Moving SkBlurImageFilter into core

src/effects/SkBlurImageFilter.cpp

Index: src/effects/SkBlurImageFilter.cpp
diff --git a/src/effects/SkBlurImageFilter.cpp b/src/effects/SkBlurImageFilter.cpp
deleted file mode 100644
index 37584ab3add0eb1ecbb731234e61a2a8d65846e9..0000000000000000000000000000000000000000
--- a/src/effects/SkBlurImageFilter.cpp
+++ /dev/null
@@ -1,259 +0,0 @@
-/*
- * 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(),
-                                                                sk_ref_sp(source->getColorSpace()),
-                                                                dstBounds,
-                                                                &inputBounds,
-                                                                sigma.x(),
-                                                                sigma.y()));
-        if (!drawContext) {
-            return nullptr;
-        }
-
-        // TODO: Get the colorSpace from the drawContext (once it has one)
-        return SkSpecialImage::MakeFromGpu(SkIRect::MakeWH(dstBounds.width(), dstBounds.height()),
-                                           kNeedNewImageUniqueID_SpecialImage,
-                                           drawContext->asTexture(),
-                                           sk_ref_sp(input->getColorSpace()), &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