How do you write a header for a 128x128x128 dds volume texture file with no mipmaps and does it have to be written in binary?

Answer

According to the documentation on MSDN, the following code should create an uncompressed volume texture DDS file that's 32x32x32 in size. Re-scale as you see fit. Note: a 128x128x128 RGBA texture will take up 8 MB of VRAM!

#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#include <string.h>


#define DDSD_CAPS	0x00000001
#define DDSD_HEIGHT	0x00000002
#define DDSD_WIDTH	0x00000004
#define DDSD_PITCH	0x00000008
#define DDSD_PIXELFORMAT	0x00001000
#define DDSD_MIPMAPCOUNT	0x00020000
#define DDSD_LINEARSIZE	0x00080000
#define DDSD_DEPTH	0x00800000

#define DDPF_ALPHAPIXELS	0x00000001
#define DDPF_FOURCC	0x00000004
#define DDPF_RGB	0x00000040

#define DDSCAPS_COMPLEX	0x00000008
#define DDSCAPS_TEXTURE	0x00001000
#define DDSCAPS_MIPMAP	0x00400000

#define DDSCAPS2_CUBEMAP	0x00000200
#define DDSCAPS2_CUBEMAP_POSITIVEX	0x00000400
#define DDSCAPS2_CUBEMAP_NEGATIVEX	0x00000800
#define DDSCAPS2_CUBEMAP_POSITIVEY	0x00001000
#define DDSCAPS2_CUBEMAP_NEGATIVEY	0x00002000
#define DDSCAPS2_CUBEMAP_POSITIVEZ	0x00004000
#define DDSCAPS2_CUBEMAP_NEGATIVEZ	0x00008000
#define DDSCAPS2_VOLUME	0x00200000


int depth = 32;
int width = 32;
int height = 32;

unsigned int header[32];

int main( int argc, char * argv[] ) {
  if( !argv[1] || !strstr( argv[1], ".dds" ) ) {
    fprintf( stderr, "Usage: noise output.dds\n" );
    return 1;
  }
  unsigned int cnt = width*height*depth*4;
  unsigned char * buf = new unsigned char[ cnt ];
  while( cnt-- ) {
    buf[cnt] = rand()>>7;
  }
  memset( header, 0, sizeof( header ) );
  header[0] = ' SDD';
  header[1] = 124;
  header[2] = DDSD_CAPS | DDSD_PIXELFORMAT | DDSD_WIDTH | DDSD_HEIGHT | DDSD_DEPTH | DDSD_PITCH;
  header[3] = height;
  header[4] = width;
  header[5] = width*4;
  header[6] = depth;
  header[19] = 32;
  header[20] = DDPF_RGB|DDPF_ALPHAPIXELS;
  header[22] = 8;
  header[23] = 0xff0000;
  header[24] = 0xff00;
  header[25] = 0xff;
  header[26] = 0xff000000;
  header[27] = DDSCAPS_TEXTURE | DDSCAPS_COMPLEX;
  header[28] = DDSCAPS2_VOLUME;
  FILE * f = fopen( argv[1], "wb" );
  if( !f ) {
    fprintf( stderr, "can't create: %s\n", argv[1] );
    return 1;
  }
  fwrite( header, 4, 32, f );
  fwrite( buf, 1, width*height*depth, f );
  fclose( f );
  fprintf( stderr, "wrote %s\n", argv[1] );
  return 0;
}