| /* |
| * 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 "include/effects/SkBlurImageFilter.h" |
| |
| #include <algorithm> |
| |
| #include "include/core/SkBitmap.h" |
| #include "include/core/SkTileMode.h" |
| #include "include/private/SkColorData.h" |
| #include "include/private/SkNx.h" |
| #include "include/private/SkTFitsIn.h" |
| #include "src/core/SkArenaAlloc.h" |
| #include "src/core/SkAutoPixmapStorage.h" |
| #include "src/core/SkGpuBlurUtils.h" |
| #include "src/core/SkImageFilter_Base.h" |
| #include "src/core/SkOpts.h" |
| #include "src/core/SkReadBuffer.h" |
| #include "src/core/SkSpecialImage.h" |
| #include "src/core/SkWriteBuffer.h" |
| |
| #if SK_SUPPORT_GPU |
| #include "include/gpu/GrContext.h" |
| #include "src/gpu/GrTextureProxy.h" |
| #include "src/gpu/SkGr.h" |
| #endif |
| |
| namespace { |
| |
| class SkBlurImageFilterImpl final : public SkImageFilter_Base { |
| public: |
| SkBlurImageFilterImpl(SkScalar sigmaX, SkScalar sigmaY, SkTileMode tileMode, |
| sk_sp<SkImageFilter> input, const CropRect* cropRect) |
| : INHERITED(&input, 1, cropRect) |
| , fSigma{sigmaX, sigmaY} |
| , fTileMode(tileMode) {} |
| |
| SkRect computeFastBounds(const SkRect&) const override; |
| |
| protected: |
| void flatten(SkWriteBuffer&) const override; |
| sk_sp<SkSpecialImage> onFilterImage(const Context&, SkIPoint* offset) const override; |
| SkIRect onFilterNodeBounds(const SkIRect& src, const SkMatrix& ctm, |
| MapDirection, const SkIRect* inputRect) const override; |
| |
| private: |
| friend void SkBlurImageFilter::RegisterFlattenables(); |
| SK_FLATTENABLE_HOOKS(SkBlurImageFilterImpl) |
| |
| #if SK_SUPPORT_GPU |
| sk_sp<SkSpecialImage> gpuFilter( |
| const Context& ctx, SkVector sigma, |
| const sk_sp<SkSpecialImage> &input, |
| SkIRect inputBounds, SkIRect dstBounds, SkIPoint inputOffset, SkIPoint* offset) const; |
| #endif |
| |
| SkSize fSigma; |
| SkTileMode fTileMode; |
| |
| typedef SkImageFilter_Base INHERITED; |
| }; |
| |
| } // end namespace |
| |
| static SkTileMode to_sktilemode(SkBlurImageFilter::TileMode tileMode) { |
| switch(tileMode) { |
| case SkBlurImageFilter::kClamp_TileMode: |
| return SkTileMode::kClamp; |
| case SkBlurImageFilter::kRepeat_TileMode: |
| return SkTileMode::kRepeat; |
| case SkBlurImageFilter::kClampToBlack_TileMode: |
| // Fall through |
| default: |
| return SkTileMode::kDecal; |
| } |
| } |
| |
| sk_sp<SkImageFilter> SkBlurImageFilter::Make(SkScalar sigmaX, SkScalar sigmaY, |
| sk_sp<SkImageFilter> input, |
| const SkImageFilter::CropRect* cropRect, |
| TileMode tileMode) { |
| return Make(sigmaX, sigmaY, to_sktilemode(tileMode), std::move(input), cropRect); |
| } |
| |
| sk_sp<SkImageFilter> SkBlurImageFilter::Make(SkScalar sigmaX, SkScalar sigmaY, SkTileMode tileMode, |
| sk_sp<SkImageFilter> input, |
| const SkImageFilter::CropRect* cropRect) { |
| if (sigmaX < SK_ScalarNearlyZero && sigmaY < SK_ScalarNearlyZero && !cropRect) { |
| return input; |
| } |
| return sk_sp<SkImageFilter>( |
| new SkBlurImageFilterImpl(sigmaX, sigmaY, tileMode, input, cropRect)); |
| } |
| |
| void SkBlurImageFilter::RegisterFlattenables() { SK_REGISTER_FLATTENABLE(SkBlurImageFilterImpl); } |
| |
| /////////////////////////////////////////////////////////////////////////////// |
| |
| sk_sp<SkFlattenable> SkBlurImageFilterImpl::CreateProc(SkReadBuffer& buffer) { |
| SK_IMAGEFILTER_UNFLATTEN_COMMON(common, 1); |
| SkScalar sigmaX = buffer.readScalar(); |
| SkScalar sigmaY = buffer.readScalar(); |
| SkTileMode tileMode; |
| if (buffer.isVersionLT(SkPicturePriv::kTileModeInBlurImageFilter_Version)) { |
| tileMode = SkTileMode::kDecal; |
| } else if (buffer.isVersionLT(SkPicturePriv::kCleanupImageFilterEnums_Version)) { |
| tileMode = to_sktilemode(buffer.read32LE(SkBlurImageFilter::kLast_TileMode)); |
| } else { |
| tileMode = buffer.read32LE(SkTileMode::kLastTileMode); |
| } |
| |
| static_assert(SkBlurImageFilter::kLast_TileMode == 2, "CreateProc"); |
| |
| return SkBlurImageFilter::Make( |
| sigmaX, sigmaY, tileMode, common.getInput(0), &common.cropRect()); |
| } |
| |
| void SkBlurImageFilterImpl::flatten(SkWriteBuffer& buffer) const { |
| this->INHERITED::flatten(buffer); |
| buffer.writeScalar(fSigma.fWidth); |
