SkMatrixConvolutionImageFilter.cpp revision 84cd099704b3896ca66081a96508572a924f850c 
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
24static 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
36SkMatrixConvolutionImageFilter::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
61SkMatrixConvolutionImageFilter::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}
91
92void SkMatrixConvolutionImageFilter::flatten(SkWriteBuffer& buffer) const {
93    this->INHERITED::flatten(buffer);
94    buffer.writeInt(fKernelSize.fWidth);
95    buffer.writeInt(fKernelSize.fHeight);
96    buffer.writeScalarArray(fKernel, fKernelSize.fWidth * fKernelSize.fHeight);
97    buffer.writeScalar(fGain);
98    buffer.writeScalar(fBias);
99    buffer.writeInt(fKernelOffset.fX);
100    buffer.writeInt(fKernelOffset.fY);
101    buffer.writeInt((int) fTileMode);
102    buffer.writeBool(fConvolveAlpha);
103}
104
105SkMatrixConvolutionImageFilter::~SkMatrixConvolutionImageFilter() {
106    delete[] fKernel;
107}
108
109class UncheckedPixelFetcher {
110public:
111    static inline SkPMColor fetch(const SkBitmap& src, int x, int y, const SkIRect& bounds) {
112        return *src.getAddr32(x, y);
113    }
114};
115
116class ClampPixelFetcher {
117public:
118    static inline SkPMColor fetch(const SkBitmap& src, int x, int y, const SkIRect& bounds) {
119        x = SkPin32(x, bounds.fLeft, bounds.fRight - 1);
120        y = SkPin32(y, bounds.fTop, bounds.fBottom - 1);
121        return *src.getAddr32(x, y);
122    }
123};
124
125class RepeatPixelFetcher {
126public:
127    static inline SkPMColor fetch(const SkBitmap& src, int x, int y, const SkIRect& bounds) {
128        x = (x - bounds.left()) % bounds.width() + bounds.left();
129        y = (y - bounds.top()) % bounds.height() + bounds.top();
130        if (x < bounds.left()) {
131            x += bounds.width();
132        }
133        if (y < bounds.top()) {
134            y += bounds.height();
135        }
136        return *src.getAddr32(x, y);
137    }
138};
139
140class ClampToBlackPixelFetcher {
141public:
142    static inline SkPMColor fetch(const SkBitmap& src, int x, int y, const SkIRect& bounds) {
143        if (x < bounds.fLeft || x >= bounds.fRight || y < bounds.fTop || y >= bounds.fBottom) {
144            return 0;
145        } else {
146            return *src.getAddr32(x, y);
147        }
148    }
149};
150
151template<class PixelFetcher, bool convolveAlpha>
152void SkMatrixConvolutionImageFilter::filterPixels(const SkBitmap& src,
153                                                  SkBitmap* result,
154                                                  const SkIRect& rect,
155                                                  const SkIRect& bounds) const {
156    for (int y = rect.fTop; y < rect.fBottom; ++y) {
157        SkPMColor* dptr = result->getAddr32(rect.fLeft - bounds.fLeft, y - bounds.fTop);
158        for (int x = rect.fLeft; x < rect.fRight; ++x) {
159            SkScalar sumA = 0, sumR = 0, sumG = 0, sumB = 0;
160            for (int cy = 0; cy < fKernelSize.fHeight; cy++) {
161                for (int cx = 0; cx < fKernelSize.fWidth; cx++) {
162                    SkPMColor s = PixelFetcher::fetch(src,
163                                                      x + cx - fKernelOffset.fX,
164                                                      y + cy - fKernelOffset.fY,
165                                                      bounds);
166                    SkScalar k = fKernel[cy * fKernelSize.fWidth + cx];
167                    if (convolveAlpha) {
168                        sumA += SkScalarMul(SkIntToScalar(SkGetPackedA32(s)), k);
169                    }
170                    sumR += SkScalarMul(SkIntToScalar(SkGetPackedR32(s)), k);
171                    sumG += SkScalarMul(SkIntToScalar(SkGetPackedG32(s)), k);
172                    sumB += SkScalarMul(SkIntToScalar(SkGetPackedB32(s)), k);
173                }
174            }
175            int a = convolveAlpha
176                  ? SkClampMax(SkScalarFloorToInt(SkScalarMul(sumA, fGain) + fBias), 255)
177                  : 255;
178            int r = SkClampMax(SkScalarFloorToInt(SkScalarMul(sumR, fGain) + fBias), a);
179            int g = SkClampMax(SkScalarFloorToInt(SkScalarMul(sumG, fGain) + fBias), a);
180            int b = SkClampMax(SkScalarFloorToInt(SkScalarMul(sumB, fGain) + fBias), a);
181            if (!convolveAlpha) {
182                a = SkGetPackedA32(PixelFetcher::fetch(src, x, y, bounds));
183                *dptr++ = SkPreMultiplyARGB(a, r, g, b);
184            } else {
185                *dptr++ = SkPackARGB32(a, r, g, b);
186            }
187        }
188    }
189}
190
191template<class PixelFetcher>
192void SkMatrixConvolutionImageFilter::filterPixels(const SkBitmap& src,
193                                                  SkBitmap* result,
194                                                  const SkIRect& rect,
195                                                  const SkIRect& bounds) const {
196    if (fConvolveAlpha) {
197        filterPixels<PixelFetcher, true>(src, result, rect, bounds);
198    } else {
199        filterPixels<PixelFetcher, false>(src, result, rect, bounds);
