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1 /*
2  * Copyright 2014 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/ganesh/effects/GrRRectEffect.h"
9 
10 #include "src/base/SkTLazy.h"
11 #include "src/core/SkRRectPriv.h"
12 #include "src/gpu/KeyBuilder.h"
13 #include "src/gpu/ganesh/GrFragmentProcessor.h"
14 #include "src/gpu/ganesh/GrProcessorUnitTest.h"
15 #include "src/gpu/ganesh/GrShaderCaps.h"
16 #include "src/gpu/ganesh/effects/GrConvexPolyEffect.h"
17 #include "src/gpu/ganesh/effects/GrOvalEffect.h"
18 #include "src/gpu/ganesh/glsl/GrGLSLFragmentShaderBuilder.h"
19 #include "src/gpu/ganesh/glsl/GrGLSLProgramDataManager.h"
20 #include "src/gpu/ganesh/glsl/GrGLSLUniformHandler.h"
21 
22 // The effects defined here only handle rrect radii >= kRadiusMin.
23 static const SkScalar kRadiusMin = SK_ScalarHalf;
24 
25 //////////////////////////////////////////////////////////////////////////////
26 
27 namespace {
28 class CircularRRectEffect : public GrFragmentProcessor {
29 public:
30     enum CornerFlags {
31         kTopLeft_CornerFlag     = (1 << SkRRect::kUpperLeft_Corner),
32         kTopRight_CornerFlag    = (1 << SkRRect::kUpperRight_Corner),
33         kBottomRight_CornerFlag = (1 << SkRRect::kLowerRight_Corner),
34         kBottomLeft_CornerFlag  = (1 << SkRRect::kLowerLeft_Corner),
35 
36         kLeft_CornerFlags   = kTopLeft_CornerFlag    | kBottomLeft_CornerFlag,
37         kTop_CornerFlags    = kTopLeft_CornerFlag    | kTopRight_CornerFlag,
38         kRight_CornerFlags  = kTopRight_CornerFlag   | kBottomRight_CornerFlag,
39         kBottom_CornerFlags = kBottomLeft_CornerFlag | kBottomRight_CornerFlag,
40 
41         kAll_CornerFlags = kTopLeft_CornerFlag    | kTopRight_CornerFlag |
42                            kBottomLeft_CornerFlag | kBottomRight_CornerFlag,
43 
44         kNone_CornerFlags = 0
45     };
46 
47     // The flags are used to indicate which corners are circluar (unflagged corners are assumed to
48     // be square).
49     static GrFPResult Make(std::unique_ptr<GrFragmentProcessor>, GrClipEdgeType,
50                            uint32_t circularCornerFlags, const SkRRect&);
51 
~CircularRRectEffect()52     ~CircularRRectEffect() override {}
53 
name() const54     const char* name() const override { return "CircularRRect"; }
55 
56     std::unique_ptr<GrFragmentProcessor> clone() const override;
57 
58 private:
59     class Impl;
60 
61     CircularRRectEffect(std::unique_ptr<GrFragmentProcessor> inputFP,
62                         GrClipEdgeType, uint32_t circularCornerFlags, const SkRRect&);
63     CircularRRectEffect(const CircularRRectEffect& that);
64 
65     std::unique_ptr<ProgramImpl> onMakeProgramImpl() const override;
66 
67     void onAddToKey(const GrShaderCaps&, skgpu::KeyBuilder*) const override;
68 
69     bool onIsEqual(const GrFragmentProcessor& other) const override;
70 
71     SkRRect           fRRect;
72     GrClipEdgeType    fEdgeType;
73     uint32_t          fCircularCornerFlags;
74 
75     GR_DECLARE_FRAGMENT_PROCESSOR_TEST
76 
77     using INHERITED = GrFragmentProcessor;
78 };
79 }  // anonymous namespace
80 
Make(std::unique_ptr<GrFragmentProcessor> inputFP,GrClipEdgeType edgeType,uint32_t circularCornerFlags,const SkRRect & rrect)81 GrFPResult CircularRRectEffect::Make(std::unique_ptr<GrFragmentProcessor> inputFP,
82                                      GrClipEdgeType edgeType,
83                                      uint32_t circularCornerFlags, const SkRRect& rrect) {
84     if (GrClipEdgeType::kFillAA != edgeType && GrClipEdgeType::kInverseFillAA != edgeType) {
85         return GrFPFailure(std::move(inputFP));
86     }
87     return GrFPSuccess(std::unique_ptr<GrFragmentProcessor>(
88                 new CircularRRectEffect(std::move(inputFP), edgeType, circularCornerFlags, rrect)));
89 }
90 
CircularRRectEffect(std::unique_ptr<GrFragmentProcessor> inputFP,GrClipEdgeType edgeType,uint32_t circularCornerFlags,const SkRRect & rrect)91 CircularRRectEffect::CircularRRectEffect(std::unique_ptr<GrFragmentProcessor> inputFP,
92                                          GrClipEdgeType edgeType,
93                                          uint32_t circularCornerFlags,
94                                          const SkRRect& rrect)
95         : INHERITED(kCircularRRectEffect_ClassID,
96                     ProcessorOptimizationFlags(inputFP.get()) &
97                             kCompatibleWithCoverageAsAlpha_OptimizationFlag)
98         , fRRect(rrect)
99         , fEdgeType(edgeType)
100         , fCircularCornerFlags(circularCornerFlags) {
101     this->registerChild(std::move(inputFP));
102 }
103 
CircularRRectEffect(const CircularRRectEffect & that)104 CircularRRectEffect::CircularRRectEffect(const CircularRRectEffect& that)
105         : INHERITED(that)
106         , fRRect(that.fRRect)
107         , fEdgeType(that.fEdgeType)
108         , fCircularCornerFlags(that.fCircularCornerFlags) {}
109 
clone() const110 std::unique_ptr<GrFragmentProcessor> CircularRRectEffect::clone() const {
111     return std::unique_ptr<GrFragmentProcessor>(new CircularRRectEffect(*this));
112 }
113 
onIsEqual(const GrFragmentProcessor & other) const114 bool CircularRRectEffect::onIsEqual(const GrFragmentProcessor& other) const {
115     const CircularRRectEffect& crre = other.cast<CircularRRectEffect>();
116     // The corner flags are derived from fRRect, so no need to check them.
