int png_save_surface(char *filename, SDL_Surface *surf)
{
FILE *fp;
png_structp png_ptr;
png_infop info_ptr;
int i, colortype;
png_bytep *row_pointers;
/* Opening output file */
fp = fopen(filename, "wb");
if (fp == NULL) {
conAdd(LERR, "png_save %s : %s", filename, strerror(errno));
return -1;
}
/* Initializing png structures and callbacks */
png_ptr = png_create_write_struct(PNG_LIBPNG_VER_STRING,
NULL, png_user_error, png_user_warn);
if (png_ptr == NULL) {
conAdd(LERR, "png_save: png_create_write_struct error!");
return -1;
}
info_ptr = png_create_info_struct(png_ptr);
if (info_ptr == NULL) {
png_destroy_write_struct(&png_ptr, (png_infopp)NULL);
conAdd(LERR, "png_save: png_create_info_struct error!");
return -1;
}
if (setjmp(png_jmpbuf(png_ptr))) {
png_destroy_write_struct(&png_ptr, &info_ptr);
fclose(fp);
return -1;
}
png_init_io(png_ptr, fp);
colortype = png_colortype_from_surface(surf);
png_set_IHDR(png_ptr, info_ptr, surf->w, surf->h, 8, colortype, PNG_INTERLACE_NONE,
PNG_COMPRESSION_TYPE_DEFAULT, PNG_FILTER_TYPE_DEFAULT);
/* Writing the image */
png_write_info(png_ptr, info_ptr);
png_set_packing(png_ptr);
row_pointers = (png_bytep*) malloc(sizeof(png_bytep)*surf->h);
for (i = 0; i < surf->h; i++)
row_pointers[i] = (png_bytep)(Uint8 *)surf->pixels + i*surf->pitch;
png_write_image(png_ptr, row_pointers);
png_write_end(png_ptr, info_ptr);
/* Cleaning out... */
free(row_pointers);
png_destroy_write_struct(&png_ptr, &info_ptr);
fclose(fp);
return 0;
}
int IMG_SavePNG_RW (SDL_Surface *face, SDL_RWops *src)
{
png_structp png_ptr = 0;
png_infop info_ptr = NULL;
//png_colorp palette = 0;
png_bytep *row_pointers = NULL;
int i;
int colortype;
int result = -1;
png_ptr = png_create_write_struct (PNG_LIBPNG_VER_STRING, NULL, png_user_error, png_user_warn);
if (png_ptr == NULL)
{
IMG_SetError ("Couldn't allocate memory for PNG file");
return -1;
}
/* Allocate/initialize the image information data. REQUIRED */
info_ptr = png_create_info_struct(png_ptr);
if (info_ptr == NULL)
{
IMG_SetError("Couldn't create image information for PNG file");
goto done;
}
/* Set error handling. */
if (setjmp(png_jmpbuf(png_ptr)))
{
/* If we get here, we had a problem reading the file */
IMG_SetError("Error writing the PNG file");
goto done;
}
png_set_write_fn (png_ptr, src, png_write_data, png_io_flush);
/* Set the image information here. Width and height are up to 2^31,
* bit_depth is one of 1, 2, 4, 8, or 16, but valid values also
* depend on the color_type selected. color_type is one of
* PNG_COLOR_TYPE_GRAY, PNG_COLOR_TYPE_GRAY_ALPHA,
* PNG_COLOR_TYPE_PALETTE, PNG_COLOR_TYPE_RGB, or
* PNG_COLOR_TYPE_RGB_ALPHA. interlace is either PNG_INTERLACE_NONE or
* PNG_INTERLACE_ADAM7, and the compression_type and filter_type
* MUST currently be PNG_COMPRESSION_TYPE_BASE and
* PNG_FILTER_TYPE_BASE. REQUIRED
*/
colortype = png_colortype_from_surface (face);