| buffer.writeScalar(fSigma.fHeight); |
| |
| // Fuzzer sanity checks |
| static_assert((int) SkTileMode::kLastTileMode == 3 && SkBlurImageFilter::kLast_TileMode == 2, |
| "SkBlurImageFilterImpl::flatten"); |
| SkASSERT(fTileMode <= SkTileMode::kLastTileMode); |
| buffer.writeInt(static_cast<int>(fTileMode)); |
| } |
| |
| #if SK_SUPPORT_GPU |
| static GrTextureDomain::Mode to_texture_domain_mode(SkTileMode tileMode) { |
| switch (tileMode) { |
| case SkTileMode::kClamp: |
| return GrTextureDomain::kClamp_Mode; |
| case SkTileMode::kDecal: |
| return GrTextureDomain::kDecal_Mode; |
| case SkTileMode::kMirror: |
| // TODO (michaelludwig) - Support mirror mode, treat as repeat for now |
| case SkTileMode::kRepeat: |
| return GrTextureDomain::kRepeat_Mode; |
| default: |
| SK_ABORT("Unsupported tile mode."); |
| } |
| } |
| #endif |
| |
| // 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 * SK_DoublePI) / 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> copy_image_with_bounds( |
| const SkImageFilter_Base::Context& ctx, const sk_sp<SkSpecialImage> &input, |
| SkIRect srcBounds, SkIRect dstBounds) { |
| SkBitmap inputBM; |
| if (!input->getROPixels(&inputBM)) { |
| return nullptr; |
| } |
| |
| if (inputBM.colorType() != kN32_SkColorType) { |
| return nullptr; |
| } |
| |
| 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(), |
| dstW = dstBounds.width(), |
| dstH = dstBounds.height(); |
| |
| SkImageInfo dstInfo = SkImageInfo::Make(dstW, dstH, inputBM.colorType(), inputBM.alphaType()); |
| |
| SkBitmap dst; |
| if (!dst.tryAllocPixels(dstInfo)) { |
| return nullptr; |
| } |
| |
| // 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, ctx.surfaceProps()); |
| } |
| |
| // TODO: Implement CPU backend for different fTileMode. |
| static sk_sp<SkSpecialImage> cpu_blur( |
| const SkImageFilter_Base::Context& ctx, |
| SkVector sigma, const sk_sp<SkSpecialImage> &input, |
| SkIRect srcBounds, SkIRect dstBounds) { |
| auto windowW = calculate_window(sigma.x()), |
| windowH = calculate_window(sigma.y()); |
| |
| if (windowW <= 1 && windowH <= 1) { |
| return copy_image_with_bounds(ctx, input, srcBounds, dstBounds); |
| } |
| |
| SkBitmap inputBM; |
| |
| if (!input->getROPixels(&inputBM)) { |
| return nullptr; |
| } |
| |
| if (inputBM.colorType() != kN32_SkColorType) { |
| return nullptr; |
| } |
| |
| 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 = inputBM.info().makeWH(dstW, dstH); |
| |
| 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)); |
| |
| // Basic Plan: The three cases to handle |
| // * Horizontal and Vertical - blur horizontally while copying values from the source to |
| // the destination. Then, do an in-place vertical blur. |
| // * Horizontal only - blur horizontally copying values from the source to the destination. |
| // * Vertical only - blur vertically copying values from the source to the destination. |
| |
| // Default to vertical only blur case. If a horizontal blur is needed, then these values |
| // will be adjusted while doing the horizontal blur. |
| auto intermediateSrc = static_cast<uint32_t *>(src.getPixels()); |
| auto intermediateRowBytesAsPixels = src.rowBytesAsPixels(); |
| auto intermediateWidth = srcW; |
| |
| // Because the border is calculated before the fork of the GPU/CPU path. The border is |
| // the maximum of the two rendering methods. In the case where sigma is zero, then the |
| // src and dst left values are the same. If sigma is small resulting in a window size of |
| // 1, then border calculations add some pixels which will always be zero. Inset the |
| // destination by those zero pixels. This case is very rare. |
| auto intermediateDst = dst.getAddr32(srcBounds.left(), 0); |
| |
| // The following code is executed very rarely, I have never seen it in a real web |
| // page. If sigma is small but not zero then shared GPU/CPU border calculation |
| // code adds extra pixels for the border. Just clear everything to clear those pixels. |
| // This solution is overkill, but very simple. |
| if (windowW == 1 || windowH == 1) { |
| dst.eraseColor(0); |
| } |
| |
| if (windowW > 1) { |
| // Make int64 to avoid overflow in multiplication below. |
| int64_t shift = srcBounds.top() - dstBounds.top(); |