117     return fEdgeType == crre.fEdgeType && fRRect == crre.fRRect;
118 }
119 
120 //////////////////////////////////////////////////////////////////////////////
121 
GR_DEFINE_FRAGMENT_PROCESSOR_TEST(CircularRRectEffect)122 GR_DEFINE_FRAGMENT_PROCESSOR_TEST(CircularRRectEffect)
123 
124 #if GR_TEST_UTILS
125 std::unique_ptr<GrFragmentProcessor> CircularRRectEffect::TestCreate(GrProcessorTestData* d) {
126     SkScalar w = d->fRandom->nextRangeScalar(20.f, 1000.f);
127     SkScalar h = d->fRandom->nextRangeScalar(20.f, 1000.f);
128     SkScalar r = d->fRandom->nextRangeF(kRadiusMin, 9.f);
129     SkRRect rrect;
130     rrect.setRectXY(SkRect::MakeWH(w, h), r, r);
131     std::unique_ptr<GrFragmentProcessor> fp = d->inputFP();
132     bool success;
133     do {
134         GrClipEdgeType et =
135                 (GrClipEdgeType)d->fRandom->nextULessThan(kGrClipEdgeTypeCnt);
136         std::tie(success, fp) = GrRRectEffect::Make(std::move(fp), et, rrect,
137                                                     *d->caps()->shaderCaps());
138     } while (!success);
139     return fp;
140 }
141 #endif
142 
143 //////////////////////////////////////////////////////////////////////////////
144 
145 class CircularRRectEffect::Impl : public ProgramImpl {
146 public:
147     void emitCode(EmitArgs&) override;
148 
149 private:
150     void onSetData(const GrGLSLProgramDataManager&, const GrFragmentProcessor&) override;
151 
152     GrGLSLProgramDataManager::UniformHandle fInnerRectUniform;
153     GrGLSLProgramDataManager::UniformHandle fRadiusPlusHalfUniform;
154     SkRRect                                 fPrevRRect;
155 };
156 
emitCode(EmitArgs & args)157 void CircularRRectEffect::Impl::emitCode(EmitArgs& args) {
158     const CircularRRectEffect& crre = args.fFp.cast<CircularRRectEffect>();
159     GrGLSLUniformHandler* uniformHandler = args.fUniformHandler;
160     const char *rectName;
161     const char *radiusPlusHalfName;
162     // The inner rect is the rrect bounds inset by the radius. Its left, top, right, and bottom
163     // edges correspond to components x, y, z, and w, respectively. When a side of the rrect has
164     // only rectangular corners, that side's value corresponds to the rect edge's value outset by
165     // half a pixel.
166     fInnerRectUniform = uniformHandler->addUniform(&crre, kFragment_GrShaderFlag, SkSLType::kFloat4,
167                                                    "innerRect", &rectName);
168     // x is (r + .5) and y is 1/(r + .5)
169     fRadiusPlusHalfUniform = uniformHandler->addUniform(&crre, kFragment_GrShaderFlag,
170                                                         SkSLType::kHalf2, "radiusPlusHalf",
171                                                         &radiusPlusHalfName);
172 
173     // If we're on a device where float != fp32 then the length calculation could overflow.
174     SkString clampedCircleDistance;
175     if (!args.fShaderCaps->fFloatIs32Bits) {
176         clampedCircleDistance.printf("saturate(%s.x * (1.0 - length(dxy * %s.y)))",
177                                      radiusPlusHalfName, radiusPlusHalfName);
178     } else {
179         clampedCircleDistance.printf("saturate(%s.x - length(dxy))", radiusPlusHalfName);
180     }
181 
182     GrGLSLFPFragmentBuilder* fragBuilder = args.fFragBuilder;
183     // At each quarter-circle corner we compute a vector that is the offset of the fragment position
184     // from the circle center. The vector is pinned in x and y to be in the quarter-plane relevant
185     // to that corner. This means that points near the interior near the rrect top edge will have
186     // a vector that points straight up for both the TL left and TR corners. Computing an
187     // alpha from this vector at either the TR or TL corner will give the correct result. Similarly,
188     // fragments near the other three edges will get the correct AA. Fragments in the interior of
189     // the rrect will have a (0,0) vector at all four corners. So long as the radius > 0.5 they will
190     // correctly produce an alpha value of 1 at all four corners. We take the min of all the alphas.
191     // The code below is a simplified version of the above that performs maxs on the vector
192     // components before computing distances and alpha values so that only one distance computation
193     // need be computed to determine the min alpha.
194     //
195     // For the cases where one half of the rrect is rectangular we drop one of the x or y
196     // computations, compute a separate rect edge alpha for the rect side, and mul the two computed
197     // alphas together.
