src/gpu/effects/GrRRectEffect.cpp

   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 "GrConvexPolyEffect.h"
  11 #include "GrFragmentProcessor.h"
  12 #include "GrInvariantOutput.h"
  13 #include "GrOvalEffect.h"
  14 #include "SkRRect.h"
  15 #include "gl/GrGLProcessor.h"
  16 #include "gl/GrGLSL.h"
  17 #include "gl/builders/GrGLProgramBuilder.h"
  18
  19 // The effects defined here only handle rrect radii >= kRadiusMin.
  20 static const SkScalar kRadiusMin = SK_ScalarHalf;
  21
  22 //////////////////////////////////////////////////////////////////////////////
  23
  24 class CircularRRectEffect : public GrFragmentProcessor {
  25 public:
  26
  27     enum CornerFlags {
  28         kTopLeft_CornerFlag     = (1 << SkRRect::kUpperLeft_Corner),
  29         kTopRight_CornerFlag    = (1 << SkRRect::kUpperRight_Corner),
  30         kBottomRight_CornerFlag = (1 << SkRRect::kLowerRight_Corner),
  31         kBottomLeft_CornerFlag  = (1 << SkRRect::kLowerLeft_Corner),
  32
  33         kLeft_CornerFlags   = kTopLeft_CornerFlag    | kBottomLeft_CornerFlag,
  34         kTop_CornerFlags    = kTopLeft_CornerFlag    | kTopRight_CornerFlag,
  35         kRight_CornerFlags  = kTopRight_CornerFlag   | kBottomRight_CornerFlag,
  36         kBottom_CornerFlags = kBottomLeft_CornerFlag | kBottomRight_CornerFlag,
  37
  38         kAll_CornerFlags = kTopLeft_CornerFlag    | kTopRight_CornerFlag |
  39                            kBottomLeft_CornerFlag | kBottomRight_CornerFlag,
  40
  41         kNone_CornerFlags = 0
  42     };
  43
  44     // The flags are used to indicate which corners are circluar (unflagged corners are assumed to
  45     // be square).
  46     static GrFragmentProcessor* Create(GrPrimitiveEdgeType, uint32_t circularCornerFlags,
  47                                        const SkRRect&);
  48
  49     virtual ~CircularRRectEffect() {};
  50
  51     const char* name() const SK_OVERRIDE { return "CircularRRect"; }
  52
  53     void getGLProcessorKey(const GrGLCaps&, GrProcessorKeyBuilder*) const SK_OVERRIDE;
  54
  55     GrGLFragmentProcessor* createGLInstance() const SK_OVERRIDE;
  56
  57     const SkRRect& getRRect() const { return fRRect; }
  58
  59     uint32_t getCircularCornerFlags() const { return fCircularCornerFlags; }
  60
  61     GrPrimitiveEdgeType getEdgeType() const { return fEdgeType; }
  62
  63 private:
  64     CircularRRectEffect(GrPrimitiveEdgeType, uint32_t circularCornerFlags, const SkRRect&);
  65
  66     bool onIsEqual(const GrFragmentProcessor& other) const SK_OVERRIDE;
  67
  68     void onComputeInvariantOutput(GrInvariantOutput* inout) const SK_OVERRIDE;
  69
  70     SkRRect                fRRect;
  71     GrPrimitiveEdgeType    fEdgeType;
  72     uint32_t               fCircularCornerFlags;
  73
  74     GR_DECLARE_FRAGMENT_PROCESSOR_TEST;
  75
  76     typedef GrFragmentProcessor INHERITED;
  77 };
  78
  79 GrFragmentProcessor* CircularRRectEffect::Create(GrPrimitiveEdgeType edgeType,
  80                                                  uint32_t circularCornerFlags,
  81                                                  const SkRRect& rrect) {
  82     if (kFillAA_GrProcessorEdgeType != edgeType && kInverseFillAA_GrProcessorEdgeType != edgeType) {
  83         return NULL;
  84     }
  85     return SkNEW_ARGS(CircularRRectEffect, (edgeType, circularCornerFlags, rrect));
  86 }
  87
  88 void CircularRRectEffect::onComputeInvariantOutput(GrInvariantOutput* inout) const {
  89     inout->mulByUnknownSingleComponent();
  90 }
  91
  92 CircularRRectEffect::CircularRRectEffect(GrPrimitiveEdgeType edgeType, uint32_t circularCornerFlags,
  93                                          const SkRRect& rrect)
  94     : fRRect(rrect)
  95     , fEdgeType(edgeType)
  96     , fCircularCornerFlags(circularCornerFlags) {
  97     this->initClassID<CircularRRectEffect>();
  98     this->setWillReadFragmentPosition();
  99 }
 100
 101 bool CircularRRectEffect::onIsEqual(const GrFragmentProcessor& other) const {
 102     const CircularRRectEffect& crre = other.cast<CircularRRectEffect>();
 103     // The corner flags are derived from fRRect, so no need to check them.
