diff options
Diffstat (limited to 'engine/smallflag.asm')
-rwxr-xr-x | engine/smallflag.asm | 142 |
1 files changed, 71 insertions, 71 deletions
diff --git a/engine/smallflag.asm b/engine/smallflag.asm index dfce475..a231d0b 100755 --- a/engine/smallflag.asm +++ b/engine/smallflag.asm @@ -1,72 +1,72 @@ -SECTION "SmallFarFlagAction", ROMX[$4d33], BANK[$03]
-
-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
+SECTION "SmallFarFlagAction", ROMX[$4d33], BANK[$03] + +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
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