bool PNGLoader::doDecodeImage(const byte *fileDataPtr, uint fileSize, byte *&uncompressedDataPtr, int &width, int &height, int &pitch) {
#ifndef USE_INTERNAL_PNG_DECODER
png_structp png_ptr = NULL;
png_infop info_ptr = NULL;
int bitDepth;
int colorType;
int interlaceType;
int i;
// Check for valid PNG signature
if (!doIsCorrectImageFormat(fileDataPtr, fileSize)) {
error("png_check_sig failed");
}
// Create both PNG structures
png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
if (!png_ptr) {
error("Could not create libpng read struct.");
}
info_ptr = png_create_info_struct(png_ptr);
if (!info_ptr) {
error("Could not create libpng info struct.");
}
// Use alternative reading function
const byte **ref = &fileDataPtr;
png_set_read_fn(png_ptr, (void *)ref, png_user_read_data);
// Read PNG header
png_read_info(png_ptr, info_ptr);
// Read out PNG informations
png_uint_32 w, h;
png_get_IHDR(png_ptr, info_ptr, &w, &h, &bitDepth, &colorType, &interlaceType, NULL, NULL);
width = w;
height = h;
// Calculate pitch of output image
pitch = GraphicEngine::calcPitch(GraphicEngine::CF_ARGB32, width);
// Allocate memory for the final image data.
// To keep memory framentation low this happens before allocating memory for temporary image data.
uncompressedDataPtr = new byte[pitch * height];
if (!uncompressedDataPtr) {
error("Could not allocate memory for output image.");
}
// Images of all color formates will be transformed into ARGB images
if (bitDepth == 16)
png_set_strip_16(png_ptr);
if (colorType == PNG_COLOR_TYPE_PALETTE)
png_set_expand(png_ptr);
if (bitDepth < 8)
png_set_expand(png_ptr);
if (png_get_valid(png_ptr, info_ptr, PNG_INFO_tRNS))
png_set_expand(png_ptr);
if (colorType == PNG_COLOR_TYPE_GRAY ||
colorType == PNG_COLOR_TYPE_GRAY_ALPHA)
png_set_gray_to_rgb(png_ptr);
png_set_bgr(png_ptr);
if (colorType != PNG_COLOR_TYPE_RGB_ALPHA)
png_set_filler(png_ptr, 0xff, PNG_FILLER_AFTER);
// After the transformations have been registered, the image data is read again.
png_read_update_info(png_ptr, info_ptr);
png_get_IHDR(png_ptr, info_ptr, &w, &h, &bitDepth, &colorType, NULL, NULL, NULL);
width = w;
height = h;
if (interlaceType == PNG_INTERLACE_NONE) {
// PNGs without interlacing can simply be read row by row.
for (i = 0; i < height; i++) {
png_read_row(png_ptr, uncompressedDataPtr + i * pitch, NULL);
}
} else {
// PNGs with interlacing require us to allocate an auxillary
// buffer with pointers to all row starts.
// Allocate row pointer buffer
png_bytep *pRowPtr = new png_bytep[height];
if (!pRowPtr) {
error("Could not allocate memory for row pointers.");
}
// Initialize row pointers
for (i = 0; i < height; i++)
pRowPtr[i] = uncompressedDataPtr + i * pitch;
// Read image data
png_read_image(png_ptr, pRowPtr);
// Free row pointer buffer
delete[] pRowPtr;
}
// Read additional data at the end.