 104     return fEdgeType == crre.fEdgeType && fRRect == crre.fRRect;
 105 }
 106
 107 //////////////////////////////////////////////////////////////////////////////
 108
 109 GR_DEFINE_FRAGMENT_PROCESSOR_TEST(CircularRRectEffect);
 110
 111 GrFragmentProcessor* CircularRRectEffect::TestCreate(SkRandom* random,
 112                                                      GrContext*,
 113                                                      const GrDrawTargetCaps& caps,
 114                                                      GrTexture*[]) {
 115     SkScalar w = random->nextRangeScalar(20.f, 1000.f);
 116     SkScalar h = random->nextRangeScalar(20.f, 1000.f);
 117     SkScalar r = random->nextRangeF(kRadiusMin, 9.f);
 118     SkRRect rrect;
 119     rrect.setRectXY(SkRect::MakeWH(w, h), r, r);
 120     GrFragmentProcessor* fp;
 121     do {
 122         GrPrimitiveEdgeType et =
 123                 (GrPrimitiveEdgeType)random->nextULessThan(kGrProcessorEdgeTypeCnt);
 124         fp = GrRRectEffect::Create(et, rrect);
 125     } while (NULL == fp);
 126     return fp;
 127 }
 128
 129 //////////////////////////////////////////////////////////////////////////////
 130
 131 class GLCircularRRectEffect : public GrGLFragmentProcessor {
 132 public:
 133     GLCircularRRectEffect(const GrProcessor&);
 134
 135     virtual void emitCode(GrGLFPBuilder* builder,
 136                           const GrFragmentProcessor& fp,
 137                           const char* outputColor,
 138                           const char* inputColor,
 139                           const TransformedCoordsArray&,
 140                           const TextureSamplerArray&) SK_OVERRIDE;
 141
 142     static inline void GenKey(const GrProcessor&, const GrGLCaps&, GrProcessorKeyBuilder*);
 143
 144     void setData(const GrGLProgramDataManager&, const GrProcessor&) SK_OVERRIDE;
 145
 146 private:
 147     GrGLProgramDataManager::UniformHandle fInnerRectUniform;
 148     GrGLProgramDataManager::UniformHandle fRadiusPlusHalfUniform;
 149     SkRRect                               fPrevRRect;
 150     typedef GrGLFragmentProcessor INHERITED;
 151 };
 152
 153 GLCircularRRectEffect::GLCircularRRectEffect(const GrProcessor& ) {
 154     fPrevRRect.setEmpty();
 155 }
 156
 157 void GLCircularRRectEffect::emitCode(GrGLFPBuilder* builder,
 158                                      const GrFragmentProcessor& fp,
 159                                      const char* outputColor,
 160                                      const char* inputColor,
 161                                      const TransformedCoordsArray&,
 162                                      const TextureSamplerArray& samplers) {
 163     const CircularRRectEffect& crre = fp.cast<CircularRRectEffect>();
 164     const char *rectName;
 165     const char *radiusPlusHalfName;
 166     // The inner rect is the rrect bounds inset by the radius. Its left, top, right, and bottom
 167     // edges correspond to components x, y, z, and w, respectively. When a side of the rrect has
 168     // only rectangular corners, that side's value corresponds to the rect edge's value outset by
 169     // half a pixel.
 170     fInnerRectUniform = builder->addUniform(GrGLProgramBuilder::kFragment_Visibility,
 171                                             kVec4f_GrSLType, kDefault_GrSLPrecision,
 172                                             "innerRect",
 173                                             &rectName);
 174     fRadiusPlusHalfUniform = builder->addUniform(GrGLProgramBuilder::kFragment_Visibility,
 175                                                  kFloat_GrSLType, kDefault_GrSLPrecision,
 176                                                  "radiusPlusHalf",
 177                                                  &radiusPlusHalfName);
 178
 179     GrGLFPFragmentBuilder* fsBuilder = builder->getFragmentShaderBuilder();
 180     const char* fragmentPos = fsBuilder->fragmentPosition();
 181     // At each quarter-circle corner we compute a vector that is the offset of the fragment position
 182     // from the circle center. The vector is pinned in x and y to be in the quarter-plane relevant
 183     // to that corner. This means that points near the interior near the rrect top edge will have
 184     // a vector that points straight up for both the TL left and TR corners. Computing an
 185     // alpha from this vector at either the TR or TL corner will give the correct result. Similarly,
 186     // fragments near the other three edges will get the correct AA. Fragments in the interior of
 187     // the rrect will have a (0,0) vector at all four corners. So long as the radius > 0.5 they will
 188     // correctly produce an alpha value of 1 at all four corners. We take the min of all the alphas.
 189     // The code below is a simplified version of the above that performs maxs on the vector
 190     // components before computing distances and alpha values so that only one distance computation
 191     // need be computed to determine the min alpha.
 192     //
 193     // For the cases where one half of the rrect is rectangular we drop one of the x or y
 194     // computations, compute a separate rect edge alpha for the rect side, and mul the two computed
 195     // alphas together.
