#define mask_width 16
#define mask_height 16
static short mask_bits[] = {
   0x0000, 0x07e0, 0x0ff0, 0x1ff8,
   0x3ffc, 0x3ffc, 0x7ffe, 0x7ffe,
   0x7ffe, 0x7ffe, 0x7ffe, 0x7ffe,
   0x7ffe, 0x7ffe, 0x7ffe, 0x0000};