| /* |
| * Copyright 2011 The Android Open Source Project |
| * |
| * Use of this source code is governed by a BSD-style license that can be |
| * found in the LICENSE file. |
| */ |
| |
| #include "SkBlurImageFilter.h" |
| |
| #include <algorithm> |
| |
| #include "SkArenaAlloc.h" |
| #include "SkAutoPixmapStorage.h" |
| #include "SkBitmap.h" |
| #include "SkColorData.h" |
| #include "SkColorSpaceXformer.h" |
| #include "SkTFitsIn.h" |
| #include "SkGpuBlurUtils.h" |
| #include "SkNx.h" |
| #include "SkOpts.h" |
| #include "SkReadBuffer.h" |
| #include "SkSpecialImage.h" |
| #include "SkWriteBuffer.h" |
| |
| #if SK_SUPPORT_GPU |
| #include "GrContext.h" |
| #include "GrTextureProxy.h" |
| #include "SkGr.h" |
| #endif |
| |
| // The value where the three pass window calculation results in a zero window. |
| // N[Solve[sigma*3*Sqrt[2 Pi]/4 == 1/2, sigma], 16] |
| static constexpr double kZeroWindow = 0.26596152026762; |
| static constexpr double kPi = 3.14159265358979323846264338327950288; |
| |
| class SkBlurImageFilterImpl final : public SkImageFilter { |
| public: |
| SkBlurImageFilterImpl(SkScalar sigmaX, |
| SkScalar sigmaY, |
| sk_sp<SkImageFilter> input, |
| const CropRect* cropRect, |
| SkBlurImageFilter::TileMode tileMode); |
| |
| SkRect computeFastBounds(const SkRect&) const override; |
| |
| SK_TO_STRING_OVERRIDE() |
| SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(SkBlurImageFilterImpl) |
| |
| protected: |
| void flatten(SkWriteBuffer&) const override; |
| sk_sp<SkSpecialImage> onFilterImage(SkSpecialImage* source, const Context&, |
| SkIPoint* offset) const override; |
| sk_sp<SkImageFilter> onMakeColorSpace(SkColorSpaceXformer*) const override; |
| SkIRect onFilterNodeBounds(const SkIRect& src, const SkMatrix&, MapDirection) const override; |
| |
| private: |
| typedef SkImageFilter INHERITED; |
| friend class SkImageFilter; |
| |
| #if SK_SUPPORT_GPU |
| sk_sp<SkSpecialImage> gpuFilter( |
| SkSpecialImage *source, |
| SkVector sigma, const sk_sp<SkSpecialImage> &input, |
| SkIRect inputBounds, SkIRect dstBounds) const; |
| #endif |
| |
| sk_sp<SkSpecialImage> cpuFilter( |
| SkSpecialImage *source, |
| SkVector sigma, const sk_sp<SkSpecialImage> &input, |
| SkIRect inputBounds, SkIRect dstBounds) const; |
| |
| SkSize fSigma; |
| SkBlurImageFilter::TileMode fTileMode; |
| }; |
| |
| SK_DEFINE_FLATTENABLE_REGISTRAR_GROUP_START(SkImageFilter) |
| SK_DEFINE_FLATTENABLE_REGISTRAR_ENTRY(SkBlurImageFilterImpl) |
| SK_DEFINE_FLATTENABLE_REGISTRAR_GROUP_END |
| |
| /////////////////////////////////////////////////////////////////////////////// |
| |
| sk_sp<SkImageFilter> SkBlurImageFilter::Make(SkScalar sigmaX, SkScalar sigmaY, |
| sk_sp<SkImageFilter> input, |
| const SkImageFilter::CropRect* cropRect, |
| TileMode tileMode) { |
| if (0 == sigmaX && 0 == sigmaY && !cropRect) { |
| return input; |
| } |
| return sk_sp<SkImageFilter>( |
| new SkBlurImageFilterImpl(sigmaX, sigmaY, input, cropRect, tileMode)); |
| } |
| |
| // This rather arbitrary-looking value results in a maximum box blur kernel size |
| // of 1000 pixels on the raster path, which matches the WebKit and Firefox |
| // implementations. Since the GPU path does not compute a box blur, putting |
| // the limit on sigma ensures consistent behaviour between the GPU and |
| // raster paths. |
| #define MAX_SIGMA SkIntToScalar(532) |
| |
| static SkVector map_sigma(const SkSize& localSigma, const SkMatrix& ctm) { |
| SkVector sigma = SkVector::Make(localSigma.width(), localSigma.height()); |
