| /* |
| * 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 "SkDevice.h" |
| #include "SkGpuBlurUtils.h" |
| #include "SkOpts.h" |
| #include "SkReadBuffer.h" |
| #include "SkWriteBuffer.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) |
| |
| static SkVector mapSigma(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, |
| SkImageFilter* input, |
| const CropRect* cropRect) |
| : INHERITED(1, &input, cropRect), fSigma(SkSize::Make(sigmaX, sigmaY)) { |
| } |
| |
| SkFlattenable* SkBlurImageFilter::CreateProc(SkReadBuffer& buffer) { |
| SK_IMAGEFILTER_UNFLATTEN_COMMON(common, 1); |
| SkScalar sigmaX = buffer.readScalar(); |
| SkScalar sigmaY = buffer.readScalar(); |
| return Create(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 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 (!this->filterInput(0, 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; |
| } |
| |
| SkAutoTUnref<SkBaseDevice> device(proxy->createDevice(srcBounds.width(), srcBounds.height())); |
| if (!device) { |
| return false; |
| } |
| *dst = device->accessBitmap(false); |
| SkAutoLockPixels alp_dst(*dst); |
| dst->getBounds(&dstBounds); |
| |
| SkVector sigma = mapSigma(fSigma, ctx.ctm()); |
| |
| 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; |
| } |
| |
| SkAutoTUnref<SkBaseDevice> tempDevice(proxy->createDevice(dst->width(), dst->height())); |
| if (!tempDevice) { |
| return false; |
| } |
| SkBitmap temp = tempDevice->accessBitmap(false); |
| SkAutoLockPixels alpTemp(temp); |
| |
| 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(); |
| |
| /** |
| * |
| * 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, t, kernelSizeX, lowOffsetX, highOffsetX, w, h); |
| SkOpts::box_blur_xx(t, w, d, kernelSizeX, highOffsetX, lowOffsetX, w, h); |
| SkOpts::box_blur_xy(d, w, t, kernelSizeX3, highOffsetX, highOffsetX, w, h); |
| SkOpts::box_blur_xx(t, h, d, kernelSizeY, lowOffsetY, highOffsetY, h, w); |
| SkOpts::box_blur_xx(d, h, t, kernelSizeY, highOffsetY, lowOffsetY, h, w); |
| SkOpts::box_blur_xy(t, h, d, kernelSizeY3, highOffsetY, highOffsetY, h, w); |
| } else if (kernelSizeX > 0) { |
| SkOpts::box_blur_xx(s, sw, d, kernelSizeX, lowOffsetX, highOffsetX, w, h); |
| SkOpts::box_blur_xx(d, w, t, kernelSizeX, highOffsetX, lowOffsetX, w, h); |
| SkOpts::box_blur_xx(t, w, d, kernelSizeX3, highOffsetX, highOffsetX, w, h); |
| } else if (kernelSizeY > 0) { |
| SkOpts::box_blur_yx(s, sw, d, kernelSizeY, lowOffsetY, highOffsetY, h, w); |
| SkOpts::box_blur_xx(d, h, t, kernelSizeY, highOffsetY, lowOffsetY, h, w); |
| SkOpts::box_blur_xy(t, h, d, kernelSizeY3, highOffsetY, highOffsetY, h, w); |
| } |
| return true; |
| } |
| |
| |
| void SkBlurImageFilter::computeFastBounds(const SkRect& src, SkRect* dst) const { |
| if (this->getInput(0)) { |
| this->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; |
| SkVector sigma = mapSigma(fSigma, ctm); |
| bounds.outset(SkScalarCeilToInt(SkScalarMul(sigma.x(), SkIntToScalar(3))), |
| SkScalarCeilToInt(SkScalarMul(sigma.y(), SkIntToScalar(3)))); |
| if (this->getInput(0) && !this->getInput(0)->filterBounds(bounds, ctm, &bounds)) { |
| return false; |
| } |
| *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 (!this->filterInputGPU(0, 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 = mapSigma(fSigma, ctx.ctm()); |
| 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())); |
| if (!tex) { |
| return false; |
| } |
| WrapTexture(tex, rect.width(), rect.height(), result); |
| return true; |
| #else |
| SkDEBUGFAIL("Should not call in GPU-less build"); |
| return false; |
| #endif |
| } |
| |
| #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 |