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      1 /*
      2  * Copyright 2012 The Android Open Source Project
      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 "SkMatrixConvolutionImageFilter.h"
      9 #include "SkBitmap.h"
     10 #include "SkColorPriv.h"
     11 #include "SkReadBuffer.h"
     12 #include "SkWriteBuffer.h"
     13 #include "SkRect.h"
     14 #include "SkUnPreMultiply.h"
     15 
     16 #if SK_SUPPORT_GPU
     17 #include "gl/GrGLEffect.h"
     18 #include "effects/GrSingleTextureEffect.h"
     19 #include "GrTBackendEffectFactory.h"
     20 #include "GrTexture.h"
     21 #include "SkMatrix.h"
     22 #endif
     23 
     24 static bool tile_mode_is_valid(SkMatrixConvolutionImageFilter::TileMode tileMode) {
     25     switch (tileMode) {
     26     case SkMatrixConvolutionImageFilter::kClamp_TileMode:
     27     case SkMatrixConvolutionImageFilter::kRepeat_TileMode:
     28     case SkMatrixConvolutionImageFilter::kClampToBlack_TileMode:
     29         return true;
     30     default:
     31         break;
     32     }
     33     return false;
     34 }
     35 
     36 SkMatrixConvolutionImageFilter::SkMatrixConvolutionImageFilter(
     37     const SkISize& kernelSize,
     38     const SkScalar* kernel,
     39     SkScalar gain,
     40     SkScalar bias,
     41     const SkIPoint& kernelOffset,
     42     TileMode tileMode,
     43     bool convolveAlpha,
     44     SkImageFilter* input,
     45     const CropRect* cropRect)
     46   : INHERITED(input, cropRect),
     47     fKernelSize(kernelSize),
     48     fGain(gain),
     49     fBias(bias),
     50     fKernelOffset(kernelOffset),
     51     fTileMode(tileMode),
     52     fConvolveAlpha(convolveAlpha) {
     53     uint32_t size = fKernelSize.fWidth * fKernelSize.fHeight;
     54     fKernel = SkNEW_ARRAY(SkScalar, size);
     55     memcpy(fKernel, kernel, size * sizeof(SkScalar));
     56     SkASSERT(kernelSize.fWidth >= 1 && kernelSize.fHeight >= 1);
     57     SkASSERT(kernelOffset.fX >= 0 && kernelOffset.fX < kernelSize.fWidth);
     58     SkASSERT(kernelOffset.fY >= 0 && kernelOffset.fY < kernelSize.fHeight);
     59 }
     60 
     61 SkMatrixConvolutionImageFilter::SkMatrixConvolutionImageFilter(SkReadBuffer& buffer)
     62     : INHERITED(1, buffer) {
     63     // We need to be able to read at most SK_MaxS32 bytes, so divide that
     64     // by the size of a scalar to know how many scalars we can read.
     65     static const int32_t kMaxSize = SK_MaxS32 / sizeof(SkScalar);
     66     fKernelSize.fWidth = buffer.readInt();
     67     fKernelSize.fHeight = buffer.readInt();
     68     if ((fKernelSize.fWidth >= 1) && (fKernelSize.fHeight >= 1) &&
     69         // Make sure size won't be larger than a signed int,
     70         // which would still be extremely large for a kernel,
     71         // but we don't impose a hard limit for kernel size
     72         (kMaxSize / fKernelSize.fWidth >= fKernelSize.fHeight)) {
     73         size_t size = fKernelSize.fWidth * fKernelSize.fHeight;
     74         fKernel = SkNEW_ARRAY(SkScalar, size);
     75         SkDEBUGCODE(bool success =) buffer.readScalarArray(fKernel, size);
     76         SkASSERT(success);
     77     } else {
     78         fKernel = 0;
     79     }
     80     fGain = buffer.readScalar();
     81     fBias = buffer.readScalar();
     82     fKernelOffset.fX = buffer.readInt();
     83     fKernelOffset.fY = buffer.readInt();
     84     fTileMode = (TileMode) buffer.readInt();
     85     fConvolveAlpha = buffer.readBool();
     86     buffer.validate((fKernel != 0) &&
     87                     SkScalarIsFinite(fGain) &&
     88                     SkScalarIsFinite(fBias) &&
     89                     tile_mode_is_valid(fTileMode) &&
     90                     (fKernelOffset.fX >= 0) && (fKernelOffset.fX < fKernelSize.fWidth) &&
     91                     (fKernelOffset.fY >= 0) && (fKernelOffset.fY < fKernelSize.fHeight));
     92 }
     93 
     94 void SkMatrixConvolutionImageFilter::flatten(SkWriteBuffer& buffer) const {
     95     this->INHERITED::flatten(buffer);
     96     buffer.writeInt(fKernelSize.fWidth);
     97     buffer.writeInt(fKernelSize.fHeight);
