targa.h

#include <stdio.h>

// Endian-ifiers
int little_endianify(int x){return x % 256;}
int big_endianify   (int x){return x / 256;}

// Targa Image Format File Header
typedef struct {
	char id_length;
	char map_type;
	char image_type;
	int  map_first;
	int  map_length;
	char map_entry_size;
	int  x;
	int  y;
	int  width;
	int  height;
	char bits_per_pixel;
	char misc;
} targaHeader;

// Write the File Header
void write_header(targaHeader header, FILE *tga)
{
	fputc(header.id_length,                    tga);
	fputc(header.map_type,                     tga);
	fputc(header.image_type,                   tga);
	fputc(little_endianify(header.map_first),  tga);
	fputc(big_endianify   (header.map_first),  tga);
	fputc(little_endianify(header.map_length), tga);
	fputc(big_endianify   (header.map_length), tga);
	fputc(header.map_entry_size,               tga);
	fputc(little_endianify(header.x),          tga);
	fputc(big_endianify   (header.x),          tga);
	fputc(little_endianify(header.y),          tga);
	fputc(big_endianify   (header.y),          tga);
	fputc(little_endianify(header.width),      tga);
	fputc(big_endianify   (header.width),      tga);
	fputc(little_endianify(header.height),     tga);
	fputc(big_endianify   (header.height),     tga);
	fputc(header.bits_per_pixel,               tga);
	fputc(header.misc,                         tga);
}