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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 "SkSpecialImage.h"
     13 #include "SkWriteBuffer.h"
     14 #include "SkRect.h"
     15 #include "SkUnPreMultiply.h"
     16 
     17 #if SK_SUPPORT_GPU
     18 #include "GrContext.h"
     19 #include "GrTextureProxy.h"
     20 #include "effects/GrMatrixConvolutionEffect.h"
     21 #endif
     22 
     23 // We need to be able to read at most SK_MaxS32 bytes, so divide that
     24 // by the size of a scalar to know how many scalars we can read.
     25 static const int32_t gMaxKernelSize = SK_MaxS32 / sizeof(SkScalar);
     26 
     27 SkMatrixConvolutionImageFilter::SkMatrixConvolutionImageFilter(const SkISize& kernelSize,
     28                                                                const SkScalar* kernel,
     29                                                                SkScalar gain,
     30                                                                SkScalar bias,
     31                                                                const SkIPoint& kernelOffset,
     32                                                                TileMode tileMode,
     33                                                                bool convolveAlpha,
     34                                                                sk_sp<SkImageFilter> input,
     35                                                                const CropRect* cropRect)
     36     : INHERITED(&input, 1, cropRect)
     37     , fKernelSize(kernelSize)
     38     , fGain(gain)
     39     , fBias(bias)
     40     , fKernelOffset(kernelOffset)
     41     , fTileMode(tileMode)
     42     , fConvolveAlpha(convolveAlpha) {
     43     size_t size = (size_t) sk_64_mul(fKernelSize.width(), fKernelSize.height());
     44     fKernel = new SkScalar[size];
     45     memcpy(fKernel, kernel, size * sizeof(SkScalar));
     46     SkASSERT(kernelSize.fWidth >= 1 && kernelSize.fHeight >= 1);
     47     SkASSERT(kernelOffset.fX >= 0 && kernelOffset.fX < kernelSize.fWidth);
     48     SkASSERT(kernelOffset.fY >= 0 && kernelOffset.fY < kernelSize.fHeight);
     49 }
     50 
     51 sk_sp<SkImageFilter> SkMatrixConvolutionImageFilter::Make(const SkISize& kernelSize,
     52                                                           const SkScalar* kernel,
     53                                                           SkScalar gain,
     54                                                           SkScalar bias,
     55                                                           const SkIPoint& kernelOffset,
     56                                                           TileMode tileMode,
     57                                                           bool convolveAlpha,
     58                                                           sk_sp<SkImageFilter> input,
     59                                                           const CropRect* cropRect) {
     60     if (kernelSize.width() < 1 || kernelSize.height() < 1) {
     61         return nullptr;
     62     }
     63     if (gMaxKernelSize / kernelSize.fWidth < kernelSize.fHeight) {
     64         return nullptr;
     65     }
     66     if (!kernel) {
     67         return nullptr;
     68     }
     69     if ((kernelOffset.fX < 0) || (kernelOffset.fX >= kernelSize.fWidth) ||
     70         (kernelOffset.fY < 0) || (kernelOffset.fY >= kernelSize.fHeight)) {
     71         return nullptr;
     72     }
     73     return sk_sp<SkImageFilter>(new SkMatrixConvolutionImageFilter(kernelSize, kernel, gain,
     74                                                                    bias, kernelOffset,
     75                                                                    tileMode, convolveAlpha,
     76                                                                    std::move(input), cropRect));
     77 }
     78 
     79 sk_sp<SkFlattenable> SkMatrixConvolutionImageFilter::CreateProc(SkReadBuffer& buffer) {
     80     SK_IMAGEFILTER_UNFLATTEN_COMMON(common, 1);
     81     SkISize kernelSize;
     82     kernelSize.fWidth = buffer.readInt();
