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/* libs/graphics/effects/SkAvoidXfermode.cpp
**
** Copyright 2006, The Android Open Source Project
**
** Licensed under the Apache License, Version 2.0 (the "License");
** you may not use this file except in compliance with the License.
** You may obtain a copy of the License at
**
** http://www.apache.org/licenses/LICENSE-2.0
**
** Unless required by applicable law or agreed to in writing, software
** distributed under the License is distributed on an "AS IS" BASIS,
** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
** See the License for the specific language governing permissions and
** limitations under the License.
*/
#include "SkAvoidXfermode.h"
#include "SkColorPriv.h"
SkAvoidXfermode::SkAvoidXfermode(SkColor opColor, U8CPU tolerance, Mode mode)
{
if (tolerance > 255) {
tolerance = 255;
}
fOpColor = opColor;
fDistMul = (256 << 14) / (tolerance + 1);
fMode = mode;
}
SkAvoidXfermode::SkAvoidXfermode(SkFlattenableReadBuffer& buffer)
: INHERITED(buffer)
{
fOpColor = buffer.readU32();
fDistMul = buffer.readU32();
fMode = (Mode)buffer.readU8();
}
void SkAvoidXfermode::flatten(SkFlattenableWriteBuffer& buffer)
{
this->INHERITED::flatten(buffer);
buffer.write32(fOpColor);
buffer.write32(fDistMul);
buffer.write8(fMode);
}
SkFlattenable* SkAvoidXfermode::Create(SkFlattenableReadBuffer& rb)
{
return SkNEW_ARGS(SkAvoidXfermode, (rb));
}
SkFlattenable::Factory SkAvoidXfermode::getFactory()
{
return Create;
}
// returns 0..31
static unsigned color_dist16(uint16_t c, unsigned r, unsigned g, unsigned b)
{
SkASSERT(r <= SK_R16_MASK);
SkASSERT(g <= SK_G16_MASK);
SkASSERT(b <= SK_B16_MASK);
unsigned dr = SkAbs32(SkGetPackedR16(c) - r);
unsigned dg = SkAbs32(SkGetPackedG16(c) - g) >> (SK_G16_BITS - SK_R16_BITS);
unsigned db = SkAbs32(SkGetPackedB16(c) - b);
return SkMax32(dr, SkMax32(dg, db));
}
// returns 0..15
static unsigned color_dist4444(uint16_t c, unsigned r, unsigned g, unsigned b)
{
SkASSERT(r <= 0xF);
SkASSERT(g <= 0xF);
SkASSERT(b <= 0xF);
unsigned dr = SkAbs32(SkGetPackedR4444(c) - r);
unsigned dg = SkAbs32(SkGetPackedG4444(c) - g);
unsigned db = SkAbs32(SkGetPackedB4444(c) - b);
return SkMax32(dr, SkMax32(dg, db));
}
// returns 0..255
static unsigned color_dist32(SkPMColor c, U8CPU r, U8CPU g, U8CPU b)
{
SkASSERT(r <= 0xFF);
SkASSERT(g <= 0xFF);
SkASSERT(b <= 0xFF);
unsigned dr = SkAbs32(SkGetPackedR32(c) - r);
unsigned dg = SkAbs32(SkGetPackedG32(c) - g);
unsigned db = SkAbs32(SkGetPackedB32(c) - b);
return SkMax32(dr, SkMax32(dg, db));
}
static int scale_dist_14(int dist, uint32_t mul, uint32_t sub)
{
int tmp = dist * mul - sub;
int result = (tmp + (1 << 13)) >> 14;
return result;
}
static SkPMColor SkFourByteInterp(SkPMColor src, SkPMColor dst, unsigned scale)
{
unsigned a = SkAlphaBlend(SkGetPackedA32(src), SkGetPackedA32(dst), scale);
unsigned r = SkAlphaBlend(SkGetPackedR32(src), SkGetPackedR32(dst), scale);
unsigned g = SkAlphaBlend(SkGetPackedG32(src), SkGetPackedG32(dst), scale);
unsigned b = SkAlphaBlend(SkGetPackedB32(src), SkGetPackedB32(dst), scale);
return SkPackARGB32(a, r, g, b);
}