198     switch (crre.fCircularCornerFlags) {
199         case CircularRRectEffect::kAll_CornerFlags:
200             fragBuilder->codeAppendf("float2 dxy0 = %s.LT - sk_FragCoord.xy;", rectName);
201             fragBuilder->codeAppendf("float2 dxy1 = sk_FragCoord.xy - %s.RB;", rectName);
202             fragBuilder->codeAppend("float2 dxy = max(max(dxy0, dxy1), 0.0);");
203             fragBuilder->codeAppendf("half alpha = half(%s);", clampedCircleDistance.c_str());
204             break;
205         case CircularRRectEffect::kTopLeft_CornerFlag:
206             fragBuilder->codeAppendf("float2 dxy = max(%s.LT - sk_FragCoord.xy, 0.0);",
207                                      rectName);
208             fragBuilder->codeAppendf("half rightAlpha = half(saturate(%s.R - sk_FragCoord.x));",
209                                      rectName);
210             fragBuilder->codeAppendf("half bottomAlpha = half(saturate(%s.B - sk_FragCoord.y));",
211                                      rectName);
212             fragBuilder->codeAppendf("half alpha = bottomAlpha * rightAlpha * half(%s);",
213                                      clampedCircleDistance.c_str());
214             break;
215         case CircularRRectEffect::kTopRight_CornerFlag:
216             fragBuilder->codeAppendf("float2 dxy = max(float2(sk_FragCoord.x - %s.R, "
217                                                              "%s.T - sk_FragCoord.y), 0.0);",
218                                      rectName, rectName);
219             fragBuilder->codeAppendf("half leftAlpha = half(saturate(sk_FragCoord.x - %s.L));",
220                                      rectName);
221             fragBuilder->codeAppendf("half bottomAlpha = half(saturate(%s.B - sk_FragCoord.y));",
222                                      rectName);
223             fragBuilder->codeAppendf("half alpha = bottomAlpha * leftAlpha * half(%s);",
224                                      clampedCircleDistance.c_str());
225             break;
226         case CircularRRectEffect::kBottomRight_CornerFlag:
227             fragBuilder->codeAppendf("float2 dxy = max(sk_FragCoord.xy - %s.RB, 0.0);",
228                                      rectName);
229             fragBuilder->codeAppendf("half leftAlpha = half(saturate(sk_FragCoord.x - %s.L));",
230                                      rectName);
231             fragBuilder->codeAppendf("half topAlpha = half(saturate(sk_FragCoord.y - %s.T));",
232                                      rectName);
233             fragBuilder->codeAppendf("half alpha = topAlpha * leftAlpha * half(%s);",
234                                      clampedCircleDistance.c_str());
235             break;
236         case CircularRRectEffect::kBottomLeft_CornerFlag:
237             fragBuilder->codeAppendf("float2 dxy = max(float2(%s.L - sk_FragCoord.x, "
238                                                              "sk_FragCoord.y - %s.B), 0.0);",
239                                      rectName, rectName);
240             fragBuilder->codeAppendf("half rightAlpha = half(saturate(%s.R - sk_FragCoord.x));",
241                                      rectName);
242             fragBuilder->codeAppendf("half topAlpha = half(saturate(sk_FragCoord.y - %s.T));",
243                                      rectName);
244             fragBuilder->codeAppendf("half alpha = topAlpha * rightAlpha * half(%s);",
245                                      clampedCircleDistance.c_str());
246             break;
247         case CircularRRectEffect::kLeft_CornerFlags:
248             fragBuilder->codeAppendf("float2 dxy0 = %s.LT - sk_FragCoord.xy;", rectName);
249             fragBuilder->codeAppendf("float dy1 = sk_FragCoord.y - %s.B;", rectName);
250             fragBuilder->codeAppend("float2 dxy = max(float2(dxy0.x, max(dxy0.y, dy1)), 0.0);");
251             fragBuilder->codeAppendf("half rightAlpha = half(saturate(%s.R - sk_FragCoord.x));",
252                                      rectName);
253             fragBuilder->codeAppendf("half alpha = rightAlpha * half(%s);",
254                                      clampedCircleDistance.c_str());
255             break;
256         case CircularRRectEffect::kTop_CornerFlags:
257             fragBuilder->codeAppendf("float2 dxy0 = %s.LT - sk_FragCoord.xy;", rectName);
258             fragBuilder->codeAppendf("float dx1 = sk_FragCoord.x - %s.R;", rectName);
259             fragBuilder->codeAppend("float2 dxy = max(float2(max(dxy0.x, dx1), dxy0.y), 0.0);");
260             fragBuilder->codeAppendf("half bottomAlpha = half(saturate(%s.B - sk_FragCoord.y));",
261                                      rectName);
262             fragBuilder->codeAppendf("half alpha = bottomAlpha * half(%s);",
263                                      clampedCircleDistance.c_str());
264             break;
265         case CircularRRectEffect::kRight_CornerFlags:
266             fragBuilder->codeAppendf("float dy0 = %s.T - sk_FragCoord.y;", rectName);
267             fragBuilder->codeAppendf("float2 dxy1 = sk_FragCoord.xy - %s.RB;", rectName);
268             fragBuilder->codeAppend("float2 dxy = max(float2(dxy1.x, max(dy0, dxy1.y)), 0.0);");
269             fragBuilder->codeAppendf("half leftAlpha = half(saturate(sk_FragCoord.x - %s.L));",
270                                      rectName);
271             fragBuilder->codeAppendf("half alpha = leftAlpha * half(%s);",
272                                      clampedCircleDistance.c_str());
273             break;
274         case CircularRRectEffect::kBottom_CornerFlags:
275             fragBuilder->codeAppendf("float dx0 = %s.L - sk_FragCoord.x;", rectName);
