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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-21 11:44:51 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-21 11:44:51 +0000 |
commit | 9e3c08db40b8916968b9f30096c7be3f00ce9647 (patch) | |
tree | a68f146d7fa01f0134297619fbe7e33db084e0aa /gfx/2d/Blur.cpp | |
parent | Initial commit. (diff) | |
download | thunderbird-9e3c08db40b8916968b9f30096c7be3f00ce9647.tar.xz thunderbird-9e3c08db40b8916968b9f30096c7be3f00ce9647.zip |
Adding upstream version 1:115.7.0.upstream/1%115.7.0upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'gfx/2d/Blur.cpp')
-rw-r--r-- | gfx/2d/Blur.cpp | 904 |
1 files changed, 904 insertions, 0 deletions
diff --git a/gfx/2d/Blur.cpp b/gfx/2d/Blur.cpp new file mode 100644 index 0000000000..5de04f7174 --- /dev/null +++ b/gfx/2d/Blur.cpp @@ -0,0 +1,904 @@ +/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ +/* vim: set ts=8 sts=2 et sw=2 tw=80: */ +/* This Source Code Form is subject to the terms of the Mozilla Public + * License, v. 2.0. If a copy of the MPL was not distributed with this + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ + +#include "Blur.h" + +#include <algorithm> +#include <math.h> +#include <string.h> + +#include "mozilla/CheckedInt.h" +#include "NumericTools.h" + +#include "2D.h" +#include "DataSurfaceHelpers.h" +#include "Tools.h" + +#ifdef USE_NEON +# include "mozilla/arm.h" +#endif + +namespace mozilla { +namespace gfx { + +/** + * Helper function to process each row of the box blur. + * It takes care of transposing the data on input or output depending + * on whether we intend a horizontal or vertical blur, and whether we're + * reading from the initial source or writing to the final destination. + * It allows starting or ending anywhere within the row to accomodate + * a skip rect. + */ +template <bool aTransposeInput, bool aTransposeOutput> +static inline void BoxBlurRow(const uint8_t* aInput, uint8_t* aOutput, + int32_t aLeftLobe, int32_t aRightLobe, + int32_t aWidth, int32_t aStride, int32_t aStart, + int32_t aEnd) { + // If the input or output is transposed, then we will move down a row + // for each step, instead of moving over a column. Since these values + // only depend on a template parameter, they will more easily get + // copy-propagated in the non-transposed case, which is why they + // are not passed as parameters. + const int32_t inputStep = aTransposeInput ? aStride : 1; + const int32_t outputStep = aTransposeOutput ? aStride : 1; + + // We need to sample aLeftLobe pixels to the left and aRightLobe pixels + // to the right of the current position, then average them. So this is + // the size of the total width of this filter. + const int32_t boxSize = aLeftLobe + aRightLobe + 1; + + // Instead of dividing the pixel sum by boxSize to average, we can just + // compute a scale that will normalize the result so that it can be quickly + // shifted into the desired range. + const uint32_t reciprocal = (1 << 24) / boxSize; + + // The shift would normally truncate the result, whereas we would rather + // prefer to round the result to the closest increment. By adding 0.5 units + // to the initial sum, we bias the sum so that it will be rounded by the + // truncation instead. + uint32_t alphaSum = (boxSize + 1) / 2; + + // We process the row with a moving filter, keeping a sum (alphaSum) of + // boxSize pixels. As we move over a pixel, we need to add on a pixel + // from the right extreme of the window that moved into range, and subtract + // off a pixel from the left extreme of window that moved out of range. + // But first, we need to initialization alphaSum to the contents of + // the window before we can get going. If the window moves out of bounds + // of the row, we clamp each sample to be