     98     buffer.writeScalarArray(fKernel, fKernelSize.fWidth * fKernelSize.fHeight);
     99     buffer.writeScalar(fGain);
    100     buffer.writeScalar(fBias);
    101     buffer.writeInt(fKernelOffset.fX);
    102     buffer.writeInt(fKernelOffset.fY);
    103     buffer.writeInt((int) fTileMode);
    104     buffer.writeBool(fConvolveAlpha);
    105 }
    106 
    107 SkMatrixConvolutionImageFilter::~SkMatrixConvolutionImageFilter() {
    108     delete[] fKernel;
    109 }
    110 
    111 class UncheckedPixelFetcher {
    112 public:
    113     static inline SkPMColor fetch(const SkBitmap& src, int x, int y, const SkIRect& bounds) {
    114         return *src.getAddr32(x, y);
    115     }
    116 };
    117 
    118 class ClampPixelFetcher {
    119 public:
    120     static inline SkPMColor fetch(const SkBitmap& src, int x, int y, const SkIRect& bounds) {
    121         x = SkPin32(x, bounds.fLeft, bounds.fRight - 1);
    122         y = SkPin32(y, bounds.fTop, bounds.fBottom - 1);
    123         return *src.getAddr32(x, y);
    124     }
    125 };
    126 
    127 class RepeatPixelFetcher {
    128 public:
    129     static inline SkPMColor fetch(const SkBitmap& src, int x, int y, const SkIRect& bounds) {
    130         x = (x - bounds.left()) % bounds.width() + bounds.left();
    131         y = (y - bounds.top()) % bounds.height() + bounds.top();
    132         if (x < bounds.left()) {
    133             x += bounds.width();
    134         }
    135         if (y < bounds.top()) {
    136             y += bounds.height();
    137         }
    138         return *src.getAddr32(x, y);
    139     }
    140 };
    141 
    142 class ClampToBlackPixelFetcher {
    143 public:
    144     static inline SkPMColor fetch(const SkBitmap& src, int x, int y, const SkIRect& bounds) {
    145         if (x < bounds.fLeft || x >= bounds.fRight || y < bounds.fTop || y >= bounds.fBottom) {
    146             return 0;
    147         } else {
    148             return *src.getAddr32(x, y);
    149         }
    150     }
    151 };
    152 
    153 template<class PixelFetcher, bool convolveAlpha>
    154 void SkMatrixConvolutionImageFilter::filterPixels(const SkBitmap& src,
    155                                                   SkBitmap* result,
    156                                                   const SkIRect& r,
    157                                                   const SkIRect& bounds) const {
    158     SkIRect rect(r);
    159     if (!rect.intersect(bounds)) {
    160         return;
    161     }
    162     for (int y = rect.fTop; y < rect.fBottom; ++y) {
    163         SkPMColor* dptr = result->getAddr32(rect.fLeft - bounds.fLeft, y - bounds.fTop);
    164         for (int x = rect.fLeft; x < rect.fRight; ++x) {
    165             SkScalar sumA = 0, sumR = 0, sumG = 0, sumB = 0;
    166             for (int cy = 0; cy < fKernelSize.fHeight; cy++) {
    167                 for (int cx = 0; cx < fKernelSize.fWidth; cx++) {
    168                     SkPMColor s = PixelFetcher::fetch(src,
    169                                                       x + cx - fKernelOffset.fX,
    170                                                       y + cy - fKernelOffset.fY,
    171                                                       bounds);
    172                     SkScalar k = fKernel[cy * fKernelSize.fWidth + cx];
    173                     if (convolveAlpha) {
    174                         sumA += SkScalarMul(SkIntToScalar(SkGetPackedA32(s)), k);
    175                     }
    176                     sumR += SkScalarMul(SkIntToScalar(SkGetPackedR32(s)), k);
    177                     sumG += SkScalarMul(SkIntToScalar(SkGetPackedG32(s)), k);
    178                     sumB += SkScalarMul(SkIntToScalar(SkGetPackedB32(s)), k);
    179                 }
    180             }
    181             int a = convolveAlpha
    182                   ? SkClampMax(SkScalarFloorToInt(SkScalarMul(sumA, fGain) + fBias), 255)
    183                   : 255;
    184             int r = SkClampMax(SkScalarFloorToInt(SkScalarMul(sumR, fGain) + fBias), a);
    185             int g = SkClampMax(SkScalarFloorToInt(SkScalarMul(sumG, fGain) + fBias), a);