276             fragBuilder->codeAppendf("float2 dxy1 = sk_FragCoord.xy - %s.RB;", rectName);
277             fragBuilder->codeAppend("float2 dxy = max(float2(max(dx0, dxy1.x), dxy1.y), 0.0);");
278             fragBuilder->codeAppendf("half topAlpha = half(saturate(sk_FragCoord.y - %s.T));",
279                                      rectName);
280             fragBuilder->codeAppendf("half alpha = topAlpha * half(%s);",
281                                      clampedCircleDistance.c_str());
282             break;
283     }
284 
285     if (GrClipEdgeType::kInverseFillAA == crre.fEdgeType) {
286         fragBuilder->codeAppend("alpha = 1.0 - alpha;");
287     }
288 
289     SkString inputSample = this->invokeChild(/*childIndex=*/0, args);
290 
291     fragBuilder->codeAppendf("return %s * alpha;", inputSample.c_str());
292 }
293 
onSetData(const GrGLSLProgramDataManager & pdman,const GrFragmentProcessor & processor)294 void CircularRRectEffect::Impl::onSetData(const GrGLSLProgramDataManager& pdman,
295                                           const GrFragmentProcessor& processor) {
296     const CircularRRectEffect& crre = processor.cast<CircularRRectEffect>();
297     const SkRRect& rrect = crre.fRRect;
298     if (rrect != fPrevRRect) {
299         SkRect rect = rrect.getBounds();
300         SkScalar radius = 0;
301         switch (crre.fCircularCornerFlags) {
302             case CircularRRectEffect::kAll_CornerFlags:
303                 SkASSERT(SkRRectPriv::IsSimpleCircular(rrect));
304                 radius = SkRRectPriv::GetSimpleRadii(rrect).fX;
305                 SkASSERT(radius >= kRadiusMin);
306                 rect.inset(radius, radius);
307                 break;
308             case CircularRRectEffect::kTopLeft_CornerFlag:
309                 radius = rrect.radii(SkRRect::kUpperLeft_Corner).fX;
310                 rect.fLeft += radius;
311                 rect.fTop += radius;
312                 rect.fRight += 0.5f;
313                 rect.fBottom += 0.5f;
314                 break;
315             case CircularRRectEffect::kTopRight_CornerFlag:
316                 radius = rrect.radii(SkRRect::kUpperRight_Corner).fX;
317                 rect.fLeft -= 0.5f;
318                 rect.fTop += radius;
319                 rect.fRight -= radius;
320                 rect.fBottom += 0.5f;
321                 break;
322             case CircularRRectEffect::kBottomRight_CornerFlag:
323                 radius = rrect.radii(SkRRect::kLowerRight_Corner).fX;
324                 rect.fLeft -= 0.5f;
325                 rect.fTop -= 0.5f;
326                 rect.fRight -= radius;
327                 rect.fBottom -= radius;
328                 break;
329             case CircularRRectEffect::kBottomLeft_CornerFlag:
330                 radius = rrect.radii(SkRRect::kLowerLeft_Corner).fX;
331                 rect.fLeft += radius;
332                 rect.fTop -= 0.5f;
333                 rect.fRight += 0.5f;
334                 rect.fBottom -= radius;
335                 break;
336             case CircularRRectEffect::kLeft_CornerFlags:
337                 radius = rrect.radii(SkRRect::kUpperLeft_Corner).fX;
338                 rect.fLeft += radius;
339                 rect.fTop += radius;
340                 rect.fRight += 0.5f;
341                 rect.fBottom -= radius;
342                 break;
343             case CircularRRectEffect::kTop_CornerFlags:
344                 radius = rrect.radii(SkRRect::kUpperLeft_Corner).fX;
345                 rect.fLeft += radius;
346                 rect.fTop += radius;
347                 rect.fRight -= radius;
348                 rect.fBottom += 0.5f;
349                 break;
350             case CircularRRectEffect::kRight_CornerFlags:
351                 radius = rrect.radii(SkRRect::kUpperRight_Corner).fX;
352                 rect.fLeft -= 0.5f;
353                 rect.fTop += radius;
354                 rect.fRight -= radius;
355                 rect.fBottom -= radius;
356                 break;
357             case CircularRRectEffect::kBottom_CornerFlags:
358                 radius = rrect.radii(SkRRect::kLowerLeft_Corner).fX;
359                 rect.fLeft += radius;
360                 rect.fTop -= 0.5f;
361                 rect.fRight -= radius;
362                 rect.fBottom -= radius;
363                 break;
364             default:
365                 SK_ABORT("Should have been one of the above cases.");
366         }
367         pdman.set4f(fInnerRectUniform, rect.fLeft, rect.fTop, rect.fRight, rect.fBottom);
368         radius += 0.5f;
369         pdman.set2f(fRadiusPlusHalfUniform, radius, 1.f / radius);
370         fPrevRRect = rrect;
371     }
372 }
373 
374 ////////////////////////////////////////////////////////////////////////////////////////////////////
375 
onAddToKey(const GrShaderCaps & caps,skgpu::KeyBuilder * b) const376 void CircularRRectEffect::onAddToKey(const GrShaderCaps& caps, skgpu::KeyBuilder* b) const {
377     static_assert(kGrClipEdgeTypeCnt <= 8);
378     b->add32((fCircularCornerFlags << 3) | static_cast<int>(fEdgeType));
379 }
380 
onMakeProgramImpl() const381 std::unique_ptr<GrFragmentProcessor::ProgramImpl> CircularRRectEffect::onMakeProgramImpl() const {
382     return std::make_unique<Impl>();
383 }
384 
385 //////////////////////////////////////////////////////////////////////////////
386 
387 namespace {
388 class EllipticalRRectEffect : public GrFragmentProcessor {
389 public:
390     static GrFPResult Make(std::unique_ptr<GrFragmentProcessor>, GrClipEdgeType, const SkRRect&);