the closest pixel from within + // row bounds, so the 0th and aWidth-1th pixel. + int32_t initLeft = aStart - aLeftLobe; + if (initLeft < 0) { + // If the left lobe samples before the row, add in clamped samples. + alphaSum += -initLeft * aInput[0]; + initLeft = 0; + } + int32_t initRight = aStart + boxSize - aLeftLobe; + if (initRight > aWidth) { + // If the right lobe samples after the row, add in clamped samples. + alphaSum += (initRight - aWidth) * aInput[(aWidth - 1) * inputStep]; + initRight = aWidth; + } + // Finally, add in all the valid, non-clamped samples to fill up the + // rest of the window. + const uint8_t* src = &aInput[initLeft * inputStep]; + const uint8_t* iterEnd = &aInput[initRight * inputStep]; + +#define INIT_ITER \ + alphaSum += *src; \ + src += inputStep; + + // We unroll the per-pixel loop here substantially. The amount of work + // done per sample is so small that the cost of a loop condition check + // and a branch can substantially add to or even dominate the performance + // of the loop. + while (src + 16 * inputStep <= iterEnd) { + INIT_ITER; + INIT_ITER; + INIT_ITER; + INIT_ITER; + INIT_ITER; + INIT_ITER; + INIT_ITER; + INIT_ITER; + INIT_ITER; + INIT_ITER; + INIT_ITER; + INIT_ITER; + INIT_ITER; + INIT_ITER; + INIT_ITER; + INIT_ITER; + } + while (src < iterEnd) { + INIT_ITER; + } + + // Now we start moving the window over the row. We will be accessing + // pixels form aStart - aLeftLobe up to aEnd + aRightLobe, which may be + // out of bounds of the row. To avoid having to check within the inner + // loops if we are in bound, we instead compute the points at which + // we will move out of bounds of the row on the left side (splitLeft) + // and right side (splitRight). + int32_t splitLeft = std::min(std::max(aLeftLobe, aStart), aEnd); + int32_t splitRight = + std::min(std::max(aWidth - (boxSize - aLeftLobe), aStart), aEnd); + // If the filter window is actually large than the size of the row, + // there will be a middle area of overlap where the leftmost and rightmost + // pixel of the filter will both be outside the row. In this case, we need + // to invert the splits so that splitLeft <= splitRight. + if (boxSize > aWidth) { + std::swap(splitLeft, splitRight); + } + + // Process all pixels up to splitLeft that would sample before the start of + // the row. Note that because inputStep and outputStep may not be a const 1 + // value, it is more performant to increment pointers here for the source and + // destination rather than use a loop counter, since doing so would entail an + // expensive multiplication that significantly slows down the loop. + uint8_t* dst = &aOutput[aStart * outputStep]; + iterEnd = &aOutput[splitLeft * outputStep]; + src = &aInput[(aStart + boxSize - aLeftLobe) * inputStep]; + uint8_t firstVal = aInput[0]; + +#define LEFT_ITER \ + *dst = (alphaSum * reciprocal) >> 24; \ + alphaSum += *src - firstVal; \ + dst += outputStep; \ + src += inputStep; + + while (dst + 16 * outputStep <= iterEnd) { + LEFT_ITER; + LEFT_ITER; + LEFT_ITER; + LEFT_ITER; + LEFT_ITER; + LEFT_ITER; + LEFT_ITER; + LEFT_ITER; + LEFT_ITER; + LEFT_ITER; + LEFT_ITER; + LEFT_ITER; + LEFT_ITER; + LEFT_ITER; + LEFT_ITER; + LEFT_ITER; + } + while (dst < iterEnd) { + LEFT_ITER; + } + + // Process all pixels between splitLeft and splitRight. + iterEnd = &aOutput[splitRight * outputStep]; + if (boxSize <= aWidth) { + // The filter window is smaller than the row size, so the leftmost and + // rightmost samples are both within row bounds. + src = &aInput[(splitLeft - aLeftLobe) * inputStep]; + int32_t boxStep = boxSize * inputStep; + +#define CENTER_ITER \ + *dst = (alphaSum * reciprocal) >> 24; \ + alphaSum += src[boxStep] - *src; \ + dst += outputStep; \ + src += inputStep; + + while (dst + 16 * outputStep <= iterEnd) { + CENTER_ITER; + CENTER_ITER; + CENTER_ITER; + CENTER_ITER; + CENTER_ITER; + CENTER_ITER; + CENTER_ITER; + CENTER_ITER; + CENTER_ITER; + CENTER_ITER; + CENTER_ITER; + CENTER_ITER; + CENTER_ITER; + CENTER_ITER; + CENTER_ITER; + CENTER_ITER; + } + while (dst < iterEnd) { + CENTER_ITER; + } + } else { + // The filter window is larger than the row size, and we're in the area of + // split overlap. So the leftmost and rightmost samples are both out of + // bounds and need to be clamped. We can just precompute the difference here + // consequently. + int32_t firstLastDiff = aInput[(aWidth - 1) * inputStep] - aInput[0]; + while (dst < iterEnd) { + *dst = (alphaSum * reciprocal) >> 24; + alphaSum += firstLastDiff; + dst += outputStep; + } + } + + // Process all remaining pixels after splitRight that would sample after the + // row end. + iterEnd = &aOutput[aEnd * outputStep]; + src = &aInput[(splitRight - aLeftLobe) * inputStep]; + uint8_t lastVal = aInput[(aWidth - 1) * inputStep]; + +#define RIGHT_ITER \ + *dst = (alphaSum * reciprocal) >> 24; \ + alphaSum += lastVal - *src; \ + dst += outputStep; \ + src += inputStep; + + while (dst + 16 * outputStep <= iterEnd) { + RIGHT_ITER; + RIGHT_ITER; + RIGHT_ITER; + RIGHT_ITER; + RIGHT_ITER; + RIGHT_ITER; + RIGHT_ITER; + RIGHT_ITER; + RIGHT_ITER; + RIGHT_ITER; + RIGHT_ITER; + RIGHT_ITER; + RIGHT_ITER; + RIGHT_ITER; + RIGHT_ITER; + RIGHT_ITER; + } + while (dst < iterEnd) { + RIGHT_ITER; + } +} + +/** + * Box blur involves looking at one pixel, and setting its value to the average + * of its neighbouring pixels. This is meant to provide a 3-pass approximation + * of a Gaussian blur. + * @param aTranspose Whether to transpose the buffer when reading and writing + * to it. + * @param aData The buffer to be blurred. + * @param aLobes The number of pixels to blend on the left and right for each of + * 3 passes. + * @param aWidth The number of columns in the buffers. + * @param aRows The number of rows in the buffers. + * @param aStride The stride of the buffer. + */ +template <bool aTranspose> +static void BoxBlur(uint8_t* aData, const int32_t aLobes[3][2], int32_t aWidth, + int32_t aRows, int32_t aStride, IntRect aSkipRect) { + if (aTranspose) { + std::swap(aWidth, aRows); + aSkipRect.Swap(); + } + + MOZ_ASSERT(aWidth > 0); + + // All three passes of the box blur that approximate the Gaussian are done + // on each row in turn, so we only need two temporary row buffers to process + // each row, instead of a full-sized buffer. Data moves from the source to the + // first temporary, from the first temporary to the second, then from the + // second back to the destination. This way is more cache-friendly than + // processing whe whole buffer in each pass and thus yields a nice speedup. + uint8_t* tmpRow = new (std::nothrow) uint8_t[2 * aWidth]; + if (!tmpRow) { + return; + } + uint8_t* tmpRow2 = tmpRow + aWidth; + + const int32_t stride = aTranspose ? 1 : aStride; + bool skipRectCoversWholeRow = + 0 >= aSkipRect.X() && aWidth <= aSkipRect.XMost(); + + for (int32_t y = 0; y < aRows; y++) { + // Check whether the skip rect intersects this row. If the skip + // rect covers the whole surface in this row, we can avoid + // this row entirely (and any others along the skip rect). + bool inSkipRectY = aSkipRect.ContainsY(y); + if (inSkipRectY && skipRectCoversWholeRow) { + aData += stride * (aSkipRect.YMost() - y); + y = aSkipRect.YMost() - 1; + continue; + } + + // Read in data from the source transposed if necessary. + BoxBlurRow<aTranspose, false>(aData, tmpRow, aLobes[0][0], aLobes[0][1], + aWidth, aStride, 0, aWidth); + + // For the middle pass, the data is already pre-transposed and does not need + // to be post-transposed yet. + BoxBlurRow<false, false>(tmpRow, tmpRow2, aLobes[1][0], aLobes[1][1], + aWidth, aStride, 