| ctm.mapVectors(&sigma, 1); |
| sigma.fX = SkMinScalar(SkScalarAbs(sigma.fX), MAX_SIGMA); |
| sigma.fY = SkMinScalar(SkScalarAbs(sigma.fY), MAX_SIGMA); |
| return sigma; |
| } |
| |
| SkBlurImageFilterImpl::SkBlurImageFilterImpl(SkScalar sigmaX, |
| SkScalar sigmaY, |
| sk_sp<SkImageFilter> input, |
| const CropRect* cropRect, |
| SkBlurImageFilter::TileMode tileMode) |
| : INHERITED(&input, 1, cropRect), fSigma{sigmaX, sigmaY}, fTileMode(tileMode) {} |
| |
| sk_sp<SkFlattenable> SkBlurImageFilterImpl::CreateProc(SkReadBuffer& buffer) { |
| SK_IMAGEFILTER_UNFLATTEN_COMMON(common, 1); |
| SkScalar sigmaX = buffer.readScalar(); |
| SkScalar sigmaY = buffer.readScalar(); |
| SkBlurImageFilter::TileMode tileMode; |
| if (buffer.isVersionLT(SkReadBuffer::kTileModeInBlurImageFilter_Version)) { |
| tileMode = SkBlurImageFilter::kClampToBlack_TileMode; |
| } else { |
| tileMode = static_cast<SkBlurImageFilter::TileMode>(buffer.readInt()); |
| } |
| |
| static_assert(SkBlurImageFilter::kMax_TileMode == 2, "CreateProc"); |
| SkASSERT(tileMode <= SkBlurImageFilter::kMax_TileMode); |
| |
| return SkBlurImageFilter::Make( |
| sigmaX, sigmaY, common.getInput(0), &common.cropRect(), tileMode); |
| } |
| |
| void SkBlurImageFilterImpl::flatten(SkWriteBuffer& buffer) const { |
| this->INHERITED::flatten(buffer); |
| buffer.writeScalar(fSigma.fWidth); |
| buffer.writeScalar(fSigma.fHeight); |
| |
| static_assert(SkBlurImageFilter::kMax_TileMode == 2, "flatten"); |
| SkASSERT(fTileMode <= SkBlurImageFilter::kMax_TileMode); |
| |
| buffer.writeInt(static_cast<int>(fTileMode)); |
| } |
| |
| #if SK_SUPPORT_GPU |
| static GrTextureDomain::Mode to_texture_domain_mode(SkBlurImageFilter::TileMode tileMode) { |
| switch (tileMode) { |
| case SkBlurImageFilter::TileMode::kClamp_TileMode: |
| return GrTextureDomain::kClamp_Mode; |
| case SkBlurImageFilter::TileMode::kClampToBlack_TileMode: |
| return GrTextureDomain::kDecal_Mode; |
| case SkBlurImageFilter::TileMode::kRepeat_TileMode: |
| return GrTextureDomain::kRepeat_Mode; |
| default: |
| SK_ABORT("Unsupported tile mode."); |
| return GrTextureDomain::kDecal_Mode; |
| } |
| } |
| #endif |
| |
| static void get_box3_params(SkScalar s, int *kernelSize, int* kernelSize3, int *lowOffset, |
| int *highOffset) { |
| float pi = SkScalarToFloat(SK_ScalarPI); |
| int d = static_cast<int>(floorf(SkScalarToFloat(s) * 3.0f * sqrtf(2.0f * pi) / 4.0f + 0.5f)); |
| *kernelSize = d; |
| if (d % 2 == 1) { |
| *lowOffset = *highOffset = (d - 1) / 2; |
| *kernelSize3 = d; |
| } else { |
| *highOffset = d / 2; |
| *lowOffset = *highOffset - 1; |
| *kernelSize3 = d + 1; |
| } |
| } |
| |
| #if !defined(SK_SUPPORT_LEGACY_BLUR_IMAGE) |
| |
| // This is defined by the SVG spec: |
| // https://drafts.fxtf.org/filter-effects/#feGaussianBlurElement |
| static int calculate_window(double sigma) { |
| // NB 136 is the largest sigma that will not cause a buffer full of 255 mask values to overflow |
| // using the Gauss filter. It also limits the size of buffers used hold intermediate values. |
| // Explanation of maximums: |
| // sum0 = window * 255 |
| // sum1 = window * sum0 -> window * window * 255 |
| // sum2 = window * sum1 -> window * window * window * 255 -> window^3 * 255 |
| // |
| // The value window^3 * 255 must fit in a uint32_t. So, |
| // window^3 < 2^32. window = 255. |
| // |
| // window = floor(sigma * 3 * sqrt(2 * kPi) / 4 + 0.5) |
| // For window <= 255, the largest value for sigma is 136. |
| sigma = SkTPin(sigma, 0.0, 136.0); |
