SkBitmapDevice* SkBitmapDevice::Create(const SkImageInfo& origInfo,
const SkSurfaceProps& surfaceProps) {
SkAlphaType newAT = origInfo.alphaType();
if (!valid_for_bitmap_device(origInfo, &newAT)) {
return nullptr;
}
const SkImageInfo info = origInfo.makeAlphaType(newAT);
SkBitmap bitmap;
if (kUnknown_SkColorType == info.colorType()) {
if (!bitmap.setInfo(info)) {
return nullptr;
}
} else if (info.isOpaque()) {
// If this bitmap is opaque, we don't have any sensible default color,
// so we just return uninitialized pixels.
if (!bitmap.tryAllocPixels(info)) {
return nullptr;
}
} else {
// This bitmap has transparency, so we'll zero the pixels (to transparent).
// We use a ZeroedPRFactory as a faster alloc-then-eraseColor(SK_ColorTRANSPARENT).
SkMallocPixelRef::ZeroedPRFactory factory;
if (!bitmap.tryAllocPixels(info, &factory, nullptr/*color table*/)) {
return nullptr;
}
}
return new SkBitmapDevice(bitmap, surfaceProps);
}
bool allocHandle(const SkImageInfo& info, Rec* rec) override {
SkASSERT(info.colorType() == kN32_SkColorType);
return Create(info.width(), info.height(), info.isOpaque(), rec);
}
bool SkJpegEncoderMgr::setParams(const SkImageInfo& srcInfo, const SkJpegEncoder::Options& options)
{
auto chooseProc8888 = [&]() {
if (kUnpremul_SkAlphaType != srcInfo.alphaType() ||
SkJpegEncoder::AlphaOption::kIgnore == options.fAlphaOption)
{
return (transform_scanline_proc) nullptr;
}
// Note that kRespect mode is only supported with sRGB or linear transfer functions.
// The legacy code path is incidentally correct when the transfer function is linear.
const bool isSRGBTransferFn = srcInfo.gammaCloseToSRGB() &&
(SkTransferFunctionBehavior::kRespect == options.fBlendBehavior);
if (isSRGBTransferFn) {
return transform_scanline_to_premul_linear;
} else {
return transform_scanline_to_premul_legacy;
}
};
J_COLOR_SPACE jpegColorType = JCS_EXT_RGBA;
int numComponents = 0;
switch (srcInfo.colorType()) {
case kRGBA_8888_SkColorType:
fProc = chooseProc8888();
jpegColorType = JCS_EXT_RGBA;
numComponents = 4;
break;
case kBGRA_8888_SkColorType:
fProc = chooseProc8888();
jpegColorType = JCS_EXT_BGRA;
numComponents = 4;
break;
case kRGB_565_SkColorType:
fProc = transform_scanline_565;
jpegColorType = JCS_RGB;
numComponents = 3;
break;
case kARGB_4444_SkColorType:
if (SkJpegEncoder::AlphaOption::kBlendOnBlack == options.fAlphaOption) {
return false;
}
fProc = transform_scanline_444;
jpegColorType = JCS_RGB;
numComponents = 3;
break;
case kGray_8_SkColorType:
SkASSERT(srcInfo.isOpaque());
jpegColorType = JCS_GRAYSCALE;
numComponents = 1;
break;
case kRGBA_F16_SkColorType:
if (!srcInfo.colorSpace() || !srcInfo.colorSpace()->gammaIsLinear() ||
SkTransferFunctionBehavior::kRespect != options.fBlendBehavior) {
return false;
}
if (kUnpremul_SkAlphaType != srcInfo.alphaType() ||
SkJpegEncoder::AlphaOption::kIgnore == options.fAlphaOption)
{
fProc = transform_scanline_F16_to_8888;
} else {
fProc = transform_scanline_F16_to_premul_8888;
}
jpegColorType = JCS_EXT_RGBA;
numComponents = 4;
break;
default:
return false;
}
fCInfo.image_width = srcInfo.width();
fCInfo.image_height = srcInfo.height();
fCInfo.in_color_space = jpegColorType;
fCInfo.input_components = numComponents;
jpeg_set_defaults(&fCInfo);
if (kGray_8_SkColorType != srcInfo.colorType()) {
switch (options.fDownsample) {
case SkJpegEncoder::Downsample::k420:
SkASSERT(2 == fCInfo.comp_info[0].h_samp_factor);
SkASSERT(2 == fCInfo.comp_info[0].v_samp_factor);
SkASSERT(1 == fCInfo.comp_info[1].h_samp_factor);
SkASSERT(1 == fCInfo.comp_info[1].v_samp_factor);
SkASSERT(1 == fCInfo.comp_info[2].h_samp_factor);
SkASSERT(1 == fCInfo.comp_info[2].v_samp_factor);
break;
case SkJpegEncoder::Downsample::k422:
fCInfo.comp_info[0].h_samp_factor = 2;
fCInfo.comp_info[0].v_samp_factor = 1;
fCInfo.comp_info[1].h_samp_factor = 1;
fCInfo.comp_info[1].v_samp_factor = 1;
fCInfo.comp_info[2].h_samp_factor = 1;
fCInfo.comp_info[2].v_samp_factor = 1;
break;
case SkJpegEncoder::Downsample::k444:
fCInfo.comp_info[0].h_samp_factor = 1;
fCInfo.comp_info[0].v_samp_factor = 1;
fCInfo.comp_info[1].h_samp_factor = 1;
fCInfo.comp_info[1].v_samp_factor = 1;
fCInfo.comp_info[2].h_samp_factor = 1;
fCInfo.comp_info[2].v_samp_factor = 1;
break;
}
}
// Tells libjpeg-turbo to compute optimal Huffman coding tables
// for the image. This improves compression at the cost of
// slower encode performance.