200    }
201}
202
203void SkMatrixConvolutionImageFilter::filterInteriorPixels(const SkBitmap& src,
204                                                          SkBitmap* result,
205                                                          const SkIRect& rect,
206                                                          const SkIRect& bounds) const {
207    filterPixels<UncheckedPixelFetcher>(src, result, rect, bounds);
208}
209
210void SkMatrixConvolutionImageFilter::filterBorderPixels(const SkBitmap& src,
211                                                        SkBitmap* result,
212                                                        const SkIRect& rect,
213                                                        const SkIRect& bounds) const {
214    switch (fTileMode) {
215        case kClamp_TileMode:
216            filterPixels<ClampPixelFetcher>(src, result, rect, bounds);
217            break;
218        case kRepeat_TileMode:
219            filterPixels<RepeatPixelFetcher>(src, result, rect, bounds);
220            break;
221        case kClampToBlack_TileMode:
222            filterPixels<ClampToBlackPixelFetcher>(src, result, rect, bounds);
223            break;
224    }
225}
226
227// FIXME:  This should be refactored to SkImageFilterUtils for
228// use by other filters.  For now, we assume the input is always
229// premultiplied and unpremultiply it
230static SkBitmap unpremultiplyBitmap(const SkBitmap& src)
231{
232    SkAutoLockPixels alp(src);
233    if (!src.getPixels()) {
234        return SkBitmap();
235    }
236    SkBitmap result;
237    result.setConfig(src.config(), src.width(), src.height());
238    result.allocPixels();
239    if (!result.getPixels()) {
240        return SkBitmap();
241    }
242    for (int y = 0; y < src.height(); ++y) {
243        const uint32_t* srcRow = src.getAddr32(0, y);
244        uint32_t* dstRow = result.getAddr32(0, y);
245        for (int x = 0; x < src.width(); ++x) {
246            dstRow[x] = SkUnPreMultiply::PMColorToColor(srcRow[x]);
247        }
248    }
249    return result;
250}
251
252bool SkMatrixConvolutionImageFilter::onFilterImage(Proxy* proxy,
253                                                   const SkBitmap& source,
254                                                   const SkMatrix& matrix,
255                                                   SkBitmap* result,
256                                                   SkIPoint* offset) const {
257    SkBitmap src = source;
258    SkIPoint srcOffset = SkIPoint::Make(0, 0);
259    if (getInput(0) && !getInput(0)->filterImage(proxy, source, matrix, &src, &srcOffset)) {
260        return false;
261    }
262
263    if (src.colorType() != kPMColor_SkColorType) {
264        return false;
265    }
266
267    SkIRect bounds;
268    src.getBounds(&bounds);
269    bounds.offset(srcOffset);
270    if (!this->applyCropRect(&bounds, matrix)) {
271        return false;
272    }
273
274    if (!fConvolveAlpha && !src.isOpaque()) {
275        src = unpremultiplyBitmap(src);
276    }
277
278    SkAutoLockPixels alp(src);
279    if (!src.getPixels()) {
280        return false;
281    }
282
283    result->setConfig(src.config(), bounds.width(), bounds.height());
284    result->allocPixels();
285    if (!result->getPixels()) {
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#if SK_SUPPORT_GPU
312
313///////////////////////////////////////////////////////////////////////////////
314
315class GrGLMatrixConvolutionEffect;
316
317class GrMatrixConvolutionEffect : public GrSingleTextureEffect {
318public:
319    typedef SkMatrixConvolutionImageFilter::TileMode TileMode;
320    static GrEffectRef* Create(GrTexture* texture,
321                               const SkIRect& bounds,
322                               const SkISize& kernelSize,
323                               const SkScalar* kernel,
324                               SkScalar gain,
325                               SkScalar bias,
326                               const SkIPoint& kernelOffset,
327                               TileMode tileMode,
328                               bool convolveAlpha) {
329        AutoEffectUnref effect(SkNEW_ARGS(GrMatrixConvolutionEffect, (texture,
330                                                                      bounds,
331                                                                      kernelSize,
332                                                                      kernel,
333                                                                      gain,
334                                                                      bias,
335                                                                      kernelOffset,
336                                                                      tileMode,
337                                                                      convolveAlpha)));
338        return CreateEffectRef(effect);
339    }
340    virtual ~GrMatrixConvolutionEffect();
341
342    virtual void getConstantColorComponents(GrColor* color,
343                                            uint32_t* validFlags) const SK_OVERRIDE {
344        // TODO: Try to do better?
