#define explosion_width 15
#define explosion_height 10
static char explosion_bits[] = {
   0x80, 0x00, 0xc0, 0x01, 0xc0, 0x01, 0x20, 0x02, 0x3e, 0x3e, 0x0d, 0x50,
   0x15, 0x48, 0x6d, 0x5b, 0x65, 0x4b, 0xff, 0x7f};