0, aWidth); + + // Write back data to the destination transposed if necessary too. + // Make sure not to overwrite the skip rect by only outputting to the + // destination before and after the skip rect, if requested. + int32_t skipStart = + inSkipRectY ? std::min(std::max(aSkipRect.X(), 0), aWidth) : aWidth; + int32_t skipEnd = std::max(skipStart, aSkipRect.XMost()); + if (skipStart > 0) { + BoxBlurRow<false, aTranspose>(tmpRow2, aData, aLobes[2][0], aLobes[2][1], + aWidth, aStride, 0, skipStart); + } + if (skipEnd < aWidth) { + BoxBlurRow<false, aTranspose>(tmpRow2, aData, aLobes[2][0], aLobes[2][1], + aWidth, aStride, skipEnd, aWidth); + } + + aData += stride; + } + + delete[] tmpRow; +} + +static void ComputeLobes(int32_t aRadius, int32_t aLobes[3][2]) { + int32_t major, minor, final; + + /* See http://www.w3.org/TR/SVG/filters.html#feGaussianBlur for + * some notes about approximating the Gaussian blur with box-blurs. + * The comments below are in the terminology of that page. + */ + int32_t z = aRadius / 3; + switch (aRadius % 3) { + case 0: + // aRadius = z*3; choose d = 2*z + 1 + major = minor = final = z; + break; + case 1: + // aRadius = z*3 + 1 + // This is a tricky case since there is no value of d which will + // yield a radius of exactly aRadius. If d is odd, i.e. d=2*k + 1 + // for some integer k, then the radius will be 3*k. If d is even, + // i.e. d=2*k, then the radius will be 3*k - 1. + // So we have to choose values that don't match the standard + // algorithm. + major = z + 1; + minor = final = z; + break; + case 2: + // aRadius = z*3 + 2; choose d = 2*z + 2 + major = final = z + 1; + minor = z; + break; + default: + // Mathematical impossibility! + MOZ_ASSERT(false); + major = minor = final = 0; + } + MOZ_ASSERT(major + minor + final == aRadius); + + aLobes[0][0] = major; + aLobes[0][1] = minor; + aLobes[1][0] = minor; + aLobes[1][1] = major; + aLobes[2][0] = final; + aLobes[2][1] = final; +} + +static void SpreadHorizontal(uint8_t* aInput, uint8_t* aOutput, int32_t aRadius, + int32_t aWidth, int32_t aRows, int32_t aStride, + const IntRect& aSkipRect) { + if (aRadius == 0) { + memcpy(aOutput, aInput, aStride * aRows); + return; + } + + bool skipRectCoversWholeRow = + 0 >= aSkipRect.X() && aWidth <= aSkipRect.XMost(); + for (int32_t y = 0; y < aRows; y++) { + // Check whether the skip rect intersects this row. If the skip + // rect covers the whole surface in this row, we can avoid + // this row entirely (and any others along the skip rect). + bool inSkipRectY = aSkipRect.ContainsY(y); + if (inSkipRectY && skipRectCoversWholeRow) { + y = aSkipRect.YMost() - 1; + continue; + } + + for (int32_t x = 0; x < aWidth; x++) { + // Check whether we are within the skip rect. If so, go + // to the next point outside the skip rect. + if (inSkipRectY && aSkipRect.ContainsX(x)) { + x = aSkipRect.XMost(); + if (x >= aWidth) break; + } + + int32_t sMin = std::max(x - aRadius, 0); + int32_t sMax = std::min(x + aRadius, aWidth - 1); + int32_t v = 0; + for (int32_t s = sMin; s <= sMax; ++s) { + v = std::max<int32_t>(v, aInput[aStride * y + s]); + } + aOutput[aStride * y + x] = v; + } + } +} + +static void SpreadVertical(uint8_t* aInput, uint8_t* aOutput, int32_t aRadius, + int32_t aWidth, int32_t aRows, int32_t aStride, + const IntRect& aSkipRect) { + if (aRadius == 0) { + memcpy(aOutput, aInput, aStride * aRows); + return; + } + + bool skipRectCoversWholeColumn = + 0 >= aSkipRect.Y() && aRows <= aSkipRect.YMost(); + for (int32_t x = 0; x < aWidth; x++) { + bool inSkipRectX = aSkipRect.ContainsX(x); + if (inSkipRectX && skipRectCoversWholeColumn) { + x = aSkipRect.XMost() - 1; + continue; + } + + for (int32_t y = 0; y < aRows; y++) { + // Check whether we are within