bool writePNG(Common::WriteStream &out, const Graphics::Surface &input, const bool bottomUp) {
#ifdef USE_PNG
const Graphics::PixelFormat requiredFormat_3byte(3, 8, 8, 8, 0, 16, 8, 0, 0);
const Graphics::PixelFormat requiredFormat_4byte(4, 8, 8, 8, 8, 0, 8, 16, 24);
if (input.format.bytesPerPixel == 3) {
if (input.format != requiredFormat_3byte) {
warning("Cannot currently write PNG with 3-byte pixel format other than %s", requiredFormat_3byte.toString().c_str());
return false;
}
} else if (input.format.bytesPerPixel != 4) {
warning("Cannot currently write PNG with pixel format of bpp other than 3, 4");
return false;
}
int colorType;
Graphics::Surface *tmp = NULL;
const Graphics::Surface *surface;
if (input.format == requiredFormat_3byte) {
surface = &input;
colorType = PNG_COLOR_TYPE_RGB;
} else {
if (input.format == requiredFormat_4byte) {
surface = &input;
} else {
surface = tmp = input.convertTo(requiredFormat_4byte);
}
colorType = PNG_COLOR_TYPE_RGB_ALPHA;
}
png_structp pngPtr = png_create_write_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
if (!pngPtr) {
return false;
}
png_infop infoPtr = png_create_info_struct(pngPtr);
if (!infoPtr) {
png_destroy_write_struct(&pngPtr, NULL);
return false;
}
png_set_error_fn(pngPtr, NULL, pngError, pngWarning);
// TODO: The manual says errors should be handled via setjmp
png_set_write_fn(pngPtr, &out, pngWriteToStream, pngFlushStream);
png_set_IHDR(pngPtr, infoPtr, surface->w, surface->h, 8, colorType, PNG_INTERLACE_NONE, PNG_COMPRESSION_TYPE_DEFAULT, PNG_FILTER_TYPE_DEFAULT);
Common::Array<const uint8 *> rows;
rows.reserve(surface->h);
if (bottomUp) {
for (uint y = surface->h; y-- > 0;) {
rows.push_back((const uint8 *)surface->getBasePtr(0, y));
}
} else {
for (uint y = 0; y < surface->h; ++y) {
rows.push_back((const uint8 *)surface->getBasePtr(0, y));
}
}
png_set_rows(pngPtr, infoPtr, const_cast<uint8 **>(&rows.front()));
png_write_png(pngPtr, infoPtr, 0, NULL);
png_destroy_write_struct(&pngPtr, &infoPtr);
// free tmp surface
if (tmp) {
tmp->free();
delete tmp;
}
return true;
#else
return false;
#endif
}
