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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 "GrRRectEffect.h"
9 
10 #include "gl/GrGLEffect.h"
11 #include "gl/GrGLSL.h"
12 #include "GrConvexPolyEffect.h"
13 #include "GrOvalEffect.h"
14 #include "GrTBackendEffectFactory.h"
15 
16 #include "SkRRect.h"
17 
18 // The effects defined here only handle rrect radii >= kRadiusMin.
19 static const SkScalar kRadiusMin = SK_ScalarHalf;
20 
21 //////////////////////////////////////////////////////////////////////////////
22 
23 class GLCircularRRectEffect;
24 
25 class CircularRRectEffect : public GrEffect {
26 public:
27 
28     enum CornerFlags {
29         kTopLeft_CornerFlag     = (1 << SkRRect::kUpperLeft_Corner),
30         kTopRight_CornerFlag    = (1 << SkRRect::kUpperRight_Corner),
31         kBottomRight_CornerFlag = (1 << SkRRect::kLowerRight_Corner),
32         kBottomLeft_CornerFlag  = (1 << SkRRect::kLowerLeft_Corner),
33 
34         kLeft_CornerFlags   = kTopLeft_CornerFlag    | kBottomLeft_CornerFlag,
35         kTop_CornerFlags    = kTopLeft_CornerFlag    | kTopRight_CornerFlag,
36         kRight_CornerFlags  = kTopRight_CornerFlag   | kBottomRight_CornerFlag,
37         kBottom_CornerFlags = kBottomLeft_CornerFlag | kBottomRight_CornerFlag,
38 
39         kAll_CornerFlags = kTopLeft_CornerFlag    | kTopRight_CornerFlag |
40                            kBottomLeft_CornerFlag | kBottomRight_CornerFlag,
41 
42         kNone_CornerFlags = 0
43     };
44 
45     // The flags are used to indicate which corners are circluar (unflagged corners are assumed to
46     // be square).
47     static GrEffectRef* Create(GrEffectEdgeType, uint32_t circularCornerFlags, const SkRRect&);
48 
~CircularRRectEffect()49     virtual ~CircularRRectEffect() {};
Name()50     static const char* Name() { return "CircularRRect"; }
51 
getRRect() const52     const SkRRect& getRRect() const { return fRRect; }
53 
getCircularCornerFlags() const54     uint32_t getCircularCornerFlags() const { return fCircularCornerFlags; }
55 
getEdgeType() const56     GrEffectEdgeType getEdgeType() const { return fEdgeType; }
57 
58     typedef GLCircularRRectEffect GLEffect;
59 
60     virtual void getConstantColorComponents(GrColor* color, uint32_t* validFlags) const SK_OVERRIDE;
61 
62     virtual const GrBackendEffectFactory& getFactory() const SK_OVERRIDE;
63 
64 private:
65     CircularRRectEffect(GrEffectEdgeType, uint32_t circularCornerFlags, const SkRRect&);
66 
67     virtual bool onIsEqual(const GrEffect& other) const SK_OVERRIDE;
68 
69     SkRRect             fRRect;
70     GrEffectEdgeType    fEdgeType;
71     uint32_t            fCircularCornerFlags;
72 
73     GR_DECLARE_EFFECT_TEST;
74 
75     typedef GrEffect INHERITED;
76 };
77 
Create(GrEffectEdgeType edgeType,uint32_t circularCornerFlags,const SkRRect & rrect)78 GrEffectRef* CircularRRectEffect::Create(GrEffectEdgeType edgeType,
79                                  uint32_t circularCornerFlags,
80                                  const SkRRect& rrect) {
81     if (kFillAA_GrEffectEdgeType != edgeType && kInverseFillAA_GrEffectEdgeType != edgeType) {
82         return NULL;
83     }
84     return CreateEffectRef(AutoEffectUnref(SkNEW_ARGS(CircularRRectEffect,
85                                                       (edgeType, circularCornerFlags, rrect))));
86 }
87 
getConstantColorComponents(GrColor * color,uint32_t * validFlags) const88 void CircularRRectEffect::getConstantColorComponents(GrColor* color, uint32_t* validFlags) const {
89     *validFlags = 0;
90 }
91 
getFactory() const92 const GrBackendEffectFactory& CircularRRectEffect::getFactory() const {
93     return GrTBackendEffectFactory<CircularRRectEffect>::getInstance();
94 }
95 
CircularRRectEffect(GrEffectEdgeType edgeType,uint32_t circularCornerFlags,const SkRRect & rrect)96 CircularRRectEffect::CircularRRectEffect(GrEffectEdgeType edgeType, uint32_t circularCornerFlags,
97                          const SkRRect& rrect)
98     : fRRect(rrect)
99     , fEdgeType(edgeType)
100     , fCircularCornerFlags(circularCornerFlags) {
101     this->setWillReadFragmentPosition();
102 }
103 
onIsEqual(const GrEffect & other) const104 bool CircularRRectEffect::onIsEqual(const GrEffect& other) const {
105     const CircularRRectEffect& crre = CastEffect<CircularRRectEffect>(other);
106     // The corner flags are derived from fRRect, so no need to check them.
