| /* |
| * 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 "SkBitmap.h" |
| #include "SkBlurImageFilter.h" |
| #include "SkColorPriv.h" |
| #include "SkReadBuffer.h" |
| #include "SkWriteBuffer.h" |
| #include "SkGpuBlurUtils.h" |
| #include "SkBlurImage_opts.h" |
| #if SK_SUPPORT_GPU |
| #include "GrContext.h" |
| #endif |
| |
| // 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) |
| |
| SkBlurImageFilter::SkBlurImageFilter(SkReadBuffer& buffer) |
| : INHERITED(1, buffer) { |
| fSigma.fWidth = buffer.readScalar(); |
| fSigma.fHeight = buffer.readScalar(); |
| buffer.validate(SkScalarIsFinite(fSigma.fWidth) && |
| SkScalarIsFinite(fSigma.fHeight) && |
| (fSigma.fWidth >= 0) && |
| (fSigma.fHeight >= 0)); |
| } |
| |
| SkBlurImageFilter::SkBlurImageFilter(SkScalar sigmaX, |
| SkScalar sigmaY, |
| SkImageFilter* input, |
| const CropRect* cropRect) |
| : INHERITED(1, &input, cropRect), fSigma(SkSize::Make(sigmaX, sigmaY)) { |
| SkASSERT(sigmaX >= 0 && sigmaY >= 0); |
| } |
| |
| void SkBlurImageFilter::flatten(SkWriteBuffer& buffer) const { |
| this->INHERITED::flatten(buffer); |
| buffer.writeScalar(fSigma.fWidth); |
| buffer.writeScalar(fSigma.fHeight); |
| } |
| |
| enum BlurDirection { |
| kX, kY |
| }; |
| |
| /** |
| * |
| * 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. |
| */ |
| |
| template<BlurDirection srcDirection, BlurDirection dstDirection> |
| static void boxBlur(const SkPMColor* src, int srcStride, SkPMColor* dst, int kernelSize, |
| int leftOffset, int rightOffset, int width, int height) |
| { |
| int rightBorder = SkMin32(rightOffset + 1, width); |
| int srcStrideX = srcDirection == kX ? 1 : srcStride; |
| int dstStrideX = dstDirection == kX ? 1 : height; |
| int srcStrideY = srcDirection == kX ? srcStride : 1; |
| int dstStrideY = dstDirection == kX ? width : 1; |
| uint32_t scale = (1 << 24) / kernelSize; |
| uint32_t half = 1 << 23; |
| for (int y = 0; y < height; ++y) { |
| int sumA = 0, sumR = 0, sumG = 0, sumB = 0; |
| const SkPMColor* p = src; |
| for (int i = 0; i < rightBorder; ++i) { |
| sumA += SkGetPackedA32(*p); |
| sumR += SkGetPackedR32(*p); |
| sumG += SkGetPackedG32(*p); |
| sumB += SkGetPackedB32(*p); |
| p += srcStrideX; |
| } |
| |
| const SkPMColor* sptr = src; |
| SkColor* dptr = dst; |
| for (int x = 0; x < width; ++x) { |
| *dptr = SkPackARGB32((sumA * scale + half) >> 24, |
| (sumR * scale + half) >> 24, |
| (sumG * scale + half) >> 24, |
| (sumB * scale + half) >> 24); |
| if (x >= leftOffset) { |
| SkColor l = *(sptr - leftOffset * srcStrideX); |
| sumA -= SkGetPackedA32(l); |
| sumR -= SkGetPackedR32(l); |
| sumG -= SkGetPackedG32(l); |
| sumB -= SkGetPackedB32(l); |
| } |
| if (x + rightOffset + 1 < width) { |
| SkColor r = *(sptr + (rightOffset + 1) * srcStrideX); |
| sumA += SkGetPackedA32(r); |
