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#include "config.h"
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <png.h>
#include "loader.h"
#ifdef USE_X11
# include "viewer.h"
#endif
static const char *ct[] = {
"gray", "X1", "rgb", "palette",
"graya", "X5", "rgba", "X7",
};
struct png_state {
FILE *infile;
png_structp png;
png_infop info;
png_bytep row;
png_uint_32 w,h;
int color_type;
};
static void*
png_init(FILE *fp, char *filename, struct ida_image_info *i)
{
struct png_state *h;
int bit_depth, interlace_type;
int pass, number_passes, y;
png_uint_32 resx, resy;
int unit;
h = malloc(sizeof(*h));
memset(h,0,sizeof(*h));
h->infile = fp;
h->png = png_create_read_struct(PNG_LIBPNG_VER_STRING,
NULL, NULL, NULL);
if (NULL == h->png)
goto oops;
h->info = png_create_info_struct(h->png);
if (NULL == h->info)
goto oops;
png_init_io(h->png, h->infile);
png_read_info(h->png, h->info);
png_get_IHDR(h->png, h->info, &h->w, &h->h,
&bit_depth,&h->color_type,&interlace_type, NULL,NULL);
png_get_pHYs(h->png, h->info, &resx, &resy, &unit);
i->width = h->w;
i->height = h->h;
if (PNG_RESOLUTION_METER == unit)
i->dpi = res_m_to_inch(resx);
if (debug)
fprintf(stderr,"png: color_type=%s #1\n",ct[h->color_type]);
png_set_packing(h->png);
if (bit_depth == 16)
png_set_strip_16(h->png);
if (h->color_type == PNG_COLOR_TYPE_PALETTE)
png_set_palette_to_rgb(h->png);
if (h->color_type == PNG_COLOR_TYPE_GRAY && bit_depth < 8)
png_set_gray_1_2_4_to_8(h->png);
number_passes = png_set_interlace_handling(h->png);
png_read_update_info(h->png, h->info);
h->color_type = png_get_color_type(h->png, h->info);
if (debug)
fprintf(stderr,"png: color_type=%s #2\n",ct[h->color_type]);
h->row = malloc(i->width * 4);
for (pass = 0; pass < number_passes-1; pass++) {
for (y = 0; y < i->height; y++) {
png_read_rows(h->png, &h->row, NULL, 1);
}
}
return h;
oops:
if (h->row)
free(h->row);
if (h->png)
png_destroy_read_struct(&h->png, NULL, NULL);
fclose(h->infile);
free(h);
return NULL;
}
static void
png_read(unsigned char *dst, int line, void *data)
{
struct png_state *h = data;
switch (h->color_type) {
case PNG_COLOR_TYPE_GRAY:
png_read_rows(h->png, &h->row, NULL, 1);
load_gray(dst,h->row,h->w);
break;
case PNG_COLOR_TYPE_RGB:
png_read_rows(h->png, &dst, NULL, 1);
break;
case PNG_COLOR_TYPE_RGB_ALPHA:
png_read_rows(h->png, &h->row, NULL, 1);
load_rgba(dst,h->row,h->w);
break;
case PNG_COLOR_TYPE_GRAY_ALPHA:
png_read_rows(h->png, &h->row, NULL, 1);
load_graya(dst,h->row,h->w);
break;
default:
/* shouldn't happen */
fprintf(stderr,"Oops: %s:%d\n",__FILE__,__LINE__);
exit(1);
}
}
static void
png_done(void *data)
{
struct png_state *h = data;
free(h->row);
png_destroy_read_struct(&h->png, &h->info, NULL);
fclose(h->infile);
free(h);
}
struct ida_loader png_loader = {
magic: "\x89PNG",
moff: 0,
mlen: 4,
name: "libpng",
init: png_init,
read: png_read,
done: png_done,
};
#ifdef USE_X11
/* ---------------------------------------------------------------------- */
/* save */
static int
png_write(FILE *fp, struct ida_image *img)
{
png_structp png_ptr = NULL;
png_infop info_ptr = NULL;
png_bytep row;
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;
}
struct ida_writer png_writer = {
label: "PNG",
ext: { "png", NULL},
write: png_write,
};
#endif
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