dos33fsprogs/tfv/keyboard.s
2020-12-30 01:00:25 -05:00

164 lines
2.5 KiB
ArmAsm

;==============================
; Get Keypress
;==============================
; returns 0 if nothing pressed
get_keypress:
; first handle joystick
lda JOYSTICK_ENABLED
beq actually_handle_keypress
; only check joystick every-other frame
lda FRAMEL
and #$1
beq actually_handle_keypress
check_button:
lda PADDLE_BUTTON0
bpl button_clear
lda JS_BUTTON_STATE
bne js_check
lda #1 ; only register on release
sta JS_BUTTON_STATE
lda #' '
jmp done_keypress
button_clear:
lda #0
sta JS_BUTTON_STATE
js_check:
jsr handle_joystick
js_check_left:
lda value0
cmp #$20
bcs js_check_right ; if less than 32, left
lda #'A'
jmp done_keypress
js_check_right:
cmp #$40
bcc js_check_up
lda #'D'
jmp done_keypress
js_check_up:
lda value1
cmp #$20
bcs js_check_down
lda #'W'
jmp done_keypress
js_check_down:
cmp #$40
bcc done_joystick
lda #'S'
jmp done_keypress
done_joystick:
actually_handle_keypress:
lda KEYPRESS
bmi keypress
jmp no_keypress
keypress:
and #$7f ; clear high bit
cmp #' '
beq check_sound ; make sure not to lose space
and #$df ; convert uppercase to lower case
check_sound:
cmp #$14 ; control-T
bne check_joystick
lda SOUND_STATUS
eor #SOUND_DISABLED
sta SOUND_STATUS
jmp no_keypress
; can't be ^J as that's the same as down
check_joystick:
cmp #'J' ; J
bne check_load
lda JOYSTICK_ENABLED
eor #1
sta JOYSTICK_ENABLED
jmp no_keypress
check_load:
; cmp #$C ; control-L
; bne check_save
; jsr load_game
; jmp done_keypress
check_save:
; cmp #$13 ; control-S
; bne check_left
; jsr save_game
; jmp done_keypress
check_left:
cmp #'A'
beq left_pressed
cmp #8 ; left key
bne check_right
left_pressed:
lda #'A'
jmp done_keypress
check_right:
cmp #'D'
beq right_pressed
cmp #$15 ; right key
bne check_up
right_pressed:
lda #'D'
jmp done_keypress
check_up:
cmp #'W'
beq up_pressed
cmp #$0B ; up key
bne check_down
up_pressed:
lda #'W'
jmp done_keypress
check_down:
cmp #'S'
beq down_pressed
cmp #$0A
bne check_return
down_pressed:
lda #'S'
jmp done_keypress
check_return:
cmp #' '
beq return_pressed
cmp #13
bne no_keypress
return_pressed:
lda #' '
jmp done_keypress
no_keypress:
lda #0
done_keypress:
bit KEYRESET
rts