ReadJoypad::
; Poll joypad input.
; Unlike the hardware register, button
; presses are indicated by a set bit.
ld a, 1 << 5 ; select direction keys
ld c, 0
ldh [rJOYP], a
REPT 6
ldh a, [rJOYP]
ENDR
cpl
and %1111
swap a
ld b, a
ld a, 1 << 4 ; select button keys
ldh [rJOYP], a
REPT 10
ldh a, [rJOYP]
ENDR
cpl
and %1111
or b
ldh [hJoyInput], a
ld a, 1 << 4 + 1 << 5 ; deselect keys
ldh [rJOYP], a
ret
Joypad::
; Update the joypad state variables:
; [hJoyReleased] keys released since last time
; [hJoyPressed] keys pressed since last time
; [hJoyHeld] currently pressed keys
homecall _Joypad
ret