     83     kernelSize.fHeight = buffer.readInt();
     84     const int count = buffer.getArrayCount();
     85 
     86     const int64_t kernelArea = sk_64_mul(kernelSize.width(), kernelSize.height());
     87     if (!buffer.validate(kernelArea == count)) {
     88         return nullptr;
     89     }
     90     SkAutoSTArray<16, SkScalar> kernel(count);
     91     if (!buffer.readScalarArray(kernel.get(), count)) {
     92         return nullptr;
     93     }
     94     SkScalar gain = buffer.readScalar();
     95     SkScalar bias = buffer.readScalar();
     96     SkIPoint kernelOffset;
     97     kernelOffset.fX = buffer.readInt();
     98     kernelOffset.fY = buffer.readInt();
     99     TileMode tileMode = (TileMode)buffer.readInt();
    100     bool convolveAlpha = buffer.readBool();
    101     return Make(kernelSize, kernel.get(), gain, bias, kernelOffset, tileMode,
    102                 convolveAlpha, common.getInput(0), &common.cropRect());
    103 }
    104 
    105 void SkMatrixConvolutionImageFilter::flatten(SkWriteBuffer& buffer) const {
    106     this->INHERITED::flatten(buffer);
    107     buffer.writeInt(fKernelSize.fWidth);
    108     buffer.writeInt(fKernelSize.fHeight);
    109     buffer.writeScalarArray(fKernel, fKernelSize.fWidth * fKernelSize.fHeight);
    110     buffer.writeScalar(fGain);
    111     buffer.writeScalar(fBias);
    112     buffer.writeInt(fKernelOffset.fX);
    113     buffer.writeInt(fKernelOffset.fY);
    114     buffer.writeInt((int) fTileMode);
    115     buffer.writeBool(fConvolveAlpha);
    116 }
    117 
    118 SkMatrixConvolutionImageFilter::~SkMatrixConvolutionImageFilter() {
    119     delete[] fKernel;
    120 }
    121 
    122 class UncheckedPixelFetcher {
    123 public:
    124     static inline SkPMColor fetch(const SkBitmap& src, int x, int y, const SkIRect& bounds) {
    125         return *src.getAddr32(x, y);
    126     }
    127 };
    128 
    129 class ClampPixelFetcher {
    130 public:
    131     static inline SkPMColor fetch(const SkBitmap& src, int x, int y, const SkIRect& bounds) {
    132         x = SkTPin(x, bounds.fLeft, bounds.fRight - 1);
    133         y = SkTPin(y, bounds.fTop, bounds.fBottom - 1);
    134         return *src.getAddr32(x, y);
    135     }
    136 };
    137 
    138 class RepeatPixelFetcher {
    139 public:
    140     static inline SkPMColor fetch(const SkBitmap& src, int x, int y, const SkIRect& bounds) {
    141         x = (x - bounds.left()) % bounds.width() + bounds.left();
    142         y = (y - bounds.top()) % bounds.height() + bounds.top();
    143         if (x < bounds.left()) {
    144             x += bounds.width();
    145         }
    146         if (y < bounds.top()) {
    147             y += bounds.height();
    148         }
    149         return *src.getAddr32(x, y);
    150     }
    151 };
    152 
    153 class ClampToBlackPixelFetcher {
    154 public:
    155     static inline SkPMColor fetch(const SkBitmap& src, int x, int y, const SkIRect& bounds) {
    156         if (x < bounds.fLeft || x >= bounds.fRight || y < bounds.fTop || y >= bounds.fBottom) {
    157             return 0;
    158         } else {
    159             return *src.getAddr32(x, y);
    160         }
    161     }
    162 };
    163 
    164 template<class PixelFetcher, bool convolveAlpha>
    165 void SkMatrixConvolutionImageFilter::filterPixels(const SkBitmap& src,
    166                                                   SkBitmap* result,
    167                                                   const SkIRect& r,
    168                                                   const SkIRect& bounds) const {
    169     SkIRect rect(r);
    170     if (!rect.intersect(bounds)) {
    171         return;
    172     }
    173     for (int y = rect.fTop; y < rect.fBottom; ++y) {
    174         SkPMColor* dptr = result->getAddr32(rect.fLeft - bounds.fLeft, y - bounds.fTop);
    175         for (int x = rect.fLeft; x < rect.fRight; ++x) {
    176             SkScalar sumA = 0, sumR = 0, sumG = 0, sumB = 0;
