C++ SkPaint::getXfermode方法代码示例

 static bool Supports(const SkPixmap& dst, const SkPixmap& src, const SkPaint& paint) {
     if (dst.colorType() != src.colorType()) {
         return false;
     }
     if (dst.info().profileType() != src.info().profileType()) {
         return false;
     }
     if (paint.getMaskFilter() || paint.getColorFilter() || paint.getImageFilter()) {
         return false;
     }
     if (0xFF != paint.getAlpha()) {
         return false;
     }
     SkXfermode::Mode mode;
     if (!SkXfermode::AsMode(paint.getXfermode(), &mode)) {
         return false;
     }
     if (SkXfermode::kSrc_Mode == mode) {
         return true;
     }
     if (SkXfermode::kSrcOver_Mode == mode && src.isOpaque()) {
         return true;
     }
     return false;
 }

void CrossfadeGeneratedImage::drawCrossfade(SkCanvas* canvas, const SkPaint& paint, ImageClampingMode clampMode)
{
    FloatRect fromImageRect(FloatPoint(), FloatSize(m_fromImage->size()));
    FloatRect toImageRect(FloatPoint(), FloatSize(m_toImage->size()));
    FloatRect destRect((FloatPoint()), FloatSize(m_crossfadeSize));

    // TODO(junov): The various effects encoded into paint should probably be applied here
    // instead of inside the layer.  This probably faulty behavior was maintained in order
    // to preserve pre-existing behavior while refactoring this code.  This should be
    // investigated further. crbug.com/472634
    SkPaint layerPaint;
    layerPaint.setXfermode(sk_ref_sp(paint.getXfermode()));
    SkAutoCanvasRestore ar(canvas, false);
    canvas->saveLayer(nullptr, &layerPaint);

    SkPaint imagePaint(paint);
    imagePaint.setXfermodeMode(SkXfermode::kSrcOver_Mode);
    int imageAlpha = clampedAlphaForBlending(1 - m_percentage);
    imagePaint.setAlpha(imageAlpha > 255 ? 255 : imageAlpha);
    imagePaint.setAntiAlias(paint.isAntiAlias());
    // TODO(junov): This code should probably be propagating the RespectImageOrientationEnum
    // form CrossfadeGeneratedImage::draw. Code was written this way during refactoring to
    // avoid modifying existing behavior, but this warrants further investigation. crbug.com/472634
    m_fromImage->draw(canvas, imagePaint, destRect, fromImageRect, DoNotRespectImageOrientation, clampMode);
    imagePaint.setXfermodeMode(SkXfermode::kPlus_Mode);
    imageAlpha = clampedAlphaForBlending(m_percentage);
    imagePaint.setAlpha(imageAlpha > 255 ? 255 : imageAlpha);
    m_toImage->draw(canvas, imagePaint, destRect, toImageRect, DoNotRespectImageOrientation, clampMode);
}

SkPDFGraphicState::SkPDFGraphicState(const SkPaint& p)
    : fStrokeWidth(p.getStrokeWidth())
    , fStrokeMiter(p.getStrokeMiter())
    , fAlpha(p.getAlpha())
    , fStrokeCap(SkToU8(p.getStrokeCap()))
    , fStrokeJoin(SkToU8(p.getStrokeJoin()))
    , fMode(SkToU8(mode_for_pdf(p.getXfermode()))) {}

SkRGB16_Black_Blitter::SkRGB16_Black_Blitter(const SkBitmap& device, const SkPaint& paint)
    : INHERITED(device, paint) {
    SkASSERT(paint.getShader() == NULL);
    SkASSERT(paint.getColorFilter() == NULL);
    SkASSERT(paint.getXfermode() == NULL);
    SkASSERT(paint.getColor() == SK_ColorBLACK);
}

    static bool Supports(const SkPixmap& dst, const SkPixmap& src, const SkPaint& paint) {
        if (dst.colorType() != src.colorType()) {
            return false;
        }
        if (dst.info().gammaCloseToSRGB() != src.info().gammaCloseToSRGB()) {
            return false;
        }
        if (paint.getMaskFilter() || paint.getColorFilter() || paint.getImageFilter()) {
            return false;
        }
        if (0xFF != paint.getAlpha()) {
            return false;
        }
        SkXfermode::Mode mode;
        if (!SkXfermode::AsMode(paint.getXfermode(), &mode)) {
            return false;
        }
        if (SkXfermode::kSrc_Mode == mode) {
            return true;
        }
        if (SkXfermode::kSrcOver_Mode == mode && src.isOpaque()) {
            return true;
        }

        // At this point memcpy can't be used. The following check for using SrcOver.

        if (dst.colorType() != kN32_SkColorType || !dst.info().gammaCloseToSRGB()) {
            return false;
        }

        return SkXfermode::kSrcOver_Mode == mode;
    }

void SkGL::SetPaint(const SkPaint& paint, bool isPremul, bool justAlpha) {
    if (justAlpha) {
        SkGL::SetAlpha(paint.getAlpha());
    } else {
        SkGL::SetColor(paint.getColor());
    }

    GLenum sm = GL_ONE;
    GLenum dm = GL_ONE_MINUS_SRC_ALPHA;

    SkXfermode* mode = paint.getXfermode();
    SkXfermode::Coeff sc, dc;
    if (mode && mode->asCoeff(&sc, &dc)) {
        sm = gXfermodeCoeff2Blend[sc];
        dm = gXfermodeCoeff2Blend[dc];
    }

