void SkLumaColorFilter::filterSpan(const SkPMColor src[], int count,
SkPMColor dst[]) const {
for (int i = 0; i < count; ++i) {
SkPMColor c = src[i];
/*
* While LuminanceToAlpha is defined to operate on un-premultiplied
* inputs, due to the final alpha scaling it can be computed based on
* premultipled components:
*
* LumA = (k1 * r / a + k2 * g / a + k3 * b / a) * a
* LumA = (k1 * r + k2 * g + k3 * b)
*/
unsigned luma = SkComputeLuminance(SkGetPackedR32(c),
SkGetPackedG32(c),
SkGetPackedB32(c));
dst[i] = SkPackARGB32(luma, 0, 0, 0);
}
}
SkColor GrTextContext::ComputeCanonicalColor(const SkPaint& paint, bool lcd) {
SkColor canonicalColor = SkPaintPriv::ComputeLuminanceColor(paint);
if (lcd) {
// This is the correct computation, but there are tons of cases where LCD can be overridden.
// For now we just regenerate if any run in a textblob has LCD.
// TODO figure out where all of these overrides are and see if we can incorporate that logic
// at a higher level *OR* use sRGB
SkASSERT(false);
//canonicalColor = SkMaskGamma::CanonicalColor(canonicalColor);
} else {
// A8, though can have mixed BMP text but it shouldn't matter because BMP text won't have
// gamma corrected masks anyways, nor color
U8CPU lum = SkComputeLuminance(SkColorGetR(canonicalColor),
SkColorGetG(canonicalColor),
SkColorGetB(canonicalColor));
// reduce to our finite number of bits
canonicalColor = SkMaskGamma::CanonicalColor(SkColorSetRGB(lum, lum, lum));
}
return canonicalColor;
}
bool SkPixmap::erase(SkColor color, const SkIRect& inArea) const {
if (nullptr == fPixels) {
return false;
}
SkIRect area;
if (!area.intersect(this->bounds(), inArea)) {
return false;
}
U8CPU a = SkColorGetA(color);
U8CPU r = SkColorGetR(color);
U8CPU g = SkColorGetG(color);
U8CPU b = SkColorGetB(color);
int height = area.height();
const int width = area.width();
const int rowBytes = this->rowBytes();
switch (this->colorType()) {
case kGray_8_SkColorType: {
if (255 != a) {
r = SkMulDiv255Round(r, a);
g = SkMulDiv255Round(g, a);
b = SkMulDiv255Round(b, a);
}
int gray = SkComputeLuminance(r, g, b);
uint8_t* p = this->writable_addr8(area.fLeft, area.fTop);
while (--height >= 0) {
memset(p, gray, width);
p += rowBytes;
}
break;
}
case kAlpha_8_SkColorType: {
uint8_t* p = this->writable_addr8(area.fLeft, area.fTop);
while (--height >= 0) {
memset(p, a, width);
p += rowBytes;
}
break;
}
case kARGB_4444_SkColorType:
case kRGB_565_SkColorType: {
uint16_t* p = this->writable_addr16(area.fLeft, area.fTop);
uint16_t v;
// make rgb premultiplied
if (255 != a) {
r = SkMulDiv255Round(r, a);
g = SkMulDiv255Round(g, a);
b = SkMulDiv255Round(b, a);
}
if (kARGB_4444_SkColorType == this->colorType()) {
v = pack_8888_to_4444(a, r, g, b);
} else {
v = SkPackRGB16(r >> (8 - SK_R16_BITS),
g >> (8 - SK_G16_BITS),
b >> (8 - SK_B16_BITS));
}
while (--height >= 0) {
sk_memset16(p, v, width);
p = (uint16_t*)((char*)p + rowBytes);
}
break;
}
case kBGRA_8888_SkColorType:
case kRGBA_8888_SkColorType: {
uint32_t* p = this->writable_addr32(area.fLeft, area.fTop);
if (255 != a && kPremul_SkAlphaType == this->alphaType()) {
r = SkMulDiv255Round(r, a);
g = SkMulDiv255Round(g, a);
b = SkMulDiv255Round(b, a);
}
uint32_t v = kRGBA_8888_SkColorType == this->colorType()
? SkPackARGB_as_RGBA(a, r, g, b)
: SkPackARGB_as_BGRA(a, r, g, b);
while (--height >= 0) {
sk_memset32(p, v, width);
p = (uint32_t*)((char*)p + rowBytes);
}
break;
}
default:
return false; // no change, so don't call notifyPixelsChanged()
}
return true;
}
static inline SkPMColor luma_proc(const SkPMColor a, const SkPMColor b) {
unsigned luma = SkComputeLuminance(SkGetPackedR32(b),
SkGetPackedG32(b),
SkGetPackedB32(b));
return SkAlphaMulQ(a, SkAlpha255To256(luma));
}
