src/gpu/effects/GrConvolutionEffect.cpp

   1 /*
   2  * Copyright 2012 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 "GrConvolutionEffect.h"
   9 #include "gl/GrGLProcessor.h"
  10 #include "gl/GrGLSL.h"
  11 #include "gl/GrGLTexture.h"
  12 #include "gl/builders/GrGLProgramBuilder.h"
  13
  14 // For brevity
  15 typedef GrGLProgramDataManager::UniformHandle UniformHandle;
  16
  17 class GrGLConvolutionEffect : public GrGLFragmentProcessor {
  18 public:
  19     GrGLConvolutionEffect(const GrProcessor&);
  20
  21     virtual void emitCode(GrGLFPBuilder*,
  22                           const GrFragmentProcessor&,
  23                           const char* outputColor,
  24                           const char* inputColor,
  25                           const TransformedCoordsArray&,
  26                           const TextureSamplerArray&) override;
  27
  28     void setData(const GrGLProgramDataManager& pdman, const GrProcessor&) override;
  29
  30     static inline void GenKey(const GrProcessor&, const GrGLCaps&, GrProcessorKeyBuilder*);
  31
  32 private:
  33     int width() const { return Gr1DKernelEffect::WidthFromRadius(fRadius); }
  34     bool useBounds() const { return fUseBounds; }
  35     Gr1DKernelEffect::Direction direction() const { return fDirection; }
  36
  37     int                 fRadius;
  38     bool                fUseBounds;
  39     Gr1DKernelEffect::Direction    fDirection;
  40     UniformHandle       fKernelUni;
  41     UniformHandle       fImageIncrementUni;
  42     UniformHandle       fBoundsUni;
  43
  44     typedef GrGLFragmentProcessor INHERITED;
  45 };
  46
  47 GrGLConvolutionEffect::GrGLConvolutionEffect(const GrProcessor& processor) {
  48     const GrConvolutionEffect& c = processor.cast<GrConvolutionEffect>();
  49     fRadius = c.radius();
  50     fUseBounds = c.useBounds();
  51     fDirection = c.direction();
  52 }
  53
  54 void GrGLConvolutionEffect::emitCode(GrGLFPBuilder* builder,
  55                                      const GrFragmentProcessor&,
  56                                      const char* outputColor,
  57                                      const char* inputColor,
  58                                      const TransformedCoordsArray& coords,
  59                                      const TextureSamplerArray& samplers) {
  60     fImageIncrementUni = builder->addUniform(GrGLProgramBuilder::kFragment_Visibility,
  61                                              kVec2f_GrSLType, kDefault_GrSLPrecision,
  62                                              "ImageIncrement");
  63     if (this->useBounds()) {
  64         fBoundsUni = builder->addUniform(GrGLProgramBuilder::kFragment_Visibility,
  65                                          kVec2f_GrSLType, kDefault_GrSLPrecision,
  66                                          "Bounds");
  67     }
  68     fKernelUni = builder->addUniformArray(GrGLProgramBuilder::kFragment_Visibility,
  69                                           kFloat_GrSLType, kDefault_GrSLPrecision,
  70                                           "Kernel", this->width());
  71
  72     GrGLFPFragmentBuilder* fsBuilder = builder->getFragmentShaderBuilder();
  73     SkString coords2D = fsBuilder->ensureFSCoords2D(coords, 0);
  74
  75     fsBuilder->codeAppendf("\t\t%s = vec4(0, 0, 0, 0);\n", outputColor);
  76
  77     int width = this->width();
  78     const GrGLShaderVar& kernel = builder->getUniformVariable(fKernelUni);
  79     const char* imgInc = builder->getUniformCStr(fImageIncrementUni);
  80
  81     fsBuilder->codeAppendf("\t\tvec2 coord = %s - %d.0 * %s;\n", coords2D.c_str(), fRadius, imgInc);
  82
  83     // Manually unroll loop because some drivers don't; yields 20-30% speedup.