    186             int b = SkClampMax(SkScalarFloorToInt(SkScalarMul(sumB, fGain) + fBias), a);
    187             if (!convolveAlpha) {
    188                 a = SkGetPackedA32(PixelFetcher::fetch(src, x, y, bounds));
    189                 *dptr++ = SkPreMultiplyARGB(a, r, g, b);
    190             } else {
    191                 *dptr++ = SkPackARGB32(a, r, g, b);
    192             }
    193         }
    194     }
    195 }
    196 
    197 template<class PixelFetcher>
    198 void SkMatrixConvolutionImageFilter::filterPixels(const SkBitmap& src,
    199                                                   SkBitmap* result,
    200                                                   const SkIRect& rect,
    201                                                   const SkIRect& bounds) const {
    202     if (fConvolveAlpha) {
    203         filterPixels<PixelFetcher, true>(src, result, rect, bounds);
    204     } else {
    205         filterPixels<PixelFetcher, false>(src, result, rect, bounds);
    206     }
    207 }
    208 
    209 void SkMatrixConvolutionImageFilter::filterInteriorPixels(const SkBitmap& src,
    210                                                           SkBitmap* result,
    211                                                           const SkIRect& rect,
    212                                                           const SkIRect& bounds) const {
    213     filterPixels<UncheckedPixelFetcher>(src, result, rect, bounds);
    214 }
    215 
    216 void SkMatrixConvolutionImageFilter::filterBorderPixels(const SkBitmap& src,
    217                                                         SkBitmap* result,
    218                                                         const SkIRect& rect,
    219                                                         const SkIRect& bounds) const {
    220     switch (fTileMode) {
    221         case kClamp_TileMode:
    222             filterPixels<ClampPixelFetcher>(src, result, rect, bounds);
    223             break;
    224         case kRepeat_TileMode:
    225             filterPixels<RepeatPixelFetcher>(src, result, rect, bounds);
    226             break;
    227         case kClampToBlack_TileMode:
    228             filterPixels<ClampToBlackPixelFetcher>(src, result, rect, bounds);
    229             break;
    230     }
    231 }
    232 
    233 // FIXME:  This should be refactored to SkImageFilterUtils for
    234 // use by other filters.  For now, we assume the input is always
    235 // premultiplied and unpremultiply it
    236 static SkBitmap unpremultiplyBitmap(const SkBitmap& src)
    237 {
    238     SkAutoLockPixels alp(src);
    239     if (!src.getPixels()) {
    240         return SkBitmap();
    241     }
    242     SkBitmap result;
    243     if (!result.allocPixels(src.info())) {
    244         return SkBitmap();
    245     }
    246     for (int y = 0; y < src.height(); ++y) {
    247         const uint32_t* srcRow = src.getAddr32(0, y);
    248         uint32_t* dstRow = result.getAddr32(0, y);
    249         for (int x = 0; x < src.width(); ++x) {
    250             dstRow[x] = SkUnPreMultiply::PMColorToColor(srcRow[x]);
    251         }
    252     }
    253     return result;
    254 }
    255 
    256 bool SkMatrixConvolutionImageFilter::onFilterImage(Proxy* proxy,
    257                                                    const SkBitmap& source,
    258                                                    const Context& ctx,
    259                                                    SkBitmap* result,
    260                                                    SkIPoint* offset) const {
    261     SkBitmap src = source;
    262     SkIPoint srcOffset = SkIPoint::Make(0, 0);
    263     if (getInput(0) && !getInput(0)->filterImage(proxy, source, ctx, &src, &srcOffset)) {
    264         return false;
    265     }
    266 
    267     if (src.colorType() != kN32_SkColorType) {
    268         return false;
    269     }
    270 
    271     SkIRect bounds;
    272     if (!this->applyCropRect(ctx, proxy, src, &srcOffset, &bounds, &src)) {
    273         return false;
    274     }
    275 
    276     if (!fConvolveAlpha && !src.isOpaque()) {
    277         src = unpremultiplyBitmap(src);