    177             for (int cy = 0; cy < fKernelSize.fHeight; cy++) {
    178                 for (int cx = 0; cx < fKernelSize.fWidth; cx++) {
    179                     SkPMColor s = PixelFetcher::fetch(src,
    180                                                       x + cx - fKernelOffset.fX,
    181                                                       y + cy - fKernelOffset.fY,
    182                                                       bounds);
    183                     SkScalar k = fKernel[cy * fKernelSize.fWidth + cx];
    184                     if (convolveAlpha) {
    185                         sumA += SkGetPackedA32(s) * k;
    186                     }
    187                     sumR += SkGetPackedR32(s) * k;
    188                     sumG += SkGetPackedG32(s) * k;
    189                     sumB += SkGetPackedB32(s) * k;
    190                 }
    191             }
    192             int a = convolveAlpha
    193                   ? SkClampMax(SkScalarFloorToInt(sumA * fGain + fBias), 255)
    194                   : 255;
    195             int r = SkClampMax(SkScalarFloorToInt(sumR * fGain + fBias), a);
    196             int g = SkClampMax(SkScalarFloorToInt(sumG * fGain + fBias), a);
    197             int b = SkClampMax(SkScalarFloorToInt(sumB * fGain + fBias), a);
    198             if (!convolveAlpha) {
    199                 a = SkGetPackedA32(PixelFetcher::fetch(src, x, y, bounds));
    200                 *dptr++ = SkPreMultiplyARGB(a, r, g, b);
    201             } else {
    202                 *dptr++ = SkPackARGB32(a, r, g, b);
    203             }
    204         }
    205     }
    206 }
    207 
    208 template<class PixelFetcher>
    209 void SkMatrixConvolutionImageFilter::filterPixels(const SkBitmap& src,
    210                                                   SkBitmap* result,
    211                                                   const SkIRect& rect,
    212                                                   const SkIRect& bounds) const {
    213     if (fConvolveAlpha) {
    214         filterPixels<PixelFetcher, true>(src, result, rect, bounds);
    215     } else {
    216         filterPixels<PixelFetcher, false>(src, result, rect, bounds);
    217     }
    218 }
    219 
    220 void SkMatrixConvolutionImageFilter::filterInteriorPixels(const SkBitmap& src,
    221                                                           SkBitmap* result,
    222                                                           const SkIRect& rect,
    223                                                           const SkIRect& bounds) const {
    224     filterPixels<UncheckedPixelFetcher>(src, result, rect, bounds);
    225 }
    226 
    227 void SkMatrixConvolutionImageFilter::filterBorderPixels(const SkBitmap& src,
    228                                                         SkBitmap* result,
    229                                                         const SkIRect& rect,
    230                                                         const SkIRect& bounds) const {
    231     switch (fTileMode) {
    232         case kClamp_TileMode:
    233             filterPixels<ClampPixelFetcher>(src, result, rect, bounds);
    234             break;
    235         case kRepeat_TileMode:
    236             filterPixels<RepeatPixelFetcher>(src, result, rect, bounds);
    237             break;
    238         case kClampToBlack_TileMode:
    239             filterPixels<ClampToBlackPixelFetcher>(src, result, rect, bounds);
    240             break;
    241     }
    242 }
    243 
    244 // FIXME:  This should be refactored to SkImageFilterUtils for
    245 // use by other filters.  For now, we assume the input is always
    246 // premultiplied and unpremultiply it
    247 static SkBitmap unpremultiply_bitmap(const SkBitmap& src)
    248 {
    249     SkAutoLockPixels alp(src);
    250     if (!src.getPixels()) {
    251         return SkBitmap();
    252     }
    253 
    254     const SkImageInfo info = SkImageInfo::MakeN32(src.width(), src.height(), src.alphaType());
    255     SkBitmap result;
    256     if (!result.tryAllocPixels(info)) {