 196     switch (crre.getCircularCornerFlags()) {
 197         case CircularRRectEffect::kAll_CornerFlags:
 198             fsBuilder->codeAppendf("\t\tvec2 dxy0 = %s.xy - %s.xy;\n", rectName, fragmentPos);
 199             fsBuilder->codeAppendf("\t\tvec2 dxy1 = %s.xy - %s.zw;\n", fragmentPos, rectName);
 200             fsBuilder->codeAppend("\t\tvec2 dxy = max(max(dxy0, dxy1), 0.0);\n");
 201             fsBuilder->codeAppendf("\t\tfloat alpha = clamp(%s - length(dxy), 0.0, 1.0);\n",
 202                                    radiusPlusHalfName);
 203             break;
 204         case CircularRRectEffect::kTopLeft_CornerFlag:
 205             fsBuilder->codeAppendf("\t\tvec2 dxy = max(%s.xy - %s.xy, 0.0);\n",
 206                                    rectName, fragmentPos);
 207             fsBuilder->codeAppendf("\t\tfloat rightAlpha = clamp(%s.z - %s.x, 0.0, 1.0);\n",
 208                                     rectName, fragmentPos);
 209             fsBuilder->codeAppendf("\t\tfloat bottomAlpha = clamp(%s.w - %s.y, 0.0, 1.0);\n",
 210                                     rectName, fragmentPos);
 211             fsBuilder->codeAppendf("\t\tfloat alpha = bottomAlpha * rightAlpha * clamp(%s - length(dxy), 0.0, 1.0);\n",
 212                                    radiusPlusHalfName);
 213             break;
 214         case CircularRRectEffect::kTopRight_CornerFlag:
 215             fsBuilder->codeAppendf("\t\tvec2 dxy = max(vec2(%s.x - %s.z, %s.y - %s.y), 0.0);\n",
 216                                    fragmentPos, rectName, rectName, fragmentPos);
 217             fsBuilder->codeAppendf("\t\tfloat leftAlpha = clamp(%s.x - %s.x, 0.0, 1.0);\n",
 218                                    fragmentPos, rectName);
 219             fsBuilder->codeAppendf("\t\tfloat bottomAlpha = clamp(%s.w - %s.y, 0.0, 1.0);\n",
 220                                     rectName, fragmentPos);
 221             fsBuilder->codeAppendf("\t\tfloat alpha = bottomAlpha * leftAlpha * clamp(%s - length(dxy), 0.0, 1.0);\n",
 222                                    radiusPlusHalfName);
 223             break;
 224         case CircularRRectEffect::kBottomRight_CornerFlag:
 225             fsBuilder->codeAppendf("\t\tvec2 dxy = max(%s.xy - %s.zw, 0.0);\n",
 226                                    fragmentPos, rectName);
 227             fsBuilder->codeAppendf("\t\tfloat leftAlpha = clamp(%s.x - %s.x, 0.0, 1.0);\n",
 228                                    fragmentPos, rectName);
 229             fsBuilder->codeAppendf("\t\tfloat topAlpha = clamp(%s.y - %s.y, 0.0, 1.0);\n",
 230                                    fragmentPos, rectName);
 231             fsBuilder->codeAppendf("\t\tfloat alpha = topAlpha * leftAlpha * clamp(%s - length(dxy), 0.0, 1.0);\n",
 232                                    radiusPlusHalfName);
 233             break;
 234         case CircularRRectEffect::kBottomLeft_CornerFlag:
 235             fsBuilder->codeAppendf("\t\tvec2 dxy = max(vec2(%s.x - %s.x, %s.y - %s.w), 0.0);\n",
 236                                    rectName, fragmentPos, fragmentPos, rectName);
 237             fsBuilder->codeAppendf("\t\tfloat rightAlpha = clamp(%s.z - %s.x, 0.0, 1.0);\n",
 238                                     rectName, fragmentPos);
 239             fsBuilder->codeAppendf("\t\tfloat topAlpha = clamp(%s.y - %s.y, 0.0, 1.0);\n",
 240                                    fragmentPos, rectName);
 241             fsBuilder->codeAppendf("\t\tfloat alpha = topAlpha * rightAlpha * clamp(%s - length(dxy), 0.0, 1.0);\n",
 242                                    radiusPlusHalfName);
 243             break;
 244         case CircularRRectEffect::kLeft_CornerFlags:
 245             fsBuilder->codeAppendf("\t\tvec2 dxy0 = %s.xy - %s.xy;\n", rectName, fragmentPos);
 246             fsBuilder->codeAppendf("\t\tfloat dy1 = %s.y - %s.w;\n", fragmentPos, rectName);
 247             fsBuilder->codeAppend("\t\tvec2 dxy = max(vec2(dxy0.x, max(dxy0.y, dy1)), 0.0);\n");
 248             fsBuilder->codeAppendf("\t\tfloat rightAlpha = clamp(%s.z - %s.x, 0.0, 1.0);\n",
 249                                     rectName, fragmentPos);
 250             fsBuilder->codeAppendf("\t\tfloat alpha = rightAlpha * clamp(%s - length(dxy), 0.0, 1.0);\n",
 251                                    radiusPlusHalfName);
 252             break;
 253         case CircularRRectEffect::kTop_CornerFlags:
 254             fsBuilder->codeAppendf("\t\tvec2 dxy0 = %s.xy - %s.xy;\n", rectName, fragmentPos);
 255             fsBuilder->codeAppendf("\t\tfloat dx1 = %s.x - %s.z;\n", fragmentPos, rectName);
 256             fsBuilder->codeAppend("\t\tvec2 dxy = max(vec2(max(dxy0.x, dx1), dxy0.y), 0.0);\n");
 257             fsBuilder->codeAppendf("\t\tfloat bottomAlpha = clamp(%s.w - %s.y, 0.0, 1.0);\n",
 258                                    rectName, fragmentPos);