107     return fEdgeType == crre.fEdgeType && fRRect == crre.fRRect;
108 }
109 
110 //////////////////////////////////////////////////////////////////////////////
111 
112 GR_DEFINE_EFFECT_TEST(CircularRRectEffect);
113 
TestCreate(SkRandom * random,GrContext *,const GrDrawTargetCaps & caps,GrTexture * [])114 GrEffectRef* CircularRRectEffect::TestCreate(SkRandom* random,
115                                      GrContext*,
116                                      const GrDrawTargetCaps& caps,
117                                      GrTexture*[]) {
118     SkScalar w = random->nextRangeScalar(20.f, 1000.f);
119     SkScalar h = random->nextRangeScalar(20.f, 1000.f);
120     SkScalar r = random->nextRangeF(kRadiusMin, 9.f);
121     SkRRect rrect;
122     rrect.setRectXY(SkRect::MakeWH(w, h), r, r);
123     GrEffectRef* effect;
124     do {
125         GrEffectEdgeType et = (GrEffectEdgeType)random->nextULessThan(kGrEffectEdgeTypeCnt);
126         effect = GrRRectEffect::Create(et, rrect);
127     } while (NULL == effect);
128     return effect;
129 }
130 
131 //////////////////////////////////////////////////////////////////////////////
132 
133 class GLCircularRRectEffect : public GrGLEffect {
134 public:
135     GLCircularRRectEffect(const GrBackendEffectFactory&, const GrDrawEffect&);
136 
137     virtual void emitCode(GrGLShaderBuilder* builder,
138                           const GrDrawEffect& drawEffect,
139                           EffectKey key,
140                           const char* outputColor,
141                           const char* inputColor,
142                           const TransformedCoordsArray&,
143                           const TextureSamplerArray&) SK_OVERRIDE;
144 
145     static inline EffectKey GenKey(const GrDrawEffect&, const GrGLCaps&);
146 
147     virtual void setData(const GrGLUniformManager&, const GrDrawEffect&) SK_OVERRIDE;
148 
149 private:
150     GrGLUniformManager::UniformHandle   fInnerRectUniform;
151     GrGLUniformManager::UniformHandle   fRadiusPlusHalfUniform;
152     SkRRect                             fPrevRRect;
153     typedef GrGLEffect INHERITED;
154 };
155 
GLCircularRRectEffect(const GrBackendEffectFactory & factory,const GrDrawEffect & drawEffect)156 GLCircularRRectEffect::GLCircularRRectEffect(const GrBackendEffectFactory& factory,
157                              const GrDrawEffect& drawEffect)
158     : INHERITED (factory) {
159     fPrevRRect.setEmpty();
160 }
161 
emitCode(GrGLShaderBuilder * builder,const GrDrawEffect & drawEffect,EffectKey key,const char * outputColor,const char * inputColor,const TransformedCoordsArray &,const TextureSamplerArray & samplers)162 void GLCircularRRectEffect::emitCode(GrGLShaderBuilder* builder,
163                              const GrDrawEffect& drawEffect,
164                              EffectKey key,
165                              const char* outputColor,
166                              const char* inputColor,
167                              const TransformedCoordsArray&,
168                              const TextureSamplerArray& samplers) {
169     const CircularRRectEffect& crre = drawEffect.castEffect<CircularRRectEffect>();
170     const char *rectName;
171     const char *radiusPlusHalfName;
172     // The inner rect is the rrect bounds inset by the radius. Its left, top, right, and bottom
173     // edges correspond to components x, y, z, and w, respectively. When a side of the rrect has
174     // only rectangular corners, that side's value corresponds to the rect edge's value outset by
175     // half a pixel.
176     fInnerRectUniform = builder->addUniform(GrGLShaderBuilder::kFragment_Visibility,
177                                             kVec4f_GrSLType,
178                                             "innerRect",
179                                             &rectName);
180     fRadiusPlusHalfUniform = builder->addUniform(GrGLShaderBuilder::kFragment_Visibility,
181                                                  kFloat_GrSLType,
182                                                  "radiusPlusHalf",
183                                                  &radiusPlusHalfName);
184     const char* fragmentPos = builder->fragmentPosition();
185     // At each quarter-circle corner we compute a vector that is the offset of the fragment position
186     // from the circle center. The vector is pinned in x and y to be in the quarter-plane relevant
187     // to that corner. This means that points near the interior near the rrect top edge will have
188     // a vector that points straight up for both the TL left and TR corners. Computing an
189     // alpha from this vector at either the TR or TL corner will give the correct result. Similarly,
190     // fragments near the other three edges will get the correct AA. Fragments in the interior of
191     // the rrect will have a (0,0) vector at all four corners. So long as the radius > 0.5 they will
192     // correctly produce an alpha value of 1 at all four corners. We take the min of all the alphas.
193     // The code below is a simplified version of the above that performs maxs on the vector
194     // components before computing distances and alpha values so that only one distance computation
195     // need be computed to determine the min alpha.
196     //
197     // For the cases where one half of the rrect is rectangular we drop one of the x or y
198     // computations, compute a separate rect edge alpha for the rect side, and mul the two computed
199     // alphas together.