| auto possibleWindow = static_cast<int>(floor(sigma * 3 * sqrt(2 * kPi) / 4 + 0.5)); |
| return std::max(1, possibleWindow); |
| } |
| |
| // Calculating the border is tricky. The border is the distance in pixels between the first dst |
| // pixel and the first src pixel (or the last src pixel and the last dst pixel). |
| // I will go through the odd case which is simpler, and then through the even case. Given a |
| // stack of filters seven wide for the odd case of three passes. |
| // |
| // S |
| // aaaAaaa |
| // bbbBbbb |
| // cccCccc |
| // D |
| // |
| // The furthest changed pixel is when the filters are in the following configuration. |
| // |
| // S |
| // aaaAaaa |
| // bbbBbbb |
| // cccCccc |
| // D |
| // |
| // The A pixel is calculated using the value S, the B uses A, and the C uses B, and |
| // finally D is C. So, with a window size of seven the border is nine. In the odd case, the |
| // border is 3*((window - 1)/2). |
| // |
| // For even cases the filter stack is more complicated. The spec specifies two passes |
| // of even filters and a final pass of odd filters. A stack for a width of six looks like |
| // this. |
| // |
| // S |
| // aaaAaa |
| // bbBbbb |
| // cccCccc |
| // D |
| // |
| // The furthest pixel looks like this. |
| // |
| // S |
| // aaaAaa |
| // bbBbbb |
| // cccCccc |
| // D |
| // |
| // For a window of six, the border value is eight. In the even case the border is 3 * |
| // (window/2) - 1. |
| static int calculate_border(int window) { |
| return (window & 1) == 1 ? 3 * ((window - 1) / 2) : 3 * (window / 2) - 1; |
| } |
| |
| static int calculate_buffer(int window) { |
| int bufferSize = window - 1; |
| return (window & 1) == 1 ? 3 * bufferSize : 3 * bufferSize + 1; |
| } |
| |
| // blur_one_direction implements the common three pass box filter approximation of Gaussian blur, |
| // but combines all three passes into a single pass. This approach is facilitated by three circular |
| // buffers the width of the window which track values for trailing edges of each of the three |
| // passes. This allows the algorithm to use more precision in the calculation because the values |
| // are not rounded each pass. And this implementation also avoids a trap that's easy to fall |
| // into resulting in blending in too many zeroes near the edge. |
| // |
| // In general, a window sum has the form: |
| // sum_n+1 = sum_n + leading_edge - trailing_edge. |
| // If instead we do the subtraction at the end of the previous iteration, we can just |
| // calculate the sums instead of having to do the subtractions too. |
| // |
| // In previous iteration: |
| // sum_n+1 = sum_n - trailing_edge. |
| // |
| // In this iteration: |
| // sum_n+1 = sum_n + leading_edge. |
| // |
| // Now we can stack all three sums and do them at once. Sum0 gets its leading edge from the |
| // actual data. Sum1's leading edge is just Sum0, and Sum2's leading edge is Sum1. So, doing the |
| // three passes at the same time has the form: |
| // |
| // sum0_n+1 = sum0_n + leading edge |
| // sum1_n+1 = sum1_n + sum0_n+1 |
| // sum2_n+1 = sum2_n + sum1_n+1 |
| // |
| // sum2_n+1 / window^3 is the new value of the destination pixel. |
| // |
| // Reduce the sums by the trailing edges which were stored in the circular buffers, |
| // for the next go around. This is the case for odd sized windows, even windows the the third |
| // circular buffer is one larger then the first two circular buffers. |
| // |
| // sum2_n+2 = sum2_n+1 - buffer2[i]; |
