kolibrios/contrib/network/netsurf/libnsbmp/examples/decode_bmp.c

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/*
* Copyright 2008 Sean Fox <dyntryx@gmail.com>
* Copyright 2008 James Bursa <james@netsurf-browser.org>
*
* This file is part of NetSurf's libnsbmp, http://www.netsurf-browser.org/
* Licenced under the MIT License,
* http://www.opensource.org/licenses/mit-license.php
*/
#include <assert.h>
#include <errno.h>
#include <stdbool.h>
#include <stdlib.h>
#include <stdint.h>
#include <stdio.h>
#include <string.h>
#include <sys/stat.h>
#include "../include/libnsbmp.h"
#define BYTES_PER_PIXEL 4
#define TRANSPARENT_COLOR 0xffffffff
unsigned char *load_file(const char *path, size_t *data_size);
void warning(const char *context, bmp_result code);
void *bitmap_create(int width, int height, unsigned int state);
unsigned char *bitmap_get_buffer(void *bitmap);
size_t bitmap_get_bpp(void *bitmap);
void bitmap_destroy(void *bitmap);
int main(int argc, char *argv[])
{
bmp_bitmap_callback_vt bitmap_callbacks = {
bitmap_create,
bitmap_destroy,
bitmap_get_buffer,
bitmap_get_bpp
};
bmp_result code;
bmp_image bmp;
size_t size;
unsigned short res = 0;
if (argc != 2) {
fprintf(stderr, "Usage: %s image.bmp\n", argv[0]);
return 1;
}
/* create our bmp image */
bmp_create(&bmp, &bitmap_callbacks);
/* load file into memory */
unsigned char *data = load_file(argv[1], &size);
/* analyse the BMP */
code = bmp_analyse(&bmp, size, data);
if (code != BMP_OK) {
warning("bmp_analyse", code);
res = 1;
goto cleanup;
}
/* decode the image */
code = bmp_decode(&bmp);
/* code = bmp_decode_trans(&bmp, TRANSPARENT_COLOR); */
if (code != BMP_OK) {
warning("bmp_decode", code);
/* allow partially decoded images */
if (code != BMP_INSUFFICIENT_DATA) {
res = 1;
goto cleanup;
}
}
printf("P3\n");
printf("# %s\n", argv[1]);
printf("# width %u \n", bmp.width);
printf("# height %u \n", bmp.height);
printf("%u %u 256\n", bmp.width, bmp.height);
{
uint16_t row, col;
uint8_t *image;
image = (uint8_t *) bmp.bitmap;
for (row = 0; row != bmp.height; row++) {
for (col = 0; col != bmp.width; col++) {
size_t z = (row * bmp.width + col) * BYTES_PER_PIXEL;
printf("%u %u %u ", image[z],
image[z + 1],
image[z + 2]);
}
printf("\n");
}
}
cleanup:
/* clean up */
bmp_finalise(&bmp);
free(data);
return res;
}
unsigned char *load_file(const char *path, size_t *data_size)
{
FILE *fd;
struct stat sb;
unsigned char *buffer;
size_t size;
size_t n;
fd = fopen(path, "rb");
if (!fd) {
perror(path);
exit(EXIT_FAILURE);
}
if (stat(path, &sb)) {
perror(path);
exit(EXIT_FAILURE);
}
size = sb.st_size;
buffer = malloc(size);
if (!buffer) {
fprintf(stderr, "Unable to allocate %lld bytes\n",
(long long) size);
exit(EXIT_FAILURE);
}
n = fread(buffer, 1, size, fd);
if (n != size) {
perror(path);
exit(EXIT_FAILURE);
}
fclose(fd);
*data_size = size;
return buffer;
}
void warning(const char *context, bmp_result code)
{
fprintf(stderr, "%s failed: ", context);
switch (code) {
case BMP_INSUFFICIENT_MEMORY:
fprintf(stderr, "BMP_INSUFFICIENT_MEMORY");
break;
case BMP_INSUFFICIENT_DATA:
fprintf(stderr, "BMP_INSUFFICIENT_DATA");
break;
case BMP_DATA_ERROR:
fprintf(stderr, "BMP_DATA_ERROR");
break;
default:
fprintf(stderr, "unknown code %i", code);
break;
}
fprintf(stderr, "\n");
}
void *bitmap_create(int width, int height, unsigned int state)
{
(void) state; /* unused */
return calloc(width * height, BYTES_PER_PIXEL);
}
unsigned char *bitmap_get_buffer(void *bitmap)
{
assert(bitmap);
return bitmap;
}
size_t bitmap_get_bpp(void *bitmap)
{
(void) bitmap; /* unused */
return BYTES_PER_PIXEL;
}
void bitmap_destroy(void *bitmap)
{
assert(bitmap);
free(bitmap);
}