C++ SkMask类代码示例

void SkRasterPipelineBlitter::blitMask(const SkMask& mask, const SkIRect& clip) {
    if (mask.fFormat == SkMask::kBW_Format) {
        // TODO: native BW masks?
        return INHERITED::blitMask(mask, clip);
    }

    int x = clip.left();
    for (int y = clip.top(); y < clip.bottom(); y++) {
        auto dst = fDst.writable_addr(0,y);

        SkRasterPipeline p;
        p.extend(fShader);
        p.extend(fColorFilter);
        this->append_load_d(&p, dst);
        p.extend(fXfermode);
        switch (mask.fFormat) {
            case SkMask::kA8_Format:
                p.append<lerp_a8, lerp_a8_1>(mask.getAddr8(x,y)-x);
                break;
            case SkMask::kLCD16_Format:
                p.append<lerp_lcd16, lerp_lcd16_1>(mask.getAddrLCD16(x,y)-x);
                break;
            default: break;
        }
        this->append_store(&p, dst);

        p.run(x, clip.width());
    }
}

void SkARGB32_Opaque_Blitter::blitMask(const SkMask& mask,
                                       const SkIRect& clip) {
    SkASSERT(mask.fBounds.contains(clip));

    if (mask.fFormat == SkMask::kBW_Format) {
        SkARGB32_BlitBW(fDevice, mask, clip, fPMColor);
        return;
    } else if (SkMask::kARGB32_Format == mask.fFormat) {
		SkARGB32_Blit32(fDevice, mask, clip, fPMColor);
		return;
    } else if (SkMask::kLCD16_Format == mask.fFormat) {
        blitmask_lcd16(fDevice, mask, clip, fPMColor);
        return;
	}

    int x = clip.fLeft;
    int y = clip.fTop;
    int width = clip.width();
    int height = clip.height();

#if defined(SK_SUPPORT_LCDTEXT)
    const bool lcdMode = mask.fFormat == SkMask::kHorizontalLCD_Format;
    const bool verticalLCDMode = mask.fFormat == SkMask::kVerticalLCD_Format;

    // In LCD mode the masks have either an extra couple of rows or columns on the edges.
    if (lcdMode || verticalLCDMode) {
        int widthAdjustment, heightAdjustment;
        const uint32_t* alpha32;
        uint32_t* device = adjustForSubpixelClip(mask, clip, fDevice, &widthAdjustment, &heightAdjustment, &alpha32);

        width += widthAdjustment;
        height += heightAdjustment;

        unsigned devRB = fDevice.rowBytes() - (width << 2);
        unsigned alphaExtraRowWords = mask.rowWordsLCD() - width;
        SkPMColor srcColor = fPMColor;

        do {
            unsigned w = width;
            do {
                const uint32_t alphaPixel = *alpha32++;
                const uint32_t originalPixel = *device;
                *device++ = BlendLCDPixelWithOpaqueColor(alphaPixel, originalPixel, srcColor);
            } while (--w != 0);
            device = (uint32_t*)((char*)device + devRB);
            alpha32 += alphaExtraRowWords;
        } while (--height != 0);

        return;
    }
#endif

    fBlitMaskProc(fDevice.getAddr32(x, y), fDevice.rowBytes(),
                  SkBitmap::kARGB_8888_Config,
                  mask.getAddr(x, y), mask.fRowBytes, fColor, width, height);
}

void SkRasterPipelineBlitter::blitMask(const SkMask& mask, const SkIRect& clip) {
    if (mask.fFormat == SkMask::kBW_Format) {
        // TODO: native BW masks?
        return INHERITED::blitMask(mask, clip);
    }

