkRect& r, SkScalar dx, SkScalar dy) {
679         return GrVertexWriter::TriFanFromRect(r.makeInset(dx, dy));
680     };
681 
682     auto maybe_coverage = [tweakAlphaForCoverage](float coverage) {
683         return GrVertexWriter::If(!tweakAlphaForCoverage, coverage);
684     };
685 
686     GrVertexColor outerColor(tweakAlphaForCoverage ? SK_PMColor4fTRANSPARENT : color, wideColor);
687 
688     // Outermost rect
689     vertices.writeQuad(inset_fan(devOutside, -SK_ScalarHalf, -SK_ScalarHalf),
690                        outerColor,
691                        maybe_coverage(0.0f));
692 
693     if (!miterStroke) {
694         // Second outermost
695         vertices.writeQuad(inset_fan(devOutsideAssist, -SK_ScalarHalf, -SK_ScalarHalf),
696                            outerColor,
697                            maybe_coverage(0.0f));
698     }
699 
700     // scale is the coverage for the the inner two rects.
701     int scale;
702     setup_scale(&scale, inset);
703 
704     float innerCoverage = GrNormalizeByteToFloat(scale);
705     SkPMColor4f scaledColor = color * innerCoverage;
706     GrVertexColor innerColor(tweakAlphaForCoverage ? scaledColor : color, wideColor);
707 
708     // Inner rect
709     vertices.writeQuad(inset_fan(devOutside, inset, inset),
710                        innerColor,
711                        maybe_coverage(innerCoverage));
712 
713     if (!miterStroke) {
714         // Second inner
715         vertices.writeQuad(inset_fan(devOutsideAssist, inset, inset),
716                            innerColor,
717                            maybe_coverage(innerCoverage));
718     }
719 
720     if (!degenerate) {
721         vertices.writeQuad(inset_fan(devInside, -inset, -inset),
722                            innerColor,
723                            maybe_coverage(innerCoverage));
724 
725         // The innermost rect has 0 coverage...
726         vertices.writeQuad(inset_fan(devInside, SK_ScalarHalf, SK_ScalarHalf),
727                            GrVertexColor(SK_PMColor4fTRANSPARENT, wideColor),
728                            maybe_coverage(0.0f));
729     } else {
730         // When the interior rect has become degenerate we smoosh to a single point
731         SkASSERT(devInside.fLeft == devInside.fRight && devInside.fTop == devInside.fBottom);
732 
733         vertices.writeQuad(GrVertexWriter::TriFanFromRect(devInside),
734                            innerColor,
735                            maybe_coverage(innerCoverage));
736 
737         // ... unless we are degenerate, in which case we must apply the scaled coverage
738         vertices.writeQuad(GrVertexWriter::TriFanFromRect(devInside),
739                            innerColor,
740                            maybe_coverage(innerCoverage));
741     }
742 }
743 
744 }  // anonymous namespace
745 
746 namespace GrStrokeRectOp {
747 
Make(GrRecordingContext * context,GrPaint && paint,GrAAType aaType,const SkMatrix & viewMatrix,const SkRect & rect,const SkStrokeRec & stroke)748 std::unique_ptr<GrDrawOp> Make(GrRecordingContext* context,
749                                GrPaint&& paint,
750                                GrAAType aaType,
751                                const SkMatrix& viewMatrix,
752                                const SkRect& rect,
753                                const SkStrokeRec& stroke) {
754     if (aaType == GrAAType::kCoverage) {
755         // The AA op only supports axis-aligned rectangles
756         if (!viewMatrix.rectStaysRect()) {
757             return nullptr;
758         }
759         return AAStrokeRectOp::Make(context, std::move(paint), viewMatrix, rect, stroke);
760     } else {
761         return NonAAStrokeRectOp::Make(context, std::move(paint), viewMatrix, rect, stroke, aaType);
762     }
763 }
764 
MakeNested(GrRecordingContext * context,GrPaint && paint,const SkMatrix & viewMatrix,const SkRect rects[2])765 std::unique_ptr<GrDrawOp> MakeNested(GrRecordingContext* context,
766                                      GrPaint&& paint,
767                                      const SkMatrix& viewMatrix,
768                                      const SkRect rects[2]) {
769     SkASSERT(viewMatrix.rectStaysRect());
770     SkASSERT(!rects[0].isEmpty() && !rects[1].isEmpty());
771 
772     SkRect devOutside, devInside;
773     viewMatrix.mapRect(&devOutside, rects[0]);
774     viewMatrix.mapRect(&devInside, rects[1]);
775     if (devInside.isEmpty()) {
776         if (devOutside.isEmpty()) {
777             return nullptr;
778         }
779         return GrFillRectOp::Make(context, std::move(paint), GrAAType::kCoverage,
780                                   GrQuadAAFlags::kAll,
781                                   GrQuad::MakeFromRect(rects[0], viewMatrix),
782                                   GrQuad(rects[0]));
783     }
784 
785     return AAStrokeRectOp::Make(context, std::move(paint), viewMatrix, devOutside, devInside);
786 }
787 
788 }  // namespace GrStrokeRectOp
789 
790 #if GR_TEST_UTILS
791 
792 #include "src/gpu/GrDrawOpTest.h"
793 
GR_DRAW_OP_TEST_DEFINE(NonAAStrokeRectOp)794 GR_DRAW_OP_TEST_DEFINE(NonAAStrokeRectOp) {
795     SkMatrix viewMatrix = GrTest::TestMatrix(random);
796     SkRect rect = GrTest::TestRect(random);
797     SkScalar strokeWidth = random->nextBool() ? 0.0f : 2.0f;
798     SkPaint strokePaint;
799     strokePaint.setStrokeWidth(strokeWidth);
800     strokePaint.setStyle(SkPaint::kStroke_Style);
801     strokePaint.setStrokeJoin(SkPaint::kMiter_Join);
802     SkStrokeRec strokeRec(strokePaint);
803     GrAAType aaType = GrAAType::kNone;
804     if (numSamples > 1) {
805         aaType = random->nextBool() ? GrAAType::kMSAA : GrAAType::kNone;
806     }
807     return NonAAStrokeRectOp::Make(context, std::move(paint), viewMatrix, rect, strokeRec, aaType);
808 }
809 
GR_DRAW_OP_TEST_DEFINE(AAStrokeRectOp)810 GR_DRAW_OP_TEST_DEFINE(AAStrokeRectOp) {
811     bool miterStroke = random->nextBool();
812 
813     // Create either a empty rect or a non-empty rect.
814     SkRect rect =
815             random->nextBool() ? SkRect::MakeXYWH(10, 10, 50, 40) : SkRect::MakeXYWH(6, 7, 0, 0);
816     SkScalar minDim = SkMinScalar(rect.width(), rect.height());
817     SkScalar strokeWidth = random->nextUScalar1() * minDim;
818 
819     SkStrokeRec rec(SkStrokeRec::kFill_InitStyle);
820     rec.setStrokeStyle(strokeWidth);
821     rec.setStrokeParams(SkPaint::kButt_Cap,
822                         miterStroke ? SkPaint::kMiter_Join : SkPaint::kBevel_Join, 1.f);
823     SkMatrix matrix = GrTest::TestMatrixRectStaysRect(random);
824     return AAStrokeRectOp::Make(context, std::move(paint), matrix, rect, rec);
825 }
826 
827 #endif
828