345        *validFlags = 0;
346    }
347
348    static const char* Name() { return "MatrixConvolution"; }
349    const SkIRect& bounds() const { return fBounds; }
350    const SkISize& kernelSize() const { return fKernelSize; }
351    const float* kernelOffset() const { return fKernelOffset; }
352    const float* kernel() const { return fKernel; }
353    float gain() const { return fGain; }
354    float bias() const { return fBias; }
355    TileMode tileMode() const { return fTileMode; }
356    bool convolveAlpha() const { return fConvolveAlpha; }
357
358    typedef GrGLMatrixConvolutionEffect GLEffect;
359
360    virtual const GrBackendEffectFactory& getFactory() const SK_OVERRIDE;
361
362private:
363    GrMatrixConvolutionEffect(GrTexture*,
364                              const SkIRect& bounds,
365                              const SkISize& kernelSize,
366                              const SkScalar* kernel,
367                              SkScalar gain,
368                              SkScalar bias,
369                              const SkIPoint& kernelOffset,
370                              TileMode tileMode,
371                              bool convolveAlpha);
372
373    virtual bool onIsEqual(const GrEffect&) const SK_OVERRIDE;
374
375    SkIRect  fBounds;
376    SkISize  fKernelSize;
377    float   *fKernel;
378    float    fGain;
379    float    fBias;
380    float    fKernelOffset[2];
381    TileMode fTileMode;
382    bool     fConvolveAlpha;
383
384    GR_DECLARE_EFFECT_TEST;
385
386    typedef GrSingleTextureEffect INHERITED;
387};
388
389class GrGLMatrixConvolutionEffect : public GrGLEffect {
390public:
391    GrGLMatrixConvolutionEffect(const GrBackendEffectFactory& factory,
392                                const GrDrawEffect& effect);
393    virtual void emitCode(GrGLShaderBuilder*,
394                          const GrDrawEffect&,
395                          EffectKey,
396                          const char* outputColor,
397                          const char* inputColor,
398                          const TransformedCoordsArray&,
399                          const TextureSamplerArray&) SK_OVERRIDE;
400
401    static inline EffectKey GenKey(const GrDrawEffect&, const GrGLCaps&);
402
403    virtual void setData(const GrGLUniformManager&, const GrDrawEffect&) SK_OVERRIDE;
404
405private:
406    typedef GrGLUniformManager::UniformHandle        UniformHandle;
407    typedef SkMatrixConvolutionImageFilter::TileMode TileMode;
408    SkISize             fKernelSize;
409    TileMode            fTileMode;
410    bool                fConvolveAlpha;
411
412    UniformHandle       fBoundsUni;
413    UniformHandle       fKernelUni;
414    UniformHandle       fImageIncrementUni;
415    UniformHandle       fKernelOffsetUni;
416    UniformHandle       fGainUni;
417    UniformHandle       fBiasUni;
418
419    typedef GrGLEffect INHERITED;
420};
421
422GrGLMatrixConvolutionEffect::GrGLMatrixConvolutionEffect(const GrBackendEffectFactory& factory,
423                                                         const GrDrawEffect& drawEffect)
424    : INHERITED(factory) {
425    const GrMatrixConvolutionEffect& m = drawEffect.castEffect<GrMatrixConvolutionEffect>();
426    fKernelSize = m.kernelSize();
427    fTileMode = m.tileMode();
428    fConvolveAlpha = m.convolveAlpha();
429}
430
431static void appendTextureLookup(GrGLShaderBuilder* builder,
432                                const GrGLShaderBuilder::TextureSampler& sampler,
433                                const char* coord,
434                                const char* bounds,
435                                SkMatrixConvolutionImageFilter::TileMode tileMode) {
436    SkString clampedCoord;
437    switch (tileMode) {
438        case SkMatrixConvolutionImageFilter::kClamp_TileMode:
439            clampedCoord.printf("clamp(%s, %s.xy, %s.zw)", coord, bounds, bounds);
440            coord = clampedCoord.c_str();
441            break;
442        case SkMatrixConvolutionImageFilter::kRepeat_TileMode:
443            clampedCoord.printf("mod(%s - %s.xy, %s.zw - %s.xy) + %s.xy", coord, bounds, bounds, bounds, bounds);
444            coord = clampedCoord.c_str();
445            break;
446        case SkMatrixConvolutionImageFilter::kClampToBlack_TileMode:
447            builder->fsCodeAppendf("clamp(%s, %s.xy, %s.zw) != %s ? vec4(0, 0, 0, 0) : ", coord, bounds, bounds, coord);
448            break;
449    }
450    builder->fsAppendTextureLookup(sampler, coord);
451}
452
453void GrGLMatrixConvolutionEffect::emitCode(GrGLShaderBuilder* builder,
454                                           const GrDrawEffect&,
455                                           EffectKey key,
456                                           const char* outputColor,
457                                           const char* inputColor,
458                                           const TransformedCoordsArray& coords,
459                                           const TextureSamplerArray& samplers) {
460    sk_ignore_unused_variable(inputColor);
461    SkString coords2D = builder->ensureFSCoords2D(coords, 0);
462    fBoundsUni = builder->addUniform(GrGLShaderBuilder::kFragment_Visibility,
463                                     kVec4f_GrSLType, "Bounds");
464    fImageIncrementUni = builder->addUniform(GrGLShaderBuilder::kFragment_Visibility,
465                                             kVec2f_GrSLType, "ImageIncrement");
466    fKernelUni = builder->addUniformArray(GrGLShaderBuilder::kFragment_Visibility,
467                                             kFloat_GrSLType,
468                                             "Kernel",
469                                             fKernelSize.width() * fKernelSize.height());
470    fKernelOffsetUni = builder->addUniform(GrGLShaderBuilder::kFragment_Visibility,
471                                             kVec2f_GrSLType, "KernelOffset");
472    fGainUni = builder->addUniform(GrGLShaderBuilder::kFragment_Visibility,
473                                   kFloat_GrSLType, "Gain");
474    fBiasUni = builder->addUniform(GrGLShaderBuilder::kFragment_Visibility,
475                                   kFloat_GrSLType, "Bias");
476
477    const char* bounds = builder->getUniformCStr(fBoundsUni);
478    const char* kernelOffset = builder->getUniformCStr(fKernelOffsetUni);
479    const char* imgInc = builder->getUniformCStr(fImageIncrementUni);
480    const char* kernel = builder->getUniformCStr(fKernelUni);
481    const char* gain = builder->getUniformCStr(fGainUni);
482    const char* bias = builder->getUniformCStr(fBiasUni);
483    int kWidth = fKernelSize.width();
484    int kHeight = fKernelSize.height();
485
486    builder->fsCodeAppend("\t\tvec4 sum = vec4(0, 0, 0, 0);\n");
487    builder->fsCodeAppendf("\t\tvec2 coord = %s - %s * %s;\n", coords2D.c_str(), kernelOffset, imgInc);
488    builder->fsCodeAppendf("\t\tfor (int y = 0; y < %d; y++) {\n", kHeight);
489    builder->fsCodeAppendf("\t\t\tfor (int x = 0; x < %d; x++) {\n", kWidth);
490    builder->fsCodeAppendf("\t\t\t\tfloat k = %s[y * %d + x];\n", kernel, kWidth);
491    builder->fsCodeAppendf("\t\t\t\tvec2 coord2 = coord + vec2(x, y) * %s;\n", imgInc);
492    builder->fsCodeAppend("\t\t\t\tvec4 c = ");
493    appendTextureLookup(builder, samplers[0], "coord2", bounds, fTileMode);
494    builder->fsCodeAppend(";\n");
495    if (!fConvolveAlpha) {
496        builder->fsCodeAppend("\t\t\t\tc.rgb /= c.a;\n");
497    }
498    builder->fsCodeAppend("\t\t\t\tsum += c * k;\n");
499    builder->fsCodeAppend("\t\t\t}\n");
500    builder->fsCodeAppend("\t\t}\n");
501    if (fConvolveAlpha) {
502        builder->fsCodeAppendf("\t\t%s = sum * %s + %s;\n", outputColor, gain, bias);
503        builder->fsCodeAppendf("\t\t%s.rgb = clamp(%s.rgb, 0.0, %s.a);\n",
504            outputColor, outputColor, outputColor);
505    } else {
506        builder->fsCodeAppend("\t\tvec4 c = ");
507        appendTextureLookup(builder, samplers[0], coords2D.c_str(), bounds, fTileMode);
508        builder->fsCodeAppend(";\n");
509        builder->fsCodeAppendf("\t\t%s.a = c.a;\n", outputColor);
