pokegold/home/lcd.asm
2021-11-23 20:50:17 -05:00

63 lines
744 B
NASM

; LCD handling
LCD::
push af
ldh a, [hLCDCPointer]
and a
jr z, .done
push hl
ldh a, [rLY]
ld l, a
ld h, HIGH(wLYOverrides)
ld h, [hl]
ldh a, [hLCDCPointer]
ld l, a
ld a, h
ld h, HIGH(rSCY)
ld [hl], a
pop hl
.done
pop af
reti
DisableLCD::
; Turn the LCD off
; Don't need to do anything if the LCD is already off
ldh a, [rLCDC]
bit rLCDC_ENABLE, a
ret z
xor a
ldh [rIF], a
ldh a, [rIE]
ld b, a
; Disable VBlank
res VBLANK, a
ldh [rIE], a
.wait
; Wait until VBlank would normally happen
ldh a, [rLY]
cp LY_VBLANK + 1
jr nz, .wait
ldh a, [rLCDC]
and ~(1 << rLCDC_ENABLE)
ldh [rLCDC], a
xor a
ldh [rIF], a
ld a, b
ldh [rIE], a
ret
EnableLCD::
ldh a, [rLCDC]
set rLCDC_ENABLE, a
ldh [rLCDC], a
ret