200     switch (crre.getCircularCornerFlags()) {
201         case CircularRRectEffect::kAll_CornerFlags:
202             builder->fsCodeAppendf("\t\tvec2 dxy0 = %s.xy - %s;\n", rectName, fragmentPos);
203             builder->fsCodeAppendf("\t\tvec2 dxy1 = %s - %s.zw;\n", fragmentPos, rectName);
204             builder->fsCodeAppend("\t\tvec2 dxy = max(max(dxy0, dxy1), 0.0);\n");
205             builder->fsCodeAppendf("\t\tfloat alpha = clamp(%s - length(dxy), 0.0, 1.0);\n",
206                                    radiusPlusHalfName);
207             break;
208         case CircularRRectEffect::kTopLeft_CornerFlag:
209             builder->fsCodeAppendf("\t\tvec2 dxy = max(%s.xy - %s.xy, 0.0);\n",
210                                    rectName, fragmentPos);
211             builder->fsCodeAppendf("\t\tfloat rightAlpha = clamp(%s.z - %s.x, 0.0, 1.0);\n",
212                                     rectName, fragmentPos);
213             builder->fsCodeAppendf("\t\tfloat bottomAlpha = clamp(%s.w - %s.y, 0.0, 1.0);\n",
214                                     rectName, fragmentPos);
215             builder->fsCodeAppendf("\t\tfloat alpha = bottomAlpha * rightAlpha * clamp(%s - length(dxy), 0.0, 1.0);\n",
216                                    radiusPlusHalfName);
217             break;
218         case CircularRRectEffect::kTopRight_CornerFlag:
219             builder->fsCodeAppendf("\t\tvec2 dxy = max(vec2(%s.x - %s.z, %s.y - %s.y), 0.0);\n",
220                                    fragmentPos, rectName, rectName, fragmentPos);
221             builder->fsCodeAppendf("\t\tfloat leftAlpha = clamp(%s.x - %s.x, 0.0, 1.0);\n",
222                                    fragmentPos, rectName);
223             builder->fsCodeAppendf("\t\tfloat bottomAlpha = clamp(%s.w - %s.y, 0.0, 1.0);\n",
224                                     rectName, fragmentPos);
225             builder->fsCodeAppendf("\t\tfloat alpha = bottomAlpha * leftAlpha * clamp(%s - length(dxy), 0.0, 1.0);\n",
226                                    radiusPlusHalfName);
227             break;
228         case CircularRRectEffect::kBottomRight_CornerFlag:
229             builder->fsCodeAppendf("\t\tvec2 dxy = max(%s.xy - %s.zw, 0.0);\n",
230                                    fragmentPos, rectName);
231             builder->fsCodeAppendf("\t\tfloat leftAlpha = clamp(%s.x - %s.x, 0.0, 1.0);\n",
232                                    fragmentPos, rectName);
233             builder->fsCodeAppendf("\t\tfloat topAlpha = clamp(%s.y - %s.y, 0.0, 1.0);\n",
234                                    fragmentPos, rectName);
235             builder->fsCodeAppendf("\t\tfloat alpha = topAlpha * leftAlpha * clamp(%s - length(dxy), 0.0, 1.0);\n",
236                                    radiusPlusHalfName);
237             break;
238         case CircularRRectEffect::kBottomLeft_CornerFlag:
239             builder->fsCodeAppendf("\t\tvec2 dxy = max(vec2(%s.x - %s.x, %s.y - %s.w), 0.0);\n",
240                                    rectName, fragmentPos, fragmentPos, rectName);
241             builder->fsCodeAppendf("\t\tfloat rightAlpha = clamp(%s.z - %s.x, 0.0, 1.0);\n",
242                                     rectName, fragmentPos);
243             builder->fsCodeAppendf("\t\tfloat topAlpha = clamp(%s.y - %s.y, 0.0, 1.0);\n",
244                                    fragmentPos, rectName);
245             builder->fsCodeAppendf("\t\tfloat alpha = topAlpha * rightAlpha * clamp(%s - length(dxy), 0.0, 1.0);\n",
246                                    radiusPlusHalfName);
247             break;
248         case CircularRRectEffect::kLeft_CornerFlags:
249             builder->fsCodeAppendf("\t\tvec2 dxy0 = %s.xy - %s.xy;\n", rectName, fragmentPos);
250             builder->fsCodeAppendf("\t\tfloat dy1 = %s.y - %s.w;\n", fragmentPos, rectName);
251             builder->fsCodeAppend("\t\tvec2 dxy = max(vec2(dxy0.x, max(dxy0.y, dy1)), 0.0);\n");
252             builder->fsCodeAppendf("\t\tfloat rightAlpha = clamp(%s.z - %s.x, 0.0, 1.0);\n",
253                                     rectName, fragmentPos);
254             builder->fsCodeAppendf("\t\tfloat alpha = rightAlpha * clamp(%s - length(dxy), 0.0, 1.0);\n",
255                                    radiusPlusHalfName);
256             break;
257         case CircularRRectEffect::kTop_CornerFlags:
258             builder->fsCodeAppendf("\t\tvec2 dxy0 = %s.xy - %s.xy;\n", rectName, fragmentPos);
259             builder->fsCodeAppendf("\t\tfloat dx1 = %s.x - %s.z;\n", fragmentPos, rectName);
260             builder->fsCodeAppend("\t\tvec2 dxy = max(vec2(max(dxy0.x, dx1), dxy0.y), 0.0);\n");
261             builder->fsCodeAppendf("\t\tfloat bottomAlpha = clamp(%s.w - %s.y, 0.0, 1.0);\n",
262                                    rectName, fragmentPos);
263             builder->fsCodeAppendf("\t\tfloat alpha = bottomAlpha * clamp(%s - length(dxy), 0.0, 1.0);\n",