| // buffer2[i] = sum1; |
| // sum1_n+2 = sum1_n+1 - buffer1[i]; |
| // buffer1[i] = sum0; |
| // sum0_n+2 = sum0_n+1 - buffer0[i]; |
| // buffer0[i] = leading edge |
| // |
| // This is all encapsulated in the processValue function below. |
| // |
| using Pass0And1 = Sk4u[2]; |
| // The would be dLeft parameter is assumed to be 0. |
| static void blur_one_direction(Sk4u* buffer, int window, |
| int srcLeft, int srcRight, int dstRight, |
| const uint32_t* src, int srcXStride, int srcYStride, int srcH, |
| uint32_t* dst, int dstXStride, int dstYStride) { |
| |
| // The circular buffers are one less than the window. |
| auto pass0Count = window - 1, |
| pass1Count = window - 1, |
| pass2Count = (window & 1) == 1 ? window - 1 : window; |
| |
| Pass0And1* buffer01Start = (Pass0And1*)buffer; |
| Sk4u* buffer2Start = buffer + pass0Count + pass1Count; |
| Pass0And1* buffer01End = (Pass0And1*)buffer2Start; |
| Sk4u* buffer2End = buffer2Start + pass2Count; |
| |
| // If the window is odd then the divisor is just window ^ 3 otherwise, |
| // it is window * window * (window + 1) = window ^ 3 + window ^ 2; |
| auto window2 = window * window; |
| auto window3 = window2 * window; |
| auto divisor = (window & 1) == 1 ? window3 : window3 + window2; |
| |
| // NB the sums in the blur code use the following technique to avoid |
| // adding 1/2 to round the divide. |
| // |
| // Sum/d + 1/2 == (Sum + h) / d |
| // Sum + d(1/2) == Sum + h |
| // h == (1/2)d |
| // |
| // But the d/2 it self should be rounded. |
| // h == d/2 + 1/2 == (d + 1) / 2 |
| // |
| // weight = 1 / d * 2 ^ 32 |
| auto weight = static_cast<uint32_t>(round(1.0 / divisor * (1ull << 32))); |
| auto half = static_cast<uint32_t>((divisor + 1) / 2); |
| |
| auto border = calculate_border(window); |
| |
| // Calculate the start and end of the source pixels with respect to the destination start. |
| auto srcStart = srcLeft - border, |
| srcEnd = srcRight - border, |
| dstEnd = dstRight; |
| |
| for (auto y = 0; y < srcH; y++) { |
| auto buffer01Cursor = buffer01Start; |
| auto buffer2Cursor = buffer2Start; |
| |
| Sk4u sum0{0u}; |
| Sk4u sum1{0u}; |
| Sk4u sum2{half}; |
| |
| sk_bzero(buffer01Start, (buffer2End - (Sk4u *) (buffer01Start)) * sizeof(*buffer2Start)); |
| |
| // Given an expanded input pixel, move the window ahead using the leadingEdge value. |
| auto processValue = [&](const Sk4u& leadingEdge) -> Sk4u { |
| sum0 += leadingEdge; |
| sum1 += sum0; |
| sum2 += sum1; |
| |
| Sk4u value = sum2.mulHi(weight); |
| |
| sum2 -= *buffer2Cursor; |
| *buffer2Cursor = sum1; |
| buffer2Cursor = (buffer2Cursor + 1) < buffer2End ? buffer2Cursor + 1 : buffer2Start; |
| |
| sum1 -= (*buffer01Cursor)[1]; |
| (*buffer01Cursor)[1] = sum0; |
| sum0 -= (*buffer01Cursor)[0]; |
| (*buffer01Cursor)[0] = leadingEdge; |
| buffer01Cursor = |
| (buffer01Cursor + 1) < buffer01End ? buffer01Cursor + 1 : buffer01Start; |
| |
| return value; |
| }; |
| |
| auto srcIdx = srcStart; |
| auto dstIdx = 0; |
| const uint32_t* srcCursor = src; |
| uint32_t* dstCursor = dst; |
| |
| // The destination pixels are not effected by the src pixels, |
| // change to zero as per the spec. |
| // https://drafts.fxtf.org/filter-effects/#FilterPrimitivesOverviewIntro |
| while (dstIdx < srcIdx) { |
| *dstCursor = 0; |
| dstCursor += dstXStride; |
| SK_PREFETCH(dstCursor); |
| dstIdx++; |
| } |
| |
| // The edge of the source is before the edge of the destination. Calculate the sums for |
| // the pixels before the start of the destination. |