the skip rect. If so, go + // to the next point outside the skip rect. + if (inSkipRectX && aSkipRect.ContainsY(y)) { + y = aSkipRect.YMost(); + if (y >= aRows) break; + } + + int32_t sMin = std::max(y - aRadius, 0); + int32_t sMax = std::min(y + aRadius, aRows - 1); + int32_t v = 0; + for (int32_t s = sMin; s <= sMax; ++s) { + v = std::max<int32_t>(v, aInput[aStride * s + x]); + } + aOutput[aStride * y + x] = v; + } + } +} + +CheckedInt<int32_t> AlphaBoxBlur::RoundUpToMultipleOf4(int32_t aVal) { + CheckedInt<int32_t> val(aVal); + + val += 3; + val /= 4; + val *= 4; + + return val; +} + +AlphaBoxBlur::AlphaBoxBlur(const Rect& aRect, const IntSize& aSpreadRadius, + const IntSize& aBlurRadius, const Rect* aDirtyRect, + const Rect* aSkipRect) + : mStride(0), mSurfaceAllocationSize(0) { + Init(aRect, aSpreadRadius, aBlurRadius, aDirtyRect, aSkipRect); +} + +AlphaBoxBlur::AlphaBoxBlur() + : mStride(0), mSurfaceAllocationSize(0), mHasDirtyRect(false) {} + +void AlphaBoxBlur::Init(const Rect& aRect, const IntSize& aSpreadRadius, + const IntSize& aBlurRadius, const Rect* aDirtyRect, + const Rect* aSkipRect) { + mSpreadRadius = aSpreadRadius; + mBlurRadius = aBlurRadius; + + Rect rect(aRect); + rect.Inflate(Size(aBlurRadius + aSpreadRadius)); + rect.RoundOut(); + + if (aDirtyRect) { + // If we get passed a dirty rect from layout, we can minimize the + // shadow size and make painting faster. + mHasDirtyRect = true; + mDirtyRect = *aDirtyRect; + Rect requiredBlurArea = mDirtyRect.Intersect(rect); + requiredBlurArea.Inflate(Size(aBlurRadius + aSpreadRadius)); + rect = requiredBlurArea.Intersect(rect); + } else { + mHasDirtyRect = false; + } + + mRect = TruncatedToInt(rect); + if (mRect.IsEmpty()) { + return; + } + + if (aSkipRect) { + // If we get passed a skip rect, we can lower the amount of + // blurring/spreading we need to do. We convert it to IntRect to avoid + // expensive int<->float conversions if we were to use Rect instead. + Rect skipRect = *aSkipRect; + skipRect.Deflate(Size(aBlurRadius + aSpreadRadius)); + mSkipRect = RoundedIn(skipRect); + mSkipRect = mSkipRect.Intersect(mRect); + if (mSkipRect.IsEqualInterior(mRect)) { + return; + } + + mSkipRect -= mRect.TopLeft(); + // Ensure the skip rect is 4-pixel-aligned in the x axis, so that all our + // accesses later are aligned as well, see bug 1622113. + mSkipRect.SetLeftEdge(RoundUpToMultiple(mSkipRect.X(), 4)); + mSkipRect.SetRightEdge(RoundDownToMultiple(mSkipRect.XMost(), 4)); + if (mSkipRect.IsEmpty()) { + mSkipRect = IntRect(); + } + } else { + mSkipRect = IntRect(); + } + + CheckedInt<int32_t> stride = RoundUpToMultipleOf4(mRect.Width()); + if (stride.isValid()) { + mStride = stride.value(); + + // We need to leave room for an additional 3 bytes for a potential overrun + // in our blurring code. + size_t size = BufferSizeFromStrideAndHeight(mStride, mRect.Height(), 3); + if (size != 0) { + mSurfaceAllocationSize = size; + } + } +} + +AlphaBoxBlur::AlphaBoxBlur(const Rect& aRect, int32_t aStride, float aSigmaX, + float aSigmaY) + : mRect(TruncatedToInt(aRect)), + mSpreadRadius(), + mBlurRadius(CalculateBlurRadius(Point(aSigmaX, aSigmaY))), + mStride(aStride), + mSurfaceAllocationSize(0), + mHasDirtyRect(false) { + IntRect intRect; + if (aRect.ToIntRect(&intRect)) { + size_t minDataSize = + BufferSizeFromStrideAndHeight(intRect.Width(), intRect.Height()); + if (minDataSize != 0) { + mSurfaceAllocationSize = minDataSize; + } + } +} + +AlphaBoxBlur::~AlphaBoxBlur() = default; + +IntSize AlphaBoxBlur::GetSize() const { + IntSize size(mRect.Width(), mRect.Height()); + return size; +} + +int32_t AlphaBoxBlur::GetStride() const { return mStride; } + +IntRect AlphaBoxBlur::GetRect() const { return mRect; } + +Rect* AlphaBoxBlur::GetDirtyRect() { + if (mHasDirtyRect) { + return &mDirtyRect; + } + + return nullptr; +} + +size_t AlphaBoxBlur::GetSurfaceAllocationSize() const { + return mSurfaceAllocationSize; +} + +void AlphaBoxBlur::Blur(uint8_t* aData) const { + if (!aData) { + return; + } + + // no need to do all this if not blurring or spreading + if (mBlurRadius != IntSize(0, 0) || mSpreadRadius != IntSize(0, 0)) { + int32_t stride = GetStride(); + + IntSize size = GetSize(); + + if (mSpreadRadius.width > 0 || mSpreadRadius.height > 0) { + // No need to use CheckedInt here - we have validated it in the + // constructor. + size_t szB = stride * size.height; + uint8_t* tmpData = new (std::nothrow) uint8_t[szB]; + + if (!tmpData) { + return; + } + + memset(tmpData, 0, szB); + + SpreadHorizontal(aData, tmpData, mSpreadRadius.width, size.width, + size.height, stride, mSkipRect); + SpreadVertical(tmpData, aData, mSpreadRadius.height, size.width, + size.height, stride, mSkipRect); + + delete[] tmpData; + } + + int32_t horizontalLobes[3][2]; + ComputeLobes(mBlurRadius.width, horizontalLobes); + int32_t verticalLobes[3][2]; + ComputeLobes(mBlurRadius.height, verticalLobes); + + // We want to allow for some extra space on the left for alignment reasons. + int32_t maxLeftLobe = + RoundUpToMultipleOf4(horizontalLobes[0][0] + 1).value(); + + IntSize integralImageSize( + size.width + maxLeftLobe + horizontalLobes[1][1], + size.height + verticalLobes[0][0] + verticalLobes[1][1] + 1); + + if ((integralImageSize.width * integralImageSize.height) > (1 << 24)) { + // Fallback to old blurring code when the surface is so large it may + // overflow our integral image! + if (mBlurRadius.width > 0) { + BoxBlur<false>(aData, horizontalLobes, size.width, size.height, stride, + mSkipRect); + } + if (mBlurRadius.height > 0) { + BoxBlur<true>(aData, verticalLobes, size.width, size.height, stride, + mSkipRect); + } + } else { + size_t integralImageStride = + GetAlignedStride<16>(integralImageSize.width, 4); + if (integralImageStride == 0) { + return; + } + + // We need to leave room for an additional 12 bytes for a maximum overrun + // of 3 pixels in the blurring code. + size_t bufLen = BufferSizeFromStrideAndHeight( + integralImageStride, integralImageSize.height, 12); + if (bufLen == 0) { + return; + } + // bufLen is a byte count, but here we want a multiple of 32-bit ints, so + // we divide by 4. + AlignedArray<uint32_t> integralImage((bufLen / 4) + + ((bufLen % 4) ? 1 : 0)); + + if (!integralImage) { + return; + } + +#ifdef USE_SSE2 + if (Factory::HasSSE2()) { + BoxBlur_SSE2(aData, horizontalLobes[0][0], horizontalLobes[0][1], + verticalLobes[0][0], verticalLobes[0][1], integralImage, + integralImageStride); + BoxBlur_SSE2(aData, horizontalLobes[1][0], horizontalLobes[1][1], + verticalLobes[1][0], verticalLobes[1][1], integralImage, + integralImageStride); + BoxBlur_SSE2(aData, horizontalLobes[2][0], horizontalLobes[2][1], + verticalLobes[2][0], verticalLobes[2][1], integralImage, + integralImageStride); + } else +#endif +#ifdef USE_NEON + if (mozilla::supports_neon()) { + BoxBlur_NEON(aData, horizontalLobes[0][0], horizontalLobes[0][1], + verticalLobes[0][0], verticalLobes[0][1], integralImage, + integralImageStride); + BoxBlur_NEON(aData, horizontalLobes[1][0], horizontalLobes[1][1], + verticalLobes[1][0], verticalLobes[1][1], integralImage, + integralImageStride); + BoxBlur_NEON(aData, horizontalLobes[2][0], horizontalLobes[2][1], + verticalLobes[2][0], verticalLobes[2][1], integralImage, + integralImageStride); + } else +#endif + { +#ifdef _MIPS_ARCH_LOONGSON3A + BoxBlur_LS3(aData, horizontalLobes[0][0], horizontalLobes[0][1], + verticalLobes[0][0], verticalLobes[0][1], integralImage, + integralImageStride); + BoxBlur_LS3(aData, horizontalLobes[1][0], horizontalLobes[1][1], + verticalLobes[1][0], verticalLobes[1][1], integralImage, + integralImageStride); + BoxBlur_LS3(aData, horizontalLobes[2][0], horizontalLobes[2][1], + verticalLobes[2][0], verticalLobes[2][1], integralImage, + integralImageStride); +#else + BoxBlur_C(aData, horizontalLobes[0][0], horizontalLobes[0][1], + verticalLobes[0][0], verticalLobes[0][1], integralImage, + integralImageStride); + BoxBlur_C(aData, horizontalLobes[1][0], horizontalLobes[1][1], + verticalLobes[1][0], verticalLobes[1][1], integralImage, + integralImageStride); + BoxBlur_C(aData, horizontalLobes[2][0], horizontalLobes[2][1], + verticalLobes[2][0], verticalLobes[2][1], integralImage, + integralImageStride); +#endif + } + } + } +} + +MOZ_ALWAYS_INLINE void GenerateIntegralRow(uint32_t* aDest, + const uint8_t* aSource, + uint32_t* aPreviousRow, + const uint32_t& aSourceWidth, + const uint32_t& aLeftInflation, + const uint32_t& aRightInflation) { + uint32_t currentRowSum = 0; + uint32_t pixel = aSource[0]; + for (uint32_t x = 0; x < aLeftInflation; x++) { + currentRowSum += pixel; + *aDest++ = currentRowSum + *aPreviousRow++; + } + for (uint32_t x = aLeftInflation; x < (aSourceWidth + aLeftInflation); + x += 4) { + uint32_t alphaValues = *(uint32_t*)(aSource + (x - aLeftInflation)); +#if defined WORDS_BIGENDIAN || defined IS_BIG_ENDIAN || defined __BIG_ENDIAN__ + currentRowSum += (alphaValues >> 24) & 0xff; + *aDest++ = *aPreviousRow++ + currentRowSum; + currentRowSum += (alphaValues >> 16) & 0xff; + *aDest++ = *aPreviousRow++ + currentRowSum; + currentRowSum += (alphaValues >> 8) & 0xff; + *aDest++ = *aPreviousRow++ + currentRowSum; + currentRowSum += alphaValues & 0xff; + *aDest++ = *aPreviousRow++ + currentRowSum; +#else + currentRowSum += alphaValues & 0xff; + *aDest++ = *aPreviousRow++ + currentRowSum; + alphaValues >>= 8; + currentRowSum += alphaValues & 0xff; + *aDest++ = *aPreviousRow++ + currentRowSum; + alphaValues >>= 8; + currentRowSum += alphaValues & 0xff; + *aDest++ = *aPreviousRow++ + currentRowSum; + alphaValues >>= 8; + currentRowSum += alphaValues & 0xff; + *aDest++ = *aPreviousRow++ + currentRowSum; +#endif + } + pixel = aSource[aSourceWidth - 1]; + for (uint32_t x = (aSourceWidth + aLeftInflation); + x < (aSourceWidth + aLeftInflation + aRightInflation); x++) { + currentRowSum += pixel; + *aDest++ = currentRowSum + *aPreviousRow++; + } +} + +MOZ_ALWAYS_INLINE void GenerateIntegralImage_C( + int32_t aLeftInflation, int32_t aRightInflation, int32_t aTopInflation, + int32_t aBottomInflation, uint32_t* aIntegralImage, + size_t aIntegralImageStride, uint8_t* aSource, int32_t aSourceStride, + const IntSize& aSize) { + uint32_t stride32bit = aIntegralImageStride / 4; + + IntSize integralImageSize(aSize.width + aLeftInflation + aRightInflation, + aSize.height + aTopInflation + aBottomInflation); + + memset(aIntegralImage, 0, aIntegralImageStride); + + GenerateIntegralRow(aIntegralImage, aSource, aIntegralImage, aSize.width, + aLeftInflation, aRightInflation); + for (int y = 1; y < aTopInflation + 1; y++) { + GenerateIntegralRow(aIntegralImage + (y * stride32bit), aSource, + aIntegralImage + (y - 1) * stride32bit, aSize.width, + aLeftInflation, aRightInflation); + } + + for (int y = aTopInflation + 1; y < (aSize.height + aTopInflation); y++) { + GenerateIntegralRow(aIntegralImage + (y * stride32bit), + aSource + aSourceStride * (y - aTopInflation), + aIntegralImage + (y - 1) * stride32bit, aSize.width, + aLeftInflation, aRightInflation); + } + + if (aBottomInflation) { + for (int y = (aSize.height + aTopInflation); y < integralImageSize.height; + y++) { + GenerateIntegralRow(aIntegralImage + (y * stride32bit), + aSource + ((aSize.height - 1) * aSourceStride), + aIntegralImage + (y - 1) * stride32bit, aSize.width, + aLeftInflation, aRightInflation); + } + } +} + +/** + * Attempt