264                                    radiusPlusHalfName);
265             break;
266         case CircularRRectEffect::kRight_CornerFlags:
267             builder->fsCodeAppendf("\t\tfloat dy0 = %s.y - %s.y;\n", rectName, fragmentPos);
268             builder->fsCodeAppendf("\t\tvec2 dxy1 = %s.xy - %s.zw;\n", fragmentPos, rectName);
269             builder->fsCodeAppend("\t\tvec2 dxy = max(vec2(dxy1.x, max(dy0, dxy1.y)), 0.0);\n");
270             builder->fsCodeAppendf("\t\tfloat leftAlpha = clamp(%s.x - %s.x, 0.0, 1.0);\n",
271                                    fragmentPos, rectName);
272             builder->fsCodeAppendf("\t\tfloat alpha = leftAlpha * clamp(%s - length(dxy), 0.0, 1.0);\n",
273                                    radiusPlusHalfName);
274             break;
275         case CircularRRectEffect::kBottom_CornerFlags:
276             builder->fsCodeAppendf("\t\tfloat dx0 = %s.x - %s.x;\n", rectName, fragmentPos);
277             builder->fsCodeAppendf("\t\tvec2 dxy1 = %s.xy - %s.zw;\n", fragmentPos, rectName);
278             builder->fsCodeAppend("\t\tvec2 dxy = max(vec2(max(dx0, dxy1.x), dxy1.y), 0.0);\n");
279             builder->fsCodeAppendf("\t\tfloat topAlpha = clamp(%s.y - %s.y, 0.0, 1.0);\n",
280                                    fragmentPos, rectName);
281             builder->fsCodeAppendf("\t\tfloat alpha = topAlpha * clamp(%s - length(dxy), 0.0, 1.0);\n",
282                                    radiusPlusHalfName);
283             break;
284     }
285 
286     if (kInverseFillAA_GrEffectEdgeType == crre.getEdgeType()) {
287         builder->fsCodeAppend("\t\talpha = 1.0 - alpha;\n");
288     }
289 
290     builder->fsCodeAppendf("\t\t%s = %s;\n", outputColor,
291                            (GrGLSLExpr4(inputColor) * GrGLSLExpr1("alpha")).c_str());
292 }
293 
GenKey(const GrDrawEffect & drawEffect,const GrGLCaps &)294 GrGLEffect::EffectKey GLCircularRRectEffect::GenKey(const GrDrawEffect& drawEffect,
295                                                     const GrGLCaps&) {
296     const CircularRRectEffect& crre = drawEffect.castEffect<CircularRRectEffect>();
297     GR_STATIC_ASSERT(kGrEffectEdgeTypeCnt <= 8);
298     return (crre.getCircularCornerFlags() << 3) | crre.getEdgeType();
299 }
300 
setData(const GrGLUniformManager & uman,const GrDrawEffect & drawEffect)301 void GLCircularRRectEffect::setData(const GrGLUniformManager& uman,
302                                     const GrDrawEffect& drawEffect) {
303     const CircularRRectEffect& crre = drawEffect.castEffect<CircularRRectEffect>();
304     const SkRRect& rrect = crre.getRRect();
305     if (rrect != fPrevRRect) {
306         SkRect rect = rrect.getBounds();
307         SkScalar radius = 0;
308         switch (crre.getCircularCornerFlags()) {
309             case CircularRRectEffect::kAll_CornerFlags:
310                 SkASSERT(rrect.isSimpleCircular());
311                 radius = rrect.getSimpleRadii().fX;
312                 SkASSERT(radius >= kRadiusMin);
313                 rect.inset(radius, radius);
314                 break;
315             case CircularRRectEffect::kTopLeft_CornerFlag:
316                 radius = rrect.radii(SkRRect::kUpperLeft_Corner).fX;
317                 rect.fLeft += radius;
318                 rect.fTop += radius;
319                 rect.fRight += 0.5f;
320                 rect.fBottom += 0.5f;
321                 break;
322             case CircularRRectEffect::kTopRight_CornerFlag:
323                 radius = rrect.radii(SkRRect::kUpperRight_Corner).fX;
324                 rect.fLeft -= 0.5f;
325                 rect.fTop += radius;
326                 rect.fRight -= radius;
327                 rect.fBottom += 0.5f;
328                 break;
329             case CircularRRectEffect::kBottomRight_CornerFlag:
330                 radius = rrect.radii(SkRRect::kLowerRight_Corner).fX;
331                 rect.fLeft -= 0.5f;
332                 rect.fTop -= 0.5f;
333                 rect.fRight -= radius;
334                 rect.fBottom -= radius;
335                 break;
336             case CircularRRectEffect::kBottomLeft_CornerFlag:
337                 radius = rrect.radii(SkRRect::kLowerLeft_Corner).fX;
338                 rect.fLeft += radius;
339                 rect.fTop -= 0.5f;
340                 rect.fRight += 0.5f;
341                 rect.fBottom -= radius;
342                 break;
343             case CircularRRectEffect::kLeft_CornerFlags:
344                 radius = rrect.radii(SkRRect::kUpperLeft_Corner).fX;
345                 rect.fLeft += radius;
346                 rect.fTop += radius;
347                 rect.fRight += 0.5f;
348                 rect.fBottom -= radius;
349                 break;
350             case CircularRRectEffect::kTop_CornerFlags:
351                 radius = rrect.radii(SkRRect::kUpperLeft_Corner).fX;
352                 rect.fLeft += radius;
353                 rect.fTop += radius;
354                 rect.fRight -= radius;
355                 rect.fBottom += 0.5f;
356                 break;
357             case CircularRRectEffect::kRight_CornerFlags:
358                 radius = rrect.radii(SkRRect::kUpperRight_Corner).fX;
359                 rect.fLeft -= 0.5f;
360                 rect.fTop += radius;
361                 rect.fRight -= radius;
362                 rect.fBottom -= radius;
363                 break;
364             case CircularRRectEffect::kBottom_CornerFlags:
365                 radius = rrect.radii(SkRRect::kLowerLeft_Corner).fX;
366                 rect.fLeft += radius;
367                 rect.fTop -= 0.5f;
368                 rect.fRight -= radius;
369                 rect.fBottom -= radius;
370                 break;
371             default:
372                 SkFAIL("Should have been one of the above cases.");
373         }
374         uman.set4f(fInnerRectUniform, rect.fLeft, rect.fTop, rect.fRight, rect.fBottom);
375         uman.set1f(fRadiusPlusHalfUniform, radius + 0.5f);
376         fPrevRRect = rrect;
377     }
378 }
379 
380 //////////////////////////////////////////////////////////////////////////////
381 
382 class GLEllipticalRRectEffect;
383 
384 class EllipticalRRectEffect : public GrEffect {
385 public:
386     static GrEffectRef* Create(GrEffectEdgeType, const SkRRect&);
387 
~EllipticalRRectEffect()388     virtual ~EllipticalRRectEffect() {};
Name()389     static const char* Name() { return "EllipticalRRect"; }
390 
getRRect() const391     const SkRRect& getRRect() const { return fRRect; }
392 
393 
getEdgeType() const394     GrEffectEdgeType getEdgeType() const { return fEdgeType; }
395 
396     typedef GLEllipticalRRectEffect GLEffect;
397 
398     virtual void getConstantColorComponents(GrColor* color, uint32_t* validFlags) const SK_OVERRIDE;
399 
400     virtual const GrBackendEffectFactory& getFactory() const SK_OVERRIDE;
401 
402 private:
403     EllipticalRRectEffect(GrEffectEdgeType, const SkRRect&);
404 
405     virtual bool onIsEqual(const GrEffect& other) const SK_OVERRIDE;
406 
407     SkRRect             fRRect;
408     GrEffectEdgeType    fEdgeType;
409 
410     GR_DECLARE_EFFECT_TEST;
411 
412     typedef GrEffect INHERITED;
413 };
414 
Create(GrEffectEdgeType edgeType,const SkRRect & rrect)415 GrEffectRef* EllipticalRRectEffect::Create(GrEffectEdgeType edgeType, const SkRRect& rrect) {
416     if (kFillAA_GrEffectEdgeType != edgeType && kInverseFillAA_GrEffectEdgeType != edgeType) {
417         return NULL;
418     }
419     return CreateEffectRef(AutoEffectUnref(SkNEW_ARGS(EllipticalRRectEffect, (edgeType, rrect))));
420 }
421 
getConstantColorComponents(GrColor * color,uint32_t * validFlags) const422 void EllipticalRRectEffect::getConstantColorComponents(GrColor* color, uint32_t* validFlags) const {
423     *validFlags = 0;
424 }
425 
getFactory() const426 const GrBackendEffectFactory& EllipticalRRectEffect::getFactory() const {
427     return GrTBackendEffectFactory<EllipticalRRectEffect>::getInstance();
428 }
429 
EllipticalRRectEffect(GrEffectEdgeType edgeType,const SkRRect & rrect)430 EllipticalRRectEffect::EllipticalRRectEffect(GrEffectEdgeType edgeType, const SkRRect& rrect)
431     : fRRect(rrect)
432     , fEdgeType(edgeType){
433     this->setWillReadFragmentPosition();
434 }
435 
onIsEqual(const GrEffect & other) const436 bool EllipticalRRectEffect::onIsEqual(const GrEffect& other) const {
437     const EllipticalRRectEffect& erre = CastEffect<EllipticalRRectEffect>(other);
438     return fEdgeType == erre.fEdgeType && fRRect == erre.fRRect;
439 }
440 
441 //////////////////////////////////////////////////////////////////////////////
442 
443 GR_DEFINE_EFFECT_TEST(EllipticalRRectEffect);
444 
TestCreate(SkRandom * random,GrContext *,const GrDrawTargetCaps & caps,GrTexture * [])445 GrEffectRef* EllipticalRRectEffect::TestCreate(SkRandom* random,
446                                                GrContext*,
447                                                const GrDrawTargetCaps& caps,
448                                                GrTexture*[]) {
449     SkScalar w = random->nextRangeScalar(20.f, 1000.f);
450     SkScalar h = random->nextRangeScalar(20.f, 1000.f);
451     SkVector r[4];
452     r[SkRRect::kUpperLeft_Corner].fX = random->nextRangeF(kRadiusMin, 9.f);
453     // ensure at least one corner really is elliptical
454     do {
455         r[SkRRect::kUpperLeft_Corner].fY = random->nextRangeF(kRadiusMin, 9.f);
456     } while (r[SkRRect::kUpperLeft_Corner].fY == r[SkRRect::kUpperLeft_Corner].fX);
457 
458     SkRRect rrect;
459     if (random->nextBool()) {
460         // half the time create a four-radii rrect.