  84     for (int i = 0; i < width; i++) {
  85         SkString index;
  86         SkString kernelIndex;
  87         index.appendS32(i);
  88         kernel.appendArrayAccess(index.c_str(), &kernelIndex);
  89         fsBuilder->codeAppendf("\t\t%s += ", outputColor);
  90         fsBuilder->appendTextureLookup(samplers[0], "coord");
  91         if (this->useBounds()) {
  92             const char* bounds = builder->getUniformCStr(fBoundsUni);
  93             const char* component = this->direction() == Gr1DKernelEffect::kY_Direction ? "y" : "x";
  94             fsBuilder->codeAppendf(" * float(coord.%s >= %s.x && coord.%s <= %s.y)",
  95                 component, bounds, component, bounds);
  96         }
  97         fsBuilder->codeAppendf(" * %s;\n", kernelIndex.c_str());
  98         fsBuilder->codeAppendf("\t\tcoord += %s;\n", imgInc);
  99     }
 100
 101     SkString modulate;
 102     GrGLSLMulVarBy4f(&modulate, outputColor, inputColor);
 103     fsBuilder->codeAppend(modulate.c_str());
 104 }
 105
 106 void GrGLConvolutionEffect::setData(const GrGLProgramDataManager& pdman,
 107                                     const GrProcessor& processor) {
 108     const GrConvolutionEffect& conv = processor.cast<GrConvolutionEffect>();
 109     GrTexture& texture = *conv.texture(0);
 110     // the code we generated was for a specific kernel radius
 111     SkASSERT(conv.radius() == fRadius);
 112     float imageIncrement[2] = { 0 };
 113     float ySign = texture.origin() != kTopLeft_GrSurfaceOrigin ? 1.0f : -1.0f;
 114     switch (conv.direction()) {
 115         case Gr1DKernelEffect::kX_Direction:
 116             imageIncrement[0] = 1.0f / texture.width();
 117             break;
 118         case Gr1DKernelEffect::kY_Direction:
 119             imageIncrement[1] = ySign / texture.height();
 120             break;
 121         default:
 122             SkFAIL("Unknown filter direction.");
 123     }
 124     pdman.set2fv(fImageIncrementUni, 1, imageIncrement);
 125     if (conv.useBounds()) {
 126         const float* bounds = conv.bounds();
 127         if (Gr1DKernelEffect::kY_Direction == conv.direction() &&
 128             texture.origin() != kTopLeft_GrSurfaceOrigin) {
 129             pdman.set2f(fBoundsUni, 1.0f - bounds[1], 1.0f - bounds[0]);
 130         } else {
 131             pdman.set2f(fBoundsUni, bounds[0], bounds[1]);
 132         }
 133     }
 134     pdman.set1fv(fKernelUni, this->width(), conv.kernel());
 135 }
 136
 137 void GrGLConvolutionEffect::GenKey(const GrProcessor& processor, const GrGLCaps&,
 138                                    GrProcessorKeyBuilder* b) {
 139     const GrConvolutionEffect& conv = processor.cast<GrConvolutionEffect>();
 140     uint32_t key = conv.radius();
 141     key <<= 2;
 142     if (conv.useBounds()) {
 143         key |= 0x2;
 144         key |= GrConvolutionEffect::kY_Direction == conv.direction() ? 0x1 : 0x0;
 145     }
 146     b->add32(key);
 147 }
 148
 149 ///////////////////////////////////////////////////////////////////////////////
 150
 151 GrConvolutionEffect::GrConvolutionEffect(GrTexture* texture,
 152                                          Direction direction,
 153                                          int radius,
 154                                          const float* kernel,
 155                                          bool useBounds,
 156                                          float bounds[2])
 157     : Gr1DKernelEffect(texture, direction, radius), fUseBounds(useBounds) {
 158     this->initClassID<GrConvolutionEffect>();
 159     SkASSERT(radius <= kMaxKernelRadius);
 160     SkASSERT(kernel);
 161     int width = this->width();
 162     for (int i = 0; i < width; i++) {
 163         fKernel[i] = kernel[i];
 164     }
 165     memcpy(fBounds, bounds, sizeof(fBounds));
 166 }
 167
 168 GrConvolutionEffect::GrConvolutionEffect(GrTexture* texture,
 169                                          Direction direction,
 170                                          int radius,
 171                                          float gaussianSigma,
 172                                          bool useBounds,
 173                                          float bounds[2])
 174     : Gr1DKernelEffect(texture, direction, radius), fUseBounds(useBounds) {
 175     this->initClassID<GrConvolutionEffect>();
 176     SkASSERT(radius <= kMaxKernelRadius);
 177     int width = this->width();
 178
 179     float sum = 0.0f;
 180     float denom = 1.0f / (2.0f * gaussianSigma * gaussianSigma);
 181     for (int i = 0; i < width; ++i) {
 182         float x = static_cast<float>(i - this->radius());
 183         // Note that the constant term (1/(sqrt(2*pi*sigma^2)) of the Gaussian
 184         // is dropped here, since we renormalize the kernel below.
