C++ SkMask::computeImageSize方法代码示例

bool SkBlurMask::BoxBlur(SkMask* dst, const SkMask& src, SkScalar sigma, SkBlurStyle style,
                         SkIPoint* margin) {
    if (src.fFormat != SkMask::kA8_Format && src.fFormat != SkMask::kARGB32_Format) {
        return false;
    }

    SkIPoint border;

    SkMaskBlurFilter blurFilter{sigma, sigma};
    if (blurFilter.hasNoBlur()) {
        return false;
    }
    border = blurFilter.blur(src, dst);
    // If src.fImage is null, then this call is only to calculate the border.
    if (src.fImage != nullptr && dst->fImage == nullptr) {
        return false;
    }

    if (src.fImage != nullptr) {
        // if need be, alloc the "real" dst (same size as src) and copy/merge
        // the blur into it (applying the src)
        if (style == kInner_SkBlurStyle) {
            // now we allocate the "real" dst, mirror the size of src
            size_t srcSize = src.computeImageSize();
            if (0 == srcSize) {
                return false;   // too big to allocate, abort
            }
            auto blur = dst->fImage;
            dst->fImage = SkMask::AllocImage(srcSize);
            auto blurStart = &blur[border.x() + border.y() * dst->fRowBytes];
            merge_src_with_blur(dst->fImage, src.fRowBytes,
                                src.fImage, src.fRowBytes,
                                blurStart,
                                dst->fRowBytes,
                                src.fBounds.width(), src.fBounds.height());
            SkMask::FreeImage(blur);
        } else if (style != kNormal_SkBlurStyle) {
            auto dstStart = &dst->fImage[border.x() + border.y() * dst->fRowBytes];
            clamp_with_orig(dstStart,
                            dst->fRowBytes, src.fImage, src.fRowBytes,
                            src.fBounds.width(), src.fBounds.height(), style);
        }
    }

    if (style == kInner_SkBlurStyle) {
        dst->fBounds = src.fBounds; // restore trimmed bounds
        dst->fRowBytes = src.fRowBytes;
    }

    if (margin != nullptr) {
        *margin = border;
    }

    return true;
}

bool SkEmbossMaskFilter::filterMask(SkMask* dst, const SkMask& src,
                                    const SkMatrix& matrix, SkIPoint* margin) const {
    SkScalar sigma = matrix.mapRadius(fBlurSigma);

    if (!SkBlurMask::BoxBlur(dst, src, sigma, SkBlurMask::kInner_Style,
                             SkBlurMask::kLow_Quality)) {
        return false;
    }

    dst->fFormat = SkMask::k3D_Format;
    if (margin) {
        margin->set(SkScalarCeilToInt(3*sigma), SkScalarCeilToInt(3*sigma));
    }

    if (src.fImage == NULL) {
        return true;
    }

    // create a larger buffer for the other two channels (should force fBlur to do this for us)

    {
        uint8_t* alphaPlane = dst->fImage;
        size_t   planeSize = dst->computeImageSize();
        if (0 == planeSize) {
            return false;   // too big to allocate, abort
        }
        dst->fImage = SkMask::AllocImage(planeSize * 3);
        memcpy(dst->fImage, alphaPlane, planeSize);
        SkMask::FreeImage(alphaPlane);
    }

    // run the light direction through the matrix...
    Light   light = fLight;
    matrix.mapVectors((SkVector*)(void*)light.fDirection,
                      (SkVector*)(void*)fLight.fDirection, 1);

    // now restore the length of the XY component
    // cast to SkVector so we can call setLength (this double cast silences alias warnings)
    SkVector* vec = (SkVector*)(void*)light.fDirection;
    vec->setLength(light.fDirection[0],
                   light.fDirection[1],
                   SkPoint::Length(fLight.fDirection[0], fLight.fDirection[1]));

    SkEmbossMask::Emboss(dst, light);

    // restore original alpha
    memcpy(dst->fImage, src.fImage, src.computeImageSize());

    return true;
}

void SkScalerContext::getImage(const SkGlyph& origGlyph) {
    const SkGlyph*  glyph = &origGlyph;
    SkGlyph         tmpGlyph;

    if (fMaskFilter) {   // restore the prefilter bounds
        tmpGlyph.init(origGlyph.fID);

        // need the original bounds, sans our maskfilter
        SkMaskFilter* mf = fMaskFilter;
        fMaskFilter = NULL;             // temp disable
        this->getMetrics(&tmpGlyph);
        fMaskFilter = mf;               // restore

        tmpGlyph.fImage = origGlyph.fImage;