    if (mask.fFormat == SkMask::kA8_Format && !fBlitMaskA8) {
        SkRasterPipeline p(fAlloc);
        p.extend(fColorPipeline);
        if (fBlend == SkBlendMode::kSrcOver) {
            p.append(SkRasterPipeline::scale_u8, &fMaskPtr);
            this->append_load_d(&p);
            this->append_blend(&p);
        } else {
            this->append_load_d(&p);
            this->append_blend(&p);
            p.append(SkRasterPipeline::lerp_u8, &fMaskPtr);
        }
        this->maybe_clamp(&p);
        this->append_store(&p);
        fBlitMaskA8 = p.compile();
    }

    if (mask.fFormat == SkMask::kLCD16_Format && !fBlitMaskLCD16) {
        SkRasterPipeline p(fAlloc);
        p.extend(fColorPipeline);
        this->append_load_d(&p);
        this->append_blend(&p);
        p.append(SkRasterPipeline::lerp_565, &fMaskPtr);
        this->maybe_clamp(&p);
        this->append_store(&p);
        fBlitMaskLCD16 = p.compile();
    }

    int x = clip.left();
    for (int y = clip.top(); y < clip.bottom(); y++) {
        fDstPtr = fDst.writable_addr(0,y);

        this->maybe_shade(x,y,clip.width());
        switch (mask.fFormat) {
            case SkMask::kA8_Format:
                fMaskPtr = mask.getAddr8(x,y)-x;
                fBlitMaskA8(x,y,clip.width());
                break;
            case SkMask::kLCD16_Format:
                fMaskPtr = mask.getAddrLCD16(x,y)-x;
                fBlitMaskLCD16(x,y,clip.width());
                break;
            default:
                // TODO
                break;
        }
    }
}

    bool makeMask(SkMask *m, const SkRect& r) override {
        SkMask src;
        r.roundOut(&src.fBounds);
        src.fBounds.offset(-src.fBounds.fLeft, -src.fBounds.fTop);  // move to origin
        src.fFormat = SkMask::kA8_Format;
        src.fRowBytes = src.fBounds.width();
        src.fImage = SkMask::AllocImage(src.computeTotalImageSize());
        SkAutoMaskFreeImage amfi(src.fImage);

        memset(src.fImage, 0xff, src.computeTotalImageSize());

        return SkBlurMask::BlurGroundTruth(SkBlurMask::ConvertRadiusToSigma(this->radius()),
                                           m, src, this->style());
    }

void SkARGB32_Opaque_Blitter::blitMask(const SkMask& mask,
                                       const SkIRect& clip) {
    SkASSERT(mask.fBounds.contains(clip));

    if (mask.fFormat == SkMask::kBW_Format) {
        SkARGB32_BlitBW(fDevice, mask, clip, fPMColor);
        return;
    } else if (SkMask::kARGB32_Format == mask.fFormat) {
		SkARGB32_Blit32(fDevice, mask, clip, fPMColor);
		return;
    } else if (SkMask::kLCD16_Format == mask.fFormat) {
        blitmask_lcd16(fDevice, mask, clip, fPMColor);
        return;
    } else if (SkMask::kLCD32_Format == mask.fFormat) {
        blitmask_lcd32(fDevice, mask, clip, fPMColor);
        return;
	}

    int x = clip.fLeft;
    int y = clip.fTop;
    int width = clip.width();
    int height = clip.height();

    fBlitMaskProc(fDevice.getAddr32(x, y), fDevice.rowBytes(),
                  SkBitmap::kARGB_8888_Config,
                  mask.getAddr(x, y), mask.fRowBytes, fColor, width, height);
}

void SkARGB32_Opaque_Blitter::blitMask(const SkMask& mask,
                                       const SkIRect& clip) {
    SkASSERT(mask.fBounds.contains(clip));

    if (mask.fFormat == SkMask::kBW_Format) {
        SkARGB32_BlitBW(fDevice, mask, clip, fPMColor);
        return;
    }

    int x = clip.fLeft;
    int y = clip.fTop;
    int width = clip.width();
    int height = clip.height();