    278     }
    279 
    280     SkAutoLockPixels alp(src);
    281     if (!src.getPixels()) {
    282         return false;
    283     }
    284 
    285     if (!result->allocPixels(src.info().makeWH(bounds.width(), bounds.height()))) {
    286         return false;
    287     }
    288 
    289     offset->fX = bounds.fLeft;
    290     offset->fY = bounds.fTop;
    291     bounds.offset(-srcOffset);
    292     SkIRect interior = SkIRect::MakeXYWH(bounds.left() + fKernelOffset.fX,
    293                                          bounds.top() + fKernelOffset.fY,
    294                                          bounds.width() - fKernelSize.fWidth + 1,
    295                                          bounds.height() - fKernelSize.fHeight + 1);
    296     SkIRect top = SkIRect::MakeLTRB(bounds.left(), bounds.top(), bounds.right(), interior.top());
    297     SkIRect bottom = SkIRect::MakeLTRB(bounds.left(), interior.bottom(),
    298                                        bounds.right(), bounds.bottom());
    299     SkIRect left = SkIRect::MakeLTRB(bounds.left(), interior.top(),
    300                                      interior.left(), interior.bottom());
    301     SkIRect right = SkIRect::MakeLTRB(interior.right(), interior.top(),
    302                                       bounds.right(), interior.bottom());
    303     filterBorderPixels(src, result, top, bounds);
    304     filterBorderPixels(src, result, left, bounds);
    305     filterInteriorPixels(src, result, interior, bounds);
    306     filterBorderPixels(src, result, right, bounds);
    307     filterBorderPixels(src, result, bottom, bounds);
    308     return true;
    309 }
    310 
    311 bool SkMatrixConvolutionImageFilter::onFilterBounds(const SkIRect& src, const SkMatrix& ctm,
    312                                                     SkIRect* dst) const {
    313     SkIRect bounds = src;
    314     bounds.fRight += fKernelSize.width() - 1;
    315     bounds.fBottom += fKernelSize.height() - 1;
    316     bounds.offset(-fKernelOffset);
    317     if (getInput(0) && !getInput(0)->filterBounds(bounds, ctm, &bounds)) {
    318         return false;
    319     }
    320     *dst = bounds;
    321     return true;
    322 }
    323 
    324 #if SK_SUPPORT_GPU
    325 
    326 ///////////////////////////////////////////////////////////////////////////////
    327 
    328 class GrGLMatrixConvolutionEffect;
    329 
    330 class GrMatrixConvolutionEffect : public GrSingleTextureEffect {
    331 public:
    332     typedef SkMatrixConvolutionImageFilter::TileMode TileMode;
    333     static GrEffectRef* Create(GrTexture* texture,
    334                                const SkIRect& bounds,
    335                                const SkISize& kernelSize,
    336                                const SkScalar* kernel,
    337                                SkScalar gain,
    338                                SkScalar bias,
    339                                const SkIPoint& kernelOffset,
    340                                TileMode tileMode,
    341                                bool convolveAlpha) {
    342         AutoEffectUnref effect(SkNEW_ARGS(GrMatrixConvolutionEffect, (texture,
    343                                                                       bounds,
    344                                                                       kernelSize,
    345                                                                       kernel,
    346                                                                       gain,
    347                                                                       bias,
    348                                                                       kernelOffset,
    349                                                                       tileMode,
    350                                                                       convolveAlpha)));
    351         return CreateEffectRef(effect);
    352     }
    353     virtual ~GrMatrixConvolutionEffect();
    354 
    355     virtual void getConstantColorComponents(GrColor* color,
    356                                             uint32_t* validFlags) const SK_OVERRIDE {
    357         // TODO: Try to do better?