| sumR += SkGetPackedR32(r); |
| sumG += SkGetPackedG32(r); |
| sumB += SkGetPackedB32(r); |
| } |
| sptr += srcStrideX; |
| if (srcDirection == kY) { |
| SK_PREFETCH(sptr + (rightOffset + 1) * srcStrideX); |
| } |
| dptr += dstStrideX; |
| } |
| src += srcStrideY; |
| dst += dstStrideY; |
| } |
| } |
| |
| static void getBox3Params(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; |
| } |
| } |
| |
| bool SkBlurImageFilter::onFilterImage(Proxy* proxy, |
| const SkBitmap& source, const Context& ctx, |
| SkBitmap* dst, SkIPoint* offset) const { |
| SkBitmap src = source; |
| SkIPoint srcOffset = SkIPoint::Make(0, 0); |
| if (getInput(0) && !getInput(0)->filterImage(proxy, source, ctx, &src, &srcOffset)) { |
| return false; |
| } |
| |
| if (src.colorType() != kN32_SkColorType) { |
| return false; |
| } |
| |
| SkIRect srcBounds, dstBounds; |
| if (!this->applyCropRect(ctx, proxy, src, &srcOffset, &srcBounds, &src)) { |
| return false; |
| } |
| |
| SkAutoLockPixels alp(src); |
| if (!src.getPixels()) { |
| return false; |
| } |
| |
| if (!dst->allocPixels(src.info().makeWH(srcBounds.width(), srcBounds.height()))) { |
| return false; |
| } |
| dst->getBounds(&dstBounds); |
| |
| SkVector sigma = SkVector::Make(fSigma.width(), fSigma.height()); |
| ctx.ctm().mapVectors(&sigma, 1); |
| sigma.fX = SkMinScalar(sigma.fX, MAX_SIGMA); |
| sigma.fY = SkMinScalar(sigma.fY, MAX_SIGMA); |
| |
| int kernelSizeX, kernelSizeX3, lowOffsetX, highOffsetX; |
| int kernelSizeY, kernelSizeY3, lowOffsetY, highOffsetY; |
| getBox3Params(sigma.x(), &kernelSizeX, &kernelSizeX3, &lowOffsetX, &highOffsetX); |
| getBox3Params(sigma.y(), &kernelSizeY, &kernelSizeY3, &lowOffsetY, &highOffsetY); |
| |
| if (kernelSizeX < 0 || kernelSizeY < 0) { |
| return false; |
| } |
| |
| if (kernelSizeX == 0 && kernelSizeY == 0) { |
| src.copyTo(dst, dst->colorType()); |
| offset->fX = srcBounds.fLeft; |
| offset->fY = srcBounds.fTop; |
| return true; |
| } |
| |
| SkBitmap temp; |
| if (!temp.allocPixels(dst->info())) { |
| return false; |
| } |
| |
| offset->fX = srcBounds.fLeft; |
| offset->fY = srcBounds.fTop; |
| srcBounds.offset(-srcOffset); |
| const SkPMColor* s = src.getAddr32(srcBounds.left(), srcBounds.top()); |
| SkPMColor* t = temp.getAddr32(0, 0); |
| SkPMColor* d = dst->getAddr32(0, 0); |
| int w = dstBounds.width(), h = dstBounds.height(); |
| int sw = src.rowBytesAsPixels(); |
| SkBoxBlurProc boxBlurX, boxBlurY, boxBlurXY, boxBlurYX; |
| if (!SkBoxBlurGetPlatformProcs(&boxBlurX, &boxBlurY, &boxBlurXY, &boxBlurYX)) { |
| boxBlurX = boxBlur<kX, kX>; |
| boxBlurY = boxBlur<kY, kY>; |
| boxBlurXY = boxBlur<kX, kY>; |
| boxBlurYX = boxBlur<kY, kX>; |
| } |
| |
| if (kernelSizeX > 0 && kernelSizeY > 0) { |
| boxBlurX(s, sw, t, kernelSizeX, lowOffsetX, highOffsetX, w, h); |
| boxBlurX(t, w, d, kernelSizeX, highOffsetX, lowOffsetX, w, h); |
