;
; player update code
;

player_update:
    ld x, [sp + 2]
    ld a, [sp + 3]

    ; read controller 1
    ld b, 0xf0
    port b, b

    inc x
    bo
    inc a
    ; x coord
    ld y, [a : x]

    ; left
    bit b, 4
    bz
    dec y
    ; right
    bit b, 5
    bz
    inc y

    ld [a : x], y

    inc x
    bo
    inc a
    ; y coord
    ld y, [a : x]

    ; up
    bit b, 2
    bz
    dec y
    ; down
    bit b, 3
    bz
    inc y

    ld [a : x], y

    ret