    358         *validFlags = 0;
    359     }
    360 
    361     static const char* Name() { return "MatrixConvolution"; }
    362     const SkIRect& bounds() const { return fBounds; }
    363     const SkISize& kernelSize() const { return fKernelSize; }
    364     const float* kernelOffset() const { return fKernelOffset; }
    365     const float* kernel() const { return fKernel; }
    366     float gain() const { return fGain; }
    367     float bias() const { return fBias; }
    368     TileMode tileMode() const { return fTileMode; }
    369     bool convolveAlpha() const { return fConvolveAlpha; }
    370 
    371     typedef GrGLMatrixConvolutionEffect GLEffect;
    372 
    373     virtual const GrBackendEffectFactory& getFactory() const SK_OVERRIDE;
    374 
    375 private:
    376     GrMatrixConvolutionEffect(GrTexture*,
    377                               const SkIRect& bounds,
    378                               const SkISize& kernelSize,
    379                               const SkScalar* kernel,
    380                               SkScalar gain,
    381                               SkScalar bias,
    382                               const SkIPoint& kernelOffset,
    383                               TileMode tileMode,
    384                               bool convolveAlpha);
    385 
    386     virtual bool onIsEqual(const GrEffect&) const SK_OVERRIDE;
    387 
    388     SkIRect  fBounds;
    389     SkISize  fKernelSize;
    390     float   *fKernel;
    391     float    fGain;
    392     float    fBias;
    393     float    fKernelOffset[2];
    394     TileMode fTileMode;
    395     bool     fConvolveAlpha;
    396 
    397     GR_DECLARE_EFFECT_TEST;
    398 
    399     typedef GrSingleTextureEffect INHERITED;
    400 };
    401 
    402 class GrGLMatrixConvolutionEffect : public GrGLEffect {
    403 public:
    404     GrGLMatrixConvolutionEffect(const GrBackendEffectFactory& factory,
    405                                 const GrDrawEffect& effect);
    406     virtual void emitCode(GrGLShaderBuilder*,
    407                           const GrDrawEffect&,
    408                           EffectKey,
    409                           const char* outputColor,
    410                           const char* inputColor,
    411                           const TransformedCoordsArray&,
    412                           const TextureSamplerArray&) SK_OVERRIDE;
    413 
    414     static inline EffectKey GenKey(const GrDrawEffect&, const GrGLCaps&);
    415 
    416     virtual void setData(const GrGLUniformManager&, const GrDrawEffect&) SK_OVERRIDE;
    417 
    418 private:
    419     typedef GrGLUniformManager::UniformHandle        UniformHandle;
    420     typedef SkMatrixConvolutionImageFilter::TileMode TileMode;
    421     SkISize             fKernelSize;
    422     TileMode            fTileMode;
    423     bool                fConvolveAlpha;
    424 
    425     UniformHandle       fBoundsUni;
    426     UniformHandle       fKernelUni;
    427     UniformHandle       fImageIncrementUni;
    428     UniformHandle       fKernelOffsetUni;
    429     UniformHandle       fGainUni;
    430     UniformHandle       fBiasUni;
    431 
    432     typedef GrGLEffect INHERITED;
    433 };
    434 
    435 GrGLMatrixConvolutionEffect::GrGLMatrixConvolutionEffect(const GrBackendEffectFactory& factory,
    436                                                          const GrDrawEffect& drawEffect)
    437     : INHERITED(factory) {
    438     const GrMatrixConvolutionEffect& m = drawEffect.castEffect<GrMatrixConvolutionEffect>();
    439     fKernelSize = m.kernelSize();
    440     fTileMode = m.tileMode();
    441     fConvolveAlpha = m.convolveAlpha();
    442 }
    443 
    444 static void appendTextureLookup(GrGLShaderBuilder* builder,
    445                                 const GrGLShaderBuilder::TextureSampler& sampler,
    446                                 const char* coord,
    447                                 const char* bounds,
    448                                 SkMatrixConvolutionImageFilter::TileMode tileMode) {
    449     SkString clampedCoord;
    450     switch (tileMode) {
    451         case SkMatrixConvolutionImageFilter::kClamp_TileMode:
    452             clampedCoord.printf("clamp(%s, %s.xy, %s.zw)", coord, bounds, bounds);
    453             coord = clampedCoord.c_str();
    454             break;
    455         case SkMatrixConvolutionImageFilter::kRepeat_TileMode:
    456             clampedCoord.printf("mod(%s - %s.xy, %s.zw - %s.xy) + %s.xy", coord, bounds, bounds, bounds, bounds);
    457             coord = clampedCoord.c_str();
    458             break;
