This snippet will write a TGA image file for you. RBitmap is a struct which has a width * height, and data (simply an array of an array, each pixel being a 32 bit int)
TGA is one of the simplest image file formats out there, so it’s great if you want a quick & dirty way of saving an image to disk.
// 32 bit image
typedef struct {
int width, height;
int** data;
} RBitmap;
int write_truecolor_tga( RBitmap* data ) {
FILE *fp = fopen("out.tga", "w");
if (fp == NULL) return 0;
// The image header
char header[ 18 ] = { 0 }; // char = byte
header[ 2 ] = 2; // truecolor
header[ 12 ] = data->width & 0xFF;
header[ 13 ] = (data->width >> 8) & 0xFF;
header[ 14 ] = data->height & 0xFF;
header[ 15 ] = (data->height >> 8) & 0xFF;
header[ 16 ] = 24; // bits per pixel
fwrite((const char*)&header, 1, sizeof(header), fp);
// The image data is stored bottom-to-top, left-to-right
for (int y = data->height -1; y >= 0; y--)
for (int x = 0; x < data->width; x++)
{
char b = (data->data[x][y] & 0x0000FF);
char g = (data->data[x][y] & 0x00FF00) >> 8;
char r = (data->data[x][y] & 0xFF0000) >> 16;
putc((int)(b & 0xFF),fp);
putc((int)(g & 0xFF),fp);
putc((int)(r & 0xFF),fp);
}
// The file footer
static const char footer[ 26 ] =
"\0\0\0\0" // no extension area
"\0\0\0\0" // no developer directory
"TRUEVISION-XFILE" // yep, this is a TGA file
".";
fwrite((const char*)&footer, 1, sizeof(footer), fp);
fclose(fp);
return 1;
}
