Avoid more redundant code and diffs

This commit is contained in:
Rangi 2019-02-17 13:38:30 -05:00
parent fcca48f2a6
commit 47495e7d66

View File

@ -630,40 +630,36 @@ ENDM
## `GetForestTreeFrame` works, but it's still bad
In [engine/tilesets/tileset_anims.asm](/engine/tilesets/tileset_anims.asm):
```asm
GetForestTreeFrame:
; Return 0 if a is even, or 2 if odd.
and a
jr z, .even
cp 1
jr z, .odd
cp 2
jr z, .even
cp 3
jr z, .odd
cp 4
jr z, .even
cp 5
jr z, .odd
cp 6
jr z, .even
.odd
ld a, 2
scf
ret
.even
xor a
ret
```
The routine `GetForestTreeFrame` in [engine/tilesets/tileset_anims.asm](/engine/tilesets/tileset_anims.asm) is hilariously inefficient.
**Fix:**
Edit `GetForestTreeFrame`:
```asm
GetForestTreeFrame:
; Return 0 if a is even, or 2 if odd.
and 1
add a
GetForestTreeFrame:
; Return 0 if a is even, or 2 if odd.
- and a
- jr z, .even
- cp 1
- jr z, .odd
- cp 2
- jr z, .even
- cp 3
- jr z, .odd
- cp 4
- jr z, .even
- cp 5
- jr z, .odd
- cp 6
- jr z, .even
-.odd
- ld a, 2
- scf
- ret
-.even
- xor a
+ and 1
+ add a
ret
```