    459         case SkMatrixConvolutionImageFilter::kClampToBlack_TileMode:
    460             builder->fsCodeAppendf("clamp(%s, %s.xy, %s.zw) != %s ? vec4(0, 0, 0, 0) : ", coord, bounds, bounds, coord);
    461             break;
    462     }
    463     builder->fsAppendTextureLookup(sampler, coord);
    464 }
    465 
    466 void GrGLMatrixConvolutionEffect::emitCode(GrGLShaderBuilder* builder,
    467                                            const GrDrawEffect&,
    468                                            EffectKey key,
    469                                            const char* outputColor,
    470                                            const char* inputColor,
    471                                            const TransformedCoordsArray& coords,
    472                                            const TextureSamplerArray& samplers) {
    473     sk_ignore_unused_variable(inputColor);
    474     SkString coords2D = builder->ensureFSCoords2D(coords, 0);
    475     fBoundsUni = builder->addUniform(GrGLShaderBuilder::kFragment_Visibility,
    476                                      kVec4f_GrSLType, "Bounds");
    477     fImageIncrementUni = builder->addUniform(GrGLShaderBuilder::kFragment_Visibility,
    478                                              kVec2f_GrSLType, "ImageIncrement");
    479     fKernelUni = builder->addUniformArray(GrGLShaderBuilder::kFragment_Visibility,
    480                                              kFloat_GrSLType,
    481                                              "Kernel",
    482                                              fKernelSize.width() * fKernelSize.height());
    483     fKernelOffsetUni = builder->addUniform(GrGLShaderBuilder::kFragment_Visibility,
    484                                              kVec2f_GrSLType, "KernelOffset");
    485     fGainUni = builder->addUniform(GrGLShaderBuilder::kFragment_Visibility,
    486                                    kFloat_GrSLType, "Gain");
    487     fBiasUni = builder->addUniform(GrGLShaderBuilder::kFragment_Visibility,
    488                                    kFloat_GrSLType, "Bias");
    489 
    490     const char* bounds = builder->getUniformCStr(fBoundsUni);
    491     const char* kernelOffset = builder->getUniformCStr(fKernelOffsetUni);
    492     const char* imgInc = builder->getUniformCStr(fImageIncrementUni);
    493     const char* kernel = builder->getUniformCStr(fKernelUni);
    494     const char* gain = builder->getUniformCStr(fGainUni);
    495     const char* bias = builder->getUniformCStr(fBiasUni);
    496     int kWidth = fKernelSize.width();
    497     int kHeight = fKernelSize.height();
    498 
    499     builder->fsCodeAppend("\t\tvec4 sum = vec4(0, 0, 0, 0);\n");
    500     builder->fsCodeAppendf("\t\tvec2 coord = %s - %s * %s;\n", coords2D.c_str(), kernelOffset, imgInc);
    501     builder->fsCodeAppendf("\t\tfor (int y = 0; y < %d; y++) {\n", kHeight);
    502     builder->fsCodeAppendf("\t\t\tfor (int x = 0; x < %d; x++) {\n", kWidth);
    503     builder->fsCodeAppendf("\t\t\t\tfloat k = %s[y * %d + x];\n", kernel, kWidth);
    504     builder->fsCodeAppendf("\t\t\t\tvec2 coord2 = coord + vec2(x, y) * %s;\n", imgInc);
    505     builder->fsCodeAppend("\t\t\t\tvec4 c = ");
    506     appendTextureLookup(builder, samplers[0], "coord2", bounds, fTileMode);
    507     builder->fsCodeAppend(";\n");
    508     if (!fConvolveAlpha) {
    509         builder->fsCodeAppend("\t\t\t\tc.rgb /= c.a;\n");
    510     }
    511     builder->fsCodeAppend("\t\t\t\tsum += c * k;\n");
    512     builder->fsCodeAppend("\t\t\t}\n");
    513     builder->fsCodeAppend("\t\t}\n");
    514     if (fConvolveAlpha) {
    515         builder->fsCodeAppendf("\t\t%s = sum * %s + %s;\n", outputColor, gain, bias);
    516         builder->fsCodeAppendf("\t\t%s.rgb = clamp(%s.rgb, 0.0, %s.a);\n",
    517             outputColor, outputColor, outputColor);
    518     } else {
    519         builder->fsCodeAppend("\t\tvec4 c = ");
    520         appendTextureLookup(builder, samplers[0], coords2D.c_str(), bounds, fTileMode);
    521         builder->fsCodeAppend(";\n");
    522         builder->fsCodeAppendf("\t\t%s.a = c.a;\n", outputColor);
    523         builder->fsCodeAppendf("\t\t%s.rgb = sum.rgb * %s + %s;\n", outputColor, gain, bias);
    524         builder->fsCodeAppendf("\t\t%s.rgb *= %s.a;\n", outputColor, outputColor);
    525     }
    526 }
    527 
    528 namespace {
    529 
    530 int encodeXY(int x, int y) {
    531     SkASSERT(x >= 1 && y >= 1 && x * y <= 32);
    532     if (y < x)
    533         return 0x40 | encodeXY(y, x);
    534     else
    535         return (0x40 >> x) | (y - x);
    536 }
    537 
    538 };
    539 