| while (dstIdx > srcIdx) { |
| Sk4u leadingEdge = srcIdx < srcEnd ? SkNx_cast<uint32_t>(Sk4b::Load(srcCursor)) : 0; |
| (void) processValue(leadingEdge); |
| srcCursor += srcXStride; |
| srcIdx++; |
| } |
| |
| // The dstIdx and srcIdx are in sync now; the code just uses the dstIdx for both now. |
| // Consume the source generating pixels to dst. |
| auto loopEnd = std::min(dstEnd, srcEnd); |
| while (dstIdx < loopEnd) { |
| Sk4u leadingEdge = SkNx_cast<uint32_t>(Sk4b::Load(srcCursor)); |
| SkNx_cast<uint8_t>(processValue(leadingEdge)).store(dstCursor); |
| srcCursor += srcXStride; |
| dstCursor += dstXStride; |
| SK_PREFETCH(dstCursor); |
| dstIdx++; |
| } |
| |
| // The leading edge is beyond the end of the source. Assume that the pixels |
| // are now 0x0000 until the end of the destination. |
| loopEnd = dstEnd; |
| while (dstIdx < loopEnd) { |
| SkNx_cast<uint8_t>(processValue(0u)).store(dstCursor); |
| dstCursor += dstXStride; |
| SK_PREFETCH(dstCursor); |
| dstIdx++; |
| } |
| |
| src += srcYStride; |
| dst += dstYStride; |
| } |
| } |
| |
| static sk_sp<SkSpecialImage> combined_pass_blur( |
| SkVector sigma, |
| SkSpecialImage* source, const sk_sp<SkSpecialImage>& input, |
| SkIRect srcBounds, SkIRect dstBounds) { |
| SkBitmap inputBM; |
| |
| if (!input->getROPixels(&inputBM)) { |
| return nullptr; |
| } |
| |
| if (inputBM.colorType() != kN32_SkColorType) { |
| return nullptr; |
| } |
| |
| auto windowW = calculate_window(sigma.x()), |
| windowH = calculate_window(sigma.y()); |
| |
| SkBitmap src; |
| inputBM.extractSubset(&src, srcBounds); |
| |
| // Make everything relative to the destination bounds. |
| srcBounds.offset(-dstBounds.x(), -dstBounds.y()); |
| dstBounds.offset(-dstBounds.x(), -dstBounds.y()); |
| |
| auto srcW = srcBounds.width(), |
| srcH = srcBounds.height(), |
| dstW = dstBounds.width(), |
| dstH = dstBounds.height(); |
| |
| SkImageInfo dstInfo = SkImageInfo::Make(dstW, dstH, inputBM.colorType(), inputBM.alphaType()); |
| |
| SkBitmap dst; |
| if (!dst.tryAllocPixels(dstInfo)) { |
| return nullptr; |
| } |
| |
| auto bufferSizeW = calculate_buffer(windowW), |
| bufferSizeH = calculate_buffer(windowH); |
| |
| // The amount 1024 is enough for buffers up to 10 sigma. The tmp bitmap will be |
| // allocated on the heap. |
| SkSTArenaAlloc<1024> alloc; |
| Sk4u* buffer = alloc.makeArrayDefault<Sk4u>(std::max(bufferSizeW, bufferSizeH)); |
| |
| if (windowW > 1 && windowH > 1) { |
| // Blur both directions. |
| |
| auto tmpW = srcH, |
| tmpH = dstW; |
| |
| auto tmp = alloc.makeArrayDefault<uint32_t>(tmpW * tmpH); |
| |
| // Blur horizontally, and transpose. |
| blur_one_direction( |
| buffer, windowW, |
| srcBounds.left(), srcBounds.right(), dstBounds.right(), |
| static_cast<uint32_t*>(src.getPixels()), 1, src.rowBytesAsPixels(), srcH, |
| tmp, tmpW, 1); |
| |
| // Blur vertically (scan in memory order because of the transposition), |
| // and transpose back to the original orientation. |
| blur_one_direction( |
| buffer, windowH, |
| srcBounds.top(), srcBounds.bottom(), dstBounds.bottom(), |
| tmp, 1, tmpW, tmpH, |
| static_cast<uint32_t*>(dst.getPixels()), dst.rowBytesAsPixels(), 1); |
| } else if (windowW > 1) { |
| // Blur only horizontally. |
| |
| blur_one_direction( |
| buffer, windowW, |
| srcBounds.left(), srcBounds.right(), dstBounds.right(), |
| static_cast<uint32_t*>(src.getPixels()), 1, src.rowBytesAsPixels(), srcH, |
| static_cast<uint32_t*>(dst.getPixels()), 1, dst.rowBytesAsPixels()); |
