include "hardware.inc"

section "home/joypad.asm@hram", hram
h_joypad: db
h_joypad_down:: db
h_joypad_pressed:: db
h_joypad_released:: db

section "home/joypad.asm", rom0

joypad_read::
    ld a, r_joyp_select_dpad
    ldh [r_joyp], a
rept 2
    ldh a, [r_joyp]
endr

    ; Save the dpad value to the high nybble
    cpl
    and r_joyp_data
    swap a
    ld b, a

    ld a, r_joyp_select_buttons
    ldh [r_joyp], a
rept 6
    ldh a, [r_joyp]
endr

    ; Save the buttons to the low nybble
    cpl
    and r_joyp_data
    or b
    ldh [h_joypad], a

    ld a, r_joyp_select
    ldh [r_joyp], a
    ret

joypad_update::
    ldh a, [h_joypad]
    ld b, a
    ldh a, [h_joypad_down]
    ld c, a

    xor b
    ld d, a
    and c
    ldh [h_joypad_released], a

    ld a, d
    and b
    ldh [h_joypad_pressed], a

    ld a, b
    ldh [h_joypad_down], a

    ret