    540 GrGLEffect::EffectKey GrGLMatrixConvolutionEffect::GenKey(const GrDrawEffect& drawEffect,
    541                                                           const GrGLCaps&) {
    542     const GrMatrixConvolutionEffect& m = drawEffect.castEffect<GrMatrixConvolutionEffect>();
    543     EffectKey key = encodeXY(m.kernelSize().width(), m.kernelSize().height());
    544     key |= m.tileMode() << 7;
    545     key |= m.convolveAlpha() ? 1 << 9 : 0;
    546     return key;
    547 }
    548 
    549 void GrGLMatrixConvolutionEffect::setData(const GrGLUniformManager& uman,
    550                                           const GrDrawEffect& drawEffect) {
    551     const GrMatrixConvolutionEffect& conv = drawEffect.castEffect<GrMatrixConvolutionEffect>();
    552     GrTexture& texture = *conv.texture(0);
    553     // the code we generated was for a specific kernel size
    554     SkASSERT(conv.kernelSize() == fKernelSize);
    555     SkASSERT(conv.tileMode() == fTileMode);
    556     float imageIncrement[2];
    557     float ySign = texture.origin() == kTopLeft_GrSurfaceOrigin ? 1.0f : -1.0f;
    558     imageIncrement[0] = 1.0f / texture.width();
    559     imageIncrement[1] = ySign / texture.height();
    560     uman.set2fv(fImageIncrementUni, 1, imageIncrement);
    561     uman.set2fv(fKernelOffsetUni, 1, conv.kernelOffset());
    562     uman.set1fv(fKernelUni, fKernelSize.width() * fKernelSize.height(), conv.kernel());
    563     uman.set1f(fGainUni, conv.gain());
    564     uman.set1f(fBiasUni, conv.bias());
    565     const SkIRect& bounds = conv.bounds();
    566     float left = (float) bounds.left() / texture.width();
    567     float top = (float) bounds.top() / texture.height();
    568     float right = (float) bounds.right() / texture.width();
    569     float bottom = (float) bounds.bottom() / texture.height();
    570     if (texture.origin() == kBottomLeft_GrSurfaceOrigin) {
    571         uman.set4f(fBoundsUni, left, 1.0f - bottom, right, 1.0f - top);
    572     } else {
    573         uman.set4f(fBoundsUni, left, top, right, bottom);
    574     }
    575 }
    576 
    577 GrMatrixConvolutionEffect::GrMatrixConvolutionEffect(GrTexture* texture,
    578                                                      const SkIRect& bounds,
    579                                                      const SkISize& kernelSize,
    580                                                      const SkScalar* kernel,
    581                                                      SkScalar gain,
    582                                                      SkScalar bias,
    583                                                      const SkIPoint& kernelOffset,
    584                                                      TileMode tileMode,
    585                                                      bool convolveAlpha)
    586   : INHERITED(texture, MakeDivByTextureWHMatrix(texture)),
    587     fBounds(bounds),
    588     fKernelSize(kernelSize),
    589     fGain(SkScalarToFloat(gain)),
    590     fBias(SkScalarToFloat(bias) / 255.0f),
    591     fTileMode(tileMode),
    592     fConvolveAlpha(convolveAlpha) {
    593     fKernel = new float[kernelSize.width() * kernelSize.height()];
    594     for (int i = 0; i < kernelSize.width() * kernelSize.height(); i++) {
    595         fKernel[i] = SkScalarToFloat(kernel[i]);
    596     }
    597     fKernelOffset[0] = static_cast<float>(kernelOffset.x());
    598     fKernelOffset[1] = static_cast<float>(kernelOffset.y());
    599     this->setWillNotUseInputColor();
    600 }
    601 
    602 GrMatrixConvolutionEffect::~GrMatrixConvolutionEffect() {
    603     delete[] fKernel;
    604 }
    605 
    606 const GrBackendEffectFactory& GrMatrixConvolutionEffect::getFactory() const {
    607     return GrTBackendEffectFactory<GrMatrixConvolutionEffect>::getInstance();
    608 }
    609 
    610 bool GrMatrixConvolutionEffect::onIsEqual(const GrEffect& sBase) const {
    611     const GrMatrixConvolutionEffect& s = CastEffect<GrMatrixConvolutionEffect>(sBase);
    612     return this->texture(0) == s.texture(0) &&
    613            fKernelSize == s.kernelSize() &&
    614            !memcmp(fKernel, s.kernel(),
    615                    fKernelSize.width() * fKernelSize.height() * sizeof(float)) &&
    616            fGain == s.gain() &&
    617            fBias == s.bias() &&
    618            fKernelOffset == s.kernelOffset() &&
    619            fTileMode == s.tileMode() &&
    620            fConvolveAlpha == s.convolveAlpha();
    621 }
    622 
    623 GR_DEFINE_EFFECT_TEST(GrMatrixConvolutionEffect);
    624 
    625 // A little bit less than the minimum # uniforms required by DX9SM2 (32).