391 
~EllipticalRRectEffect()392     ~EllipticalRRectEffect() override {}
393 
name() const394     const char* name() const override { return "EllipticalRRect"; }
395 
396     std::unique_ptr<GrFragmentProcessor> clone() const override;
397 
398 private:
399     class Impl;
400 
401     EllipticalRRectEffect(std::unique_ptr<GrFragmentProcessor>, GrClipEdgeType, const SkRRect&);
402     EllipticalRRectEffect(const EllipticalRRectEffect& that);
403 
404     std::unique_ptr<ProgramImpl> onMakeProgramImpl() const override;
405 
406     void onAddToKey(const GrShaderCaps&, skgpu::KeyBuilder*) const override;
407 
408     bool onIsEqual(const GrFragmentProcessor& other) const override;
409 
410     SkRRect fRRect;
411     GrClipEdgeType fEdgeType;
412 
413     GR_DECLARE_FRAGMENT_PROCESSOR_TEST
414 
415     using INHERITED = GrFragmentProcessor;
416 };
417 
Make(std::unique_ptr<GrFragmentProcessor> inputFP,GrClipEdgeType edgeType,const SkRRect & rrect)418 GrFPResult EllipticalRRectEffect::Make(std::unique_ptr<GrFragmentProcessor> inputFP,
419                                        GrClipEdgeType edgeType,
420                                        const SkRRect& rrect) {
421     if (GrClipEdgeType::kFillAA != edgeType && GrClipEdgeType::kInverseFillAA != edgeType) {
422         return GrFPFailure(std::move(inputFP));
423     }
424     return GrFPSuccess(std::unique_ptr<GrFragmentProcessor>(
425             new EllipticalRRectEffect(std::move(inputFP), edgeType, rrect)));
426 }
427 
EllipticalRRectEffect(std::unique_ptr<GrFragmentProcessor> inputFP,GrClipEdgeType edgeType,const SkRRect & rrect)428 EllipticalRRectEffect::EllipticalRRectEffect(std::unique_ptr<GrFragmentProcessor> inputFP,
429                                              GrClipEdgeType edgeType,
430                                              const SkRRect& rrect)
431         : INHERITED(kEllipticalRRectEffect_ClassID,
432                     ProcessorOptimizationFlags(inputFP.get()) &
433                             kCompatibleWithCoverageAsAlpha_OptimizationFlag)
434         , fRRect(rrect)
435         , fEdgeType(edgeType) {
436     this->registerChild(std::move(inputFP));
437 }
438 
EllipticalRRectEffect(const EllipticalRRectEffect & that)439 EllipticalRRectEffect::EllipticalRRectEffect(const EllipticalRRectEffect& that)
440         : INHERITED(that)
441         , fRRect(that.fRRect)
442         , fEdgeType(that.fEdgeType) {}
443 
clone() const444 std::unique_ptr<GrFragmentProcessor> EllipticalRRectEffect::clone() const {
445     return std::unique_ptr<GrFragmentProcessor>(new EllipticalRRectEffect(*this));
446 }
447 
onIsEqual(const GrFragmentProcessor & other) const448 bool EllipticalRRectEffect::onIsEqual(const GrFragmentProcessor& other) const {
449     const EllipticalRRectEffect& erre = other.cast<EllipticalRRectEffect>();
450     return fEdgeType == erre.fEdgeType && fRRect == erre.fRRect;
451 }
452 }  // anonymous namespace
453 
454 //////////////////////////////////////////////////////////////////////////////
455 
GR_DEFINE_FRAGMENT_PROCESSOR_TEST(EllipticalRRectEffect)456 GR_DEFINE_FRAGMENT_PROCESSOR_TEST(EllipticalRRectEffect)
457 
458 #if GR_TEST_UTILS
459 std::unique_ptr<GrFragmentProcessor> EllipticalRRectEffect::TestCreate(GrProcessorTestData* d) {
460     SkScalar w = d->fRandom->nextRangeScalar(20.f, 1000.f);
461     SkScalar h = d->fRandom->nextRangeScalar(20.f, 1000.f);
462     SkVector r[4];
463     r[SkRRect::kUpperLeft_Corner].fX = d->fRandom->nextRangeF(kRadiusMin, 9.f);
464     // ensure at least one corner really is elliptical
465     do {
466         r[SkRRect::kUpperLeft_Corner].fY = d->fRandom->nextRangeF(kRadiusMin, 9.f);
467     } while (r[SkRRect::kUpperLeft_Corner].fY == r[SkRRect::kUpperLeft_Corner].fX);
468 
469     SkRRect rrect;
470     if (d->fRandom->nextBool()) {
471         // half the time create a four-radii rrect.
472         r[SkRRect::kLowerRight_Corner].fX = d->fRandom->nextRangeF(kRadiusMin, 9.f);
473         r[SkRRect::kLowerRight_Corner].fY = d->fRandom->nextRangeF(kRadiusMin, 9.f);
474 
475         r[SkRRect::kUpperRight_Corner].fX = r[SkRRect::kLowerRight_Corner].fX;
476         r[SkRRect::kUpperRight_Corner].fY = r[SkRRect::kUpperLeft_Corner].fY;
477 
478         r[SkRRect::kLowerLeft_Corner].fX = r[SkRRect::kUpperLeft_Corner].fX;
479         r[SkRRect::kLowerLeft_Corner].fY = r[SkRRect::kLowerRight_Corner].fY;
480 
481         rrect.setRectRadii(SkRect::MakeWH(w, h), r);
482     } else {
483         rrect.setRectXY(SkRect::MakeWH(w, h), r[SkRRect::kUpperLeft_Corner].fX,
484                                               r[SkRRect::kUpperLeft_Corner].fY);
485     }
486     std::unique_ptr<GrFragmentProcessor> fp = d->inputFP();
487     bool success;
488     do {
489         GrClipEdgeType et = (GrClipEdgeType)d->fRandom->nextULessThan(kGrClipEdgeTypeCnt);
490         std::tie(success, fp) = GrRRectEffect::Make(std::move(fp), et, rrect,
491                                                     *d->caps()->shaderCaps());
492     } while (!success);
493     return fp;
494 }
495 #endif
496 
497 //////////////////////////////////////////////////////////////////////////////
498 
elliptical_effect_uses_scale(const GrShaderCaps & caps,const SkRRect & rrect)499 static bool elliptical_effect_uses_scale(const GrShaderCaps& caps, const SkRRect& rrect) {
500     // If we're on a device where float != fp32 then we'll do the distance computation in a space
501     // that is normalized by the largest radius. The scale uniform will be scale, 1/scale. The
502     // radii uniform values are already in this normalized space.