        // we need the prefilter bounds to be <= filter bounds
        SkASSERT(tmpGlyph.fWidth <= origGlyph.fWidth);
        SkASSERT(tmpGlyph.fHeight <= origGlyph.fHeight);
        glyph = &tmpGlyph;
    }

    if (fRec.fFrameWidth > 0 || fPathEffect != NULL || fRasterizer != NULL) {
        SkPath      devPath, fillPath;
        SkMatrix    fillToDevMatrix;

        this->internalGetPath(*glyph, &fillPath, &devPath, &fillToDevMatrix);

        if (fRasterizer) {
            SkMask  mask;

            glyph->toMask(&mask);
            mask.fFormat = SkMask::kA8_Format;
            sk_bzero(glyph->fImage, mask.computeImageSize());

            if (!fRasterizer->rasterize(fillPath, fillToDevMatrix, NULL,
                                        fMaskFilter, &mask,
                                        SkMask::kJustRenderImage_CreateMode)) {
                return;
            }
        } else {
            SkBitmap    bm;
            SkBitmap::Config config;
            SkMatrix    matrix;
            SkRegion    clip;
            SkPaint     paint;
            SkDraw      draw;

            if (SkMask::kA8_Format == fRec.fMaskFormat) {
                config = SkBitmap::kA8_Config;
                paint.setAntiAlias(true);
            } else {
                SkASSERT(SkMask::kBW_Format == fRec.fMaskFormat);
                config = SkBitmap::kA1_Config;
                paint.setAntiAlias(false);
            }

            clip.setRect(0, 0, glyph->fWidth, glyph->fHeight);
            matrix.setTranslate(-SkIntToScalar(glyph->fLeft),
                                -SkIntToScalar(glyph->fTop));
            bm.setConfig(config, glyph->fWidth, glyph->fHeight,
                         glyph->rowBytes());
            bm.setPixels(glyph->fImage);
            sk_bzero(glyph->fImage, bm.height() * bm.rowBytes());

            draw.fClip  = &clip;
            draw.fMatrix = &matrix;
            draw.fBitmap = &bm;
            draw.fBounder = NULL;
            draw.drawPath(devPath, paint);
        }
    } else {
        this->getGlyphContext(*glyph)->generateImage(*glyph);
    }

    if (fMaskFilter) {
        SkMask      srcM, dstM;
        SkMatrix    matrix;

        // the src glyph image shouldn't be 3D
        SkASSERT(SkMask::k3D_Format != glyph->fMaskFormat);
        glyph->toMask(&srcM);
        fRec.getMatrixFrom2x2(&matrix);

        if (fMaskFilter->filterMask(&dstM, srcM, matrix, NULL)) {
            int width = SkFastMin32(origGlyph.fWidth, dstM.fBounds.width());
            int height = SkFastMin32(origGlyph.fHeight, dstM.fBounds.height());
            int dstRB = origGlyph.rowBytes();
            int srcRB = dstM.fRowBytes;

            const uint8_t* src = (const uint8_t*)dstM.fImage;
            uint8_t* dst = (uint8_t*)origGlyph.fImage;

            if (SkMask::k3D_Format == dstM.fFormat) {
                // we have to copy 3 times as much
                height *= 3;
            }

            // clean out our glyph, since it may be larger than dstM
            //sk_bzero(dst, height * dstRB);

//.........这里部分代码省略.........

void SkScalerContext::getImage(const SkGlyph& origGlyph) {
    const SkGlyph*  glyph = &origGlyph;
    SkGlyph         tmpGlyph;

    if (fMaskFilter) {   // restore the prefilter bounds
        tmpGlyph.init(origGlyph.fID);

        // need the original bounds, sans our maskfilter
        SkMaskFilter* mf = fMaskFilter;
        fMaskFilter = NULL;             // temp disable
        this->getMetrics(&tmpGlyph);
        fMaskFilter = mf;               // restore

        tmpGlyph.fImage = origGlyph.fImage;

        // we need the prefilter bounds to be <= filter bounds
        SkASSERT(tmpGlyph.fWidth <= origGlyph.fWidth);
        SkASSERT(tmpGlyph.fHeight <= origGlyph.fHeight);
        glyph = &tmpGlyph;
    }

    if (fGenerateImageFromPath) {
        SkPath      devPath, fillPath;
        SkMatrix    fillToDevMatrix;
        SkMask      mask;

        this->internalGetPath(*glyph, &fillPath, &devPath, &fillToDevMatrix);
        glyph->toMask(&mask);

        if (fRasterizer) {
            mask.fFormat = SkMask::kA8_Format;
            sk_bzero(glyph->fImage, mask.computeImageSize());

            if (!fRasterizer->rasterize(fillPath, fillToDevMatrix, NULL,
                                        fMaskFilter, &mask,
                                        SkMask::kJustRenderImage_CreateMode)) {
                return;
            }
        } else {
            generateMask(mask, devPath);
        }
    } else {
        this->getGlyphContext(*glyph)->generateImage(*glyph);
    }

    if (fMaskFilter) {
        SkMask      srcM, dstM;
        SkMatrix    matrix;