| |
| // For the horizontal blur, starts part way down in anticipation of the vertical blur. |
| // For a vertical sigma of zero shift should be zero. But, for small sigma, |
| // shift may be > 0 but the vertical window could be 1. |
| intermediateSrc = static_cast<uint32_t *>(dst.getPixels()) |
| + (shift > 0 ? shift * dst.rowBytesAsPixels() : 0); |
| intermediateRowBytesAsPixels = dst.rowBytesAsPixels(); |
| intermediateWidth = dstW; |
| intermediateDst = static_cast<uint32_t *>(dst.getPixels()); |
| |
| blur_one_direction( |
| buffer, windowW, |
| srcBounds.left(), srcBounds.right(), dstBounds.right(), |
| static_cast<uint32_t *>(src.getPixels()), 1, src.rowBytesAsPixels(), srcH, |
| intermediateSrc, 1, intermediateRowBytesAsPixels); |
| } |
| |
| if (windowH > 1) { |
| blur_one_direction( |
| buffer, windowH, |
| srcBounds.top(), srcBounds.bottom(), dstBounds.bottom(), |
| intermediateSrc, intermediateRowBytesAsPixels, 1, intermediateWidth, |
| intermediateDst, dst.rowBytesAsPixels(), 1); |
| } |
| |
| return SkSpecialImage::MakeFromRaster(SkIRect::MakeWH(dstBounds.width(), |
| dstBounds.height()), |
| dst, ctx.surfaceProps()); |
| } |
| |
| // 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; |
| } |
| |
| sk_sp<SkSpecialImage> SkBlurImageFilterImpl::onFilterImage(const Context& ctx, |
| SkIPoint* offset) const { |
| SkIPoint inputOffset = SkIPoint::Make(0, 0); |
| |
| sk_sp<SkSpecialImage> input(this->filterInput(0, 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); |
| |
| 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 (ctx.gpuBacked()) { |
| // 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.colorType(), ctx.colorSpace()); |
| result = this->gpuFilter(ctx, sigma, input, inputBounds, dstBounds, inputOffset, |
| &resultOffset); |
| } else |
| #endif |
| { |
| // NB 135 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. The |
| // additional + 1 added to window represents adding one more leading element before subtracting the |
| // trailing element. |
| // Explanation of maximums: |
| // sum0 = (window + 1) * 255 |
| // sum1 = (window + 1) * sum0 -> (window + 1) * (window + 1) * 255 |
| // sum2 = (window + 1) * sum1 -> (window + 1) * (window + 1) * (window + 1) * 255 -> window^3 * 255 |
| // |
| // The value (window + 1)^3 * 255 must fit in a uint32_t. So, |
| // (window + 1)^3 * 255 < 2^32. window = 255. |
| // |
| // window = floor(sigma * 3 * sqrt(2 * kPi) / 4) |
| // For window <= 255, the largest value for sigma is 135. |
| sigma.fX = SkTPin(sigma.fX, 0.0f, 135.0f); |
| sigma.fY = SkTPin(sigma.fY, 0.0f, 135.0f); |
| |
| result = cpu_blur(ctx, sigma, input, inputBounds, dstBounds); |
| } |
| |
| // Return the resultOffset if the blur succeeded. |
| if (result != nullptr) { |
| *offset = resultOffset; |
| } |
| return result; |
| } |
| |
| #if SK_SUPPORT_GPU |
| sk_sp<SkSpecialImage> SkBlurImageFilterImpl::gpuFilter( |
| const Context& ctx, SkVector sigma, const sk_sp<SkSpecialImage> &input, SkIRect inputBounds, |
| SkIRect dstBounds, SkIPoint inputOffset, SkIPoint* offset) const { |
| if (0 == sigma.x() && 0 == sigma.y()) { |
| offset->fX = inputBounds.x() + inputOffset.fX; |
| offset->fY = inputBounds.y() + inputOffset.fY; |
| return input->makeSubset(inputBounds); |
| } |
| |
| auto context = ctx.getContext(); |
| |
| sk_sp<GrTextureProxy> inputTexture(input->asTextureProxyRef(context)); |
| if (!inputTexture) { |
| return nullptr; |
| } |
| |
| // TODO (michaelludwig) - The color space choice is odd, should it just be ctx.refColorSpace()? |
| auto renderTargetContext = SkGpuBlurUtils::GaussianBlur( |
| context, |
| std::move(inputTexture), |
| SkColorTypeToGrColorType(input->colorType()), |
| input->alphaType(), |
| input->subset().topLeft(), |
| ctx.colorSpace() ? sk_ref_sp(input->getColorSpace()) : nullptr, |
| 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->colorInfo().colorType(), |
| sk_ref_sp(input->getColorSpace()), |
| ctx.surfaceProps()); |
| } |
| #endif |
| |
| 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 SkIRect* inputRect) const { |
| SkVector sigma = map_sigma(fSigma, ctm); |
| return src.makeOutset(SkScalarCeilToInt(sigma.x() * 3), SkScalarCeilToInt(sigma.y() * 3)); |
| } |