| } else if (windowH > 1) { |
| // Blur only vertically. |
| |
| blur_one_direction( |
| buffer, windowH, |
| srcBounds.top(), srcBounds.bottom(), dstBounds.bottom(), |
| static_cast<uint32_t*>(src.getPixels()), src.rowBytesAsPixels(), 1, srcW, |
| static_cast<uint32_t*>(dst.getPixels()), dst.rowBytesAsPixels(), 1); |
| } else { |
| // There is no blurring to do, but we still need to copy the source while accounting for the |
| // dstBounds. Remember that the src was intersected with the dst. |
| int y = 0; |
| size_t dstWBytes = dstW * sizeof(uint32_t); |
| for (;y < srcBounds.top(); y++) { |
| sk_bzero(dst.getAddr32(0, y), dstWBytes); |
| } |
| for (;y < srcBounds.bottom(); y++) { |
| int x = 0; |
| uint32_t* dstPtr = dst.getAddr32(0, y); |
| for (;x < srcBounds.left(); x++) { |
| *dstPtr++ = 0; |
| } |
| |
| memcpy(dstPtr, |
| src.getAddr32(x - srcBounds.left(), y - srcBounds.top()), |
| srcW * sizeof(uint32_t)); |
| |
| dstPtr += srcW; |
| x += srcW; |
| |
| for (;x < dstBounds.right(); x++) { |
| *dstPtr++ = 0; |
| } |
| } |
| for (;y < dstBounds.bottom(); y++) { |
| sk_bzero(dst.getAddr32(0, y), dstWBytes); |
| } |
| } |
| |
| return SkSpecialImage::MakeFromRaster(SkIRect::MakeWH(dstBounds.width(), |
| dstBounds.height()), |
| dst, &source->props()); |
| } |
| #endif |
| |
| sk_sp<SkSpecialImage> SkBlurImageFilterImpl::onFilterImage(SkSpecialImage* source, |
| const Context& ctx, |
| SkIPoint* offset) const { |
| SkIPoint inputOffset = SkIPoint::Make(0, 0); |
| |
| sk_sp<SkSpecialImage> input(this->filterInput(0, source, ctx, &inputOffset)); |
| if (!input) { |
| return nullptr; |
| } |
| |
| SkIRect inputBounds = SkIRect::MakeXYWH(inputOffset.fX, inputOffset.fY, |
| input->width(), input->height()); |
| |
| // Calculate the destination bounds. |
| SkIRect dstBounds; |
| if (!this->applyCropRect(this->mapContext(ctx), inputBounds, &dstBounds)) { |
| return nullptr; |
| } |
| if (!inputBounds.intersect(dstBounds)) { |
| return nullptr; |
| } |
| |
| // Save the offset in preparation to make all rectangles relative to the inputOffset. |
| SkIPoint resultOffset = SkIPoint::Make(dstBounds.fLeft, dstBounds.fTop); |
| |
| // Make all bounds relative to the inputOffset. |
| inputBounds.offset(-inputOffset); |
| dstBounds.offset(-inputOffset); |
| |
| const SkVector sigma = map_sigma(fSigma, ctx.ctm()); |
| if (sigma.x() < 0 || sigma.y() < 0) { |
| return nullptr; |
| } |
| |
| sk_sp<SkSpecialImage> result; |
| #if SK_SUPPORT_GPU |
| if (source->isTextureBacked()) { |
| // Ensure the input is in the destination's gamut. This saves us from having to do the |
| // xform during the filter itself. |
| input = ImageToColorSpace(input.get(), ctx.outputProperties()); |
| |
| result = this->gpuFilter(source, sigma, input, inputBounds, dstBounds); |
| } else |
| #endif |
| { |
| // If both sigmas will result in a zero width window, there is nothing to do. |
| if (sigma.x() < kZeroWindow && sigma.y() < kZeroWindow) { |
| result = input->makeSubset(inputBounds); |
| } else { |
| #if defined(SK_SUPPORT_LEGACY_BLUR_IMAGE) |
| result = this->cpuFilter(source, sigma, input, inputBounds, dstBounds); |
| #else |
| result = combined_pass_blur(sigma, source, input, inputBounds, dstBounds); |
| #endif |
| } |
| } |
| |
| // Return the resultOffset if the blur succeeded. |
| if (result != nullptr) { |
| *offset = resultOffset; |
| } |
| return result; |
| } |
| |
| #if SK_SUPPORT_GPU |
| sk_sp<SkSpecialImage> SkBlurImageFilterImpl::gpuFilter( |
| SkSpecialImage *source, |
