thirdparty/scummvm
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IMAGE: Don't perform color conversion when decoding PNGs

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This commit is contained in:
Bastien Bouclet 2019-01-31 18:47:29 +01:00
parent 0d5d04ca3a
commit 9f98cddf8d
2 changed files with 19 additions and 14 deletions
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29
image/png.cpp
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@ -39,7 +39,11 @@
namespace Image { namespace Image {
PNGDecoder::PNGDecoder() : _outputSurface(0), _palette(0), _paletteColorCount(0), _skipSignature(false) { PNGDecoder::PNGDecoder() :
_outputSurface(0),
_palette(0),
_paletteColorCount(0),
_skipSignature(false) {
} }
PNGDecoder::~PNGDecoder() { PNGDecoder::~PNGDecoder() {
@ -56,6 +60,14 @@ void PNGDecoder::destroy() {
_palette = NULL; _palette = NULL;
} }
Graphics::PixelFormat PNGDecoder::getByteOrderRgbaPixelFormat() const {
#ifdef SCUMM_BIG_ENDIAN
return Graphics::PixelFormat(4, 8, 8, 8, 8, 24, 16, 8, 0);
#else
return Graphics::PixelFormat(4, 8, 8, 8, 8, 0, 8, 16, 24);
#endif
}
#ifdef USE_PNG #ifdef USE_PNG
// libpng-error-handling: // libpng-error-handling:
void pngError(png_structp pngptr, png_const_charp errorMsg) { void pngError(png_structp pngptr, png_const_charp errorMsg) {
@ -166,13 +178,11 @@ bool PNGDecoder::loadStream(Common::SeekableReadStream &stream) {
_outputSurface->create(width, height, Graphics::PixelFormat::createFormatCLUT8()); _outputSurface->create(width, height, Graphics::PixelFormat::createFormatCLUT8());
png_set_packing(pngPtr); png_set_packing(pngPtr);
} else { } else {
bool isAlpha = (colorType & PNG_COLOR_MASK_ALPHA);
if (png_get_valid(pngPtr, infoPtr, PNG_INFO_tRNS)) { if (png_get_valid(pngPtr, infoPtr, PNG_INFO_tRNS)) {
isAlpha = true;
png_set_expand(pngPtr); png_set_expand(pngPtr);
} }
_outputSurface->create(width, height, Graphics::PixelFormat(4,
8, 8, 8, isAlpha ? 8 : 0, 24, 16, 8, 0)); _outputSurface->create(width, height, getByteOrderRgbaPixelFormat());
if (!_outputSurface->getPixels()) { if (!_outputSurface->getPixels()) {
error("Could not allocate memory for output image."); error("Could not allocate memory for output image.");
} }
@ -184,17 +194,8 @@ bool PNGDecoder::loadStream(Common::SeekableReadStream &stream) {
colorType == PNG_COLOR_TYPE_GRAY_ALPHA) colorType == PNG_COLOR_TYPE_GRAY_ALPHA)
png_set_gray_to_rgb(pngPtr); png_set_gray_to_rgb(pngPtr);
// PNGs are Big-Endian:
#ifdef SCUMM_LITTLE_ENDIAN
png_set_bgr(pngPtr);
png_set_swap_alpha(pngPtr);
if (colorType != PNG_COLOR_TYPE_RGB_ALPHA)
png_set_filler(pngPtr, 0xff, PNG_FILLER_BEFORE);
#else
if (colorType != PNG_COLOR_TYPE_RGB_ALPHA) if (colorType != PNG_COLOR_TYPE_RGB_ALPHA)
png_set_filler(pngPtr, 0xff, PNG_FILLER_AFTER); png_set_filler(pngPtr, 0xff, PNG_FILLER_AFTER);
#endif
} }
// After the transformations have been registered, the image data is read again. // After the transformations have been registered, the image data is read again.

4
image/png.h
View file

@ -33,6 +33,7 @@
#include "common/scummsys.h" #include "common/scummsys.h"
#include "common/textconsole.h" #include "common/textconsole.h"
#include "graphics/pixelformat.h"
#include "image/image_decoder.h" #include "image/image_decoder.h"
namespace Common { namespace Common {
@ -57,7 +58,10 @@ public:
const byte *getPalette() const { return _palette; } const byte *getPalette() const { return _palette; }
uint16 getPaletteColorCount() const { return _paletteColorCount; } uint16 getPaletteColorCount() const { return _paletteColorCount; }
void setSkipSignature(bool skip) { _skipSignature = skip; } void setSkipSignature(bool skip) { _skipSignature = skip; }
private: private:
Graphics::PixelFormat getByteOrderRgbaPixelFormat() const;
byte *_palette; byte *_palette;
uint16 _paletteColorCount; uint16 _paletteColorCount;