to do an in-place box blur using an integral image. + */ +void AlphaBoxBlur::BoxBlur_C(uint8_t* aData, int32_t aLeftLobe, + int32_t aRightLobe, int32_t aTopLobe, + int32_t aBottomLobe, uint32_t* aIntegralImage, + size_t aIntegralImageStride) const { + IntSize size = GetSize(); + + MOZ_ASSERT(size.width > 0); + + // Our 'left' or 'top' lobe will include the current pixel. i.e. when + // looking at an integral image the value of a pixel at 'x,y' is calculated + // using the value of the integral image values above/below that. + aLeftLobe++; + aTopLobe++; + int32_t boxSize = (aLeftLobe + aRightLobe) * (aTopLobe + aBottomLobe); + + MOZ_ASSERT(boxSize > 0); + + if (boxSize == 1) { + return; + } + + int32_t stride32bit = aIntegralImageStride / 4; + + int32_t leftInflation = RoundUpToMultipleOf4(aLeftLobe).value(); + + GenerateIntegralImage_C(leftInflation, aRightLobe, aTopLobe, aBottomLobe, + aIntegralImage, aIntegralImageStride, aData, mStride, + size); + + uint32_t reciprocal = uint32_t((uint64_t(1) << 32) / boxSize); + + uint32_t* innerIntegral = + aIntegralImage + (aTopLobe * stride32bit) + leftInflation; + + // Storing these locally makes this about 30% faster! Presumably the compiler + // can't be sure we're not altering the member variables in this loop. + IntRect skipRect = mSkipRect; + uint8_t* data = aData; + int32_t stride = mStride; + for (int32_t y = 0; y < size.height; y++) { + // Not using ContainsY(y) because we do not skip y == skipRect.Y() + // although that may not be done on purpose + bool inSkipRectY = y > skipRect.Y() && y < skipRect.YMost(); + + uint32_t* topLeftBase = + innerIntegral + ((y - aTopLobe) * stride32bit - aLeftLobe); + uint32_t* topRightBase = + innerIntegral + ((y - aTopLobe) * stride32bit + aRightLobe); + uint32_t* bottomRightBase = + innerIntegral + ((y + aBottomLobe) * stride32bit + aRightLobe); + uint32_t* bottomLeftBase = + innerIntegral + ((y + aBottomLobe) * stride32bit - aLeftLobe); + + for (int32_t x = 0; x < size.width; x++) { + // Not using ContainsX(x) because we do not skip x == skipRect.X() + // although that may not be done on purpose + if (inSkipRectY && x > skipRect.X() && x < skipRect.XMost()) { + x = skipRect.XMost() - 1; + // Trigger early jump on coming loop iterations, this will be reset + // next line anyway. + inSkipRectY = false; + continue; + } + int32_t topLeft = topLeftBase[x]; + int32_t topRight = topRightBase[x]; + int32_t bottomRight = bottomRightBase[x]; + int32_t bottomLeft = bottomLeftBase[x]; + + uint32_t value = bottomRight - topRight - bottomLeft; + value += topLeft; + + data[stride * y + x] = + (uint64_t(reciprocal) * value + (uint64_t(1) << 31)) >> 32; + } + } +} + +/** + * Compute the box blur size (which we're calling the blur radius) from + * the standard deviation. + * + * Much of this, the 3 * sqrt(2 * pi) / 4, is the known value for + * approximating a Gaussian using box blurs. This yields quite a good + * approximation for a Gaussian. Then we multiply this by 1.5 since our + * code wants the radius of the entire triple-box-blur kernel instead of + * the diameter of an individual box blur. For more details, see: + * http://www.w3.org/TR/SVG11/filters.html#feGaussianBlurElement + * https://bugzilla.mozilla.org/show_bug.cgi?id=590039#c19 + */ +static const Float GAUSSIAN_SCALE_FACTOR = + Float((3 * sqrt(2 * M_PI) / 4) * 1.5); + +IntSize AlphaBoxBlur::CalculateBlurRadius(const Point& aStd) { + IntSize size( + static_cast<int32_t>(floor(aStd.x * GAUSSIAN_SCALE_FACTOR + 0.5f)), + static_cast<int32_t>(floor(aStd.y * GAUSSIAN_SCALE_FACTOR + 0.5f))); + + return size; +} + +Float AlphaBoxBlur::CalculateBlurSigma(int32_t aBlurRadius) { + return aBlurRadius / GAUSSIAN_SCALE_FACTOR; +} + +} // namespace gfx +} // namespace mozilla |