ld iy, playerX
    ld ix,(iy)
    ld hl,tileX
    ld (hl),ix ;(tileX) = (playerX)

    ld a,(iy+2)
    and 16
    ld (offsetX),a ;(offsetX) = (playerX) % 16

    xor a
    rrd
    inc hl
    rrd
    inc hl
    rrd ;(tileX) = (playerX) / 16