503     if (!caps.fFloatIs32Bits) {
504         return true;
505     }
506     // Additionally, even if we have fp32, large radii can underflow 1/radii^2 terms leading to
507     // blurry coverage. This effect applies to simple and nine-patch, so only need to check TL+BR
508     const SkVector& r0 = rrect.radii(SkRRect::kUpperLeft_Corner);
509     const SkVector& r1 = rrect.radii(SkRRect::kLowerRight_Corner);
510     float maxRadius = std::max(std::max(r0.fX, r0.fY), std::max(r1.fX, r1.fY));
511     return SkScalarNearlyZero(1.f / (maxRadius * maxRadius));
512 }
513 
514 class EllipticalRRectEffect::Impl : public ProgramImpl {
515 public:
516     void emitCode(EmitArgs&) override;
517 
518 private:
519     void onSetData(const GrGLSLProgramDataManager&, const GrFragmentProcessor&) override;
520 
521     GrGLSLProgramDataManager::UniformHandle fInnerRectUniform;
522     GrGLSLProgramDataManager::UniformHandle fInvRadiiSqdUniform;
523     GrGLSLProgramDataManager::UniformHandle fScaleUniform;
524     SkRRect                                 fPrevRRect;
525 };
526 
emitCode(EmitArgs & args)527 void EllipticalRRectEffect::Impl::emitCode(EmitArgs& args) {
528     const EllipticalRRectEffect& erre = args.fFp.cast<EllipticalRRectEffect>();
529     GrGLSLUniformHandler* uniformHandler = args.fUniformHandler;
530     const char *rectName;
531     // The inner rect is the rrect bounds inset by the x/y radii
532     fInnerRectUniform = uniformHandler->addUniform(&erre, kFragment_GrShaderFlag, SkSLType::kFloat4,
533                                                    "innerRect", &rectName);
534 
535     GrGLSLFPFragmentBuilder* fragBuilder = args.fFragBuilder;
536     // At each quarter-ellipse corner we compute a vector that is the offset of the fragment pos
537     // to the ellipse center. The vector is pinned in x and y to be in the quarter-plane relevant
538     // to that corner. This means that points near the interior near the rrect top edge will have
539     // a vector that points straight up for both the TL left and TR corners. Computing an
540     // alpha from this vector at either the TR or TL corner will give the correct result. Similarly,
541     // fragments near the other three edges will get the correct AA. Fragments in the interior of
542     // the rrect will have a (0,0) vector at all four corners. So long as the radii > 0.5 they will
543     // correctly produce an alpha value of 1 at all four corners. We take the min of all the alphas.
544     //
545     // The code below is a simplified version of the above that performs maxs on the vector
546     // components before computing distances and alpha values so that only one distance computation
547     // need be computed to determine the min alpha.
548     fragBuilder->codeAppendf("float2 dxy0 = %s.LT - sk_FragCoord.xy;", rectName);
549     fragBuilder->codeAppendf("float2 dxy1 = sk_FragCoord.xy - %s.RB;", rectName);
550 
551 
552     const char* scaleName = nullptr;
553     if (elliptical_effect_uses_scale(*args.fShaderCaps, erre.fRRect)) {
554         fScaleUniform = uniformHandler->addUniform(&erre, kFragment_GrShaderFlag, SkSLType::kHalf2,
555                                                    "scale", &scaleName);
556     }
557 
558     // The uniforms with the inv squared radii are highp to prevent underflow.
559     switch (erre.fRRect.getType()) {
560         case SkRRect::kSimple_Type: {
561             const char *invRadiiXYSqdName;
562             fInvRadiiSqdUniform = uniformHandler->addUniform(&erre,
563                                                              kFragment_GrShaderFlag,
564                                                              SkSLType::kFloat2,
565                                                              "invRadiiXY",
566                                                              &invRadiiXYSqdName);
567             fragBuilder->codeAppend("float2 dxy = max(max(dxy0, dxy1), 0.0);");
568             if (scaleName) {
569                 fragBuilder->codeAppendf("dxy *= %s.y;", scaleName);
570             }
571             // Z is the x/y offsets divided by squared radii.
572             fragBuilder->codeAppendf("float2 Z = dxy * %s.xy;", invRadiiXYSqdName);
573             break;
574         }
575         case SkRRect::kNinePatch_Type: {
576             const char *invRadiiLTRBSqdName;
577             fInvRadiiSqdUniform = uniformHandler->addUniform(&erre,
578                                                              kFragment_GrShaderFlag,
579                                                              SkSLType::kFloat4,
580                                                              "invRadiiLTRB",
581                                                              &invRadiiLTRBSqdName);
582             if (scaleName) {
583                 fragBuilder->codeAppendf("dxy0 *= %s.y;", scaleName);
584                 fragBuilder->codeAppendf("dxy1 *= %s.y;", scaleName);
585             }
586             fragBuilder->codeAppend("float2 dxy = max(max(dxy0, dxy1), 0.0);");
587             // Z is the x/y offsets divided by squared radii. We only care about the (at most) one
588             // corner where both the x and y offsets are positive, hence the maxes. (The inverse
589             // squared radii will always be positive.)