        // the src glyph image shouldn't be 3D
        SkASSERT(SkMask::k3D_Format != glyph->fMaskFormat);
        glyph->toMask(&srcM);
        fRec.getMatrixFrom2x2(&matrix);

        if (fMaskFilter->filterMask(&dstM, srcM, matrix, NULL)) {
            int width = SkFastMin32(origGlyph.fWidth, dstM.fBounds.width());
            int height = SkFastMin32(origGlyph.fHeight, dstM.fBounds.height());
            int dstRB = origGlyph.rowBytes();
            int srcRB = dstM.fRowBytes;

            const uint8_t* src = (const uint8_t*)dstM.fImage;
            uint8_t* dst = (uint8_t*)origGlyph.fImage;

            if (SkMask::k3D_Format == dstM.fFormat) {
                // we have to copy 3 times as much
                height *= 3;
            }

            // clean out our glyph, since it may be larger than dstM
            //sk_bzero(dst, height * dstRB);

            while (--height >= 0) {
                memcpy(dst, src, width);
                src += srcRB;
                dst += dstRB;
            }
            SkMask::FreeImage(dstM.fImage);
        }
    }
}

bool SkBlurMask::BlurGroundTruth(SkMask* dst, const SkMask& src, SkScalar provided_radius,
                            Style style, SkIPoint* margin) {

    if (src.fFormat != SkMask::kA8_Format) {
        return false;
    }

    float radius = SkScalarToFloat(SkScalarMul(provided_radius, kBlurRadiusFudgeFactor));
    float stddev = SkScalarToFloat(radius) /2.0f;
    float variance = stddev * stddev;

    int windowSize = SkScalarCeil(stddev*4);
    // round window size up to nearest odd number
    windowSize |= 1;

    SkAutoTMalloc<float> gaussWindow(windowSize);

    int halfWindow = windowSize >> 1;

    gaussWindow[halfWindow] = 1;

    float windowSum = 1;
    for (int x = 1 ; x <= halfWindow ; ++x) {
        float gaussian = expf(-x*x / variance);
        gaussWindow[halfWindow + x] = gaussWindow[halfWindow-x] = gaussian;
        windowSum += 2*gaussian;
    }

    // leave the filter un-normalized for now; we will divide by the normalization
    // sum later;

    int pad = halfWindow;
    if (margin) {
        margin->set( pad, pad );
    }

    dst->fBounds = src.fBounds;
    dst->fBounds.outset(pad, pad);

    dst->fRowBytes = dst->fBounds.width();
    dst->fFormat = SkMask::kA8_Format;
    dst->fImage = NULL;

    if (src.fImage) {

        size_t dstSize = dst->computeImageSize();
        if (0 == dstSize) {
            return false;   // too big to allocate, abort
        }

        int             srcWidth = src.fBounds.width();
        int             srcHeight = src.fBounds.height();
        int             dstWidth = dst->fBounds.width();

        const uint8_t*  srcPixels = src.fImage;
        uint8_t*        dstPixels = SkMask::AllocImage(dstSize);
        SkAutoTCallVProc<uint8_t, SkMask_FreeImage> autoCall(dstPixels);

        // do the actual blur.  First, make a padded copy of the source.
        // use double pad so we never have to check if we're outside anything

        int padWidth = srcWidth + 4*pad;
        int padHeight = srcHeight;
        int padSize = padWidth * padHeight;

        SkAutoTMalloc<uint8_t> padPixels(padSize);
        memset(padPixels, 0, padSize);

        for (int y = 0 ; y < srcHeight; ++y) {
            uint8_t* padptr = padPixels + y * padWidth + 2*pad;
            const uint8_t* srcptr = srcPixels + y * srcWidth;
            memcpy(padptr, srcptr, srcWidth);
        }

        // blur in X, transposing the result into a temporary floating point buffer.
        // also double-pad the intermediate result so that the second blur doesn't
        // have to do extra conditionals.

        int tmpWidth = padHeight + 4*pad;
        int tmpHeight = padWidth - 2*pad;
        int tmpSize = tmpWidth * tmpHeight;

        SkAutoTMalloc<float> tmpImage(tmpSize);
        memset(tmpImage, 0, tmpSize*sizeof(tmpImage[0]));

        for (int y = 0 ; y < padHeight ; ++y) {
            uint8_t *srcScanline = padPixels + y*padWidth;
            for (int x = pad ; x < padWidth - pad ; ++x) {
                float *outPixel = tmpImage + (x-pad)*tmpWidth + y + 2*pad; // transposed output
                uint8_t *windowCenter = srcScanline + x;
                for (int i = -pad ; i <= pad ; ++i) {
                    *outPixel += gaussWindow[pad+i]*windowCenter[i];
                }
                *outPixel /= windowSum;
            }
        }

