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#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <png.h>
#include "readers.h"
#include "writers.h"
#include "viewer.h"
/* ---------------------------------------------------------------------- */
/* save */
static int
png_write(FILE *fp, struct ida_image *img)
{
png_structp png_ptr = NULL;
png_infop info_ptr = NULL;
png_bytep row;
unsigned int y;
/* Create and initialize the png_struct with the desired error handler
* functions. If you want to use the default stderr and longjump method,
* you can supply NULL for the last three parameters. We also check that
* the library version is compatible with the one used at compile time,
* in case we are using dynamically linked libraries. REQUIRED.
*/
png_ptr = png_create_write_struct(PNG_LIBPNG_VER_STRING,NULL,NULL,NULL);
if (png_ptr == NULL)
goto oops;
/* Allocate/initialize the image information data. REQUIRED */
info_ptr = png_create_info_struct(png_ptr);
if (info_ptr == NULL)
goto oops;
if (setjmp(png_jmpbuf(png_ptr)))
goto oops;
png_init_io(png_ptr, fp);
png_set_IHDR(png_ptr, info_ptr, img->i.width, img->i.height, 8,
PNG_COLOR_TYPE_RGB, PNG_INTERLACE_NONE,
PNG_COMPRESSION_TYPE_BASE, PNG_FILTER_TYPE_BASE);
if (img->i.dpi) {
png_set_pHYs(png_ptr, info_ptr,
res_inch_to_m(img->i.dpi),
res_inch_to_m(img->i.dpi),
PNG_RESOLUTION_METER);
}
png_write_info(png_ptr, info_ptr);
png_set_packing(png_ptr);
for (y = 0; y < img->i.height; y++) {
row = img->data + y * 3 * img->i.width;
png_write_rows(png_ptr, &row, 1);
}
png_write_end(png_ptr, info_ptr);
png_destroy_write_struct(&png_ptr, &info_ptr);
return 0;
oops:
fprintf(stderr,"can't save image: libpng error\n");
if (png_ptr)
png_destroy_write_struct(&png_ptr, (png_infopp)NULL);
return -1;
}
static struct ida_writer png_writer = {
label: "PNG",
ext: { "png", NULL},
write: png_write,
};
static void __init init_wr(void)
{
write_register(&png_writer);
}
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