/* save_png:
* Writes a non-interlaced, no-frills PNG, taking the usual save_xyz
* parameters. Returns non-zero on error.
*/
static int really_save_png(PACKFILE *fp, BITMAP *bmp, AL_CONST RGB *pal)
{
png_structp png_ptr = NULL;
png_infop info_ptr = NULL;
int depth;
int colour_type;
depth = bitmap_color_depth(bmp);
if (depth == 8 && !pal)
return -1;
/* Create and initialize the png_struct with the
* desired error handler functions.
*/
png_ptr = png_create_write_struct(PNG_LIBPNG_VER_STRING,
(void *)NULL, NULL, NULL);
if (!png_ptr)
goto Error;
/* Allocate/initialize the image information data. */
info_ptr = png_create_info_struct(png_ptr);
if (!info_ptr)
goto Error;
/* Set error handling. */
if (setjmp(png_ptr->jmpbuf)) {
/* If we get here, we had a problem reading the file. */
goto Error;
}
/* Use packfile routines. */
png_set_write_fn(png_ptr, fp, (png_rw_ptr)write_data, flush_data);
/* 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.
*/
if (depth == 8)
colour_type = PNG_COLOR_TYPE_PALETTE;
else if (depth == 32)
colour_type = PNG_COLOR_TYPE_RGB_ALPHA;
else
colour_type = PNG_COLOR_TYPE_RGB;
/* Set compression level. */
png_set_compression_level(png_ptr, _png_compression_level);
png_set_IHDR(png_ptr, info_ptr, bmp->w, bmp->h, 8, colour_type,
PNG_INTERLACE_NONE, PNG_COMPRESSION_TYPE_BASE,
PNG_FILTER_TYPE_BASE);
/* Set the palette if there is one. Required for indexed-color images. */
if (colour_type == PNG_COLOR_TYPE_PALETTE) {
png_color palette[256];
int i;
for (i = 0; i < 256; i++) {
palette[i].red = _rgb_scale_6[pal[i].r]; /* 64 -> 256 */
palette[i].green = _rgb_scale_6[pal[i].g];
palette[i].blue = _rgb_scale_6[pal[i].b];
}
/* Set palette colors. */
png_set_PLTE(png_ptr, info_ptr, palette, 256);
}
/* Optionally write comments into the image ... Nah. */
/* Write the file header information. */
png_write_info(png_ptr, info_ptr);
/* Once we write out the header, the compression type on the text
* chunks gets changed to PNG_TEXT_COMPRESSION_NONE_WR or
* PNG_TEXT_COMPRESSION_zTXt_WR, so it doesn't get written out again
* at the end.
*/
/* Save the data. */
switch (depth) {
case 8:
if (!save_indexed(png_ptr, bmp))
goto Error;
break;
case 15:
case 16:
case 24:
if (!save_rgb(png_ptr, bmp))
goto Error;
break;
case 32:
if (!save_rgba(png_ptr, bmp))
goto Error;
break;
default:
ASSERT(FALSE);
goto Error;
}
png_write_end(png_ptr, info_ptr);
png_destroy_write_struct(&png_ptr, &info_ptr);
return 0;
Error:
if (png_ptr) {
if (info_ptr)
png_destroy_write_struct(&png_ptr, &info_ptr);
else
png_destroy_write_struct(&png_ptr, NULL);
}
return -1;
}
/* Writes a non-interlaced, no-frills PNG, taking the usual save_xyz
* parameters. Returns non-zero on error.
*/
bool _al_save_png_f(ALLEGRO_FILE *fp, ALLEGRO_BITMAP *bmp)
{
jmp_buf jmpbuf;
png_structp png_ptr = NULL;
png_infop info_ptr = NULL;
int colour_type;
/* Create and initialize the png_struct with the
* desired error handler functions.
*/
png_ptr = png_create_write_struct(PNG_LIBPNG_VER_STRING,
(void *)NULL, NULL, NULL);
if (!png_ptr)
goto Error;
/* Allocate/initialize the image information data. */
info_ptr = png_create_info_struct(png_ptr);
if (!info_ptr)
goto Error;
/* Set error handling. */
if (setjmp(jmpbuf)) {
goto Error;
}
png_set_error_fn(png_ptr, jmpbuf, user_error_fn, NULL);
/* Use packfile routines. */
png_set_write_fn(png_ptr, fp, (png_rw_ptr) write_data, flush_data);
/* 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.
*/
colour_type = PNG_COLOR_TYPE_RGB_ALPHA;
/* Set compression level. */
png_set_compression_level(png_ptr, _al_png_compression_level);
png_set_IHDR(png_ptr, info_ptr,
al_get_bitmap_width(bmp), al_get_bitmap_height(bmp),
8, colour_type,
PNG_INTERLACE_NONE, PNG_COMPRESSION_TYPE_BASE,
PNG_FILTER_TYPE_BASE);
/* Optionally write comments into the image ... Nah. */
/* Write the file header information. */
png_write_info(png_ptr, info_ptr);
/* Once we write out the header, the compression type on the text
* chunks gets changed to PNG_TEXT_COMPRESSION_NONE_WR or
* PNG_TEXT_COMPRESSION_zTXt_WR, so it doesn't get written out again
* at the end.
*/
if (!save_rgba(png_ptr, bmp))
goto Error;
png_write_end(png_ptr, info_ptr);
png_destroy_write_struct(&png_ptr, &info_ptr);
return true;
Error:
if (png_ptr) {
if (info_ptr)
png_destroy_write_struct(&png_ptr, &info_ptr);
else
png_destroy_write_struct(&png_ptr, NULL);
}
return false;
}