461         r[SkRRect::kLowerRight_Corner].fX = random->nextRangeF(kRadiusMin, 9.f);
462         r[SkRRect::kLowerRight_Corner].fY = random->nextRangeF(kRadiusMin, 9.f);
463 
464         r[SkRRect::kUpperRight_Corner].fX = r[SkRRect::kLowerRight_Corner].fX;
465         r[SkRRect::kUpperRight_Corner].fY = r[SkRRect::kUpperLeft_Corner].fY;
466 
467         r[SkRRect::kLowerLeft_Corner].fX = r[SkRRect::kUpperLeft_Corner].fX;
468         r[SkRRect::kLowerLeft_Corner].fY = r[SkRRect::kLowerRight_Corner].fY;
469 
470         rrect.setRectRadii(SkRect::MakeWH(w, h), r);
471     } else {
472         rrect.setRectXY(SkRect::MakeWH(w, h), r[SkRRect::kUpperLeft_Corner].fX,
473                                               r[SkRRect::kUpperLeft_Corner].fY);
474     }
475     GrEffectRef* effect;
476     do {
477         GrEffectEdgeType et = (GrEffectEdgeType)random->nextULessThan(kGrEffectEdgeTypeCnt);
478         effect = GrRRectEffect::Create(et, rrect);
479     } while (NULL == effect);
480     return effect;
481 }
482 
483 //////////////////////////////////////////////////////////////////////////////
484 
485 class GLEllipticalRRectEffect : public GrGLEffect {
486 public:
487     GLEllipticalRRectEffect(const GrBackendEffectFactory&, const GrDrawEffect&);
488 
489     virtual void emitCode(GrGLShaderBuilder* builder,
490                           const GrDrawEffect& drawEffect,
491                           EffectKey key,
492                           const char* outputColor,
493                           const char* inputColor,
494                           const TransformedCoordsArray&,
495                           const TextureSamplerArray&) SK_OVERRIDE;
496 
497     static inline EffectKey GenKey(const GrDrawEffect&, const GrGLCaps&);
498 
499     virtual void setData(const GrGLUniformManager&, const GrDrawEffect&) SK_OVERRIDE;
500 
501 private:
502     GrGLUniformManager::UniformHandle   fInnerRectUniform;
503     GrGLUniformManager::UniformHandle   fInvRadiiSqdUniform;
504     SkRRect                             fPrevRRect;
505     typedef GrGLEffect INHERITED;
506 };
507 
GLEllipticalRRectEffect(const GrBackendEffectFactory & factory,const GrDrawEffect & drawEffect)508 GLEllipticalRRectEffect::GLEllipticalRRectEffect(const GrBackendEffectFactory& factory,
509                              const GrDrawEffect& drawEffect)
510     : INHERITED (factory) {
511     fPrevRRect.setEmpty();
512 }
513 
emitCode(GrGLShaderBuilder * builder,const GrDrawEffect & drawEffect,EffectKey key,const char * outputColor,const char * inputColor,const TransformedCoordsArray &,const TextureSamplerArray & samplers)514 void GLEllipticalRRectEffect::emitCode(GrGLShaderBuilder* builder,
515                                        const GrDrawEffect& drawEffect,
516                                        EffectKey key,
517                                        const char* outputColor,
518                                        const char* inputColor,
519                                        const TransformedCoordsArray&,
520                                        const TextureSamplerArray& samplers) {
521     const EllipticalRRectEffect& erre = drawEffect.castEffect<EllipticalRRectEffect>();
522     const char *rectName;
523     // The inner rect is the rrect bounds inset by the x/y radii
524     fInnerRectUniform = builder->addUniform(GrGLShaderBuilder::kFragment_Visibility,
525                                             kVec4f_GrSLType,
526                                             "innerRect",
527                                             &rectName);
528     const char* fragmentPos = builder->fragmentPosition();
529     // At each quarter-ellipse corner we compute a vector that is the offset of the fragment pos
530     // to the ellipse center. The vector is pinned in x and y to be in the quarter-plane relevant
531     // to that corner. This means that points near the interior near the rrect top edge will have
532     // a vector that points straight up for both the TL left and TR corners. Computing an
533     // alpha from this vector at either the TR or TL corner will give the correct result. Similarly,
534     // fragments near the other three edges will get the correct AA. Fragments in the interior of
535     // the rrect will have a (0,0) vector at all four corners. So long as the radii > 0.5 they will
536     // correctly produce an alpha value of 1 at all four corners. We take the min of all the alphas.