    uint32_t*       device = fDevice.getAddr32(x, y);
    const uint8_t*  alpha = mask.getAddr(x, y);
    uint32_t        srcColor = fPMColor;
    unsigned        devRB = fDevice.rowBytes() - (width << 2);
    unsigned        maskRB = mask.fRowBytes - width;

    do {
        int w = width;
        do {
            unsigned aa = *alpha++;
            *device = SkAlphaMulQ(srcColor, SkAlpha255To256(aa)) + SkAlphaMulQ(*device, SkAlpha255To256(255 - aa));
            device += 1;
        } while (--w != 0);
        device = (uint32_t*)((char*)device + devRB);
        alpha += maskRB;
    } while (--height != 0);
}

    void blitMask(const SkMask& mask, const SkIRect& clip) override {
        if (SkMask::kLCD16_Format == mask.fFormat) {
            this->blitLCDMask(mask, clip);
            return;
        }
        if (SkMask::kA8_Format != mask.fFormat) {
            this->INHERITED::blitMask(mask, clip);
            return;
        }

        SkASSERT(mask.fBounds.contains(clip));

        const int x = clip.fLeft;
        const int width = clip.width();
        const int y = clip.fTop;
        const int height = clip.height();

        typename State::DstType* device = State::WritableAddr(fDevice, x, y);
        const size_t dstRB = fDevice.rowBytes();
        const uint8_t* maskRow = (const uint8_t*)mask.getAddr(x, y);
        const size_t maskRB = mask.fRowBytes;

        for (int i = 0; i < height; ++i) {
            fState.fProc1(fState.fXfer, device, &fState.fPM4f, width, maskRow);
            device = (typename State::DstType*)((char*)device + dstRB);
            maskRow += maskRB;
        }
    }

void SkRGB16_Black_Blitter::blitMask(const SkMask& mask,
                                     const SkIRect& clip) {
    if (mask.fFormat == SkMask::kBW_Format) {
        SkRGB16_Black_BlitBW(fDevice, mask, clip);
    } else {
        uint16_t* SK_RESTRICT device = fDevice.getAddr16(clip.fLeft, clip.fTop);
        const uint8_t* SK_RESTRICT alpha = mask.getAddr8(clip.fLeft, clip.fTop);
        unsigned width = clip.width();
        unsigned height = clip.height();
        size_t deviceRB = fDevice.rowBytes() - (width << 1);
        unsigned maskRB = mask.fRowBytes - width;

        SkASSERT((int)height > 0);
        SkASSERT((int)width > 0);
        SkASSERT((int)deviceRB >= 0);
        SkASSERT((int)maskRB >= 0);

        do {
            unsigned w = width;
            do {
                unsigned aa = *alpha++;
                *device = SkAlphaMulRGB16(*device, SkAlpha255To256(255 - aa));
                device += 1;
            } while (--w != 0);
            device = (uint16_t*)((char*)device + deviceRB);
            alpha += maskRB;
        } while (--height != 0);
    }
}

static void dump(const SkMask& mask) {
    for (int y = mask.fBounds.top(); y < mask.fBounds.bottom(); ++y) {
        for (int x = mask.fBounds.left(); x < mask.fBounds.right(); ++x) {
            SkDebugf("%02X", *mask.getAddr8(x, y));
        }
        SkDebugf("\n");
    }
    SkDebugf("\n");
}

void SkARGB32_Shader_Blitter::blitMask(const SkMask& mask, const SkIRect& clip) {
    // we only handle kA8 with an xfermode
    if (fXfermode && (SkMask::kA8_Format != mask.fFormat)) {
        this->INHERITED::blitMask(mask, clip);
        return;
    }

    SkASSERT(mask.fBounds.contains(clip));