 259             fsBuilder->codeAppendf("\t\tfloat alpha = bottomAlpha * clamp(%s - length(dxy), 0.0, 1.0);\n",
 260                                    radiusPlusHalfName);
 261             break;
 262         case CircularRRectEffect::kRight_CornerFlags:
 263             fsBuilder->codeAppendf("\t\tfloat dy0 = %s.y - %s.y;\n", rectName, fragmentPos);
 264             fsBuilder->codeAppendf("\t\tvec2 dxy1 = %s.xy - %s.zw;\n", fragmentPos, rectName);
 265             fsBuilder->codeAppend("\t\tvec2 dxy = max(vec2(dxy1.x, max(dy0, dxy1.y)), 0.0);\n");
 266             fsBuilder->codeAppendf("\t\tfloat leftAlpha = clamp(%s.x - %s.x, 0.0, 1.0);\n",
 267                                    fragmentPos, rectName);
 268             fsBuilder->codeAppendf("\t\tfloat alpha = leftAlpha * clamp(%s - length(dxy), 0.0, 1.0);\n",
 269                                    radiusPlusHalfName);
 270             break;
 271         case CircularRRectEffect::kBottom_CornerFlags:
 272             fsBuilder->codeAppendf("\t\tfloat dx0 = %s.x - %s.x;\n", rectName, fragmentPos);
 273             fsBuilder->codeAppendf("\t\tvec2 dxy1 = %s.xy - %s.zw;\n", fragmentPos, rectName);
 274             fsBuilder->codeAppend("\t\tvec2 dxy = max(vec2(max(dx0, dxy1.x), dxy1.y), 0.0);\n");
 275             fsBuilder->codeAppendf("\t\tfloat topAlpha = clamp(%s.y - %s.y, 0.0, 1.0);\n",
 276                                    fragmentPos, rectName);
 277             fsBuilder->codeAppendf("\t\tfloat alpha = topAlpha * clamp(%s - length(dxy), 0.0, 1.0);\n",
 278                                    radiusPlusHalfName);
 279             break;
 280     }
 281
 282     if (kInverseFillAA_GrProcessorEdgeType == crre.getEdgeType()) {
 283         fsBuilder->codeAppend("\t\talpha = 1.0 - alpha;\n");
 284     }
 285
 286     fsBuilder->codeAppendf("\t\t%s = %s;\n", outputColor,
 287                            (GrGLSLExpr4(inputColor) * GrGLSLExpr1("alpha")).c_str());
 288 }
 289
 290 void GLCircularRRectEffect::GenKey(const GrProcessor& processor, const GrGLCaps&,
 291                                    GrProcessorKeyBuilder* b) {
 292     const CircularRRectEffect& crre = processor.cast<CircularRRectEffect>();
 293     GR_STATIC_ASSERT(kGrProcessorEdgeTypeCnt <= 8);
 294     b->add32((crre.getCircularCornerFlags() << 3) | crre.getEdgeType());
 295 }
 296
 297 void GLCircularRRectEffect::setData(const GrGLProgramDataManager& pdman,
 298                                     const GrProcessor& processor) {
 299     const CircularRRectEffect& crre = processor.cast<CircularRRectEffect>();
 300     const SkRRect& rrect = crre.getRRect();
 301     if (rrect != fPrevRRect) {
 302         SkRect rect = rrect.getBounds();
 303         SkScalar radius = 0;
 304         switch (crre.getCircularCornerFlags()) {
 305             case CircularRRectEffect::kAll_CornerFlags:
 306                 SkASSERT(rrect.isSimpleCircular());
 307                 radius = rrect.getSimpleRadii().fX;
 308                 SkASSERT(radius >= kRadiusMin);
 309                 rect.inset(radius, radius);
 310                 break;
 311             case CircularRRectEffect::kTopLeft_CornerFlag:
 312                 radius = rrect.radii(SkRRect::kUpperLeft_Corner).fX;
 313                 rect.fLeft += radius;
 314                 rect.fTop += radius;
 315                 rect.fRight += 0.5f;
 316                 rect.fBottom += 0.5f;
 317                 break;
 318             case CircularRRectEffect::kTopRight_CornerFlag:
 319                 radius = rrect.radii(SkRRect::kUpperRight_Corner).fX;
 320                 rect.fLeft -= 0.5f;
 321                 rect.fTop += radius;
 322                 rect.fRight -= radius;
 323                 rect.fBottom += 0.5f;
 324                 break;
 325             case CircularRRectEffect::kBottomRight_CornerFlag:
 326                 radius = rrect.radii(SkRRect::kLowerRight_Corner).fX;
 327                 rect.fLeft -= 0.5f;
 328                 rect.fTop -= 0.5f;
 329                 rect.fRight -= radius;
 330                 rect.fBottom -= radius;
 331                 break;
 332             case CircularRRectEffect::kBottomLeft_CornerFlag:
 333                 radius = rrect.radii(SkRRect::kLowerLeft_Corner).fX;
 334                 rect.fLeft += radius;
 335                 rect.fTop -= 0.5f;
 336                 rect.fRight += 0.5f;
 337                 rect.fBottom -= radius;
 338                 break;
 339             case CircularRRectEffect::kLeft_CornerFlags:
 340                 radius = rrect.radii(SkRRect::kUpperLeft_Corner).fX;
 341                 rect.fLeft += radius;
 342                 rect.fTop += radius;
 343                 rect.fRight += 0.5f;
 344                 rect.fBottom -= radius;
 345                 break;
 346             case CircularRRectEffect::kTop_CornerFlags:
 347                 radius = rrect.radii(SkRRect::kUpperLeft_Corner).fX;
