/*
* Copyright 2014 Google Inc.
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#include "SkBitmap.h"
#include "SkCanvas.h"
#include "SkConfig8888.h"
#include "SkColorPriv.h"
#include "SkDither.h"
#include "SkMathPriv.h"
#include "SkUnPreMultiply.h"
enum AlphaVerb {
kNothing_AlphaVerb,
kPremul_AlphaVerb,
kUnpremul_AlphaVerb,
};
template <bool doSwapRB, AlphaVerb doAlpha> uint32_t convert32(uint32_t c) {
if (doSwapRB) {
c = SkSwizzle_RB(c);
}
// Lucky for us, in both RGBA and BGRA, the alpha component is always in the same place, so
// we can perform premul or unpremul the same way without knowing the swizzles for RGB.
switch (doAlpha) {
case kNothing_AlphaVerb:
// no change
break;
case kPremul_AlphaVerb:
c = SkPreMultiplyARGB(SkGetPackedA32(c), SkGetPackedR32(c),
SkGetPackedG32(c), SkGetPackedB32(c));
break;
case kUnpremul_AlphaVerb:
c = SkUnPreMultiply::UnPreMultiplyPreservingByteOrder(c);
break;
}
return c;
}
template <bool doSwapRB, AlphaVerb doAlpha>
void convert32_row(uint32_t* dst, const uint32_t* src, int count) {
// This has to be correct if src == dst (but not partial overlap)
for (int i = 0; i < count; ++i) {
dst[i] = convert32<doSwapRB, doAlpha>(src[i]);
}
}
static bool is_32bit_colortype(SkColorType ct) {
return kRGBA_8888_SkColorType == ct || kBGRA_8888_SkColorType == ct;
}
static AlphaVerb compute_AlphaVerb(SkAlphaType src, SkAlphaType dst) {
SkASSERT(kUnknown_SkAlphaType != src);
SkASSERT(kUnknown_SkAlphaType != dst);
if (kOpaque_SkAlphaType == src || kOpaque_SkAlphaType == dst || src == dst) {
return kNothing_AlphaVerb;
}
if (kPremul_SkAlphaType == dst) {
SkASSERT(kUnpremul_SkAlphaType == src);
return kPremul_AlphaVerb;
} else {
SkASSERT(kPremul_SkAlphaType == src);
SkASSERT(kUnpremul_SkAlphaType == dst);
return kUnpremul_AlphaVerb;
}
}
static void memcpy32_row(uint32_t* dst, const uint32_t* src, int count) {
memcpy(dst, src, count * 4);
}
bool SkSrcPixelInfo::convertPixelsTo(SkDstPixelInfo* dst, int width, int height) const {
if (width <= 0 || height <= 0) {
return false;
}
if (!is_32bit_colortype(fColorType) || !is_32bit_colortype(dst->fColorType)) {
return false;
}
void (*proc)(uint32_t* dst, const uint32_t* src, int count);
AlphaVerb doAlpha = compute_AlphaVerb(fAlphaType, dst->fAlphaType);
bool doSwapRB = fColorType != dst->fColorType;
switch (doAlpha) {
case kNothing_AlphaVerb:
if (doSwapRB) {
proc = convert32_row<true, kNothing_AlphaVerb>;
} else {
if (fPixels == dst->fPixels) {
return true;
}
proc = memcpy32_row;
}
break;
case kPremul_AlphaVerb:
if (doSwapRB) {
proc = convert32_row<true, kPremul_AlphaVerb>;
} else {
proc = convert32_row<false, kPremul_AlphaVerb>;
}
break;
case kUnpremul_AlphaVerb:
if (doSwapRB) {
proc = convert32_row<true, kUnpremul_AlphaVerb>;
} else {
proc = convert32_row<false, kUnpremul_AlphaVerb>;
}
break;
}
uint32_t* dstP = static_cast<uint32_t*>(dst->fPixels);
const uint32_t* srcP = static_cast<const uint32_t*>(fPixels);
size_t srcInc = fRowBytes >> 2;
size_t dstInc = dst->fRowBytes >> 2;
for (int y = 0; y < height; ++y) {
proc(dstP, srcP, width);
dstP += dstInc;
srcP += srcInc;
}
return true;
}
static void rect_memcpy(void* dst, size_t dstRB, const void* src, size_t srcRB, size_t bytesPerRow,
int rowCount) {
SkASSERT(bytesPerRow <= srcRB);
SkASSERT(bytesPerRow <= dstRB);
for (int i = 0; i < rowCount; ++i) {
memcpy(dst, src, bytesPerRow);
dst = (char*)dst + dstRB;
src = (const char*)src + srcRB;
}
}
static void copy_g8_to_32(void* dst, size_t dstRB, const void* src, size_t srcRB, int w, int h) {
uint32_t* dst32 = (uint32_t*)dst;
const uint8_t* src8 = (const uint8_t*)src;
for (int y = 0; y < h; ++y) {
for (int x = 0; x < w; ++x) {
dst32[x] = SkPackARGB32(0xFF, src8[x], src8[x], src8[x]);
}
dst32 = (uint32_t*)((char*)dst32 + dstRB);
src8 += srcRB;
}
}
static void copy_32_to_g8(void* dst, size_t dstRB, const void* src, size_t srcRB,
const SkImageInfo& srcInfo) {
uint8_t* dst8 = (uint8_t*)dst;
const uint32_t* src32 = (const uint32_t*)src;
const int w = srcInfo.width();
const int h = srcInfo.height();
