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#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#include <string.h>
#include <errno.h>
#include "color.h"
#include "bmp.h"
#define BYTES_PER_PIXEL 3
#define OFFSET_bfSize 2
#define OFFSET_biWidth 18
#define OFFSET_biHeight 22
#define HEADERSIZE 54
static const char* header_template = "BM \0\0\0\0\x36\0\0\0\x28\0\0\0 \x01\0\x18\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0";
int
bmp_write_header(FILE* fh, int32_t width, int32_t height) {
char* header;
uint32_t filesize;
if(!(header = malloc(HEADERSIZE))) {
fputs("Could not allocate memory for BMP header.\n", stderr);
return 0;
}
filesize = HEADERSIZE + (width * height * BYTES_PER_PIXEL);
height *= -1;
memcpy(header, header_template, HEADERSIZE);
memcpy(header + OFFSET_bfSize, &filesize, 4);
memcpy(header + OFFSET_biWidth, &width, 4);
memcpy(header + OFFSET_biHeight, &height, 4);
if(fwrite(header, HEADERSIZE, 1, fh) != 1) {
fprintf(stderr, "Could not write BMP header: %s\n", strerror(errno));
free(header);
return 0;
}
free(header);
return 1;
}
int
bmp_write_pixel(FILE* fh, color_t col) {
uint8_t pixel[3];
pixel[0] = col.b;
pixel[1] = col.g;
pixel[2] = col.r;
return (fwrite(pixel, 3, 1, fh) == 1);
}
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