| SkVector sigma, const sk_sp<SkSpecialImage> &input, |
| SkIRect inputBounds, SkIRect dstBounds) const |
| { |
| // If both sigmas produce arms of the cross that are less than 1/2048, then they |
| // do not contribute to the sum of the filter in a way to change a gamma corrected result. |
| // Let s = 1/(2*sigma^2) |
| // The normalizing value n = 1 + 4*E^(-s) + 4*E^(-2s) |
| // The raw cross arm value c = E^-s |
| // The normalized cross arm value = c/n |
| // N[Solve[{c/n == 1/2048, sigma > 0}, sigma], 16] |
| static constexpr double kZeroWindowGPU = 0.2561130112451658; |
| if (sigma.x() < kZeroWindowGPU && sigma.y() < kZeroWindowGPU) { |
| return input->makeSubset(inputBounds); |
| } |
| |
| GrContext* context = source->getContext(); |
| |
| sk_sp<GrTextureProxy> inputTexture(input->asTextureProxyRef(context)); |
| if (!inputTexture) { |
| return nullptr; |
| } |
| |
| // Typically, we would create the RTC with the output's color space (from ctx), but we |
| // always blur in the PixelConfig of the *input*. Those might not be compatible (if they |
| // have different transfer functions). We've already guaranteed that those color spaces |
| // have the same gamut, so in this case, we do everything in the input's color space. |
| sk_sp<GrRenderTargetContext> renderTargetContext(SkGpuBlurUtils::GaussianBlur( |
| context, |
| std::move(inputTexture), |
| sk_ref_sp(input->getColorSpace()), |
| dstBounds, |
| inputBounds, |
| sigma.x(), |
| sigma.y(), |
| to_texture_domain_mode(fTileMode))); |
| if (!renderTargetContext) { |
| return nullptr; |
| } |
| |
| return SkSpecialImage::MakeDeferredFromGpu( |
| context, |
| SkIRect::MakeWH(dstBounds.width(), dstBounds.height()), |
| kNeedNewImageUniqueID_SpecialImage, |
| renderTargetContext->asTextureProxyRef(), |
| renderTargetContext->colorSpaceInfo().refColorSpace(), |
| &source->props()); |
| } |
| #endif |
| |
| // TODO: Implement CPU backend for different fTileMode. |
| sk_sp<SkSpecialImage> SkBlurImageFilterImpl::cpuFilter( |
| SkSpecialImage *source, |
| SkVector sigma, const sk_sp<SkSpecialImage> &input, |
| SkIRect inputBounds, SkIRect dstBounds) const |
| { |
| int kernelSizeX, kernelSizeX3, lowOffsetX, highOffsetX; |
| int kernelSizeY, kernelSizeY3, lowOffsetY, highOffsetY; |
| get_box3_params(sigma.x(), &kernelSizeX, &kernelSizeX3, &lowOffsetX, &highOffsetX); |
| get_box3_params(sigma.y(), &kernelSizeY, &kernelSizeY3, &lowOffsetY, &highOffsetY); |
| |
| SkBitmap inputBM; |
| |
| if (!input->getROPixels(&inputBM) && inputBM.colorType() != kN32_SkColorType) { |
| return nullptr; |
| } |
| |
| SkImageInfo info = SkImageInfo::Make(dstBounds.width(), dstBounds.height(), |
| inputBM.colorType(), inputBM.alphaType()); |
| |
| SkBitmap tmp, dst; |
| if (!tmp.tryAllocPixels(info) || !dst.tryAllocPixels(info)) { |
| return nullptr; |
| } |
| |
| // Get ready to blur. |
| const SkPMColor* s = inputBM.getAddr32(inputBounds.x(), inputBounds.y()); |
| SkPMColor* t = tmp.getAddr32(0, 0); |
| SkPMColor* d = dst.getAddr32(0, 0); |
| |
| // Shift everything from being relative to the orignal input bounds to the destination bounds. |
| inputBounds.offset(-dstBounds.x(), -dstBounds.y()); |
| dstBounds.offset(-dstBounds.x(), -dstBounds.y()); |
| |
| int w = dstBounds.width(), |
| h = dstBounds.height(), |
| sw = inputBM.rowBytesAsPixels(); |
| |
| SkIRect inputBoundsT = SkIRect::MakeLTRB(inputBounds.top(), inputBounds.left(), |
| inputBounds.bottom(), inputBounds.right()); |
| SkIRect dstBoundsT = SkIRect::MakeWH(dstBounds.height(), dstBounds.width()); |