static inline unsigned Accurate255To256(unsigned x) {
return x + (x >> 7);
}
void SkAvoidXfermode::xfer32(SkPMColor dst[], const SkPMColor src[], int count,
const SkAlpha aa[])
{
unsigned opR = SkColorGetR(fOpColor);
unsigned opG = SkColorGetG(fOpColor);
unsigned opB = SkColorGetB(fOpColor);
uint32_t mul = fDistMul;
uint32_t sub = (fDistMul - (1 << 14)) << 8;
int MAX, mask;
if (kTargetColor_Mode == fMode) {
mask = -1;
MAX = 255;
} else {
mask = 0;
MAX = 0;
}
for (int i = 0; i < count; i++) {
int d = color_dist32(dst[i], opR, opG, opB);
// now reverse d if we need to
d = MAX + (d ^ mask) - mask;
SkASSERT((unsigned)d <= 255);
d = Accurate255To256(d);
d = scale_dist_14(d, mul, sub);
SkASSERT(d <= 256);
if (d > 0) {
if (NULL != aa) {
d = SkAlphaMul(d, Accurate255To256(*aa++));
if (0 == d) {
continue;
}
}
dst[i] = SkFourByteInterp(src[i], dst[i], d);
}
}
}
static inline U16CPU SkBlend3216(SkPMColor src, U16CPU dst, unsigned scale)
{
SkASSERT(scale <= 32);
scale <<= 3;
return SkPackRGB16( SkAlphaBlend(SkPacked32ToR16(src), SkGetPackedR16(dst), scale),
SkAlphaBlend(SkPacked32ToG16(src), SkGetPackedG16(dst), scale),
SkAlphaBlend(SkPacked32ToB16(src), SkGetPackedB16(dst), scale));
}
void SkAvoidXfermode::xfer16(uint16_t dst[], const SkPMColor src[], int count,
const SkAlpha aa[])
{
unsigned opR = SkColorGetR(fOpColor) >> (8 - SK_R16_BITS);
unsigned opG = SkColorGetG(fOpColor) >> (8 - SK_G16_BITS);
unsigned opB = SkColorGetB(fOpColor) >> (8 - SK_R16_BITS);
uint32_t mul = fDistMul;
uint32_t sub = (fDistMul - (1 << 14)) << SK_R16_BITS;
int MAX, mask;
if (kTargetColor_Mode == fMode) {
mask = -1;
MAX = 31;
} else {
mask = 0;
MAX = 0;
}
for (int i = 0; i < count; i++) {
int d = color_dist16(dst[i], opR, opG, opB);
// now reverse d if we need to
d = MAX + (d ^ mask) - mask;
SkASSERT((unsigned)d <= 31);
// convert from 0..31 to 0..32
d += d >> 4;
d = scale_dist_14(d, mul, sub);
SkASSERT(d <= 32);
if (d > 0) {
if (NULL != aa) {
d = SkAlphaMul(d, Accurate255To256(*aa++));
if (0 == d) {
continue;
}
}
dst[i] = SkBlend3216(src[i], dst[i], d);
}
}
}
void SkAvoidXfermode::xfer4444(uint16_t dst[], const SkPMColor src[], int count,
const SkAlpha aa[])
{
unsigned opR = SkColorGetR(fOpColor) >> 4;
unsigned opG = SkColorGetG(fOpColor) >> 4;
unsigned opB = SkColorGetB(fOpColor) >> 4;
uint32_t mul = fDistMul;
uint32_t sub = (fDistMul - (1 << 14)) << 4;
int MAX, mask;
if (kTargetColor_Mode == fMode) {
mask = -1;
MAX = 15;
} else {
mask = 0;
MAX = 0;
}
for (int i = 0; i < count; i++) {
int d = color_dist4444(dst[i], opR, opG, opB);
// now reverse d if we need to
d = MAX + (d ^ mask) - mask;
SkASSERT((unsigned)d <= 15);
// convert from 0..15 to 0..16
d += d >> 3;
d = scale_dist_14(d, mul, sub);
SkASSERT(d <= 16);
if (d > 0) {
if (NULL != aa) {
d = SkAlphaMul(d, Accurate255To256(*aa++));
if (0 == d) {
continue;
}
}
dst[i] = SkBlend4444(SkPixel32ToPixel4444(src[i]), dst[i], d);
}
}
}
void SkAvoidXfermode::xferA8(SkAlpha dst[], const SkPMColor src[], int count, const SkAlpha aa[])
{
// override in subclass
}
static SkFlattenable::Registrar
gSkAvoidXfermodeReg("SkAvoidXfermode", SkAvoidXfermode::CreateProc);