    257         return SkBitmap();
    258     }
    259     SkAutoLockPixels resultLock(result);
    260     for (int y = 0; y < src.height(); ++y) {
    261         const uint32_t* srcRow = src.getAddr32(0, y);
    262         uint32_t* dstRow = result.getAddr32(0, y);
    263         for (int x = 0; x < src.width(); ++x) {
    264             dstRow[x] = SkUnPreMultiply::PMColorToColor(srcRow[x]);
    265         }
    266     }
    267     return result;
    268 }
    269 
    270 #if SK_SUPPORT_GPU
    271 
    272 static GrTextureDomain::Mode convert_tilemodes(SkMatrixConvolutionImageFilter::TileMode tileMode) {
    273     switch (tileMode) {
    274     case SkMatrixConvolutionImageFilter::kClamp_TileMode:
    275         return GrTextureDomain::kClamp_Mode;
    276     case SkMatrixConvolutionImageFilter::kRepeat_TileMode:
    277         return GrTextureDomain::kRepeat_Mode;
    278     case SkMatrixConvolutionImageFilter::kClampToBlack_TileMode:
    279         return GrTextureDomain::kDecal_Mode;
    280     default:
    281         SkASSERT(false);
    282     }
    283     return GrTextureDomain::kIgnore_Mode;
    284 }
    285 #endif
    286 
    287 sk_sp<SkSpecialImage> SkMatrixConvolutionImageFilter::onFilterImage(SkSpecialImage* source,
    288                                                                     const Context& ctx,
    289                                                                     SkIPoint* offset) const {
    290     SkIPoint inputOffset = SkIPoint::Make(0, 0);
    291     sk_sp<SkSpecialImage> input(this->filterInput(0, source, ctx, &inputOffset));
    292     if (!input) {
    293         return nullptr;
    294     }
    295 
    296     SkIRect bounds;
    297     input = this->applyCropRect(this->mapContext(ctx), input.get(), &inputOffset, &bounds);
    298     if (!input) {
    299         return nullptr;
    300     }
    301 
    302 #if SK_SUPPORT_GPU
    303     // Note: if the kernel is too big, the GPU path falls back to SW
    304     if (source->isTextureBacked() &&
    305         fKernelSize.width() * fKernelSize.height() <= MAX_KERNEL_SIZE) {
    306         GrContext* context = source->getContext();
    307 
    308         // Ensure the input is in the destination color space. Typically applyCropRect will have
    309         // called pad_image to account for our dilation of bounds, so the result will already be
    310         // moved to the destination color space. If a filter DAG avoids that, then we use this
    311         // fall-back, which saves us from having to do the xform during the filter itself.
    312         input = ImageToColorSpace(input.get(), ctx.outputProperties());
    313 
    314         sk_sp<GrTextureProxy> inputProxy(input->asTextureProxyRef(context));
    315         SkASSERT(inputProxy);
    316 
    317         offset->fX = bounds.left();
    318         offset->fY = bounds.top();
    319         bounds.offset(-inputOffset);
    320 
    321         sk_sp<GrFragmentProcessor> fp(GrMatrixConvolutionEffect::Make(context->resourceProvider(),
    322                                                                       std::move(inputProxy),
    323                                                                       bounds,
    324                                                                       fKernelSize,
    325                                                                       fKernel,
    326                                                                       fGain,
    327                                                                       fBias,
    328                                                                       fKernelOffset,
    329                                                                       convert_tilemodes(fTileMode),
    330                                                                       fConvolveAlpha));
    331         if (!fp) {
    332             return nullptr;
    333         }
    334 
    335         return DrawWithFP(context, std::move(fp), bounds, ctx.outputProperties());
    336     }
    337 #endif
    338 
    339     SkBitmap inputBM;
