shithub: pokecrystal

ref: 8e135931a6358c831f9197a44c15d8c0c26eaf43
dir: /home/game_time.asm/

ResetGameTime::
	xor a
	ld [wGameTimeCap], a
	ld [wGameTimeHours], a
	ld [wGameTimeHours + 1], a
	ld [wGameTimeMinutes], a
	ld [wGameTimeSeconds], a
	ld [wGameTimeFrames], a
	ret

GameTimer::
	nop

	ldh a, [rSVBK]
	push af
	ld a, BANK(wGameTime)
	ldh [rSVBK], a

	call .Function

	pop af
	ldh [rSVBK], a
	ret

.Function:
; Increment the game timer by one frame.
; The game timer is capped at 999:59:59.00.

; Don't update if game logic is paused.
	ld a, [wGameLogicPaused]
	and a
	ret nz

; Is the timer paused?
	ld hl, wGameTimerPaused
	bit GAME_TIMER_PAUSED_F, [hl]
	ret z

; Is the timer already capped?
	ld hl, wGameTimeCap
	bit 0, [hl]
	ret nz

; +1 frame
	ld hl, wGameTimeFrames
	ld a, [hl]
	inc a

	cp 60 ; frames/second
	jr nc, .second

	ld [hl], a
	ret

.second
	xor a
	ld [hl], a

; +1 second
	ld hl, wGameTimeSeconds
	ld a, [hl]
	inc a

	cp 60 ; seconds/minute
	jr nc, .minute

	ld [hl], a
	ret

.minute
	xor a
	ld [hl], a

; +1 minute
	ld hl, wGameTimeMinutes
	ld a, [hl]
	inc a

	cp 60 ; minutes/hour
	jr nc, .hour

	ld [hl], a
	ret

.hour
	xor a
	ld [hl], a

; +1 hour
	ld a, [wGameTimeHours]
	ld h, a
	ld a, [wGameTimeHours + 1]
	ld l, a
	inc hl

; Cap the timer after 1000 hours.
	ld a, h
	cp HIGH(1000)
	jr c, .ok

	ld a, l
	cp LOW(1000)
	jr c, .ok

	ld hl, wGameTimeCap
	set 0, [hl]

	ld a, 59 ; 999:59:59.00
	ld [wGameTimeMinutes], a
	ld [wGameTimeSeconds], a
	ret

.ok
	ld a, h
	ld [wGameTimeHours], a
	ld a, l
	ld [wGameTimeHours + 1], a
	ret