fCInfo.optimize_coding = TRUE;
return true;
}
bool SkPngEncoderMgr::setHeader(const SkImageInfo& srcInfo, const SkPngEncoder::Options& options) {
if (setjmp(png_jmpbuf(fPngPtr))) {
return false;
}
int pngColorType;
png_color_8 sigBit;
int bitDepth = 8;
switch (srcInfo.colorType()) {
case kRGBA_F16_SkColorType:
case kRGBA_F32_SkColorType:
sigBit.red = 16;
sigBit.green = 16;
sigBit.blue = 16;
sigBit.alpha = 16;
bitDepth = 16;
pngColorType = srcInfo.isOpaque() ? PNG_COLOR_TYPE_RGB : PNG_COLOR_TYPE_RGB_ALPHA;
fPngBytesPerPixel = 8;
break;
case kGray_8_SkColorType:
sigBit.gray = 8;
pngColorType = PNG_COLOR_TYPE_GRAY;
fPngBytesPerPixel = 1;
SkASSERT(srcInfo.isOpaque());
break;
case kRGBA_8888_SkColorType:
case kBGRA_8888_SkColorType:
sigBit.red = 8;
sigBit.green = 8;
sigBit.blue = 8;
sigBit.alpha = 8;
pngColorType = srcInfo.isOpaque() ? PNG_COLOR_TYPE_RGB : PNG_COLOR_TYPE_RGB_ALPHA;
fPngBytesPerPixel = srcInfo.isOpaque() ? 3 : 4;
break;
case kRGB_888x_SkColorType:
sigBit.red = 8;
sigBit.green = 8;
sigBit.blue = 8;
pngColorType = PNG_COLOR_TYPE_RGB;
fPngBytesPerPixel = 3;
SkASSERT(srcInfo.isOpaque());
break;
case kARGB_4444_SkColorType:
if (kUnpremul_SkAlphaType == srcInfo.alphaType()) {
return false;
}
sigBit.red = 4;
sigBit.green = 4;
sigBit.blue = 4;
sigBit.alpha = 4;
pngColorType = srcInfo.isOpaque() ? PNG_COLOR_TYPE_RGB : PNG_COLOR_TYPE_RGB_ALPHA;
fPngBytesPerPixel = srcInfo.isOpaque() ? 3 : 4;
break;
case kRGB_565_SkColorType:
sigBit.red = 5;
sigBit.green = 6;
sigBit.blue = 5;
pngColorType = PNG_COLOR_TYPE_RGB;
fPngBytesPerPixel = 3;
SkASSERT(srcInfo.isOpaque());
break;
case kAlpha_8_SkColorType: // store as gray+alpha, but ignore gray
sigBit.gray = kGraySigBit_GrayAlphaIsJustAlpha;
sigBit.alpha = 8;
pngColorType = PNG_COLOR_TYPE_GRAY_ALPHA;
fPngBytesPerPixel = 2;
break;
case kRGBA_1010102_SkColorType:
bitDepth = 16;
sigBit.red = 10;
sigBit.green = 10;
sigBit.blue = 10;
sigBit.alpha = 2;
pngColorType = srcInfo.isOpaque() ? PNG_COLOR_TYPE_RGB : PNG_COLOR_TYPE_RGB_ALPHA;
fPngBytesPerPixel = 8;
break;
case kRGB_101010x_SkColorType:
bitDepth = 16;
sigBit.red = 10;
sigBit.green = 10;
sigBit.blue = 10;
pngColorType = PNG_COLOR_TYPE_RGB;
fPngBytesPerPixel = 6;
break;
default:
return false;
}
png_set_IHDR(fPngPtr, fInfoPtr, srcInfo.width(), srcInfo.height(),
bitDepth, pngColorType,
PNG_INTERLACE_NONE, PNG_COMPRESSION_TYPE_BASE,
PNG_FILTER_TYPE_BASE);
png_set_sBIT(fPngPtr, fInfoPtr, &sigBit);
int filters = (int)options.fFilterFlags & (int)SkPngEncoder::FilterFlag::kAll;
SkASSERT(filters == (int)options.fFilterFlags);
png_set_filter(fPngPtr, PNG_FILTER_TYPE_BASE, filters);
int zlibLevel = SkTMin(SkTMax(0, options.fZLibLevel), 9);
SkASSERT(zlibLevel == options.fZLibLevel);
png_set_compression_level(fPngPtr, zlibLevel);
// Set comments in tEXt chunk
const sk_sp<SkDataTable>& comments = options.fComments;
if (comments != nullptr) {
std::vector<png_text> png_texts(comments->count());
std::vector<SkString> clippedKeys;
for (int i = 0; i < comments->count() / 2; ++i) {
const char* keyword;
const char* originalKeyword = comments->atStr(2 * i);
const char* text = comments->atStr(2 * i + 1);
if (strlen(originalKeyword) <= PNG_KEYWORD_MAX_LENGTH) {
keyword = originalKeyword;
} else {
SkDEBUGFAILF("PNG tEXt keyword should be no longer than %d.",
PNG_KEYWORD_MAX_LENGTH);
clippedKeys.emplace_back(originalKeyword, PNG_KEYWORD_MAX_LENGTH);
keyword = clippedKeys.back().c_str();
}
// It seems safe to convert png_const_charp to png_charp for key/text,
// and we don't have to provide text_length and other fields as we're providing
// 0-terminated c_str with PNG_TEXT_COMPRESSION_NONE (no compression, no itxt).
png_texts[i].compression = PNG_TEXT_COMPRESSION_NONE;
png_texts[i].key = (png_charp)keyword;
png_texts[i].text = (png_charp)text;
}
png_set_text(fPngPtr, fInfoPtr, png_texts.data(), png_texts.size());
}
return true;
}