    // hack for text, which is not-premul (afaik)
    if (!isPremul) {
        if (GL_ONE == sm) {
            sm = GL_SRC_ALPHA;
        }
    }

    glEnable(GL_BLEND);
    glBlendFunc(sm, dm);

    if (paint.isDither()) {
        glEnable(GL_DITHER);
    } else {
        glDisable(GL_DITHER);
    }
}

SkARGB32_Shader_Blitter::SkARGB32_Shader_Blitter(const SkBitmap& device,
                                                 const SkPaint& paint)
        : INHERITED(device, paint) {
    fBuffer = (SkPMColor*)sk_malloc_throw(device.width() * (sizeof(SkPMColor)));

    (fXfermode = paint.getXfermode())->safeRef();
}

static void apply_paint_xfermode(const SkPaint& paint, Json::Value* target, bool sendBinaries) {
    SkFlattenable* xfermode = paint.getXfermode();
    if (xfermode != nullptr) {
        Json::Value jsonXfermode;
        flatten(xfermode, &jsonXfermode, sendBinaries);
        (*target)[SKJSONCANVAS_ATTRIBUTE_XFERMODE] = jsonXfermode;
    }
}

bool GrTextUtils::ShouldDisableLCD(const SkPaint& paint) {
    return !SkXfermode::AsMode(paint.getXfermode(), nullptr) ||
           paint.getMaskFilter() ||
           paint.getRasterizer() ||
           paint.getPathEffect() ||
           paint.isFakeBoldText() ||
           paint.getStyle() != SkPaint::kFill_Style;
}

 State4f(const SkImageInfo& info, const SkPaint& paint, const SkShader::Context* shaderContext) {
     fXfer = paint.getXfermode();
     if (shaderContext) {
         fBuffer.reset(info.width());
     } else {
         fPM4f = SkColor4f::FromColor(paint.getColor()).premul();
     }
     fFlags = 0;
 }

static bool fold_opacity_layer_color_to_paint(const SkPaint& layerPaint,
                                              bool isSaveLayer,
                                              SkPaint* paint) {
    // We assume layerPaint is always from a saveLayer.  If isSaveLayer is
    // true, we assume paint is too.

    // The alpha folding can proceed if the filter layer paint does not have properties which cause
    // the resulting filter layer to be "blended" in complex ways to the parent layer. For example,
    // looper drawing unmodulated filter layer twice and then modulating the result produces
    // different image to drawing modulated filter layer twice.
    // TODO: most likely the looper and only some xfer modes are the hard constraints
    if (paint->getXfermode() || paint->getLooper()) {
        return false;
    }

    if (!isSaveLayer && paint->getImageFilter()) {
        // For normal draws, the paint color is used as one input for the color for the draw. Image
        // filter will operate on the result, and thus we can not change the input.
        // For layer saves, the image filter is applied to the layer contents. The layer is then
        // modulated with the paint color, so it's fine to proceed with the fold for saveLayer
        // paints with image filters.
        return false;
    }

    if (paint->getColorFilter()) {
        // Filter input depends on the paint color.

        // Here we could filter the color if we knew the draw is going to be uniform color.  This
        // should be detectable as drawPath/drawRect/.. without a shader being uniform, while
        // drawBitmap/drawSprite or a shader being non-uniform. However, current matchers don't
        // give the type out easily, so just do not optimize that at the moment.
        return false;
    }

    const uint32_t layerColor = layerPaint.getColor();
    // The layer paint color must have only alpha component.
    if (SK_ColorTRANSPARENT != SkColorSetA(layerColor, SK_AlphaTRANSPARENT)) {
        return false;
    }

    // The layer paint can not have any effects.
    if (layerPaint.getPathEffect() ||
        layerPaint.getShader()      ||
        layerPaint.getXfermode()    ||
        layerPaint.getMaskFilter()  ||
        layerPaint.getColorFilter() ||
        layerPaint.getRasterizer()  ||
        layerPaint.getLooper()      ||
        layerPaint.getImageFilter()) {
        return false;
    }

    paint->setAlpha(SkMulDiv255Round(paint->getAlpha(), SkColorGetA(layerColor)));

    return true;
}

// Is the supplied paint simply a color?
static bool is_simple(const SkPaint& p) {
    return NULL == p.getPathEffect() &&
           NULL == p.getShader() &&
           NULL == p.getXfermode() &&
           NULL == p.getMaskFilter() &&
           NULL == p.getColorFilter() &&
           NULL == p.getRasterizer() &&
           NULL == p.getLooper() &&
           NULL == p.getImageFilter();
}

 static bool HasAnyEffect(const SkPaint& paint) {
     return paint.getPathEffect()  ||
            paint.getShader()      ||
            paint.getXfermode()    ||
            paint.getMaskFilter()  ||
            paint.getColorFilter() ||
            paint.getRasterizer()  ||
            paint.getLooper()      ||
            paint.getImageFilter();
 }

bool SkBitmapDevice::onShouldDisableLCD(const SkPaint& paint) const {
    if (kN32_SkColorType != fBitmap.colorType() ||
        paint.getRasterizer() ||
        paint.getPathEffect() ||
        paint.isFakeBoldText() ||
        paint.getStyle() != SkPaint::kFill_Style ||
        !SkXfermode::IsMode(paint.getXfermode(), SkXfermode::kSrcOver_Mode))
    {
        return true;
    }
    return false;
}

static bool drawNeedsLayer(const SkPaint& paint)
{
    if (SkColorGetA(paint.getColor()) < 255)
        return true;

    SkXfermode::Mode xfermode;
    if (SkXfermode::AsMode(paint.getXfermode(), &xfermode)) {
        if (xfermode != SkXfermode::kSrcOver_Mode)
            return true;
    }

    return false;
}