 348                 rect.fLeft += radius;
 349                 rect.fTop += radius;
 350                 rect.fRight -= radius;
 351                 rect.fBottom += 0.5f;
 352                 break;
 353             case CircularRRectEffect::kRight_CornerFlags:
 354                 radius = rrect.radii(SkRRect::kUpperRight_Corner).fX;
 355                 rect.fLeft -= 0.5f;
 356                 rect.fTop += radius;
 357                 rect.fRight -= radius;
 358                 rect.fBottom -= radius;
 359                 break;
 360             case CircularRRectEffect::kBottom_CornerFlags:
 361                 radius = rrect.radii(SkRRect::kLowerLeft_Corner).fX;
 362                 rect.fLeft += radius;
 363                 rect.fTop -= 0.5f;
 364                 rect.fRight -= radius;
 365                 rect.fBottom -= radius;
 366                 break;
 367             default:
 368                 SkFAIL("Should have been one of the above cases.");
 369         }
 370         pdman.set4f(fInnerRectUniform, rect.fLeft, rect.fTop, rect.fRight, rect.fBottom);
 371         pdman.set1f(fRadiusPlusHalfUniform, radius + 0.5f);
 372         fPrevRRect = rrect;
 373     }
 374 }
 375
 376 ////////////////////////////////////////////////////////////////////////////////////////////////////
 377
 378 void CircularRRectEffect::getGLProcessorKey(const GrGLCaps& caps,
 379                                             GrProcessorKeyBuilder* b) const {
 380     GLCircularRRectEffect::GenKey(*this, caps, b);
 381 }
 382
 383 GrGLFragmentProcessor* CircularRRectEffect::createGLInstance() const  {
 384     return SkNEW_ARGS(GLCircularRRectEffect, (*this));
 385 }
 386
 387 //////////////////////////////////////////////////////////////////////////////
 388
 389 class EllipticalRRectEffect : public GrFragmentProcessor {
 390 public:
 391     static GrFragmentProcessor* Create(GrPrimitiveEdgeType, const SkRRect&);
 392
 393     virtual ~EllipticalRRectEffect() {};
 394
 395     const char* name() const SK_OVERRIDE { return "EllipticalRRect"; }
 396
 397     void getGLProcessorKey(const GrGLCaps&, GrProcessorKeyBuilder*) const SK_OVERRIDE;
 398
 399     GrGLFragmentProcessor* createGLInstance() const SK_OVERRIDE;
 400
 401     const SkRRect& getRRect() const { return fRRect; }
 402
 403     GrPrimitiveEdgeType getEdgeType() const { return fEdgeType; }
 404
 405 private:
 406     EllipticalRRectEffect(GrPrimitiveEdgeType, const SkRRect&);
 407
 408     bool onIsEqual(const GrFragmentProcessor& other) const SK_OVERRIDE;
 409
 410     void onComputeInvariantOutput(GrInvariantOutput* inout) const SK_OVERRIDE;
 411
 412     SkRRect             fRRect;
 413     GrPrimitiveEdgeType    fEdgeType;
 414
 415     GR_DECLARE_FRAGMENT_PROCESSOR_TEST;
 416
 417     typedef GrFragmentProcessor INHERITED;
 418 };
 419
 420 GrFragmentProcessor*
 421 EllipticalRRectEffect::Create(GrPrimitiveEdgeType edgeType, const SkRRect& rrect) {
 422     if (kFillAA_GrProcessorEdgeType != edgeType && kInverseFillAA_GrProcessorEdgeType != edgeType) {
 423         return NULL;
 424     }
 425     return SkNEW_ARGS(EllipticalRRectEffect, (edgeType, rrect));
 426 }
 427
 428 void EllipticalRRectEffect::onComputeInvariantOutput(GrInvariantOutput* inout) const {
 429     inout->mulByUnknownSingleComponent();
 430 }
 431
 432 EllipticalRRectEffect::EllipticalRRectEffect(GrPrimitiveEdgeType edgeType, const SkRRect& rrect)
 433     : fRRect(rrect)
 434     , fEdgeType(edgeType) {
 435     this->initClassID<EllipticalRRectEffect>();
 436     this->setWillReadFragmentPosition();
 437 }
 438
 439 bool EllipticalRRectEffect::onIsEqual(const GrFragmentProcessor& other) const {
 440     const EllipticalRRectEffect& erre = other.cast<EllipticalRRectEffect>();
 441     return fEdgeType == erre.fEdgeType && fRRect == erre.fRRect;
 442 }
 443
 444 //////////////////////////////////////////////////////////////////////////////
 445
 446 GR_DEFINE_FRAGMENT_PROCESSOR_TEST(EllipticalRRectEffect);
 447
 448 GrFragmentProcessor* EllipticalRRectEffect::TestCreate(SkRandom* random,
 449                                                        GrContext*,
 450                                                        const GrDrawTargetCaps& caps,
 451                                                        GrTexture*[]) {
 452     SkScalar w = random->nextRangeScalar(20.f, 1000.f);
 453     SkScalar h = random->nextRangeScalar(20.f, 1000.f);
 454     SkVector r[4];
 455     r[SkRRect::kUpperLeft_Corner].fX = random->nextRangeF(kRadiusMin, 9.f);
 456     // ensure at least one corner really is elliptical
 457     do {
 458         r[SkRRect::kUpperLeft_Corner].fY = random->nextRangeF(kRadiusMin, 9.f);
 459     } while (r[SkRRect::kUpperLeft_Corner].fY == r[SkRRect::kUpperLeft_Corner].fX);
 460
 461     SkRRect rrect;
 462     if (random->nextBool()) {
 463         // half the time create a four-radii rrect.
