src/third_party/skia/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/GrGLEffect.h"
  10 #include "gl/GrGLShaderBuilder.h"
  11 #include "gl/GrGLSL.h"
  12 #include "gl/GrGLTexture.h"
  13 #include "GrTBackendEffectFactory.h"
  14
  15 // For brevity
  16 typedef GrGLProgramDataManager::UniformHandle UniformHandle;
  17
  18 class GrGLConvolutionEffect : public GrGLEffect {
  19 public:
  20     GrGLConvolutionEffect(const GrBackendEffectFactory&, const GrDrawEffect&);
  21
  22     virtual void emitCode(GrGLShaderBuilder*,
  23                           const GrDrawEffect&,
  24                           const GrEffectKey&,
  25                           const char* outputColor,
  26                           const char* inputColor,
  27                           const TransformedCoordsArray&,
  28                           const TextureSamplerArray&) SK_OVERRIDE;
  29
  30     virtual void setData(const GrGLProgramDataManager& pdman, const GrDrawEffect&) SK_OVERRIDE;
  31
  32     static inline void GenKey(const GrDrawEffect&, const GrGLCaps&, GrEffectKeyBuilder*);
  33
  34 private:
  35     int width() const { return Gr1DKernelEffect::WidthFromRadius(fRadius); }
  36     bool useBounds() const { return fUseBounds; }
  37     Gr1DKernelEffect::Direction direction() const { return fDirection; }
  38
  39     int                 fRadius;
  40     bool                fUseBounds;
  41     Gr1DKernelEffect::Direction    fDirection;
  42     UniformHandle       fKernelUni;
  43     UniformHandle       fImageIncrementUni;
  44     UniformHandle       fBoundsUni;
  45
  46     typedef GrGLEffect INHERITED;
  47 };
  48
  49 GrGLConvolutionEffect::GrGLConvolutionEffect(const GrBackendEffectFactory& factory,
  50                                              const GrDrawEffect& drawEffect)
  51     : INHERITED(factory) {
  52     const GrConvolutionEffect& c = drawEffect.castEffect<GrConvolutionEffect>();
  53     fRadius = c.radius();
  54     fUseBounds = c.useBounds();
  55     fDirection = c.direction();
  56 }
  57
  58 void GrGLConvolutionEffect::emitCode(GrGLShaderBuilder* builder,
  59                                      const GrDrawEffect&,
  60                                      const GrEffectKey& key,
  61                                      const char* outputColor,
  62                                      const char* inputColor,
  63                                      const TransformedCoordsArray& coords,
  64                                      const TextureSamplerArray& samplers) {
  65     SkString coords2D = builder->ensureFSCoords2D(coords, 0);
  66     fImageIncrementUni = builder->addUniform(GrGLShaderBuilder::kFragment_Visibility,
  67                                              kVec2f_GrSLType, "ImageIncrement");
  68     if (this->useBounds()) {
  69         fBoundsUni = builder->addUniform(GrGLShaderBuilder::kFragment_Visibility,
  70                                          kVec2f_GrSLType, "Bounds");
  71     }
  72     fKernelUni = builder->addUniformArray(GrGLShaderBuilder::kFragment_Visibility,
  73                                           kFloat_GrSLType, "Kernel", this->width());
  74
  75     builder->fsCodeAppendf("\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     builder->fsCodeAppendf("\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         builder->fsCodeAppendf("\t\t%s += ", outputColor);
  90         builder->fsAppendTextureLookup(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             builder->fsCodeAppendf(" * float(coord.%s >= %s.x && coord.%s <= %s.y)",
  95                 component, bounds, component, bounds);
  96         }
  97         builder->fsCodeAppendf(" * %s;\n", kernelIndex.c_str());
  98         builder->fsCodeAppendf("\t\tcoord += %s;\n", imgInc);
  99     }
 100
 101     SkString modulate;
 102     GrGLSLMulVarBy4f(&modulate, 2, outputColor, inputColor);
 103     builder->fsCodeAppend(modulate.c_str());
 104 }
 105
 106 void GrGLConvolutionEffect::setData(const GrGLProgramDataManager& pdman,