537     // The code below is a simplified version of the above that performs maxs on the vector
538     // components before computing distances and alpha values so that only one distance computation
539     // need be computed to determine the min alpha.
540     builder->fsCodeAppendf("\t\tvec2 dxy0 = %s.xy - %s;\n", rectName, fragmentPos);
541     builder->fsCodeAppendf("\t\tvec2 dxy1 = %s - %s.zw;\n", fragmentPos, rectName);
542     switch (erre.getRRect().getType()) {
543         case SkRRect::kSimple_Type: {
544             const char *invRadiiXYSqdName;
545             fInvRadiiSqdUniform = builder->addUniform(GrGLShaderBuilder::kFragment_Visibility,
546                                                       kVec2f_GrSLType,
547                                                       "invRadiiXY",
548                                                       &invRadiiXYSqdName);
549             builder->fsCodeAppend("\t\tvec2 dxy = max(max(dxy0, dxy1), 0.0);\n");
550             // Z is the x/y offsets divided by squared radii.
551             builder->fsCodeAppendf("\t\tvec2 Z = dxy * %s;\n", invRadiiXYSqdName);
552             break;
553         }
554         case SkRRect::kNinePatch_Type: {
555             const char *invRadiiLTRBSqdName;
556             fInvRadiiSqdUniform = builder->addUniform(GrGLShaderBuilder::kFragment_Visibility,
557                                                       kVec4f_GrSLType,
558                                                       "invRadiiLTRB",
559                                                       &invRadiiLTRBSqdName);
560             builder->fsCodeAppend("\t\tvec2 dxy = max(max(dxy0, dxy1), 0.0);\n");
561             // Z is the x/y offsets divided by squared radii. We only care about the (at most) one
562             // corner where both the x and y offsets are positive, hence the maxes. (The inverse
563             // squared radii will always be positive.)
564             builder->fsCodeAppendf("\t\tvec2 Z = max(max(dxy0 * %s.xy, dxy1 * %s.zw), 0.0);\n",
565                                    invRadiiLTRBSqdName, invRadiiLTRBSqdName);
566             break;
567         }
568         default:
569             SkFAIL("RRect should always be simple or nine-patch.");
570     }
571     // implicit is the evaluation of (x/a)^2 + (y/b)^2 - 1.
572     builder->fsCodeAppend("\t\tfloat implicit = dot(Z, dxy) - 1.0;\n");
573     // grad_dot is the squared length of the gradient of the implicit.
574     builder->fsCodeAppendf("\t\tfloat grad_dot = 4.0 * dot(Z, Z);\n");
575     // avoid calling inversesqrt on zero.
576     builder->fsCodeAppend("\t\tgrad_dot = max(grad_dot, 1.0e-4);\n");
577     builder->fsCodeAppendf("\t\tfloat approx_dist = implicit * inversesqrt(grad_dot);\n");
578 
579     if (kFillAA_GrEffectEdgeType == erre.getEdgeType()) {
580         builder->fsCodeAppend("\t\tfloat alpha = clamp(0.5 - approx_dist, 0.0, 1.0);\n");
581     } else {
582         builder->fsCodeAppend("\t\tfloat alpha = clamp(0.5 + approx_dist, 0.0, 1.0);\n");
583     }
584 
585     builder->fsCodeAppendf("\t\t%s = %s;\n", outputColor,
586                            (GrGLSLExpr4(inputColor) * GrGLSLExpr1("alpha")).c_str());
587 }
588 
GenKey(const GrDrawEffect & drawEffect,const GrGLCaps &)589 GrGLEffect::EffectKey GLEllipticalRRectEffect::GenKey(const GrDrawEffect& drawEffect,
590                                                       const GrGLCaps&) {
591     const EllipticalRRectEffect& erre = drawEffect.castEffect<EllipticalRRectEffect>();
592     GR_STATIC_ASSERT(kLast_GrEffectEdgeType < (1 << 3));
593     return erre.getRRect().getType() | erre.getEdgeType() << 3;
594 }
595 
setData(const GrGLUniformManager & uman,const GrDrawEffect & drawEffect)596 void GLEllipticalRRectEffect::setData(const GrGLUniformManager& uman,
597                                       const GrDrawEffect& drawEffect) {
598     const EllipticalRRectEffect& erre = drawEffect.castEffect<EllipticalRRectEffect>();
599     const SkRRect& rrect = erre.getRRect();
600     if (rrect != fPrevRRect) {
601         SkRect rect = rrect.getBounds();
602         const SkVector& r0 = rrect.radii(SkRRect::kUpperLeft_Corner);
603         SkASSERT(r0.fX >= kRadiusMin);
604         SkASSERT(r0.fY >= kRadiusMin);
605         switch (erre.getRRect().getType()) {
606             case SkRRect::kSimple_Type:
607                 rect.inset(r0.fX, r0.fY);
608                 uman.set2f(fInvRadiiSqdUniform, 1.f / (r0.fX * r0.fX),
609                                                 1.f / (r0.fY * r0.fY));
610                 break;
611             case SkRRect::kNinePatch_Type: {
612                 const SkVector& r1 = rrect.radii(SkRRect::kLowerRight_Corner);
613                 SkASSERT(r1.fX >= kRadiusMin);
614                 SkASSERT(r1.fY >= kRadiusMin);
615                 rect.fLeft += r0.fX;
616                 rect.fTop += r0.fY;
617                 rect.fRight -= r1.fX;
618                 rect.fBottom -= r1.fY;
619                 uman.set4f(fInvRadiiSqdUniform, 1.f / (r0.fX * r0.fX),