590             fragBuilder->codeAppendf("float2 Z = max(max(dxy0 * %s.xy, dxy1 * %s.zw), 0.0);",
591                                      invRadiiLTRBSqdName, invRadiiLTRBSqdName);
592 
593             break;
594         }
595         default:
596             SK_ABORT("RRect should always be simple or nine-patch.");
597     }
598     // implicit is the evaluation of (x/a)^2 + (y/b)^2 - 1.
599     fragBuilder->codeAppend("half implicit = half(dot(Z, dxy) - 1.0);");
600     // grad_dot is the squared length of the gradient of the implicit.
601     fragBuilder->codeAppend("half grad_dot = half(4.0 * dot(Z, Z));");
602     // avoid calling inversesqrt on zero.
603     fragBuilder->codeAppend("grad_dot = max(grad_dot, 1.0e-4);");
604     fragBuilder->codeAppend("half approx_dist = implicit * half(inversesqrt(grad_dot));");
605     if (scaleName) {
606         fragBuilder->codeAppendf("approx_dist *= %s.x;", scaleName);
607     }
608 
609     if (erre.fEdgeType == GrClipEdgeType::kFillAA) {
610         fragBuilder->codeAppend("half alpha = clamp(0.5 - approx_dist, 0.0, 1.0);");
611     } else {
612         fragBuilder->codeAppend("half alpha = clamp(0.5 + approx_dist, 0.0, 1.0);");
613     }
614 
615     SkString inputSample = this->invokeChild(/*childIndex=*/0, args);
616 
617     fragBuilder->codeAppendf("return %s * alpha;", inputSample.c_str());
618 }
619 
onSetData(const GrGLSLProgramDataManager & pdman,const GrFragmentProcessor & effect)620 void EllipticalRRectEffect::Impl::onSetData(const GrGLSLProgramDataManager& pdman,
621                                             const GrFragmentProcessor& effect) {
622     const EllipticalRRectEffect& erre = effect.cast<EllipticalRRectEffect>();
623     const SkRRect& rrect = erre.fRRect;
624     // If we're using a scale factor to work around precision issues, choose the largest radius
625     // as the scale factor. The inv radii need to be pre-adjusted by the scale factor.
626     if (rrect != fPrevRRect) {
627         SkRect rect = rrect.getBounds();
628         const SkVector& r0 = rrect.radii(SkRRect::kUpperLeft_Corner);
629         SkASSERT(r0.fX >= kRadiusMin);
630         SkASSERT(r0.fY >= kRadiusMin);
631         switch (rrect.getType()) {
632             case SkRRect::kSimple_Type:
633                 rect.inset(r0.fX, r0.fY);
634                 if (fScaleUniform.isValid()) {
635                     if (r0.fX > r0.fY) {
636                         pdman.set2f(fInvRadiiSqdUniform, 1.f, (r0.fX * r0.fX) / (r0.fY * r0.fY));
637                         pdman.set2f(fScaleUniform, r0.fX, 1.f / r0.fX);
638                     } else {
639                         pdman.set2f(fInvRadiiSqdUniform, (r0.fY * r0.fY) / (r0.fX * r0.fX), 1.f);
640                         pdman.set2f(fScaleUniform, r0.fY, 1.f / r0.fY);
641                     }
642                 } else {
643                     pdman.set2f(fInvRadiiSqdUniform, 1.f / (r0.fX * r0.fX),
644                                                      1.f / (r0.fY * r0.fY));
645                 }
646                 break;
647             case SkRRect::kNinePatch_Type: {
648                 const SkVector& r1 = rrect.radii(SkRRect::kLowerRight_Corner);
649                 SkASSERT(r1.fX >= kRadiusMin);
650                 SkASSERT(r1.fY >= kRadiusMin);
651                 rect.fLeft += r0.fX;
652                 rect.fTop += r0.fY;
653                 rect.fRight -= r1.fX;
654                 rect.fBottom -= r1.fY;
655                 if (fScaleUniform.isValid()) {
656                     float scale = std::max(std::max(r0.fX, r0.fY), std::max(r1.fX, r1.fY));
657                     float scaleSqd = scale * scale;
658                     pdman.set4f(fInvRadiiSqdUniform, scaleSqd / (r0.fX * r0.fX),
659                                                      scaleSqd / (r0.fY * r0.fY),
660                                                      scaleSqd / (r1.fX * r1.fX),
661                                                      scaleSqd / (r1.fY * r1.fY));
662                     pdman.set2f(fScaleUniform, scale, 1.f / scale);
663                 } else {
664                     pdman.set4f(fInvRadiiSqdUniform, 1.f / (r0.fX * r0.fX),
665                                                      1.f / (r0.fY * r0.fY),
666                                                      1.f / (r1.fX * r1.fX),
667                                                      1.f / (r1.fY * r1.fY));
668                 }
669                 break;
670             }
671         default:
672             SK_ABORT("RRect should always be simple or nine-patch.");
673         }
674         pdman.set4f(fInnerRectUniform, rect.fLeft, rect.fTop, rect.fRight, rect.fBottom);
675         fPrevRRect = rrect;
676     }
677 }
678 
679 ////////////////////////////////////////////////////////////////////////////////////////////////////
680 
onAddToKey(const GrShaderCaps & caps,skgpu::KeyBuilder * b) const681 void EllipticalRRectEffect::onAddToKey(const GrShaderCaps& caps, skgpu::KeyBuilder* b) const {
682     static_assert(kGrClipEdgeTypeCnt <= 4); // 2 bits
683     static_assert((int)SkRRect::kLastType + 1 <= 8); // 3 bits
684     b->addBits(2, static_cast<int>(fEdgeType), "edge_type");
685     b->addBits(3, static_cast<int>(fRRect.getType()), "rrect_type");
686     b->addBool(elliptical_effect_uses_scale(caps, fRRect), "scale_radii");