 107                                     const GrDrawEffect& drawEffect) {
 108     const GrConvolutionEffect& conv = drawEffect.castEffect<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 GrDrawEffect& drawEffect, const GrGLCaps&,
 138                                    GrEffectKeyBuilder* b) {
 139     const GrConvolutionEffect& conv = drawEffect.castEffect<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     SkASSERT(radius <= kMaxKernelRadius);
 159     SkASSERT(NULL != kernel);
 160     int width = this->width();
 161     for (int i = 0; i < width; i++) {
 162         fKernel[i] = kernel[i];
 163     }
 164     memcpy(fBounds, bounds, sizeof(fBounds));
 165 }
 166
 167 GrConvolutionEffect::GrConvolutionEffect(GrTexture* texture,
 168                                          Direction direction,
 169                                          int radius,
 170                                          float gaussianSigma,
 171                                          bool useBounds,
 172                                          float bounds[2])
 173     : Gr1DKernelEffect(texture, direction, radius), fUseBounds(useBounds) {
 174     SkASSERT(radius <= kMaxKernelRadius);
 175     int width = this->width();
 176
 177     float sum = 0.0f;
 178     float denom = 1.0f / (2.0f * gaussianSigma * gaussianSigma);
 179     for (int i = 0; i < width; ++i) {
 180         float x = static_cast<float>(i - this->radius());
 181         // Note that the constant term (1/(sqrt(2*pi*sigma^2)) of the Gaussian
 182         // is dropped here, since we renormalize the kernel below.
 183         fKernel[i] = sk_float_exp(- x * x * denom);
 184         sum += fKernel[i];
 185     }
 186     // Normalize the kernel
 187     float scale = 1.0f / sum;
 188     for (int i = 0; i < width; ++i) {
 189         fKernel[i] *= scale;
 190     }
 191     memcpy(fBounds, bounds, sizeof(fBounds));
 192 }
 193
 194 GrConvolutionEffect::~GrConvolutionEffect() {
 195 }
 196
 197 const GrBackendEffectFactory& GrConvolutionEffect::getFactory() const {
 198     return GrTBackendEffectFactory<GrConvolutionEffect>::getInstance();
 199 }
 200
 201 bool GrConvolutionEffect::onIsEqual(const GrEffect& sBase) const {
 202     const GrConvolutionEffect& s = CastEffect<GrConvolutionEffect>(sBase);
 203     return (this->texture(0) == s.texture(0) &&
 204             this->radius() == s.radius() &&
 205             this->direction() == s.direction() &&
 206             this->useBounds() == s.useBounds() &&
 207             0 == memcmp(fBounds, s.fBounds, sizeof(fBounds)) &&
 208             0 == memcmp(fKernel, s.fKernel, this->width() * sizeof(float)));
 209 }
 210
 211 ///////////////////////////////////////////////////////////////////////////////
 212
 213 GR_DEFINE_EFFECT_TEST(GrConvolutionEffect);
 214
 215 GrEffect* GrConvolutionEffect::TestCreate(SkRandom* random,
 216                                           GrContext*,
 217                                           const GrDrawTargetCaps&,
 218                                           GrTexture* textures[]) {
 219     int texIdx = random->nextBool() ? GrEffectUnitTest::kSkiaPMTextureIdx :
 220                                       GrEffectUnitTest::kAlphaTextureIdx;
 221     Direction dir = random->nextBool() ? kX_Direction : kY_Direction;
 222     int radius = random->nextRangeU(1, kMaxKernelRadius);
 223     float kernel[kMaxKernelWidth];
 224     for (size_t i = 0; i < SK_ARRAY_COUNT(kernel); ++i) {
 225         kernel[i] = random->nextSScalar1();
 226     }
 227     float bounds[2];
 228     for (size_t i = 0; i < SK_ARRAY_COUNT(bounds); ++i) {
 229         bounds[i] = random->nextF();
 230     }
 231
 232     bool useBounds = random->nextBool();
 233     return GrConvolutionEffect::Create(textures[texIdx],
 234                                        dir,
 235                                        radius,
 236                                        kernel,
 237                                        useBounds,
 238                                        bounds);
 239 }