From 538e1a10b75380fe271e79a2726018f50aed24cb Mon Sep 17 00:00:00 2001 From: Mike Reed Date: Tue, 26 Jun 2018 10:37:06 -0400 Subject: move blurimagefilter.cpp back into effects Bug: skia: Change-Id: I5711a9a8fcd135344e75cb4b505bd06044414c85 Reviewed-on: https://skia-review.googlesource.com/137581 Reviewed-by: Ben Wagner Commit-Queue: Mike Reed --- src/effects/imagefilters/SkBlurImageFilter.cpp | 698 +++++++++++++++++++++++++ 1 file changed, 698 insertions(+) create mode 100644 src/effects/imagefilters/SkBlurImageFilter.cpp (limited to 'src/effects') diff --git a/src/effects/imagefilters/SkBlurImageFilter.cpp b/src/effects/imagefilters/SkBlurImageFilter.cpp new file mode 100644 index 0000000000..818644818c --- /dev/null +++ b/src/effects/imagefilters/SkBlurImageFilter.cpp @@ -0,0 +1,698 @@ +/* + * 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 + +#include "SkArenaAlloc.h" +#include "SkAutoPixmapStorage.h" +#include "SkBitmap.h" +#include "SkColorData.h" +#include "SkColorSpaceXformer.h" +#include "SkImageFilterPriv.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 + +static constexpr double kPi = 3.14159265358979323846264338327950288; + +class SkBlurImageFilterImpl final : public SkImageFilter { +public: + SkBlurImageFilterImpl(SkScalar sigmaX, + SkScalar sigmaY, + sk_sp input, + const CropRect* cropRect, + SkBlurImageFilter::TileMode tileMode); + + SkRect computeFastBounds(const SkRect&) const override; + + SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(SkBlurImageFilterImpl) + +protected: + void flatten(SkWriteBuffer&) const override; + sk_sp onFilterImage(SkSpecialImage* source, const Context&, + SkIPoint* offset) const override; + sk_sp onMakeColorSpace(SkColorSpaceXformer*) const override; + SkIRect onFilterNodeBounds(const SkIRect& src, const SkMatrix& ctm, + MapDirection, const SkIRect* inputRect) const override; + +private: + typedef SkImageFilter INHERITED; + friend class SkImageFilter; + +#if SK_SUPPORT_GPU + sk_sp gpuFilter( + SkSpecialImage *source, SkVector sigma, const sk_sp &input, + SkIRect inputBounds, SkIRect dstBounds, SkIPoint inputOffset, + const OutputProperties& outProps, SkIPoint* offset) const; +#endif + + 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 SkBlurImageFilter::Make(SkScalar sigmaX, SkScalar sigmaY, + sk_sp input, + const SkImageFilter::CropRect* cropRect, + TileMode tileMode) { + if (sigmaX < SK_ScalarNearlyZero && sigmaY < SK_ScalarNearlyZero && !cropRect) { + return input; + } + return sk_sp( + 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 input, + const CropRect* cropRect, + SkBlurImageFilter::TileMode tileMode) + : INHERITED(&input, 1, cropRect), fSigma{sigmaX, sigmaY}, fTileMode(tileMode) {} + +sk_sp 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 = buffer.read32LE(SkBlurImageFilter::kLast_TileMode); + } + + static_assert(SkBlurImageFilter::kLast_TileMode == 2, "CreateProc"); + + 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::kLast_TileMode == 2, "flatten"); + SkASSERT(fTileMode <= SkBlurImageFilter::kLast_TileMode); + + buffer.writeInt(static_cast(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 + +// 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(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(round(1.0 / divisor * (1ull << 32))); + auto half = static_cast((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(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(Sk4b::Load(srcCursor)); + SkNx_cast(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(processValue(0u)).store(dstCursor); + dstCursor += dstXStride; + SK_PREFETCH(dstCursor); + dstIdx++; + } + + src += srcYStride; + dst += dstYStride; + } +} + +static sk_sp copy_image_with_bounds( + SkSpecialImage *source, const sk_sp &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, &source->props()); +} + +// TODO: Implement CPU backend for different fTileMode. +static sk_sp cpu_blur( + SkVector sigma, + SkSpecialImage *source, const sk_sp &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(source, 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 = 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(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(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(dst.getPixels()) + + (shift > 0 ? shift * dst.rowBytesAsPixels() : 0); + intermediateRowBytesAsPixels = dst.rowBytesAsPixels(); + intermediateWidth = dstW; + intermediateDst = static_cast(dst.getPixels()); + + blur_one_direction( + buffer, windowW, + srcBounds.left(), srcBounds.right(), dstBounds.right(), + static_cast(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, &source->props()); +} + +sk_sp SkBlurImageFilterImpl::onFilterImage(SkSpecialImage* source, + const Context& ctx, + SkIPoint* offset) const { + SkIPoint inputOffset = SkIPoint::Make(0, 0); + + sk_sp 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 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, inputOffset, + ctx.outputProperties(), &resultOffset); + } else +#endif + { + result = cpu_blur(sigma, source, input, inputBounds, dstBounds); + } + + // Return the resultOffset if the blur succeeded. + if (result != nullptr) { + *offset = resultOffset; + } + return result; +} + +#if SK_SUPPORT_GPU +sk_sp SkBlurImageFilterImpl::gpuFilter( + SkSpecialImage *source, SkVector sigma, const sk_sp &input, + SkIRect inputBounds, SkIRect dstBounds, SkIPoint inputOffset, + const OutputProperties& outProps, 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); + } + + GrContext* context = source->getContext(); + + sk_sp 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. + // ... + // Unless the output is legacy. In that case, the input could be almost anything (if we're + // using SkColorSpaceXformCanvas), but we can't make a corresponding RTC. We don't care to, + // either, we want to do our blending (and blurring) without any color correction, so pass + // nullptr here, causing us to operate entirely in the input's color space, with no decoding. + // Then, when we create the output image later, we tag it with the input's color space, so + // it will be tagged correctly, regardless of how we created the intermediate RTCs. + sk_sp renderTargetContext(SkGpuBlurUtils::GaussianBlur( + context, + std::move(inputTexture), + outProps.colorSpace() ? sk_ref_sp(input->getColorSpace()) : nullptr, + dstBounds, + inputBounds, + sigma.x(), + sigma.y(), + to_texture_domain_mode(fTileMode), + input->alphaType())); + if (!renderTargetContext) { + return nullptr; + } + + return SkSpecialImage::MakeDeferredFromGpu( + context, + SkIRect::MakeWH(dstBounds.width(), dstBounds.height()), + kNeedNewImageUniqueID_SpecialImage, + renderTargetContext->asTextureProxyRef(), + sk_ref_sp(input->getColorSpace()), + &source->props()); +} +#endif + +sk_sp 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 SkIRect* inputRect) const { + SkVector sigma = map_sigma(fSigma, ctm); + return src.makeOutset(SkScalarCeilToInt(sigma.x() * 3), SkScalarCeilToInt(sigma.y() * 3)); +} -- cgit v1.2.3