SkImageFilter* CanvasRenderingContext2DState::shadowAndForegroundImageFilter() const
{
if (!m_shadowAndForegroundImageFilter) {
double sigma = skBlurRadiusToSigma(m_shadowBlur);
m_shadowAndForegroundImageFilter = adoptRef(SkDropShadowImageFilter::Create(m_shadowOffset.width(), m_shadowOffset.height(), sigma, sigma, m_shadowColor, SkDropShadowImageFilter::kDrawShadowAndForeground_ShadowMode));
}
return m_shadowAndForegroundImageFilter.get();
}
SkImageFilter* CanvasRenderingContext2DState::shadowOnlyImageFilter() const
{
if (!m_shadowOnlyImageFilter) {
double sigma = skBlurRadiusToSigma(m_shadowBlur);
m_shadowOnlyImageFilter = SkDropShadowImageFilter::Make(m_shadowOffset.width(), m_shadowOffset.height(), sigma, sigma, m_shadowColor, SkDropShadowImageFilter::kDrawShadowOnly_ShadowMode, nullptr);
}
return m_shadowOnlyImageFilter.get();
}
void DrawLooperBuilder::addShadow(const FloatSize& offset, float blur, const Color& color,
ShadowTransformMode shadowTransformMode, ShadowAlphaMode shadowAlphaMode)
{
// Negative blurs are not allowed, so just pin the value to 0
if (blur < 0)
blur = 0;
// Detect when there's no effective shadow.
if (!color.alpha())
return;
SkColor skColor = color.rgb();
SkLayerDrawLooper::LayerInfo info;
switch (shadowAlphaMode) {
case ShadowRespectsAlpha:
info.fColorMode = SkXfermode::kDst_Mode;
break;
case ShadowIgnoresAlpha:
info.fColorMode = SkXfermode::kSrc_Mode;
break;
default:
ASSERT_NOT_REACHED();
}
if (blur)
info.fPaintBits |= SkLayerDrawLooper::kMaskFilter_Bit; // our blur
info.fPaintBits |= SkLayerDrawLooper::kColorFilter_Bit;
info.fOffset.set(offset.width(), offset.height());
info.fPostTranslate = (shadowTransformMode == ShadowIgnoresTransforms);
SkPaint* paint = m_skDrawLooperBuilder.addLayerOnTop(info);
if (blur) {
const SkScalar sigma = skBlurRadiusToSigma(blur);
uint32_t mfFlags = SkBlurMaskFilter::kHighQuality_BlurFlag;
if (shadowTransformMode == ShadowIgnoresTransforms)
mfFlags |= SkBlurMaskFilter::kIgnoreTransform_BlurFlag;
RefPtr<SkMaskFilter> mf = adoptRef(SkBlurMaskFilter::Create(kNormal_SkBlurStyle, sigma, mfFlags));
paint->setMaskFilter(mf.get());
}
RefPtr<SkColorFilter> cf = adoptRef(SkColorFilter::CreateModeFilter(skColor, SkXfermode::kSrcIn_Mode));
paint->setColorFilter(cf.get());
}