620                                                 1.f / (r0.fY * r0.fY),
621                                                 1.f / (r1.fX * r1.fX),
622                                                 1.f / (r1.fY * r1.fY));
623                 break;
624             }
625         default:
626             SkFAIL("RRect should always be simple or nine-patch.");
627         }
628         uman.set4f(fInnerRectUniform, rect.fLeft, rect.fTop, rect.fRight, rect.fBottom);
629         fPrevRRect = rrect;
630     }
631 }
632 
633 //////////////////////////////////////////////////////////////////////////////
634 
Create(GrEffectEdgeType edgeType,const SkRRect & rrect)635 GrEffectRef* GrRRectEffect::Create(GrEffectEdgeType edgeType, const SkRRect& rrect) {
636     if (rrect.isRect()) {
637         return GrConvexPolyEffect::Create(edgeType, rrect.getBounds());
638     }
639 
640     if (rrect.isOval()) {
641         return GrOvalEffect::Create(edgeType, rrect.getBounds());
642     }
643 
644     if (rrect.isSimple()) {
645         if (rrect.getSimpleRadii().fX < kRadiusMin || rrect.getSimpleRadii().fY < kRadiusMin) {
646             // In this case the corners are extremely close to rectangular and we collapse the
647             // clip to a rectangular clip.
648             return GrConvexPolyEffect::Create(edgeType, rrect.getBounds());
649         }
650         if (rrect.getSimpleRadii().fX == rrect.getSimpleRadii().fY) {
651             return CircularRRectEffect::Create(edgeType, CircularRRectEffect::kAll_CornerFlags,
652                                                rrect);
653         } else {
654             return EllipticalRRectEffect::Create(edgeType, rrect);
655         }
656     }
657 
658     if (rrect.isComplex() || rrect.isNinePatch()) {
659         // Check for the "tab" cases - two adjacent circular corners and two square corners.
660         SkScalar circularRadius = 0;
661         uint32_t cornerFlags  = 0;
662 
663         SkVector radii[4];
664         bool squashedRadii = false;
665         for (int c = 0; c < 4; ++c) {
666             radii[c] = rrect.radii((SkRRect::Corner)c);
667             SkASSERT((0 == radii[c].fX) == (0 == radii[c].fY));
668             if (0 == radii[c].fX) {
669                 // The corner is square, so no need to squash or flag as circular.
670                 continue;
671             }
672             if (radii[c].fX < kRadiusMin || radii[c].fY < kRadiusMin) {
673                 radii[c].set(0, 0);
674                 squashedRadii = true;
675                 continue;
676             }
677             if (radii[c].fX != radii[c].fY) {
678                 cornerFlags = ~0U;
679                 break;
680             }
681             if (!cornerFlags) {
682                 circularRadius = radii[c].fX;
683                 cornerFlags = 1 << c;
684             } else {
685                 if (radii[c].fX != circularRadius) {
686                    cornerFlags = ~0U;
687                    break;
688                 }
689                 cornerFlags |= 1 << c;
690             }
691         }
692 
693         switch (cornerFlags) {
694             case CircularRRectEffect::kAll_CornerFlags:
695                 // This rrect should have been caught in the simple case above. Though, it would
696                 // be correctly handled in the fallthrough code.
697                 SkASSERT(false);
698             case CircularRRectEffect::kTopLeft_CornerFlag:
699             case CircularRRectEffect::kTopRight_CornerFlag:
700             case CircularRRectEffect::kBottomRight_CornerFlag:
701             case CircularRRectEffect::kBottomLeft_CornerFlag:
702             case CircularRRectEffect::kLeft_CornerFlags:
703             case CircularRRectEffect::kTop_CornerFlags:
704             case CircularRRectEffect::kRight_CornerFlags:
705             case CircularRRectEffect::kBottom_CornerFlags: {
706                 SkTCopyOnFirstWrite<SkRRect> rr(rrect);
707                 if (squashedRadii) {
708                     rr.writable()->setRectRadii(rrect.getBounds(), radii);
709                 }
710                 return CircularRRectEffect::Create(edgeType, cornerFlags, *rr);
711             }
712             case CircularRRectEffect::kNone_CornerFlags:
713                 return GrConvexPolyEffect::Create(edgeType, rrect.getBounds());
714             default: {
715                 if (squashedRadii) {
716                     // If we got here then we squashed some but not all the radii to zero. (If all
717                     // had been squashed cornerFlags would be 0.) The elliptical effect doesn't
718                     // support some rounded and some square corners.
719                     return NULL;
720                 }
721                 if (rrect.isNinePatch()) {
722                     return EllipticalRRectEffect::Create(edgeType, rrect);
723                 }
724                 return NULL;
725             }
726         }
727     }
728 
729     return NULL;
730 }
731