pokecrystal-board/home/lcd.asm
2021-11-23 20:37:18 -05:00

73 lines
916 B
NASM

; LCD handling
Function547:: ; unreferenced
ldh a, [hLCDCPointer]
cp LOW(rSCX)
ret nz
ld c, a
ld a, [wLYOverrides]
ldh [c], a
ret
LCD::
push af
ldh a, [hLCDCPointer]
and a
jr z, .done
; At this point it's assumed we're in BANK(wLYOverrides)!
push bc
ldh a, [rLY]
ld c, a
ld b, HIGH(wLYOverrides)
ld a, [bc]
ld b, a
ldh a, [hLCDCPointer]
ld c, a
ld a, b
ldh [c], a
pop bc
.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