    340 
    341     if (!input->getROPixels(&inputBM)) {
    342         return nullptr;
    343     }
    344 
    345     if (inputBM.colorType() != kN32_SkColorType) {
    346         return nullptr;
    347     }
    348 
    349     if (!fConvolveAlpha && !inputBM.isOpaque()) {
    350         inputBM = unpremultiply_bitmap(inputBM);
    351     }
    352 
    353     SkAutoLockPixels alp(inputBM);
    354     if (!inputBM.getPixels()) {
    355         return nullptr;
    356     }
    357 
    358     const SkImageInfo info = SkImageInfo::MakeN32(bounds.width(), bounds.height(),
    359                                                   inputBM.alphaType());
    360 
    361     SkBitmap dst;
    362     if (!dst.tryAllocPixels(info)) {
    363         return nullptr;
    364     }
    365 
    366     SkAutoLockPixels dstLock(dst);
    367 
    368     offset->fX = bounds.fLeft;
    369     offset->fY = bounds.fTop;
    370     bounds.offset(-inputOffset);
    371     SkIRect interior = SkIRect::MakeXYWH(bounds.left() + fKernelOffset.fX,
    372                                          bounds.top() + fKernelOffset.fY,
    373                                          bounds.width() - fKernelSize.fWidth + 1,
    374                                          bounds.height() - fKernelSize.fHeight + 1);
    375     SkIRect top = SkIRect::MakeLTRB(bounds.left(), bounds.top(), bounds.right(), interior.top());
    376     SkIRect bottom = SkIRect::MakeLTRB(bounds.left(), interior.bottom(),
    377                                        bounds.right(), bounds.bottom());
    378     SkIRect left = SkIRect::MakeLTRB(bounds.left(), interior.top(),
    379                                      interior.left(), interior.bottom());
    380     SkIRect right = SkIRect::MakeLTRB(interior.right(), interior.top(),
    381                                       bounds.right(), interior.bottom());
    382     this->filterBorderPixels(inputBM, &dst, top, bounds);
    383     this->filterBorderPixels(inputBM, &dst, left, bounds);
    384     this->filterInteriorPixels(inputBM, &dst, interior, bounds);
    385     this->filterBorderPixels(inputBM, &dst, right, bounds);
    386     this->filterBorderPixels(inputBM, &dst, bottom, bounds);
    387     return SkSpecialImage::MakeFromRaster(SkIRect::MakeWH(bounds.width(), bounds.height()),
    388                                           dst);
    389 }
    390 
    391 SkIRect SkMatrixConvolutionImageFilter::onFilterNodeBounds(const SkIRect& src, const SkMatrix& ctm,
    392                                                            MapDirection direction) const {
    393     SkIRect dst = src;
    394     int w = fKernelSize.width() - 1, h = fKernelSize.height() - 1;
    395     dst.fRight += w;
    396     dst.fBottom += h;
    397     if (kReverse_MapDirection == direction) {
    398         dst.offset(-fKernelOffset);
    399     } else {
    400         dst.offset(fKernelOffset - SkIPoint::Make(w, h));
    401     }
    402     return dst;
    403 }
    404 
    405 bool SkMatrixConvolutionImageFilter::affectsTransparentBlack() const {
    406     // Because the kernel is applied in device-space, we have no idea what
    407     // pixels it will affect in object-space.
    408     return true;
    409 }
    410 
    411 #ifndef SK_IGNORE_TO_STRING
    412 void SkMatrixConvolutionImageFilter::toString(SkString* str) const {
    413     str->appendf("SkMatrixConvolutionImageFilter: (");
    414     str->appendf("size: (%d,%d) kernel: (", fKernelSize.width(), fKernelSize.height());
    415     for (int y = 0; y < fKernelSize.height(); y++) {
    416         for (int x = 0; x < fKernelSize.width(); x++) {
    417             str->appendf("%f ", fKernel[y * fKernelSize.width() + x]);
    418         }
    419     }
    420     str->appendf(")");
    421     str->appendf("gain: %f bias: %f ", fGain, fBias);
    422     str->appendf("offset: (%d, %d) ", fKernelOffset.fX, fKernelOffset.fY);
    423     str->appendf("convolveAlpha: %s", fConvolveAlpha ? "true" : "false");
    424     str->append(")");
    425 }
    426 #endif
    427