pokeyellow/engine/joypad.asm

96 lines
1.3 KiB
NASM

ReadJoypad_::
; Poll joypad input.
; Unlike the hardware register, button
; presses are indicated by a set bit.
ldh a, [hDisableJoypadPolling]
and a
ret nz
ld a, 1 << 5 ; select direction keys
ldh [rJOYP], a
ldh a, [rJOYP]
ldh a, [rJOYP]
cpl
and %1111
swap a
ld b, a
ld a, 1 << 4 ; select button keys
ldh [rJOYP], a
REPT 6
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::
; hJoyReleased: (hJoyLast ^ hJoyInput) & hJoyLast
; hJoyPressed: (hJoyLast ^ hJoyInput) & hJoyInput
ldh a, [hJoyInput]
ld b, a
and PAD_BUTTONS | PAD_UP
cp PAD_BUTTONS ; soft reset
jp z, TrySoftReset
ldh a, [hJoyLast]
ld e, a
xor b
ld d, a
and e
ldh [hJoyReleased], a
ld a, d
and b
ldh [hJoyPressed], a
ld a, b
ldh [hJoyLast], a
ld a, [wStatusFlags5]
bit BIT_DISABLE_JOYPAD, a
jr nz, DiscardButtonPresses
ldh a, [hJoyLast]
ldh [hJoyHeld], a
ld a, [wJoyIgnore]
and a
ret z
cpl
ld b, a
ldh a, [hJoyHeld]
and b
ldh [hJoyHeld], a
ldh a, [hJoyPressed]
and b
ldh [hJoyPressed], a
ret
DiscardButtonPresses:
xor a
ldh [hJoyHeld], a
ldh [hJoyPressed], a
ldh [hJoyReleased], a
ret
TrySoftReset:
call DelayFrame
; deselect (redundant)
ld a, $30
ldh [rJOYP], a
ld hl, hSoftReset
dec [hl]
jp z, SoftReset
jp Joypad