510        builder->fsCodeAppendf("\t\t%s.rgb = sum.rgb * %s + %s;\n", outputColor, gain, bias);
511        builder->fsCodeAppendf("\t\t%s.rgb *= %s.a;\n", outputColor, outputColor);
512    }
513}
514
515namespace {
516
517int encodeXY(int x, int y) {
518    SkASSERT(x >= 1 && y >= 1 && x * y <= 32);
519    if (y < x)
520        return 0x40 | encodeXY(y, x);
521    else
522        return (0x40 >> x) | (y - x);
523}
524
525};
526
527GrGLEffect::EffectKey GrGLMatrixConvolutionEffect::GenKey(const GrDrawEffect& drawEffect,
528                                                          const GrGLCaps&) {
529    const GrMatrixConvolutionEffect& m = drawEffect.castEffect<GrMatrixConvolutionEffect>();
530    EffectKey key = encodeXY(m.kernelSize().width(), m.kernelSize().height());
531    key |= m.tileMode() << 7;
532    key |= m.convolveAlpha() ? 1 << 9 : 0;
533    return key;
534}
535
536void GrGLMatrixConvolutionEffect::setData(const GrGLUniformManager& uman,
537                                          const GrDrawEffect& drawEffect) {
538    const GrMatrixConvolutionEffect& conv = drawEffect.castEffect<GrMatrixConvolutionEffect>();
539    GrTexture& texture = *conv.texture(0);
540    // the code we generated was for a specific kernel size
541    SkASSERT(conv.kernelSize() == fKernelSize);
542    SkASSERT(conv.tileMode() == fTileMode);
543    float imageIncrement[2];
544    float ySign = texture.origin() == kTopLeft_GrSurfaceOrigin ? 1.0f : -1.0f;
545    imageIncrement[0] = 1.0f / texture.width();
546    imageIncrement[1] = ySign / texture.height();
547    uman.set2fv(fImageIncrementUni, 1, imageIncrement);
548    uman.set2fv(fKernelOffsetUni, 1, conv.kernelOffset());
549    uman.set1fv(fKernelUni, fKernelSize.width() * fKernelSize.height(), conv.kernel());
550    uman.set1f(fGainUni, conv.gain());
551    uman.set1f(fBiasUni, conv.bias());
552    const SkIRect& bounds = conv.bounds();
553    float left = (float) bounds.left() / texture.width();
554    float top = (float) bounds.top() / texture.height();
555    float right = (float) bounds.right() / texture.width();
556    float bottom = (float) bounds.bottom() / texture.height();
557    if (texture.origin() == kBottomLeft_GrSurfaceOrigin) {
558        uman.set4f(fBoundsUni, left, 1.0f - bottom, right, 1.0f - top);
559    } else {
560        uman.set4f(fBoundsUni, left, top, right, bottom);
561    }
562}
563
564GrMatrixConvolutionEffect::GrMatrixConvolutionEffect(GrTexture* texture,
565                                                     const SkIRect& bounds,
566                                                     const SkISize& kernelSize,
567                                                     const SkScalar* kernel,
568                                                     SkScalar gain,
569                                                     SkScalar bias,
570                                                     const SkIPoint& kernelOffset,
571                                                     TileMode tileMode,
572                                                     bool convolveAlpha)
573  : INHERITED(texture, MakeDivByTextureWHMatrix(texture)),
574    fBounds(bounds),
575    fKernelSize(kernelSize),
576    fGain(SkScalarToFloat(gain)),
577    fBias(SkScalarToFloat(bias) / 255.0f),
578    fTileMode(tileMode),
579    fConvolveAlpha(convolveAlpha) {
580    fKernel = new float[kernelSize.width() * kernelSize.height()];
581    for (int i = 0; i < kernelSize.width() * kernelSize.height(); i++) {
582        fKernel[i] = SkScalarToFloat(kernel[i]);
583    }
584    fKernelOffset[0] = static_cast<float>(kernelOffset.x());
585    fKernelOffset[1] = static_cast<float>(kernelOffset.y());
586    this->setWillNotUseInputColor();
587}
588
589GrMatrixConvolutionEffect::~GrMatrixConvolutionEffect() {
590    delete[] fKernel;
591}
592
593const GrBackendEffectFactory& GrMatrixConvolutionEffect::getFactory() const {
594    return GrTBackendEffectFactory<GrMatrixConvolutionEffect>::getInstance();
595}
596
597bool GrMatrixConvolutionEffect::onIsEqual(const GrEffect& sBase) const {