 464         r[SkRRect::kLowerRight_Corner].fX = random->nextRangeF(kRadiusMin, 9.f);
 465         r[SkRRect::kLowerRight_Corner].fY = random->nextRangeF(kRadiusMin, 9.f);
 466
 467         r[SkRRect::kUpperRight_Corner].fX = r[SkRRect::kLowerRight_Corner].fX;
 468         r[SkRRect::kUpperRight_Corner].fY = r[SkRRect::kUpperLeft_Corner].fY;
 469
 470         r[SkRRect::kLowerLeft_Corner].fX = r[SkRRect::kUpperLeft_Corner].fX;
 471         r[SkRRect::kLowerLeft_Corner].fY = r[SkRRect::kLowerRight_Corner].fY;
 472
 473         rrect.setRectRadii(SkRect::MakeWH(w, h), r);
 474     } else {
 475         rrect.setRectXY(SkRect::MakeWH(w, h), r[SkRRect::kUpperLeft_Corner].fX,
 476                                               r[SkRRect::kUpperLeft_Corner].fY);
 477     }
 478     GrFragmentProcessor* fp;
 479     do {
 480         GrPrimitiveEdgeType et = (GrPrimitiveEdgeType)random->nextULessThan(kGrProcessorEdgeTypeCnt);
 481         fp = GrRRectEffect::Create(et, rrect);
 482     } while (NULL == fp);
 483     return fp;
 484 }
 485
 486 //////////////////////////////////////////////////////////////////////////////
 487
 488 class GLEllipticalRRectEffect : public GrGLFragmentProcessor {
 489 public:
 490     GLEllipticalRRectEffect(const GrProcessor&);
 491
 492     virtual void emitCode(GrGLFPBuilder* builder,
 493                           const GrFragmentProcessor& effect,
 494                           const char* outputColor,
 495                           const char* inputColor,
 496                           const TransformedCoordsArray&,
 497                           const TextureSamplerArray&) SK_OVERRIDE;
 498
 499     static inline void GenKey(const GrProcessor&, const GrGLCaps&, GrProcessorKeyBuilder*);
 500
 501     void setData(const GrGLProgramDataManager&, const GrProcessor&) SK_OVERRIDE;
 502
 503 private:
 504     GrGLProgramDataManager::UniformHandle fInnerRectUniform;
 505     GrGLProgramDataManager::UniformHandle fInvRadiiSqdUniform;
 506     SkRRect                               fPrevRRect;
 507     typedef GrGLFragmentProcessor INHERITED;
 508 };
 509
 510 GLEllipticalRRectEffect::GLEllipticalRRectEffect(const GrProcessor& effect) {
 511     fPrevRRect.setEmpty();
 512 }
 513
 514 void GLEllipticalRRectEffect::emitCode(GrGLFPBuilder* builder,
 515                                        const GrFragmentProcessor& effect,
 516                                        const char* outputColor,
 517                                        const char* inputColor,
 518                                        const TransformedCoordsArray&,
 519                                        const TextureSamplerArray& samplers) {
 520     const EllipticalRRectEffect& erre = effect.cast<EllipticalRRectEffect>();
 521     const char *rectName;
 522     // The inner rect is the rrect bounds inset by the x/y radii
 523     fInnerRectUniform = builder->addUniform(GrGLProgramBuilder::kFragment_Visibility,
 524                                             kVec4f_GrSLType, kDefault_GrSLPrecision,
 525                                             "innerRect",
 526                                             &rectName);
 527
 528     GrGLFPFragmentBuilder* fsBuilder = builder->getFragmentShaderBuilder();
 529     const char* fragmentPos = fsBuilder->fragmentPosition();
 530     // At each quarter-ellipse corner we compute a vector that is the offset of the fragment pos
 531     // to the ellipse center. The vector is pinned in x and y to be in the quarter-plane relevant
 532     // to that corner. This means that points near the interior near the rrect top edge will have
 533     // a vector that points straight up for both the TL left and TR corners. Computing an
 534     // alpha from this vector at either the TR or TL corner will give the correct result. Similarly,
 535     // fragments near the other three edges will get the correct AA. Fragments in the interior of
 536     // the rrect will have a (0,0) vector at all four corners. So long as the radii > 0.5 they will
 537     // correctly produce an alpha value of 1 at all four corners. We take the min of all the alphas.
 538     // The code below is a simplified version of the above that performs maxs on the vector
 539     // components before computing distances and alpha values so that only one distance computation
 540     // need be computed to determine the min alpha.