| boxBlurXY(d, w, t, kernelSizeX3, highOffsetX, highOffsetX, w, h); |
| boxBlurX(t, h, d, kernelSizeY, lowOffsetY, highOffsetY, h, w); |
| boxBlurX(d, h, t, kernelSizeY, highOffsetY, lowOffsetY, h, w); |
| boxBlurXY(t, h, d, kernelSizeY3, highOffsetY, highOffsetY, h, w); |
| } else if (kernelSizeX > 0) { |
| boxBlurX(s, sw, d, kernelSizeX, lowOffsetX, highOffsetX, w, h); |
| boxBlurX(d, w, t, kernelSizeX, highOffsetX, lowOffsetX, w, h); |
| boxBlurX(t, w, d, kernelSizeX3, highOffsetX, highOffsetX, w, h); |
| } else if (kernelSizeY > 0) { |
| boxBlurYX(s, sw, d, kernelSizeY, lowOffsetY, highOffsetY, h, w); |
| boxBlurX(d, h, t, kernelSizeY, highOffsetY, lowOffsetY, h, w); |
| boxBlurXY(t, h, d, kernelSizeY3, highOffsetY, highOffsetY, h, w); |
| } |
| return true; |
| } |
| |
| |
| void SkBlurImageFilter::computeFastBounds(const SkRect& src, SkRect* dst) const { |
| if (getInput(0)) { |
| getInput(0)->computeFastBounds(src, dst); |
| } else { |
| *dst = src; |
| } |
| |
| dst->outset(SkScalarMul(fSigma.width(), SkIntToScalar(3)), |
| SkScalarMul(fSigma.height(), SkIntToScalar(3))); |
| } |
| |
| bool SkBlurImageFilter::onFilterBounds(const SkIRect& src, const SkMatrix& ctm, |
| SkIRect* dst) const { |
| SkIRect bounds = src; |
| if (getInput(0) && !getInput(0)->filterBounds(src, ctm, &bounds)) { |
| return false; |
| } |
| SkVector sigma = SkVector::Make(fSigma.width(), fSigma.height()); |
| ctm.mapVectors(&sigma, 1); |
| bounds.outset(SkScalarCeilToInt(SkScalarMul(sigma.x(), SkIntToScalar(3))), |
| SkScalarCeilToInt(SkScalarMul(sigma.y(), SkIntToScalar(3)))); |
| *dst = bounds; |
| return true; |
| } |
| |
| bool SkBlurImageFilter::filterImageGPU(Proxy* proxy, const SkBitmap& src, const Context& ctx, |
| SkBitmap* result, SkIPoint* offset) const { |
| #if SK_SUPPORT_GPU |
| SkBitmap input = src; |
| SkIPoint srcOffset = SkIPoint::Make(0, 0); |
| if (getInput(0) && !getInput(0)->getInputResultGPU(proxy, src, ctx, &input, &srcOffset)) { |
| return false; |
| } |
| SkIRect rect; |
| if (!this->applyCropRect(ctx, proxy, input, &srcOffset, &rect, &input)) { |
| return false; |
| } |
| GrTexture* source = input.getTexture(); |
| SkVector sigma = SkVector::Make(fSigma.width(), fSigma.height()); |
| ctx.ctm().mapVectors(&sigma, 1); |
| sigma.fX = SkMinScalar(sigma.fX, MAX_SIGMA); |
| sigma.fY = SkMinScalar(sigma.fY, MAX_SIGMA); |
| offset->fX = rect.fLeft; |
| offset->fY = rect.fTop; |
| rect.offset(-srcOffset); |
| SkAutoTUnref<GrTexture> tex(SkGpuBlurUtils::GaussianBlur(source->getContext(), |
| source, |
| false, |
| SkRect::Make(rect), |
| true, |
| sigma.x(), |
| sigma.y())); |
| WrapTexture(tex, rect.width(), rect.height(), result); |
| return true; |
| #else |
| SkDEBUGFAIL("Should not call in GPU-less build"); |
| return false; |
| #endif |
| } |