| |
| /** |
| * |
| * In order to make memory accesses cache-friendly, we reorder the passes to |
| * use contiguous memory reads wherever possible. |
| * |
| * For example, the 6 passes of the X-and-Y blur case are rewritten as |
| * follows. Instead of 3 passes in X and 3 passes in Y, we perform |
| * 2 passes in X, 1 pass in X transposed to Y on write, 2 passes in X, |
| * then 1 pass in X transposed to Y on write. |
| * |
| * +----+ +----+ +----+ +---+ +---+ +---+ +----+ |
| * + AB + ----> | AB | ----> | AB | -----> | A | ----> | A | ----> | A | -----> | AB | |
| * +----+ blurX +----+ blurX +----+ blurXY | B | blurX | B | blurX | B | blurXY +----+ |
| * +---+ +---+ +---+ |
| * |
| * In this way, two of the y-blurs become x-blurs applied to transposed |
| * images, and all memory reads are contiguous. |
| */ |
| if (kernelSizeX > 0 && kernelSizeY > 0) { |
| SkOpts::box_blur_xx(s, sw, inputBounds, t, kernelSizeX, lowOffsetX, highOffsetX, w, h); |
| SkOpts::box_blur_xx(t, w, dstBounds, d, kernelSizeX, highOffsetX, lowOffsetX, w, h); |
| SkOpts::box_blur_xy(d, w, dstBounds, t, kernelSizeX3, highOffsetX, highOffsetX, w, h); |
| SkOpts::box_blur_xx(t, h, dstBoundsT, d, kernelSizeY, lowOffsetY, highOffsetY, h, w); |
| SkOpts::box_blur_xx(d, h, dstBoundsT, t, kernelSizeY, highOffsetY, lowOffsetY, h, w); |
| SkOpts::box_blur_xy(t, h, dstBoundsT, d, kernelSizeY3, highOffsetY, highOffsetY, h, w); |
| } else if (kernelSizeX > 0) { |
| SkOpts::box_blur_xx(s, sw, inputBounds, d, kernelSizeX, lowOffsetX, highOffsetX, w, h); |
| SkOpts::box_blur_xx(d, w, dstBounds, t, kernelSizeX, highOffsetX, lowOffsetX, w, h); |
| SkOpts::box_blur_xx(t, w, dstBounds, d, kernelSizeX3, highOffsetX, highOffsetX, w, h); |
| } else if (kernelSizeY > 0) { |
| SkOpts::box_blur_yx(s, sw, inputBoundsT, d, kernelSizeY, lowOffsetY, highOffsetY, h, w); |
| SkOpts::box_blur_xx(d, h, dstBoundsT, t, kernelSizeY, highOffsetY, lowOffsetY, h, w); |
| SkOpts::box_blur_xy(t, h, dstBoundsT, d, kernelSizeY3, highOffsetY, highOffsetY, h, w); |
| } |
| |
| return SkSpecialImage::MakeFromRaster(SkIRect::MakeSize(dstBounds.size()), |
| dst, &source->props()); |
| } |
| |
| sk_sp<SkImageFilter> SkBlurImageFilterImpl::onMakeColorSpace(SkColorSpaceXformer* xformer) |
| const { |
| SkASSERT(1 == this->countInputs()); |
| |
| auto input = xformer->apply(this->getInput(0)); |
| if (this->getInput(0) != input.get()) { |
| return SkBlurImageFilter::Make(fSigma.width(), fSigma.height(), std::move(input), |
| this->getCropRectIfSet(), fTileMode); |
| } |
| return this->refMe(); |
| } |
| |
| SkRect SkBlurImageFilterImpl::computeFastBounds(const SkRect& src) const { |
| SkRect bounds = this->getInput(0) ? this->getInput(0)->computeFastBounds(src) : src; |
| bounds.outset(fSigma.width() * 3, fSigma.height() * 3); |
| return bounds; |
| } |
| |
| SkIRect SkBlurImageFilterImpl::onFilterNodeBounds(const SkIRect& src, const SkMatrix& ctm, |
| MapDirection) const { |
| SkVector sigma = map_sigma(fSigma, ctm); |
| return src.makeOutset(SkScalarCeilToInt(sigma.x() * 3), SkScalarCeilToInt(sigma.y() * 3)); |
| } |
| |
| #ifndef SK_IGNORE_TO_STRING |
| void SkBlurImageFilterImpl::toString(SkString* str) const { |
| str->appendf("SkBlurImageFilterImpl: ("); |
| str->appendf("sigma: (%f, %f) tileMode: %d input (", fSigma.fWidth, fSigma.fHeight, |
| static_cast<int>(fTileMode)); |
| |
| if (this->getInput(0)) { |
| this->getInput(0)->toString(str); |
| } |
| |
| str->append("))"); |
| } |
| #endif |