 541     fsBuilder->codeAppendf("\t\tvec2 dxy0 = %s.xy - %s.xy;\n", rectName, fragmentPos);
 542     fsBuilder->codeAppendf("\t\tvec2 dxy1 = %s.xy - %s.zw;\n", fragmentPos, rectName);
 543     switch (erre.getRRect().getType()) {
 544         case SkRRect::kSimple_Type: {
 545             const char *invRadiiXYSqdName;
 546             fInvRadiiSqdUniform = builder->addUniform(GrGLProgramBuilder::kFragment_Visibility,
 547                                                       kVec2f_GrSLType, kDefault_GrSLPrecision,
 548                                                       "invRadiiXY",
 549                                                       &invRadiiXYSqdName);
 550             fsBuilder->codeAppend("\t\tvec2 dxy = max(max(dxy0, dxy1), 0.0);\n");
 551             // Z is the x/y offsets divided by squared radii.
 552             fsBuilder->codeAppendf("\t\tvec2 Z = dxy * %s;\n", invRadiiXYSqdName);
 553             break;
 554         }
 555         case SkRRect::kNinePatch_Type: {
 556             const char *invRadiiLTRBSqdName;
 557             fInvRadiiSqdUniform = builder->addUniform(GrGLProgramBuilder::kFragment_Visibility,
 558                                                       kVec4f_GrSLType, kDefault_GrSLPrecision,
 559                                                       "invRadiiLTRB",
 560                                                       &invRadiiLTRBSqdName);
 561             fsBuilder->codeAppend("\t\tvec2 dxy = max(max(dxy0, dxy1), 0.0);\n");
 562             // Z is the x/y offsets divided by squared radii. We only care about the (at most) one
 563             // corner where both the x and y offsets are positive, hence the maxes. (The inverse
 564             // squared radii will always be positive.)
 565             fsBuilder->codeAppendf("\t\tvec2 Z = max(max(dxy0 * %s.xy, dxy1 * %s.zw), 0.0);\n",
 566                                    invRadiiLTRBSqdName, invRadiiLTRBSqdName);
 567             break;
 568         }
 569         default:
 570             SkFAIL("RRect should always be simple or nine-patch.");
 571     }
 572     // implicit is the evaluation of (x/a)^2 + (y/b)^2 - 1.
 573     fsBuilder->codeAppend("\t\tfloat implicit = dot(Z, dxy) - 1.0;\n");
 574     // grad_dot is the squared length of the gradient of the implicit.
 575     fsBuilder->codeAppendf("\t\tfloat grad_dot = 4.0 * dot(Z, Z);\n");
 576     // avoid calling inversesqrt on zero.
 577     fsBuilder->codeAppend("\t\tgrad_dot = max(grad_dot, 1.0e-4);\n");
 578     fsBuilder->codeAppendf("\t\tfloat approx_dist = implicit * inversesqrt(grad_dot);\n");
 579
 580     if (kFillAA_GrProcessorEdgeType == erre.getEdgeType()) {
 581         fsBuilder->codeAppend("\t\tfloat alpha = clamp(0.5 - approx_dist, 0.0, 1.0);\n");
 582     } else {
 583         fsBuilder->codeAppend("\t\tfloat alpha = clamp(0.5 + approx_dist, 0.0, 1.0);\n");
 584     }
 585
 586     fsBuilder->codeAppendf("\t\t%s = %s;\n", outputColor,
 587                            (GrGLSLExpr4(inputColor) * GrGLSLExpr1("alpha")).c_str());
 588 }
 589
 590 void GLEllipticalRRectEffect::GenKey(const GrProcessor& effect, const GrGLCaps&,
 591                                      GrProcessorKeyBuilder* b) {
 592     const EllipticalRRectEffect& erre = effect.cast<EllipticalRRectEffect>();
 593     GR_STATIC_ASSERT(kLast_GrProcessorEdgeType < (1 << 3));
 594     b->add32(erre.getRRect().getType() | erre.getEdgeType() << 3);
 595 }
 596
 597 void GLEllipticalRRectEffect::setData(const GrGLProgramDataManager& pdman,
 598                                       const GrProcessor& effect) {
 599     const EllipticalRRectEffect& erre = effect.cast<EllipticalRRectEffect>();
 600     const SkRRect& rrect = erre.getRRect();
 601     if (rrect != fPrevRRect) {
 602         SkRect rect = rrect.getBounds();
 603         const SkVector& r0 = rrect.radii(SkRRect::kUpperLeft_Corner);
 604         SkASSERT(r0.fX >= kRadiusMin);
 605         SkASSERT(r0.fY >= kRadiusMin);
 606         switch (erre.getRRect().getType()) {
 607             case SkRRect::kSimple_Type:
 608                 rect.inset(r0.fX, r0.fY);
 609                 pdman.set2f(fInvRadiiSqdUniform, 1.f / (r0.fX * r0.fX),
 610                                                 1.f / (r0.fY * r0.fY));
 611                 break;
 612             case SkRRect::kNinePatch_Type: {
 613                 const SkVector& r1 = rrect.radii(SkRRect::kLowerRight_Corner);
 614                 SkASSERT(r1.fX >= kRadiusMin);
 615                 SkASSERT(r1.fY >= kRadiusMin);
 616                 rect.fLeft += r0.fX;
 617                 rect.fTop += r0.fY;
 618                 rect.fRight -= r1.fX;
 619                 rect.fBottom -= r1.fY;
 620                 pdman.set4f(fInvRadiiSqdUniform, 1.f / (r0.fX * r0.fX),
 621                                                 1.f / (r0.fY * r0.fY),
 622                                                 1.f / (r1.fX * r1.fX),
 623                                                 1.f / (r1.fY * r1.fY));
 624                 break;
 625             }
 626         default:
 627             SkFAIL("RRect should always be simple or nine-patch.");
 628         }