 185         fKernel[i] = sk_float_exp(- x * x * denom);
 186         sum += fKernel[i];
 187     }
 188     // Normalize the kernel
 189     float scale = 1.0f / sum;
 190     for (int i = 0; i < width; ++i) {
 191         fKernel[i] *= scale;
 192     }
 193     memcpy(fBounds, bounds, sizeof(fBounds));
 194 }
 195
 196 GrConvolutionEffect::~GrConvolutionEffect() {
 197 }
 198
 199 void GrConvolutionEffect::getGLProcessorKey(const GrGLCaps& caps,
 200                                         GrProcessorKeyBuilder* b) const {
 201     GrGLConvolutionEffect::GenKey(*this, caps, b);
 202 }
 203
 204 GrGLFragmentProcessor* GrConvolutionEffect::createGLInstance() const  {
 205     return SkNEW_ARGS(GrGLConvolutionEffect, (*this));
 206 }
 207
 208 bool GrConvolutionEffect::onIsEqual(const GrFragmentProcessor& sBase) const {
 209     const GrConvolutionEffect& s = sBase.cast<GrConvolutionEffect>();
 210     return (this->radius() == s.radius() &&
 211             this->direction() == s.direction() &&
 212             this->useBounds() == s.useBounds() &&
 213             0 == memcmp(fBounds, s.fBounds, sizeof(fBounds)) &&
 214             0 == memcmp(fKernel, s.fKernel, this->width() * sizeof(float)));
 215 }
 216
 217 ///////////////////////////////////////////////////////////////////////////////
 218
 219 GR_DEFINE_FRAGMENT_PROCESSOR_TEST(GrConvolutionEffect);
 220
 221 GrFragmentProcessor* GrConvolutionEffect::TestCreate(SkRandom* random,
 222                                                      GrContext*,
 223                                                      const GrDrawTargetCaps&,
 224                                                      GrTexture* textures[]) {
 225     int texIdx = random->nextBool() ? GrProcessorUnitTest::kSkiaPMTextureIdx :
 226                                       GrProcessorUnitTest::kAlphaTextureIdx;
 227     Direction dir = random->nextBool() ? kX_Direction : kY_Direction;
 228     int radius = random->nextRangeU(1, kMaxKernelRadius);
 229     float kernel[kMaxKernelWidth];
 230     for (size_t i = 0; i < SK_ARRAY_COUNT(kernel); ++i) {
 231         kernel[i] = random->nextSScalar1();
 232     }
 233     float bounds[2];
 234     for (size_t i = 0; i < SK_ARRAY_COUNT(bounds); ++i) {
 235         bounds[i] = random->nextF();
 236     }
 237
 238     bool useBounds = random->nextBool();
 239     return GrConvolutionEffect::Create(textures[texIdx],
 240                                        dir,
 241                                        radius,
 242                                        kernel,
 243                                        useBounds,
 244                                        bounds);
 245 }