    SkBlitMask::RowProc proc = NULL;
    if (!fXfermode) {
        unsigned flags = 0;
        if (fShader->getFlags() & SkShader::kOpaqueAlpha_Flag) {
            flags |= SkBlitMask::kSrcIsOpaque_RowFlag;
        }
        proc = SkBlitMask::RowFactory(SkBitmap::kARGB_8888_Config, mask.fFormat,
                                      (SkBlitMask::RowFlags)flags);
        if (NULL == proc) {
            this->INHERITED::blitMask(mask, clip);
            return;
        }
    }

    const int x = clip.fLeft;
    const int width = clip.width();
    int y = clip.fTop;
    int height = clip.height();

    char* dstRow = (char*)fDevice.getAddr32(x, y);
    const size_t dstRB = fDevice.rowBytes();
    const uint8_t* maskRow = (const uint8_t*)mask.getAddr(x, y);
    const size_t maskRB = mask.fRowBytes;

    SkShader* shader = fShader;
    SkPMColor* span = fBuffer;

    if (fXfermode) {
        SkASSERT(SkMask::kA8_Format == mask.fFormat);
        SkXfermode* xfer = fXfermode;
        do {
            shader->shadeSpan(x, y, span, width);
            xfer->xfer32((SkPMColor*)dstRow, span, width, maskRow);
            dstRow += dstRB;
            maskRow += maskRB;
            y += 1;
        } while (--height > 0);
    } else {
        do {
            shader->shadeSpan(x, y, span, width);
            proc(dstRow, maskRow, span, width);
            dstRow += dstRB;
            maskRow += maskRB;
            y += 1;
        } while (--height > 0);
    }
}

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;
}

static void blitmask_lcd16(const SkBitmap& device, const SkMask& mask,
                           const SkIRect& clip, SkPMColor srcColor) {
    int x = clip.fLeft;
    int y = clip.fTop;
    int width = clip.width();
    int height = clip.height();

    SkPMColor*		dstRow = device.getAddr32(x, y);
    const uint16_t* srcRow = mask.getAddrLCD16(x, y);

    do {
        blit_lcd16_opaque(dstRow, srcRow, srcColor, width);
        dstRow = (SkPMColor*)((char*)dstRow + device.rowBytes());
        srcRow = (const uint16_t*)((const char*)srcRow + mask.fRowBytes);
    } while (--height != 0);
}

    void blitLCDMask(const SkMask& mask, const SkIRect& clip) {
        auto proc = fState.getLCDProc(SkXfermode::kSrcIsSingle_LCDFlag);

        const int x = clip.fLeft;
        const int width = clip.width();
        const int y = clip.fTop;
        const int height = clip.height();

        typename State::DstType* device = State::WritableAddr(fDevice, x, y);
        const size_t dstRB = fDevice.rowBytes();
        const uint16_t* maskRow = (const uint16_t*)mask.getAddr(x, y);
        const size_t maskRB = mask.fRowBytes;

        for (int i = 0; i < height; ++i) {
            proc(device, &fState.fPM4f, width, maskRow);
            device = (typename State::DstType*)((char*)device + dstRB);
            maskRow = (const uint16_t*)((const char*)maskRow + maskRB);
        }
    }

static void SkARGB32_Blit32(const SkPixmap& device, const SkMask& mask,
                            const SkIRect& clip, SkPMColor srcColor) {
    U8CPU alpha = SkGetPackedA32(srcColor);
    unsigned flags = SkBlitRow::kSrcPixelAlpha_Flag32;
    if (alpha != 255) {
        flags |= SkBlitRow::kGlobalAlpha_Flag32;
    }
    SkBlitRow::Proc32 proc = SkBlitRow::Factory32(flags);

    int x = clip.fLeft;
    int y = clip.fTop;
    int width = clip.width();
    int height = clip.height();

    SkPMColor* dstRow = device.writable_addr32(x, y);
    const SkPMColor* srcRow = reinterpret_cast<const SkPMColor*>(mask.getAddr8(x, y));

    do {
        proc(dstRow, srcRow, width, alpha);
        dstRow = (SkPMColor*)((char*)dstRow + device.rowBytes());
        srcRow = (const SkPMColor*)((const char*)srcRow + mask.fRowBytes);
    } while (--height != 0);
}