png_set_IHDR (png_ptr, info_ptr, face->w, face->h, 8, colortype, PNG_INTERLACE_NONE, PNG_COMPRESSION_TYPE_BASE, PNG_FILTER_TYPE_BASE);
/* Write the file header information. REQUIRED */
png_write_info (png_ptr, info_ptr);
/* pack pixels into bytes */
png_set_packing (png_ptr);
/* Create the array of pointers to image data */
row_pointers = (png_bytep*) malloc (sizeof(png_bytep)*face->h);
if (row_pointers == NULL)
{
IMG_SetError("Couldn't allocate PNG row pointers");
goto done;
}
for (i = 0; i < face->h; i++)
row_pointers[i] = (png_bytep)(Uint8 *)face->pixels + i*face->pitch;
/* write out the entire image data in one call */
png_write_image (png_ptr, row_pointers);
png_write_end(png_ptr, info_ptr);
result = 0; /* success! */
done:
if (row_pointers != NULL)
free (row_pointers);
if (info_ptr != NULL)
png_free_data(png_ptr, info_ptr, PNG_FREE_ALL, -1);
png_destroy_write_struct (&png_ptr, (png_infopp)NULL);
return result;
}
/* This is taken from http://encelo.netsons.org/programming/sdl (GPLed) */
void *sdl_surface_to_png(SDL_Surface *surf, size_t *out_sz)
{
png_structp png_ptr;
png_infop info_ptr;
int i, colortype;
png_bytep *row_pointers;
png_colorp palette;
struct png_write_user_struct out;
if (!surf)
return NULL;
out.sz = 0;
out.data = NULL;
/* Initializing png structures and callbacks */
png_ptr = png_create_write_struct(PNG_LIBPNG_VER_STRING,
NULL, png_user_error, png_user_warn);
if (png_ptr == NULL) {
printf("png_create_write_struct error!\n");
return NULL;
}
info_ptr = png_create_info_struct(png_ptr);
if (info_ptr == NULL) {
png_destroy_write_struct(&png_ptr, (png_infopp)NULL);
printf("png_create_info_struct error!\n");
exit(-1);
}
if (setjmp(png_jmpbuf(png_ptr))) {
png_destroy_write_struct(&png_ptr, &info_ptr);
exit(-1);
}
png_set_write_fn(png_ptr, (void *)&out, user_write_fn, NULL);
colortype = png_colortype_from_surface(surf);
png_set_IHDR(png_ptr, info_ptr, surf->w, surf->h, 8, colortype, PNG_INTERLACE_NONE,
PNG_COMPRESSION_TYPE_DEFAULT, PNG_FILTER_TYPE_DEFAULT);
if (colortype & PNG_COLOR_MASK_PALETTE)
{
/* Set the palette if there is one. REQUIRED for indexed-color images */
palette = (png_colorp)png_malloc(png_ptr,
PNG_MAX_PALETTE_LENGTH * sizeof(png_color));
/* KLUDGE! For some reason, surf->format->palette doesn't work... */
for (int i = 0; i < PALETTE_SIZE; i++)
{
SDL_Color *p = &sdl_palette[i];
palette[i].red = p->r;
palette[i].green = p->g;
palette[i].blue = p->b;
}
/* ... Set palette colors ... */
png_set_PLTE(png_ptr, info_ptr, palette, PNG_MAX_PALETTE_LENGTH);
}
/* Writing the image */
png_write_info(png_ptr, info_ptr);
png_set_packing(png_ptr);
row_pointers = (png_bytep*) xmalloc(sizeof(png_bytep)*surf->h);
for (i = 0; i < surf->h; i++)
row_pointers[i] = (png_bytep)(Uint8 *)surf->pixels + i*surf->pitch;
png_write_image(png_ptr, row_pointers);
png_write_end(png_ptr, info_ptr);
/* Cleaning out... */
free(row_pointers);
png_destroy_write_struct(&png_ptr, &info_ptr);
*out_sz = out.sz;
return out.data;
}
