| /* |
| * 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 "SkAutoPixmapStorage.h" |
| #include "SkColorPriv.h" |
| #include "SkGpuBlurUtils.h" |
| #include "SkOpts.h" |
| #include "SkReadBuffer.h" |
| #include "SkSpecialImage.h" |
| #include "SkWriteBuffer.h" |
| |
| #if SK_SUPPORT_GPU |
| #include "GrContext.h" |
| #include "SkGr.h" |
| #endif |
| |
| sk_sp<SkImageFilter> SkBlurImageFilter::Make(SkScalar sigmaX, SkScalar sigmaY, |
| sk_sp<SkImageFilter> input, |
| const CropRect* cropRect) { |
| if (0 == sigmaX && 0 == sigmaY && !cropRect) { |
| return input; |
| } |
| return sk_sp<SkImageFilter>(new SkBlurImageFilter(sigmaX, sigmaY, input, cropRect)); |
| } |
| |
| // 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; |
| } |
| |
| SkBlurImageFilter::SkBlurImageFilter(SkScalar sigmaX, |
| SkScalar sigmaY, |
| sk_sp<SkImageFilter> input, |
| const CropRect* cropRect) |
| : INHERITED(&input, 1, cropRect) |
| , fSigma(SkSize::Make(sigmaX, sigmaY)) { |
| } |
| |
| sk_sp<SkFlattenable> SkBlurImageFilter::CreateProc(SkReadBuffer& buffer) { |
| SK_IMAGEFILTER_UNFLATTEN_COMMON(common, 1); |
| SkScalar sigmaX = buffer.readScalar(); |
| SkScalar sigmaY = buffer.readScalar(); |
| return Make(sigmaX, sigmaY, common.getInput(0), &common.cropRect()); |
| } |
| |
| void SkBlurImageFilter::flatten(SkWriteBuffer& buffer) const { |
| this->INHERITED::flatten(buffer); |
| buffer.writeScalar(fSigma.fWidth); |
| buffer.writeScalar(fSigma.fHeight); |
| } |
| |
| 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; |
| } |
| } |
| |
| sk_sp<SkSpecialImage> SkBlurImageFilter::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()); |
| |
| SkIRect dstBounds; |
| if (!this->applyCropRect(this->mapContext(ctx), inputBounds, &dstBounds)) { |
| return nullptr; |
| } |
| if (!inputBounds.intersect(dstBounds)) { |
| return nullptr; |
| } |
| |
| const SkVector sigma = map_sigma(fSigma, ctx.ctm()); |
| |
| #if SK_SUPPORT_GPU |
| if (source->isTextureBacked()) { |
| GrContext* context = source->getContext(); |
| sk_sp<GrTexture> inputTexture(input->asTextureRef(context)); |
| SkASSERT(inputTexture); |
| |
| if (0 == sigma.x() && 0 == sigma.y()) { |
| offset->fX = inputBounds.x(); |
| offset->fY = inputBounds.y(); |
| return input->makeSubset(inputBounds.makeOffset(-inputOffset.x(), |
| -inputOffset.y())); |
| } |
| |
| offset->fX = dstBounds.fLeft; |
| offset->fY = dstBounds.fTop; |
| inputBounds.offset(-inputOffset); |
| dstBounds.offset(-inputOffset); |
| sk_sp<GrDrawContext> drawContext(SkGpuBlurUtils::GaussianBlur( |
| context, |
| inputTexture.get(), |
| source->props().isGammaCorrect(), |
| dstBounds, |
| &inputBounds, |
| sigma.x(), |
| sigma.y())); |
| if (!drawContext) { |
| return nullptr; |
| } |
| |
| return SkSpecialImage::MakeFromGpu(SkIRect::MakeWH(dstBounds.width(), dstBounds.height()), |
| kNeedNewImageUniqueID_SpecialImage, |
| drawContext->asTexture(), &source->props()); |
| } |
| #endif |
| |
| 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); |
| |
| if (kernelSizeX < 0 || kernelSizeY < 0) { |
| return nullptr; |
| } |
| |
| if (kernelSizeX == 0 && kernelSizeY == 0) { |
| offset->fX = inputBounds.x(); |
| offset->fY = inputBounds.y(); |
| return input->makeSubset(inputBounds.makeOffset(-inputOffset.x(), |
| -inputOffset.y())); |
| } |
| |
| SkBitmap inputBM; |
| |
| if (!input->getROPixels(&inputBM)) { |
| return nullptr; |
| } |
| |
| if (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; |
| } |
| |
| SkAutoLockPixels inputLock(inputBM), tmpLock(tmp), dstLock(dst); |
| |
| offset->fX = dstBounds.fLeft; |
| offset->fY = dstBounds.fTop; |
| SkPMColor* t = tmp.getAddr32(0, 0); |
| SkPMColor* d = dst.getAddr32(0, 0); |
| int w = dstBounds.width(), h = dstBounds.height(); |
| const SkPMColor* s = inputBM.getAddr32(inputBounds.x() - inputOffset.x(), |
| inputBounds.y() - inputOffset.y()); |
| inputBounds.offset(-dstBounds.x(), -dstBounds.y()); |
| dstBounds.offset(-dstBounds.x(), -dstBounds.y()); |
| SkIRect inputBoundsT = SkIRect::MakeLTRB(inputBounds.top(), inputBounds.left(), |
| inputBounds.bottom(), inputBounds.right()); |
| SkIRect dstBoundsT = SkIRect::MakeWH(dstBounds.height(), dstBounds.width()); |
| int sw = int(inputBM.rowBytes() >> 2); |
| |
| /** |
| * |
| * 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::MakeWH(dstBounds.width(), |
| dstBounds.height()), |
| dst, &source->props()); |
| } |
| |
| |
| SkRect SkBlurImageFilter::computeFastBounds(const SkRect& src) const { |
| SkRect bounds = this->getInput(0) ? this->getInput(0)->computeFastBounds(src) : src; |
| bounds.outset(SkScalarMul(fSigma.width(), SkIntToScalar(3)), |
| SkScalarMul(fSigma.height(), SkIntToScalar(3))); |
| return bounds; |
| } |
| |
| SkIRect SkBlurImageFilter::onFilterNodeBounds(const SkIRect& src, const SkMatrix& ctm, |
| MapDirection) const { |
| SkVector sigma = map_sigma(fSigma, ctm); |
| return src.makeOutset(SkScalarCeilToInt(SkScalarMul(sigma.x(), SkIntToScalar(3))), |
| SkScalarCeilToInt(SkScalarMul(sigma.y(), SkIntToScalar(3)))); |
| } |
| |
| #ifndef SK_IGNORE_TO_STRING |
| void SkBlurImageFilter::toString(SkString* str) const { |
| str->appendf("SkBlurImageFilter: ("); |
| str->appendf("sigma: (%f, %f) input (", fSigma.fWidth, fSigma.fHeight); |
| |
| if (this->getInput(0)) { |
| this->getInput(0)->toString(str); |
| } |
| |
| str->append("))"); |
| } |
| #endif |