    626 // Allows for a 5x5 kernel (or 25x1, for that matter).
    627 #define MAX_KERNEL_SIZE 25
    628 
    629 GrEffectRef* GrMatrixConvolutionEffect::TestCreate(SkRandom* random,
    630                                                    GrContext* context,
    631                                                    const GrDrawTargetCaps&,
    632                                                    GrTexture* textures[]) {
    633     int texIdx = random->nextBool() ? GrEffectUnitTest::kSkiaPMTextureIdx :
    634                                       GrEffectUnitTest::kAlphaTextureIdx;
    635     int width = random->nextRangeU(1, MAX_KERNEL_SIZE);
    636     int height = random->nextRangeU(1, MAX_KERNEL_SIZE / width);
    637     SkISize kernelSize = SkISize::Make(width, height);
    638     SkAutoTDeleteArray<SkScalar> kernel(new SkScalar[width * height]);
    639     for (int i = 0; i < width * height; i++) {
    640         kernel.get()[i] = random->nextSScalar1();
    641     }
    642     SkScalar gain = random->nextSScalar1();
    643     SkScalar bias = random->nextSScalar1();
    644     SkIPoint kernelOffset = SkIPoint::Make(random->nextRangeU(0, kernelSize.width()),
    645                                            random->nextRangeU(0, kernelSize.height()));
    646     SkIRect bounds = SkIRect::MakeXYWH(random->nextRangeU(0, textures[texIdx]->width()),
    647                                        random->nextRangeU(0, textures[texIdx]->height()),
    648                                        random->nextRangeU(0, textures[texIdx]->width()),
    649                                        random->nextRangeU(0, textures[texIdx]->height()));
    650     TileMode tileMode = static_cast<TileMode>(random->nextRangeU(0, 2));
    651     bool convolveAlpha = random->nextBool();
    652     return GrMatrixConvolutionEffect::Create(textures[texIdx],
    653                                              bounds,
    654                                              kernelSize,
    655                                              kernel.get(),
    656                                              gain,
    657                                              bias,
    658                                              kernelOffset,
    659                                              tileMode,
    660                                              convolveAlpha);
    661 }
    662 
    663 bool SkMatrixConvolutionImageFilter::asNewEffect(GrEffectRef** effect,
    664                                                  GrTexture* texture,
    665                                                  const SkMatrix&,
    666                                                  const SkIRect& bounds
    667                                                  ) const {
    668     if (!effect) {
    669         return fKernelSize.width() * fKernelSize.height() <= MAX_KERNEL_SIZE;
    670     }
    671     SkASSERT(fKernelSize.width() * fKernelSize.height() <= MAX_KERNEL_SIZE);
    672     *effect = GrMatrixConvolutionEffect::Create(texture,
    673                                                 bounds,
    674                                                 fKernelSize,
    675                                                 fKernel,
    676                                                 fGain,
    677                                                 fBias,
    678                                                 fKernelOffset,
    679                                                 fTileMode,
    680                                                 fConvolveAlpha);
    681     return true;
    682 }
    683 
    684 ///////////////////////////////////////////////////////////////////////////////
    685 
    686 #endif
    687