blob: d76efb839e484a063d515c3eb325def0308c5ff6 [file] [log] [blame]
/*
* Copyright 2006 The Android Open Source Project
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#include "SkAvoidXfermode.h"
#include "SkColorPriv.h"
#include "SkFlattenableBuffers.h"
#include "SkString.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.readColor();
fDistMul = buffer.readUInt();
fMode = (Mode)buffer.readUInt();
}
void SkAvoidXfermode::flatten(SkFlattenableWriteBuffer& buffer) const {
this->INHERITED::flatten(buffer);
buffer.writeColor(fOpColor);
buffer.writeUInt(fDistMul);
buffer.writeUInt(fMode);
}
// 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..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 inline unsigned Accurate255To256(unsigned x) {
return x + (x >> 7);
}
void SkAvoidXfermode::xfer32(SkPMColor dst[], const SkPMColor src[], int count,
const SkAlpha aa[]) const {
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] = SkFourByteInterp256(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[]) const {
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::xferA8(SkAlpha dst[], const SkPMColor src[], int count,
const SkAlpha aa[]) const {
// override in subclass
}
#ifdef SK_DEVELOPER
void SkAvoidXfermode::toString(SkString* str) const {
str->append("SkAvoidXfermode: opColor: ");
str->appendHex(fOpColor);
str->appendf("distMul: %d ", fDistMul);
static const char* gModeStrings[] = { "Avoid", "Target" };
str->appendf("mode: %s", gModeStrings[fMode]);
}
#endif