598    const GrMatrixConvolutionEffect& s = CastEffect<GrMatrixConvolutionEffect>(sBase);
599    return this->texture(0) == s.texture(0) &&
600           fKernelSize == s.kernelSize() &&
601           !memcmp(fKernel, s.kernel(),
602                   fKernelSize.width() * fKernelSize.height() * sizeof(float)) &&
603           fGain == s.gain() &&
604           fBias == s.bias() &&
605           fKernelOffset == s.kernelOffset() &&
606           fTileMode == s.tileMode() &&
607           fConvolveAlpha == s.convolveAlpha();
608}
609
610GR_DEFINE_EFFECT_TEST(GrMatrixConvolutionEffect);
611
612// A little bit less than the minimum # uniforms required by DX9SM2 (32).
613// Allows for a 5x5 kernel (or 25x1, for that matter).
614#define MAX_KERNEL_SIZE 25
615
616GrEffectRef* GrMatrixConvolutionEffect::TestCreate(SkRandom* random,
617                                                   GrContext* context,
618                                                   const GrDrawTargetCaps&,
619                                                   GrTexture* textures[]) {
620    int texIdx = random->nextBool() ? GrEffectUnitTest::kSkiaPMTextureIdx :
621                                      GrEffectUnitTest::kAlphaTextureIdx;
622    int width = random->nextRangeU(1, MAX_KERNEL_SIZE);
623    int height = random->nextRangeU(1, MAX_KERNEL_SIZE / width);
624    SkISize kernelSize = SkISize::Make(width, height);
625    SkAutoTDeleteArray<SkScalar> kernel(new SkScalar[width * height]);
626    for (int i = 0; i < width * height; i++) {
627        kernel.get()[i] = random->nextSScalar1();
628    }
629    SkScalar gain = random->nextSScalar1();
630    SkScalar bias = random->nextSScalar1();
631    SkIPoint kernelOffset = SkIPoint::Make(random->nextRangeU(0, kernelSize.width()),
632                                           random->nextRangeU(0, kernelSize.height()));
633    SkIRect bounds = SkIRect::MakeXYWH(random->nextRangeU(0, textures[texIdx]->width()),
634                                       random->nextRangeU(0, textures[texIdx]->height()),
635                                       random->nextRangeU(0, textures[texIdx]->width()),
636                                       random->nextRangeU(0, textures[texIdx]->height()));
637    TileMode tileMode = static_cast<TileMode>(random->nextRangeU(0, 2));
638    bool convolveAlpha = random->nextBool();
639    return GrMatrixConvolutionEffect::Create(textures[texIdx],
640                                             bounds,
641                                             kernelSize,
642                                             kernel.get(),
643                                             gain,
644                                             bias,
645                                             kernelOffset,
646                                             tileMode,
647                                             convolveAlpha);
648}
649
650bool SkMatrixConvolutionImageFilter::asNewEffect(GrEffectRef** effect,
651                                                 GrTexture* texture,
652                                                 const SkMatrix&,
653                                                 const SkIRect& bounds
654                                                 ) const {
655    if (!effect) {
656        return fKernelSize.width() * fKernelSize.height() <= MAX_KERNEL_SIZE;
657    }
658    SkASSERT(fKernelSize.width() * fKernelSize.height() <= MAX_KERNEL_SIZE);
659    *effect = GrMatrixConvolutionEffect::Create(texture,
660                                                bounds,
661                                                fKernelSize,
662                                                fKernel,
663                                                fGain,
664                                                fBias,
665                                                fKernelOffset,
666                                                fTileMode,
667                                                fConvolveAlpha);
668    return true;
669}
670
671///////////////////////////////////////////////////////////////////////////////
672
673#endif
674