        // blur in Y; now filling in the actual desired destination.  We have to do
        // the transpose again; these transposes guarantee that we read memory in
        // linear order.
//.........这里部分代码省略.........

bool SkBlurMask::Blur(SkMask* dst, const SkMask& src,
                      SkScalar radius, Style style, Quality quality,
                      SkIPoint* margin)
{

    if (src.fFormat != SkMask::kA8_Format) {
        return false;
    }

    // Force high quality off for small radii (performance)
    if (radius < SkIntToScalar(3)) {
        quality = kLow_Quality;
    }

    // highQuality: use three box blur passes as a cheap way
    // to approximate a Gaussian blur
    int passCount = (kHigh_Quality == quality) ? 3 : 1;
    SkScalar passRadius = (kHigh_Quality == quality) ?
                          SkScalarMul( radius, kBlurRadiusFudgeFactor):
                          radius;

    int rx = SkScalarCeil(passRadius);
    int outerWeight = 255 - SkScalarRound((SkIntToScalar(rx) - passRadius) * 255);

    SkASSERT(rx >= 0);
    SkASSERT((unsigned)outerWeight <= 255);
    if (rx <= 0) {
        return false;
    }

    int ry = rx;    // only do square blur for now

    int padx = passCount * rx;
    int pady = passCount * ry;

    if (margin) {
        margin->set(padx, pady);
    }
    dst->fBounds.set(src.fBounds.fLeft - padx, src.fBounds.fTop - pady,
        src.fBounds.fRight + padx, src.fBounds.fBottom + pady);

    dst->fRowBytes = dst->fBounds.width();
    dst->fFormat = SkMask::kA8_Format;
    dst->fImage = NULL;

    if (src.fImage) {
        size_t dstSize = dst->computeImageSize();
        if (0 == dstSize) {
            return false;   // too big to allocate, abort
        }

        int             sw = src.fBounds.width();
        int             sh = src.fBounds.height();
        const uint8_t*  sp = src.fImage;
        uint8_t*        dp = SkMask::AllocImage(dstSize);
        SkAutoTCallVProc<uint8_t, SkMask_FreeImage> autoCall(dp);

        // build the blurry destination
        SkAutoTMalloc<uint8_t>  tmpBuffer(dstSize);
        uint8_t*                tp = tmpBuffer.get();
        int w = sw, h = sh;

        if (outerWeight == 255) {
            int loRadius, hiRadius;
            get_adjusted_radii(passRadius, &loRadius, &hiRadius);
            if (kHigh_Quality == quality) {
                // Do three X blurs, with a transpose on the final one.
                w = boxBlur(sp, src.fRowBytes, tp, loRadius, hiRadius, w, h, false);
                w = boxBlur(tp, w,             dp, hiRadius, loRadius, w, h, false);
                w = boxBlur(dp, w,             tp, hiRadius, hiRadius, w, h, true);
                // Do three Y blurs, with a transpose on the final one.
                h = boxBlur(tp, h,             dp, loRadius, hiRadius, h, w, false);
                h = boxBlur(dp, h,             tp, hiRadius, loRadius, h, w, false);
                h = boxBlur(tp, h,             dp, hiRadius, hiRadius, h, w, true);
            } else {
                w = boxBlur(sp, src.fRowBytes, tp, rx, rx, w, h, true);
                h = boxBlur(tp, h,             dp, ry, ry, h, w, true);
            }
        } else {
            if (kHigh_Quality == quality) {
                // Do three X blurs, with a transpose on the final one.
                w = boxBlurInterp(sp, src.fRowBytes, tp, rx, w, h, false, outerWeight);
                w = boxBlurInterp(tp, w,             dp, rx, w, h, false, outerWeight);
                w = boxBlurInterp(dp, w,             tp, rx, w, h, true, outerWeight);
                // Do three Y blurs, with a transpose on the final one.
                h = boxBlurInterp(tp, h,             dp, ry, h, w, false, outerWeight);
                h = boxBlurInterp(dp, h,             tp, ry, h, w, false, outerWeight);
                h = boxBlurInterp(tp, h,             dp, ry, h, w, true, outerWeight);
            } else {
                w = boxBlurInterp(sp, src.fRowBytes, tp, rx, w, h, true, outerWeight);
                h = boxBlurInterp(tp, h,             dp, ry, h, w, true, outerWeight);
            }
        }

        dst->fImage = dp;
        // if need be, alloc the "real" dst (same size as src) and copy/merge
        // the blur into it (applying the src)
        if (style == kInner_Style) {
            // now we allocate the "real" dst, mirror the size of src
            size_t srcSize = src.computeImageSize();
//.........这里部分代码省略.........

