pokecrystal-board/home/flag.asm
2017-12-28 13:15:46 +01:00

113 lines
1.3 KiB
NASM

ResetMapBufferEventFlags:: ; 2e50
xor a
ld hl, EventFlags
ld [hli], a
ret
; 2e56
ResetBikeFlags:: ; 2e56
xor a
ld hl, wBikeFlags
ld [hli], a
ld [hl], a
ret
; 2e5d
ResetFlashIfOutOfCave:: ; 2e5d
ld a, [wEnvironment]
cp $2
jr z, .asm_2e69
cp $1
jr z, .asm_2e69
ret
.asm_2e69
ld hl, wStatusFlags
res 2, [hl]
ret
; 2e6f
EventFlagAction:: ; 0x2e6f
ld hl, EventFlags
call FlagAction
ret
FlagAction:: ; 0x2e76
; Perform action b on bit de in flag array hl.
; inputs:
; b: function
; 0 RESET_FLAG clear bit
; 1 SET_FLAG set bit
; 2 CHECK_FLAG check bit
; de: bit number
; hl: index within bit table
; get index within the byte
ld a, e
and 7
; shift de right by three bits (get the index within memory)
srl d
rr e
srl d
rr e
srl d
rr e
add hl, de
; implement a decoder
ld c, 1
rrca
jr nc, .one
rlc c
.one
rrca
jr nc, .two
rlc c
rlc c
.two
rrca
jr nc, .three
swap c
.three
; check b's value: 0, 1, 2
ld a, b
cp SET_FLAG
jr c, .clearbit ; RESET_FLAG
jr z, .setbit ; SET_FLAG
; check bit
ld a, [hl]
and c
ld c, a
ret
.setbit
; set bit
ld a, [hl]
or c
ld [hl], a
ret
.clearbit
; clear bit
ld a, c
cpl
and [hl]
ld [hl], a
ret
; 0x2ead
CheckReceivedDex:: ; 2ead
ld de, ENGINE_POKEDEX
ld b, CHECK_FLAG
farcall EngineFlagAction
ld a, c
and a
ret
; 2ebb