pokegold-spaceworld/engine/smallflag.asm
luckytyphlosion e1659ecd41 Introduce linkerscript.
Addresses of sections will now be added to the linkerscript via `org`, and the section name will be the path/to/file. If there is more than one section in the file, then add a @SectionName after the path/to/file to describe the section.
2018-07-03 17:07:05 -04:00

72 lines
838 B
NASM
Executable File

SECTION "engine/smallflag.asm", ROMX
SmallFarFlagAction: ; 03:4d33
; Perform action b on bit c in flag array hl.
; If checking a flag, check flag array d:hl unless d is 0.
; For longer flag arrays, see FlagAction.
push hl
push bc
; Divide by 8 to get the byte we want.
push bc
srl c
srl c
srl c
ld b, 0
add hl, bc
pop bc
; Which bit we want from the byte
ld a, c
and 7
ld c, a
; Shift left until we can mask the bit
ld a, 1
jr z, .shifted
.shift
add a
dec c
jr nz, .shift
.shifted
ld c, a
; What are we doing to this flag?
dec b
jr z, .set ; 1
dec b
jr z, .check ; 2
.reset
ld a, c
cpl
and [hl]
ld [hl], a
jr .done
.set
ld a, [hl]
or c
ld [hl], a
jr .done
.check
ld a, d
cp 0
jr nz, .farcheck
ld a, [hl]
and c
jr .done
.farcheck
call GetFarByte
and c
.done
pop bc
pop hl
ld c, a
ret