void SkScalerContext::getImage(const SkGlyph& origGlyph) {
    const SkGlyph*  glyph = &origGlyph;
    SkGlyph         tmpGlyph;

    // in case we need to call generateImage on a mask-format that is different
    // (i.e. larger) than what our caller allocated by looking at origGlyph.
    SkAutoMalloc tmpGlyphImageStorage;

    // If we are going to draw-from-path, then we cannot generate color, since
    // the path only makes a mask. This case should have been caught up in
    // generateMetrics().
    SkASSERT(!fGenerateImageFromPath ||
             SkMask::kARGB32_Format != origGlyph.fMaskFormat);

    if (fMaskFilter) {   // restore the prefilter bounds
        tmpGlyph.initGlyphIdFrom(origGlyph);

        // need the original bounds, sans our maskfilter
        SkMaskFilter* mf = fMaskFilter;
        fMaskFilter = nullptr;             // temp disable
        this->getMetrics(&tmpGlyph);
        fMaskFilter = mf;               // restore

        // we need the prefilter bounds to be <= filter bounds
        SkASSERT(tmpGlyph.fWidth <= origGlyph.fWidth);
        SkASSERT(tmpGlyph.fHeight <= origGlyph.fHeight);

        if (tmpGlyph.fMaskFormat == origGlyph.fMaskFormat) {
            tmpGlyph.fImage = origGlyph.fImage;
        } else {
            tmpGlyphImageStorage.reset(tmpGlyph.computeImageSize());
            tmpGlyph.fImage = tmpGlyphImageStorage.get();
        }
        glyph = &tmpGlyph;
    }

    if (fGenerateImageFromPath) {
        SkPath      devPath, fillPath;
        SkMatrix    fillToDevMatrix;
        SkMask      mask;

        this->internalGetPath(*glyph, &fillPath, &devPath, &fillToDevMatrix);
        glyph->toMask(&mask);

        if (fRasterizer) {
            mask.fFormat = SkMask::kA8_Format;
            sk_bzero(glyph->fImage, mask.computeImageSize());

            if (!fRasterizer->rasterize(fillPath, fillToDevMatrix, nullptr,
                                        fMaskFilter, &mask,
                                        SkMask::kJustRenderImage_CreateMode)) {
                return;
            }
            if (fPreBlend.isApplicable()) {
                applyLUTToA8Mask(mask, fPreBlend.fG);
            }
        } else {
            SkASSERT(SkMask::kARGB32_Format != mask.fFormat);
            generateMask(mask, devPath, fPreBlend);
        }
    } else {
        generateImage(*glyph);
    }

    if (fMaskFilter) {
        SkMask      srcM, dstM;
        SkMatrix    matrix;

        // the src glyph image shouldn't be 3D
        SkASSERT(SkMask::k3D_Format != glyph->fMaskFormat);

        SkAutoSMalloc<32*32> a8storage;
        glyph->toMask(&srcM);
        if (SkMask::kARGB32_Format == srcM.fFormat) {
            // now we need to extract the alpha-channel from the glyph's image
            // and copy it into a temp buffer, and then point srcM at that temp.
            srcM.fFormat = SkMask::kA8_Format;
            srcM.fRowBytes = SkAlign4(srcM.fBounds.width());
            size_t size = srcM.computeImageSize();
            a8storage.reset(size);
            srcM.fImage = (uint8_t*)a8storage.get();
            extract_alpha(srcM,
                          (const SkPMColor*)glyph->fImage, glyph->rowBytes());
        }

        fRec.getMatrixFrom2x2(&matrix);

        if (fMaskFilter->filterMask(&dstM, srcM, matrix, nullptr)) {
            int width = SkFastMin32(origGlyph.fWidth, dstM.fBounds.width());
            int height = SkFastMin32(origGlyph.fHeight, dstM.fBounds.height());
            int dstRB = origGlyph.rowBytes();
            int srcRB = dstM.fRowBytes;

            const uint8_t* src = (const uint8_t*)dstM.fImage;
            uint8_t* dst = (uint8_t*)origGlyph.fImage;

            if (SkMask::k3D_Format == dstM.fFormat) {
                // we have to copy 3 times as much
                height *= 3;
            }
//.........这里部分代码省略.........

static void generateMask(const SkMask& mask, const SkPath& path,
                         const SkMaskGamma::PreBlend& maskPreBlend) {
    SkPaint paint;

    int srcW = mask.fBounds.width();
    int srcH = mask.fBounds.height();
    int dstW = srcW;
    int dstH = srcH;
    int dstRB = mask.fRowBytes;

