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