blob: 7b92fde6dbbfcec15584e17dd9c8aeb7f02aef4e [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 "SkTransparentShader.h"
#include "SkColorPriv.h"
#include "SkString.h"
bool SkTransparentShader::setContext(const SkBitmap& device,
const SkPaint& paint,
const SkMatrix& matrix) {
fDevice = &device;
fAlpha = paint.getAlpha();
return this->INHERITED::setContext(device, paint, matrix);
}
uint32_t SkTransparentShader::getFlags() {
uint32_t flags = this->INHERITED::getFlags();
switch (fDevice->getConfig()) {
case SkBitmap::kRGB_565_Config:
flags |= kHasSpan16_Flag;
if (fAlpha == 255)
flags |= kOpaqueAlpha_Flag;
break;
case SkBitmap::kARGB_8888_Config:
case SkBitmap::kARGB_4444_Config:
if (fAlpha == 255 && fDevice->isOpaque())
flags |= kOpaqueAlpha_Flag;
break;
default:
break;
}
return flags;
}
void SkTransparentShader::shadeSpan(int x, int y, SkPMColor span[], int count) {
unsigned scale = SkAlpha255To256(fAlpha);
switch (fDevice->getConfig()) {
case SkBitmap::kARGB_8888_Config:
if (scale == 256) {
SkPMColor* src = fDevice->getAddr32(x, y);
if (src != span) {
memcpy(span, src, count * sizeof(SkPMColor));
}
} else {
const SkPMColor* src = fDevice->getAddr32(x, y);
for (int i = count - 1; i >= 0; --i) {
span[i] = SkAlphaMulQ(src[i], scale);
}
}
break;
case SkBitmap::kRGB_565_Config: {
const uint16_t* src = fDevice->getAddr16(x, y);
if (scale == 256) {
for (int i = count - 1; i >= 0; --i) {
span[i] = SkPixel16ToPixel32(src[i]);
}
} else {
unsigned alpha = fAlpha;
for (int i = count - 1; i >= 0; --i) {
uint16_t c = src[i];
unsigned r = SkPacked16ToR32(c);
unsigned g = SkPacked16ToG32(c);
unsigned b = SkPacked16ToB32(c);
span[i] = SkPackARGB32( alpha,
SkAlphaMul(r, scale),
SkAlphaMul(g, scale),
SkAlphaMul(b, scale));
}
}
break;
}
case SkBitmap::kARGB_4444_Config: {
const uint16_t* src = fDevice->getAddr16(x, y);
if (scale == 256) {
for (int i = count - 1; i >= 0; --i) {
span[i] = SkPixel4444ToPixel32(src[i]);
}
} else {
unsigned scale16 = scale >> 4;
for (int i = count - 1; i >= 0; --i) {
uint32_t c = SkExpand_4444(src[i]) * scale16;
span[i] = SkCompact_8888(c);
}
}
break;
}
case SkBitmap::kIndex8_Config:
SkDEBUGFAIL("index8 not supported as a destination device");
break;
case SkBitmap::kA8_Config: {
const uint8_t* src = fDevice->getAddr8(x, y);
if (scale == 256) {
for (int i = count - 1; i >= 0; --i) {
span[i] = SkPackARGB32(src[i], 0, 0, 0);
}
} else {
for (int i = count - 1; i >= 0; --i) {
span[i] = SkPackARGB32(SkAlphaMul(src[i], scale), 0, 0, 0);
}
}
break;
}
case SkBitmap::kA1_Config:
SkDEBUGFAIL("kA1_Config umimplemented at this time");
break;
default: // to avoid warnings
break;
}
}
void SkTransparentShader::shadeSpan16(int x, int y, uint16_t span[], int count) {
SkASSERT(fDevice->getConfig() == SkBitmap::kRGB_565_Config);
uint16_t* src = fDevice->getAddr16(x, y);
if (src != span) {
memcpy(span, src, count << 1);
}
}
#ifdef SK_DEVELOPER
void SkTransparentShader::toString(SkString* str) const {
str->append("SkTransparentShader: (");
this->INHERITED::toString(str);
str->append(")");
}
#endif