    SkMatrix matrix;
    matrix.setTranslate(-SkIntToScalar(mask.fBounds.fLeft),
                        -SkIntToScalar(mask.fBounds.fTop));

    paint.setAntiAlias(SkMask::kBW_Format != mask.fFormat);
    switch (mask.fFormat) {
        case SkMask::kBW_Format:
            dstRB = 0;  // signals we need a copy
            break;
        case SkMask::kA8_Format:
            break;
        case SkMask::kLCD16_Format:
            // TODO: trigger off LCD orientation
            dstW = 4*dstW - 8;
            matrix.setTranslate(-SkIntToScalar(mask.fBounds.fLeft + 1),
                                -SkIntToScalar(mask.fBounds.fTop));
            matrix.postScale(SkIntToScalar(4), SK_Scalar1);
            dstRB = 0;  // signals we need a copy
            break;
        default:
            SkDEBUGFAIL("unexpected mask format");
    }

    SkRasterClip clip;
    clip.setRect(SkIRect::MakeWH(dstW, dstH));

    const SkImageInfo info = SkImageInfo::MakeA8(dstW, dstH);
    SkAutoPixmapStorage dst;

    if (0 == dstRB) {
        if (!dst.tryAlloc(info)) {
            // can't allocate offscreen, so empty the mask and return
            sk_bzero(mask.fImage, mask.computeImageSize());
            return;
        }
    } else {
        dst.reset(info, mask.fImage, dstRB);
    }
    sk_bzero(dst.writable_addr(), dst.getSafeSize());

    SkDraw  draw;
    draw.fDst   = dst;
    draw.fRC    = &clip;
    draw.fClip  = &clip.bwRgn();
    draw.fMatrix = &matrix;
    draw.drawPath(path, paint);

    switch (mask.fFormat) {
        case SkMask::kBW_Format:
            packA8ToA1(mask, dst.addr8(0, 0), dst.rowBytes());
            break;
        case SkMask::kA8_Format:
            if (maskPreBlend.isApplicable()) {
                applyLUTToA8Mask(mask, maskPreBlend.fG);
            }
            break;
        case SkMask::kLCD16_Format:
            if (maskPreBlend.isApplicable()) {
                pack4xHToLCD16<true>(dst, mask, maskPreBlend);
            } else {
                pack4xHToLCD16<false>(dst, mask, maskPreBlend);
            }
            break;
        default:
            break;
    }
}

bool SkBlurMask::BoxBlur(SkMask* dst, const SkMask& src,
                         SkScalar sigma, SkBlurStyle style, SkBlurQuality quality,
                         SkIPoint* margin, bool force_quality) {

    if (src.fFormat != SkMask::kA8_Format) {
        return false;
    }

    SkIPoint border;

#ifdef SK_SUPPORT_LEGACY_MASK_BLUR

    auto get_adjusted_radii = [](SkScalar passRadius, int *loRadius, int *hiRadius) {
        *loRadius = *hiRadius = SkScalarCeilToInt(passRadius);
        if (SkIntToScalar(*hiRadius) - passRadius > 0.5f) {
            *loRadius = *hiRadius - 1;
        }
    };

    // Force high quality off for small radii (performance)
    if (!force_quality && sigma <= SkIntToScalar(2)) {
        quality = kLow_SkBlurQuality;
    }

    SkScalar passRadius;
    if (kHigh_SkBlurQuality == quality) {
        // For the high quality path the 3 pass box blur kernel width is
        // 6*rad+1 while the full Gaussian width is 6*sigma.
        passRadius = sigma - (1 / 6.0f);
    } else {
        // For the low quality path we only attempt to cover 3*sigma of the
        // Gaussian blur area (1.5*sigma on each side). The single pass box
        // blur's kernel size is 2*rad+1.
        passRadius = 1.5f * sigma - 0.5f;
    }

    // highQuality: use three box blur passes as a cheap way
    // to approximate a Gaussian blur
    int passCount = (kHigh_SkBlurQuality == quality) ? 3 : 1;

    int rx = SkScalarCeilToInt(passRadius);
    int outerWeight = 255 - SkScalarRoundToInt((SkIntToScalar(rx) - passRadius) * 255);