687 }
688 
onMakeProgramImpl() const689 std::unique_ptr<GrFragmentProcessor::ProgramImpl> EllipticalRRectEffect::onMakeProgramImpl() const {
690     return std::make_unique<Impl>();
691 }
692 
693 //////////////////////////////////////////////////////////////////////////////
694 
Make(std::unique_ptr<GrFragmentProcessor> inputFP,GrClipEdgeType edgeType,const SkRRect & rrect,const GrShaderCaps & caps)695 GrFPResult GrRRectEffect::Make(std::unique_ptr<GrFragmentProcessor> inputFP,
696                                GrClipEdgeType edgeType, const SkRRect& rrect,
697                                const GrShaderCaps& caps) {
698     if (rrect.isRect()) {
699         auto fp = GrFragmentProcessor::Rect(std::move(inputFP), edgeType, rrect.getBounds());
700         return GrFPSuccess(std::move(fp));
701     }
702 
703     if (rrect.isOval()) {
704         return GrOvalEffect::Make(std::move(inputFP), edgeType, rrect.getBounds(), caps);
705     }
706 
707     if (rrect.isSimple()) {
708         if (SkRRectPriv::GetSimpleRadii(rrect).fX < kRadiusMin ||
709             SkRRectPriv::GetSimpleRadii(rrect).fY < kRadiusMin) {
710             // In this case the corners are extremely close to rectangular and we collapse the
711             // clip to a rectangular clip.
712             auto fp = GrFragmentProcessor::Rect(std::move(inputFP), edgeType, rrect.getBounds());
713             return GrFPSuccess(std::move(fp));
714         }
715         if (SkRRectPriv::IsSimpleCircular(rrect)) {
716             return CircularRRectEffect::Make(std::move(inputFP), edgeType,
717                                              CircularRRectEffect::kAll_CornerFlags, rrect);
718         } else {
719             return EllipticalRRectEffect::Make(std::move(inputFP), edgeType, rrect);
720         }
721     }
722 
723     if (rrect.isComplex() || rrect.isNinePatch()) {
724         // Check for the "tab" cases - two adjacent circular corners and two square corners.
725         SkScalar circularRadius = 0;
726         uint32_t cornerFlags  = 0;
727 
728         SkVector radii[4];
729         bool squashedRadii = false;
730         for (int c = 0; c < 4; ++c) {
731             radii[c] = rrect.radii((SkRRect::Corner)c);
732             SkASSERT((0 == radii[c].fX) == (0 == radii[c].fY));
733             if (0 == radii[c].fX) {
734                 // The corner is square, so no need to squash or flag as circular.
735                 continue;
736             }
737             if (radii[c].fX < kRadiusMin || radii[c].fY < kRadiusMin) {
738                 radii[c].set(0, 0);
739                 squashedRadii = true;
740                 continue;
741             }
742             if (radii[c].fX != radii[c].fY) {
743                 cornerFlags = ~0U;
744                 break;
745             }
746             if (!cornerFlags) {
747                 circularRadius = radii[c].fX;
748                 cornerFlags = 1 << c;
749             } else {
750                 if (radii[c].fX != circularRadius) {
751                    cornerFlags = ~0U;
752                    break;
753                 }
754                 cornerFlags |= 1 << c;
755             }
756         }
757 
758         switch (cornerFlags) {
759             case CircularRRectEffect::kAll_CornerFlags:
760                 // This rrect should have been caught in the simple case above. Though, it would
761                 // be correctly handled in the fallthrough code.
762                 SkASSERT(false);
763                 [[fallthrough]];
764             case CircularRRectEffect::kTopLeft_CornerFlag:
765             case CircularRRectEffect::kTopRight_CornerFlag:
766             case CircularRRectEffect::kBottomRight_CornerFlag:
767             case CircularRRectEffect::kBottomLeft_CornerFlag:
768             case CircularRRectEffect::kLeft_CornerFlags:
769             case CircularRRectEffect::kTop_CornerFlags:
770             case CircularRRectEffect::kRight_CornerFlags:
771             case CircularRRectEffect::kBottom_CornerFlags: {
772                 SkTCopyOnFirstWrite<SkRRect> rr(rrect);
773                 if (squashedRadii) {
774                     rr.writable()->setRectRadii(rrect.getBounds(), radii);
775                 }
776                 return CircularRRectEffect::Make(std::move(inputFP), edgeType, cornerFlags, *rr);
777             }
778             case CircularRRectEffect::kNone_CornerFlags: {
779                 auto fp =
780                         GrFragmentProcessor::Rect(std::move(inputFP), edgeType, rrect.getBounds());
781                 return GrFPSuccess(std::move(fp));
782             }
783             default: {
784                 const SkVector ul = rrect.radii(SkRRect::kUpperLeft_Corner);
785                 const SkVector lr = rrect.radii(SkRRect::kLowerRight_Corner);
786                 if (rrect.isNinePatch()  &&
787                     ul.fX >= kRadiusMin  &&
788                     ul.fY >= kRadiusMin  &&
789                     lr.fX >= kRadiusMin  &&
790                     lr.fY >= kRadiusMin) {
791                     return EllipticalRRectEffect::Make(std::move(inputFP), edgeType, rrect);
792                 }
793                 return GrFPFailure(std::move(inputFP));
794             }
795         }
796     }
797     return GrFPFailure(std::move(inputFP));
798 }
799