 629         pdman.set4f(fInnerRectUniform, rect.fLeft, rect.fTop, rect.fRight, rect.fBottom);
 630         fPrevRRect = rrect;
 631     }
 632 }
 633
 634 ////////////////////////////////////////////////////////////////////////////////////////////////////
 635
 636 void EllipticalRRectEffect::getGLProcessorKey(const GrGLCaps& caps,
 637                                               GrProcessorKeyBuilder* b) const {
 638     GLEllipticalRRectEffect::GenKey(*this, caps, b);
 639 }
 640
 641 GrGLFragmentProcessor* EllipticalRRectEffect::createGLInstance() const  {
 642     return SkNEW_ARGS(GLEllipticalRRectEffect, (*this));
 643 }
 644
 645 //////////////////////////////////////////////////////////////////////////////
 646
 647 GrFragmentProcessor* GrRRectEffect::Create(GrPrimitiveEdgeType edgeType, const SkRRect& rrect) {
 648     if (rrect.isRect()) {
 649         return GrConvexPolyEffect::Create(edgeType, rrect.getBounds());
 650     }
 651
 652     if (rrect.isOval()) {
 653         return GrOvalEffect::Create(edgeType, rrect.getBounds());
 654     }
 655
 656     if (rrect.isSimple()) {
 657         if (rrect.getSimpleRadii().fX < kRadiusMin || rrect.getSimpleRadii().fY < kRadiusMin) {
 658             // In this case the corners are extremely close to rectangular and we collapse the
 659             // clip to a rectangular clip.
 660             return GrConvexPolyEffect::Create(edgeType, rrect.getBounds());
 661         }
 662         if (rrect.getSimpleRadii().fX == rrect.getSimpleRadii().fY) {
 663             return CircularRRectEffect::Create(edgeType, CircularRRectEffect::kAll_CornerFlags,
 664                                                rrect);
 665         } else {
 666             return EllipticalRRectEffect::Create(edgeType, rrect);
 667         }
 668     }
 669
 670     if (rrect.isComplex() || rrect.isNinePatch()) {
 671         // Check for the "tab" cases - two adjacent circular corners and two square corners.
 672         SkScalar circularRadius = 0;
 673         uint32_t cornerFlags  = 0;
 674
 675         SkVector radii[4];
 676         bool squashedRadii = false;
 677         for (int c = 0; c < 4; ++c) {
 678             radii[c] = rrect.radii((SkRRect::Corner)c);
 679             SkASSERT((0 == radii[c].fX) == (0 == radii[c].fY));
 680             if (0 == radii[c].fX) {
 681                 // The corner is square, so no need to squash or flag as circular.
 682                 continue;
 683             }
 684             if (radii[c].fX < kRadiusMin || radii[c].fY < kRadiusMin) {
 685                 radii[c].set(0, 0);
 686                 squashedRadii = true;
 687                 continue;
 688             }
 689             if (radii[c].fX != radii[c].fY) {
 690                 cornerFlags = ~0U;
 691                 break;
 692             }
 693             if (!cornerFlags) {
 694                 circularRadius = radii[c].fX;
 695                 cornerFlags = 1 << c;
 696             } else {
 697                 if (radii[c].fX != circularRadius) {
 698                    cornerFlags = ~0U;
 699                    break;
 700                 }
 701                 cornerFlags |= 1 << c;
 702             }
 703         }
 704
 705         switch (cornerFlags) {
 706             case CircularRRectEffect::kAll_CornerFlags:
 707                 // This rrect should have been caught in the simple case above. Though, it would
 708                 // be correctly handled in the fallthrough code.
 709                 SkASSERT(false);
 710             case CircularRRectEffect::kTopLeft_CornerFlag:
 711             case CircularRRectEffect::kTopRight_CornerFlag:
 712             case CircularRRectEffect::kBottomRight_CornerFlag:
 713             case CircularRRectEffect::kBottomLeft_CornerFlag:
 714             case CircularRRectEffect::kLeft_CornerFlags:
 715             case CircularRRectEffect::kTop_CornerFlags:
 716             case CircularRRectEffect::kRight_CornerFlags:
 717             case CircularRRectEffect::kBottom_CornerFlags: {
 718                 SkTCopyOnFirstWrite<SkRRect> rr(rrect);
 719                 if (squashedRadii) {
 720                     rr.writable()->setRectRadii(rrect.getBounds(), radii);
 721                 }
 722                 return CircularRRectEffect::Create(edgeType, cornerFlags, *rr);
 723             }
 724             case CircularRRectEffect::kNone_CornerFlags:
 725                 return GrConvexPolyEffect::Create(edgeType, rrect.getBounds());
 726             default: {
 727                 if (squashedRadii) {
 728                     // If we got here then we squashed some but not all the radii to zero. (If all
 729                     // had been squashed cornerFlags would be 0.) The elliptical effect doesn't
 730                     // support some rounded and some square corners.
 731                     return NULL;
 732                 }
 733                 if (rrect.isNinePatch()) {
 734                     return EllipticalRRectEffect::Create(edgeType, rrect);
 735                 }
 736                 return NULL;
 737             }
 738         }
 739     }
 740
 741     return NULL;
 742 }