    SkASSERT(rx >= 0);
    SkASSERT((unsigned)outerWeight <= 255);
    if (rx <= 0) {
        return false;
    }

    int ry = rx;    // only do square blur for now

    int padx = passCount * rx;
    int pady = passCount * ry;

    border = {padx, pady};

    dst->fBounds.set(src.fBounds.fLeft - padx, src.fBounds.fTop - pady,
                     src.fBounds.fRight + padx, src.fBounds.fBottom + pady);

    dst->fRowBytes = dst->fBounds.width();
    dst->fFormat = SkMask::kA8_Format;
    dst->fImage = nullptr;

    if (src.fImage) {
        size_t dstSize = dst->computeImageSize();
        if (0 == dstSize) {
            return false;   // too big to allocate, abort
        }

        int sw = src.fBounds.width();
        int sh = src.fBounds.height();
        const uint8_t* sp = src.fImage;
        uint8_t* dp = SkMask::AllocImage(dstSize);
        SkAutoTCallVProc<uint8_t, SkMask_FreeImage> autoCall(dp);

        // build the blurry destination
        SkAutoTMalloc<uint8_t> tmpBuffer(dstSize);
        uint8_t* tp = tmpBuffer.get();
        int w = sw, h = sh;

        if (outerWeight == 255) {
            int loRadius, hiRadius;
            get_adjusted_radii(passRadius, &loRadius, &hiRadius);
            if (kHigh_SkBlurQuality == quality) {
                // Do three X blurs, with a transpose on the final one.
                w = boxBlur<false>(sp, src.fRowBytes, tp, loRadius, hiRadius, w, h);
                w = boxBlur<false>(tp, w, dp, hiRadius, loRadius, w, h);
                w = boxBlur<true>(dp, w, tp, hiRadius, hiRadius, w, h);
                // Do three Y blurs, with a transpose on the final one.
                h = boxBlur<false>(tp, h, dp, loRadius, hiRadius, h, w);
                h = boxBlur<false>(dp, h, tp, hiRadius, loRadius, h, w);
                h = boxBlur<true>(tp, h, dp, hiRadius, hiRadius, h, w);
            } else {
                w = boxBlur<true>(sp, src.fRowBytes, tp, rx, rx, w, h);
                h = boxBlur<true>(tp, h, dp, ry, ry, h, w);
            }
        } else {
            if (kHigh_SkBlurQuality == quality) {
                // Do three X blurs, with a transpose on the final one.
                w = boxBlurInterp<false>(sp, src.fRowBytes, tp, rx, w, h, outerWeight);
//.........这里部分代码省略.........

static void generateMask(const SkMask& mask, const SkPath& path,
                         const SkMaskGamma::PreBlend& maskPreBlend) {
    SkBitmap::Config config;
    SkPaint     paint;

    int srcW = mask.fBounds.width();
    int srcH = mask.fBounds.height();
    int dstW = srcW;
    int dstH = srcH;
    int dstRB = mask.fRowBytes;

    SkMatrix matrix;
    matrix.setTranslate(-SkIntToScalar(mask.fBounds.fLeft),
                        -SkIntToScalar(mask.fBounds.fTop));

    if (SkMask::kBW_Format == mask.fFormat) {
        config = SkBitmap::kA1_Config;
        paint.setAntiAlias(false);
    } else {
        config = SkBitmap::kA8_Config;
        paint.setAntiAlias(true);
        switch (mask.fFormat) {
            case SkMask::kA8_Format:
                break;
            case SkMask::kLCD16_Format:
            case SkMask::kLCD32_Format:
                // TODO: trigger off LCD orientation
                dstW *= 3;
                matrix.postScale(SkIntToScalar(3), SK_Scalar1);
                dstRB = 0;  // signals we need a copy
                break;
            default:
                SkDEBUGFAIL("unexpected mask format");
        }
    }

    SkRasterClip clip;
    clip.setRect(SkIRect::MakeWH(dstW, dstH));

    SkBitmap bm;
    bm.setConfig(config, dstW, dstH, dstRB);

    if (0 == dstRB) {
        if (!bm.allocPixels()) {
            // can't allocate offscreen, so empty the mask and return
            sk_bzero(mask.fImage, mask.computeImageSize());
            return;
        }
        bm.lockPixels();
    } else {
        bm.setPixels(mask.fImage);
    }
    sk_bzero(bm.getPixels(), bm.getSafeSize());

    SkDraw  draw;
    draw.fRC    = &clip;
    draw.fClip  = &clip.bwRgn();
    draw.fMatrix = &matrix;
    draw.fBitmap = &bm;
    draw.drawPath(path, paint);

    switch (mask.fFormat) {
        case SkMask::kA8_Format:
            if (maskPreBlend.isApplicable()) {
                applyLUTToA8Mask(mask, maskPreBlend.fG);
            }
            break;
        case SkMask::kLCD16_Format:
            if (maskPreBlend.isApplicable()) {
                pack3xHToLCD16<true>(bm, mask, maskPreBlend);
            } else {
                pack3xHToLCD16<false>(bm, mask, maskPreBlend);
            }
            break;
        case SkMask::kLCD32_Format:
            if (maskPreBlend.isApplicable()) {
                pack3xHToLCD32<true>(bm, mask, maskPreBlend);
            } else {
                pack3xHToLCD32<false>(bm, mask, maskPreBlend);
            }
            break;
        default:
            break;
    }
}

bool SkBlurMask::Blur(SkMask* dst, const SkMask& src,
                      SkScalar radius, Style style, Quality quality,
                      SkIPoint* margin)
{
    if (src.fFormat != SkMask::kA8_Format) {
        return false;
    }