const bool isBGRA = (kBGRA_8888_SkColorType == srcInfo.colorType());
for (int y = 0; y < h; ++y) {
if (isBGRA) {
// BGRA
for (int x = 0; x < w; ++x) {
uint32_t s = src32[x];
dst8[x] = SkComputeLuminance((s >> 16) & 0xFF, (s >> 8) & 0xFF, s & 0xFF);
}
} else {
// RGBA
for (int x = 0; x < w; ++x) {
uint32_t s = src32[x];
dst8[x] = SkComputeLuminance(s & 0xFF, (s >> 8) & 0xFF, (s >> 16) & 0xFF);
}
}
src32 = (const uint32_t*)((const char*)src32 + srcRB);
dst8 += dstRB;
}
}
bool SkPixelInfo::CopyPixels(const SkImageInfo& dstInfo, void* dstPixels, size_t dstRB,
const SkImageInfo& srcInfo, const void* srcPixels, size_t srcRB,
SkColorTable* ctable) {
if (srcInfo.dimensions() != dstInfo.dimensions()) {
return false;
}
const int width = srcInfo.width();
const int height = srcInfo.height();
// Handle fancy alpha swizzling if both are ARGB32
if (4 == srcInfo.bytesPerPixel() && 4 == dstInfo.bytesPerPixel()) {
SkDstPixelInfo dstPI;
dstPI.fColorType = dstInfo.colorType();
dstPI.fAlphaType = dstInfo.alphaType();
dstPI.fPixels = dstPixels;
dstPI.fRowBytes = dstRB;
SkSrcPixelInfo srcPI;
srcPI.fColorType = srcInfo.colorType();
srcPI.fAlphaType = srcInfo.alphaType();
srcPI.fPixels = srcPixels;
srcPI.fRowBytes = srcRB;
return srcPI.convertPixelsTo(&dstPI, width, height);
}
// If they agree on colorType and the alphaTypes are compatible, then we just memcpy.
// Note: we've already taken care of 32bit colortypes above.
if (srcInfo.colorType() == dstInfo.colorType()) {
switch (srcInfo.colorType()) {
case kRGB_565_SkColorType:
case kAlpha_8_SkColorType:
case kGray_8_SkColorType:
break;
case kIndex_8_SkColorType:
case kARGB_4444_SkColorType:
if (srcInfo.alphaType() != dstInfo.alphaType()) {
return false;
}
break;
default:
return false;
}
rect_memcpy(dstPixels, dstRB, srcPixels, srcRB, width * srcInfo.bytesPerPixel(), height);
return true;
}
/*
* Begin section where we try to change colorTypes along the way. Not all combinations
* are supported.
*/
if (kGray_8_SkColorType == srcInfo.colorType() && 4 == dstInfo.bytesPerPixel()) {
copy_g8_to_32(dstPixels, dstRB, srcPixels, srcRB, width, height);
return true;
}
if (kGray_8_SkColorType == dstInfo.colorType() && 4 == srcInfo.bytesPerPixel()) {
copy_32_to_g8(dstPixels, dstRB, srcPixels, srcRB, srcInfo);
return true;
}
// Can no longer draw directly into 4444, but we can manually whack it for a few combinations
if (kARGB_4444_SkColorType == dstInfo.colorType() &&
(kN32_SkColorType == srcInfo.colorType() || kIndex_8_SkColorType == srcInfo.colorType())) {
if (srcInfo.alphaType() == kUnpremul_SkAlphaType) {
// Our method for converting to 4444 assumes premultiplied.
return false;
}
const SkPMColor* table = NULL;
if (kIndex_8_SkColorType == srcInfo.colorType()) {
if (NULL == ctable) {
return false;
}
table = ctable->readColors();
}
for (int y = 0; y < height; ++y) {
DITHER_4444_SCAN(y);
SkPMColor16* SK_RESTRICT dstRow = (SkPMColor16*)dstPixels;
if (table) {
const uint8_t* SK_RESTRICT srcRow = (const uint8_t*)srcPixels;
for (int x = 0; x < width; ++x) {
dstRow[x] = SkDitherARGB32To4444(table[srcRow[x]], DITHER_VALUE(x));
}
} else {
const SkPMColor* SK_RESTRICT srcRow = (const SkPMColor*)srcPixels;
for (int x = 0; x < width; ++x) {
dstRow[x] = SkDitherARGB32To4444(srcRow[x], DITHER_VALUE(x));
}
}
dstPixels = (char*)dstPixels + dstRB;
srcPixels = (const char*)srcPixels + srcRB;
}
return true;
}
if (dstInfo.alphaType() == kUnpremul_SkAlphaType) {
// We do not support drawing to unpremultiplied bitmaps.
return false;
}
// Final fall-back, draw with a canvas
//
// Always clear the dest in case one of the blitters accesses it
// TODO: switch the allocation of tmpDst to call sk_calloc_throw
{
SkBitmap bm;
if (!bm.installPixels(srcInfo, const_cast<void*>(srcPixels), srcRB, ctable, NULL, NULL)) {
return false;
}
SkAutoTUnref<SkCanvas> canvas(SkCanvas::NewRasterDirect(dstInfo, dstPixels, dstRB));
if (NULL == canvas.get()) {
return false;
}
SkPaint paint;
paint.setDither(true);
canvas->clear(0);
canvas->drawBitmap(bm, 0, 0, &paint);
return true;
}
}