png_read_end(png_ptr, NULL);
// Destroy libpng structures
png_destroy_read_struct(&png_ptr, &info_ptr, NULL);
#else
Common::MemoryReadStream *fileStr = new Common::MemoryReadStream(fileDataPtr, fileSize, DisposeAfterUse::NO);
Graphics::PNG *png = new Graphics::PNG();
if (!png->read(fileStr)) // the fileStr pointer, and thus pFileData will be deleted after this is done
error("Error while reading PNG image");
Graphics::PixelFormat format = Graphics::PixelFormat(4, 8, 8, 8, 8, 16, 8, 0, 24);
Graphics::Surface *pngSurface = png->getSurface(format);
width = pngSurface->w;
height = pngSurface->h;
uncompressedDataPtr = new byte[pngSurface->pitch * pngSurface->h];
memcpy(uncompressedDataPtr, (byte *)pngSurface->pixels, pngSurface->pitch * pngSurface->h);
pngSurface->free();
delete pngSurface;
delete png;
#endif
// Signal success
return true;
}
bool PNGLoader::doDecodeImage(const byte *fileDataPtr, uint fileSize, byte *&uncompressedDataPtr, int &width, int &height, int &pitch) {
#ifndef USE_INTERNAL_PNG_DECODER
png_structp png_ptr = NULL;
png_infop info_ptr = NULL;
int bitDepth;
int colorType;
int interlaceType;
int i;
// Check for valid PNG signature
if (!doIsCorrectImageFormat(fileDataPtr, fileSize)) {
error("png_check_sig failed");
}
// Die beiden PNG Strukturen erstellen
png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
if (!png_ptr) {
error("Could not create libpng read struct.");
}
info_ptr = png_create_info_struct(png_ptr);
if (!info_ptr) {
error("Could not create libpng info struct.");
}
// Alternative Lesefunktion benutzen
const byte **ref = &fileDataPtr;
png_set_read_fn(png_ptr, (void *)ref, png_user_read_data);
// PNG Header einlesen
png_read_info(png_ptr, info_ptr);
// PNG Informationen auslesen
png_uint_32 w, h;
png_get_IHDR(png_ptr, info_ptr, &w, &h, &bitDepth, &colorType, &interlaceType, NULL, NULL);
width = w;
height = h;
// Pitch des Ausgabebildes berechnen
pitch = GraphicEngine::calcPitch(GraphicEngine::CF_ARGB32, width);
// Speicher für die endgültigen Bilddaten reservieren
// Dieses geschieht vor dem reservieren von Speicher für temporäre Bilddaten um die Fragmentierung des Speichers gering zu halten
uncompressedDataPtr = new byte[pitch * height];
if (!uncompressedDataPtr) {
error("Could not allocate memory for output image.");
}
// Bilder jeglicher Farbformate werden zunächst in ARGB Bilder umgewandelt
if (bitDepth == 16)
png_set_strip_16(png_ptr);
if (colorType == PNG_COLOR_TYPE_PALETTE)
png_set_expand(png_ptr);
if (bitDepth < 8)
png_set_expand(png_ptr);
if (png_get_valid(png_ptr, info_ptr, PNG_INFO_tRNS))
png_set_expand(png_ptr);
if (colorType == PNG_COLOR_TYPE_GRAY ||
colorType == PNG_COLOR_TYPE_GRAY_ALPHA)
png_set_gray_to_rgb(png_ptr);
png_set_bgr(png_ptr);
if (colorType != PNG_COLOR_TYPE_RGB_ALPHA)
png_set_filler(png_ptr, 0xff, PNG_FILLER_AFTER);
// Nachdem die Transformationen registriert wurden, werden die Bilddaten erneut eingelesen
png_read_update_info(png_ptr, info_ptr);
png_get_IHDR(png_ptr, info_ptr, &w, &h, &bitDepth, &colorType, NULL, NULL, NULL);
width = w;
height = h;
if (interlaceType == PNG_INTERLACE_NONE) {
// PNGs without interlacing can simply be read row by row.
for (i = 0; i < height; i++) {
png_read_row(png_ptr, uncompressedDataPtr + i * pitch, NULL);
}
} else {
// PNGs with interlacing require us to allocate an auxillary
// buffer with pointers to all row starts.
// Allocate row pointer buffer
png_bytep *pRowPtr = new png_bytep[height];
if (!pRowPtr) {
error("Could not allocate memory for row pointers.");
}
// Initialize row pointers
for (i = 0; i < height; i++)
pRowPtr[i] = uncompressedDataPtr + i * pitch;
// Read image data
png_read_image(png_ptr, pRowPtr);
// Free row pointer buffer
delete[] pRowPtr;
}
// Read additional data at the end.
png_read_end(png_ptr, NULL);
// Destroy libpng structures
png_destroy_read_struct(&png_ptr, &info_ptr, NULL);
#else
Common::MemoryReadStream *fileStr = new Common::MemoryReadStream(fileDataPtr, fileSize, DisposeAfterUse::NO);
Graphics::PNG *png = new Graphics::PNG();
if (!png->read(fileStr)) // the fileStr pointer, and thus pFileData will be deleted after this is done
error("Error while reading PNG image");
Graphics::PixelFormat format = Graphics::PixelFormat(4, 8, 8, 8, 8, 16, 8, 0, 24);
Graphics::Surface *pngSurface = png->getSurface(format);
width = pngSurface->w;
height = pngSurface->h;
uncompressedDataPtr = new byte[pngSurface->pitch * pngSurface->h];
memcpy(uncompressedDataPtr, (byte *)pngSurface->pixels, pngSurface->pitch * pngSurface->h);
pngSurface->free();
delete pngSurface;
delete png;
#endif
// Signal success
return true;
}
