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/* See LICENSE file for copyright and license details. */
#include <arpa/inet.h>
#include <errno.h>
#include <inttypes.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "arg.h"
char *argv0;
static void
usage(void)
{
fprintf(stderr, "usage: %s [-b #rrggbb]\n", argv0);
exit(1);
}
int
main(int argc, char *argv[])
{
size_t rowlen;
uint32_t hdr[4], width, height, i, j, k;
uint16_t *row, mr = 0xffff, mg = 0xffff, mb = 0xffff;
uint8_t *rowout;
char *color;
unsigned int r = 0xff, g = 0xff, b = 0xff;
float a;
argv0 = argv[0];
ARGBEGIN {
case 'b':
for (color = EARGF(usage()); *color && *color == '#'; color++)
;
switch (strlen(color)) {
case 3:
if (sscanf(color, "%1x%1x%1x", &r, &g, &b) != 3)
usage();
mr = (r | r << 4) * 257;
mg = (g | g << 4) * 257;
mb = (b | b << 4) * 257;
break;
case 6:
if (sscanf(color, "%2x%2x%2x", &r, &g, &b) != 3)
usage();
mr = r * 257;
mg = g * 257;
mb = b * 257;
break;
case 12:
if (sscanf(color, "%4x%4x%4x", &r, &g, &b) != 3)
usage();
mr = r;
mg = g;
mb = b;
break;
default:
usage();
}
break;
default:
usage();
} ARGEND
if (argc)
usage();
/* header */
if (fread(hdr, sizeof(*hdr), 4, stdin) != 4) {
fprintf(stderr, "%s: fread: %s\n", argv0, strerror(errno));
return 1;
}
if (memcmp("farbfeld", hdr, sizeof("farbfeld") - 1)) {
fprintf(stderr, "%s: invalid magic value\n", argv0);
return 1;
}
if (!(width = ntohl(hdr[2]))) {
fprintf(stderr, "%s: invalid width: zero\n", argv0);
return 1;
}
if (!(height = ntohl(hdr[3]))) {
fprintf(stderr, "%s: invalid height: zero\n", argv0);
return 1;
}
if (width > SIZE_MAX / ((sizeof("RGBA") - 1) * sizeof(uint16_t))) {
fprintf(stderr, "%s: row length integer overflow\n", argv0);
return 1;
}
rowlen = width * (sizeof("RGBA") - 1);
if (!(row = malloc(rowlen * sizeof(uint16_t)))) {
fprintf(stderr, "%s: malloc: %s\n", argv0, strerror(errno));
return 1;
}
if (!(rowout = malloc(width * sizeof("RGB") - 1))) {
fprintf(stderr, "%s: malloc: %s\n", argv0, strerror(errno));
return 1;
}
/* PPM binary */
printf("P6\n%" PRIu32 " %" PRIu32 "\n255\n", width, height);
/* write rows */
for (i = 0; i < height; ++i) {
if (fread(row, sizeof(uint16_t), rowlen, stdin) != rowlen) {
fprintf(stderr, "%s: fread: %s\n", argv0, strerror(errno));
return 1;
}
for (j = 0, k = 0; j < rowlen; j += 4, k += 3) {
a = ntohs(row[j + 3]) / 65535.0f;
rowout[k] = ((ntohs(row[j]) * a) + (mr * (1 - a))) / 257;
rowout[k + 1] = ((ntohs(row[j + 1]) * a) + (mg * (1 - a))) / 257;
rowout[k + 2] = ((ntohs(row[j + 2]) * a) + (mb * (1 - a))) / 257;
}
if (fwrite(rowout, 3, width, stdout) != width) {
fprintf(stderr, "%s: fwrite: %s\n", argv0, strerror(errno));
return 1;
}
}
return 0;
}
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