#define tet_width 16
#define tet_height 16
static char tet_bits[] = {
   0x00, 0x00, 0x00, 0x00, 0x08, 0x07, 0x98, 0x0f, 0xb8, 0x1f, 0xb8, 0x1d,
   0xb8, 0x18, 0x10, 0x10, 0x18, 0x10, 0x18, 0x10, 0x18, 0x10, 0xf8, 0x1f,
   0xf8, 0x1f, 0xf8, 0x0f, 0x00, 0x00, 0x00, 0x00};