    // Force high quality off for small radii (performance)
    if (radius < SkIntToScalar(3)) quality = kLow_Quality;

    // highQuality: use three box blur passes as a cheap way to approximate a Gaussian blur
    int passCount = (quality == kHigh_Quality) ? 3 : 1;
    SkScalar passRadius = SkScalarDiv(radius, SkScalarSqrt(SkIntToScalar(passCount)));

    int rx = SkScalarCeil(passRadius);
    int outer_weight = 255 - SkScalarRound((SkIntToScalar(rx) - passRadius) * 255);

    SkASSERT(rx >= 0);
    SkASSERT((unsigned)outer_weight <= 255);
    if (rx <= 0) {
        return false;
    }

    int ry = rx;    // only do square blur for now

    int padx = passCount * rx;
    int pady = passCount * ry;
    if (margin) {
        margin->set(padx, pady);
    }
    dst->fBounds.set(src.fBounds.fLeft - padx, src.fBounds.fTop - pady,
        src.fBounds.fRight + padx, src.fBounds.fBottom + pady);
    dst->fRowBytes = dst->fBounds.width();
    dst->fFormat = SkMask::kA8_Format;
    dst->fImage = NULL;

    if (src.fImage) {
        size_t dstSize = dst->computeImageSize();
        if (0 == dstSize) {
            return false;   // too big to allocate, abort
        }

        int             sw = src.fBounds.width();
        int             sh = src.fBounds.height();
        const uint8_t*  sp = src.fImage;
        uint8_t*        dp = SkMask::AllocImage(dstSize);

        SkAutoTCallVProc<uint8_t, SkMask_FreeImage> autoCall(dp);

        // build the blurry destination
        {
            const size_t storageW = sw + 2 * (passCount - 1) * rx + 1;
            const size_t storageH = sh + 2 * (passCount - 1) * ry + 1;
            SkAutoTMalloc<uint32_t> storage(storageW * storageH);
            uint32_t*               sumBuffer = storage.get();

            //pass1: sp is source, dp is destination
            build_sum_buffer(sumBuffer, sw, sh, sp, src.fRowBytes);
            if (outer_weight == 255) {
                apply_kernel(dp, rx, ry, sumBuffer, sw, sh);
            } else {
                apply_kernel_interp(dp, rx, ry, sumBuffer, sw, sh, outer_weight);
            }

            if (quality == kHigh_Quality) {
                //pass2: dp is source, tmpBuffer is destination
                int tmp_sw = sw + 2 * rx;
                int tmp_sh = sh + 2 * ry;
                SkAutoTMalloc<uint8_t>  tmpBuffer(dstSize);
                build_sum_buffer(sumBuffer, tmp_sw, tmp_sh, dp, tmp_sw);
                if (outer_weight == 255)
                    apply_kernel(tmpBuffer.get(), rx, ry, sumBuffer, tmp_sw, tmp_sh);
                else
                    apply_kernel_interp(tmpBuffer.get(), rx, ry, sumBuffer,
                                        tmp_sw, tmp_sh, outer_weight);

                //pass3: tmpBuffer is source, dp is destination
                tmp_sw += 2 * rx;
                tmp_sh += 2 * ry;
                build_sum_buffer(sumBuffer, tmp_sw, tmp_sh, tmpBuffer.get(), tmp_sw);
                if (outer_weight == 255)
                    apply_kernel(dp, rx, ry, sumBuffer, tmp_sw, tmp_sh);
                else
                    apply_kernel_interp(dp, rx, ry, sumBuffer, tmp_sw, tmp_sh,
                                        outer_weight);
            }
        }

        dst->fImage = dp;
        // if need be, alloc the "real" dst (same size as src) and copy/merge
        // the blur into it (applying the src)
        if (style == kInner_Style) {
            // now we allocate the "real" dst, mirror the size of src
            size_t srcSize = src.computeImageSize();
            if (0 == srcSize) {
                return false;   // too big to allocate, abort
            }
            dst->fImage = SkMask::AllocImage(srcSize);
            merge_src_with_blur(dst->fImage, src.fRowBytes,
//.........这里部分代码省略.........