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Macro factors out sine code, just like sine data, since it's used 5 times

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Rangi
2018-02-03 21:11:55 -05:00
parent 271aa20b73
commit 73ea7c6326
9 changed files with 127 additions and 411 deletions
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242
docs/design_flaws.md
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@@ -461,53 +461,9 @@ PokedexShow_GetDexEntryBank:
```asm
_Sine:: ; 84d9
; A simple sine function.
; Return d * sin(e) in hl.
; e is a signed 6-bit value.
; a = d * sin(e * pi/32)
ld a, e
and %111111
cp %100000
jr nc, .negative
call .ApplySineWave
ld a, h
ret
.negative
and %011111
call .ApplySineWave
ld a, h
xor $ff
inc a
ret
.ApplySineWave: ; 84ef
ld e, a
ld a, d
ld d, 0
ld hl, .sinewave
add hl, de
add hl, de
ld e, [hl]
inc hl
ld d, [hl]
ld hl, 0
; Factor amplitude
.multiply
srl a
jr nc, .even
add hl, de
.even
sla e
rl d
and a
jr nz, .multiply
ret
.sinewave ; 850b
; A 32-word table representing a sine wave.
; sin(90 degrees) is index $10 with an amplitude of $100.
sine_wave 32
calc_sine_wave
```
`Sprites_Cosine` and `Sprites_Sine` in [engine/sprites.asm](/engine/sprites.asm):
@@ -515,50 +471,11 @@ _Sine:: ; 84d9
```asm
Sprites_Cosine: ; 8e72a
; a = d * cos(a * pi/32)
add %010000
add %010000 ; cos(x) = sin(x + pi/2)
; fallthrough
Sprites_Sine: ; 8e72c
; a = d * sin(a * pi/32)
and %111111
cp %100000
jr nc, .negative
call .ApplySineWave
ld a, h
ret
.negative
and %011111
call .ApplySineWave
ld a, h
xor $ff
inc a
ret
; 8e741
.ApplySineWave: ; 8e741
ld e, a
ld a, d
ld d, 0
ld hl, .sinewave
add hl, de
add hl, de
ld e, [hl]
inc hl
ld d, [hl]
ld hl, 0
.multiply
srl a
jr nc, .even
add hl, de
.even
sla e
rl d
and a
jr nz, .multiply
ret
; 8e75d
.sinewave ; 8e75d
sine_wave 32
calc_sine_wave
```
`BattleAnim_Cosine` and `BattleAnim_Sine` in [engine/battle_anims/functions.asm](/engine/battle_anims/functions.asm):
@@ -566,50 +483,16 @@ Sprites_Sine: ; 8e72c
```asm
BattleAnim_Cosine: ; ce732 (33:6732)
; a = d * cos(a * pi/32)
add %010000
add %010000 ; cos(x) = sin(x + pi/2)
; fallthrough
BattleAnim_Sine: ; ce734 (33:6734)
; a = d * sin(a * pi/32)
and %111111
cp %100000
jr nc, .negative
call .ApplySineWave
ld a, h
ret
.negative
and %011111
call .ApplySineWave
ld a, h
xor $ff
inc a
ret
.ApplySineWave:
ld e, a
ld a, d
ld d, 0
ld hl, BattleAnimSineWave
add hl, de
add hl, de
ld e, [hl]
inc hl
ld d, [hl]
ld hl, 0
.multiply
srl a
jr nc, .even
add hl, de
.even
sla e
rl d
and a
jr nz, .multiply
ret
calc_sine_wave BattleAnimSineWave
...
BattleAnimSineWave: ; ce77f
sine_wave 32
sine_table 32
; ce7bf
```
@@ -617,47 +500,7 @@ BattleAnimSineWave: ; ce77f
```asm
StartTrainerBattle_DrawSineWave: ; 8c6f7 (23:46f7)
; a = d * sin(a * pi/32)
and %111111
cp %100000
jr nc, .negative
call .ApplySineWave
ld a, h
ret
.negative
and %011111
call .ApplySineWave
ld a, h
xor $ff
inc a
ret
.ApplySineWave: ; 8c70c (23:470c)
ld e, a
ld a, d
ld d, 0
ld hl, .sinewave
add hl, de
add hl, de
ld e, [hl]
inc hl
ld d, [hl]
ld hl, 0
.multiply
srl a
jr nc, .even
add hl, de
.even
sla e
rl d
and a
jr nz, .multiply
ret
; 8c728 (23:4728)
.sinewave ; 8c728
sine_wave 32
calc_sine_wave
; 8c768
```
@@ -666,51 +509,76 @@ And `CelebiEvent_Cosine` in [engine/events/celebi.asm](/engine/events/celebi.asm
```asm
CelebiEvent_Cosine: ; 49b3b (12:5b3b)
; a = d * cos(a * pi/32)
add %010000
add %010000 ; cos(x) = sin(x + pi/2)
calc_sine_wave
; 49bae
```
They all rely on `calc_sine_wave` in [macros/code.asm](/macros/code.asm):
```asm
calc_sine_wave: MACRO
; input: a = a signed 6-bit value
; output: a = d * sin(a * pi/32)
and %111111
cp %100000
jr nc, .negative
call .ApplySineWave
cp %100000
jr nc, .negative\@
call .apply\@
ld a, h
ret
.negative
.negative\@
and %011111
call .ApplySineWave
call .apply\@
ld a, h
xor $ff
inc a
ret
.ApplySineWave: ; 49b52 (12:5b52)
.apply\@
ld e, a
ld a, d
ld d, 0
ld hl, .sinewave
if _NARG == 1
ld hl, \1
else
ld hl, .sinetable\@
endc
add hl, de
add hl, de
ld e, [hl]
inc hl
ld d, [hl]
ld hl, 0
.multiply
.multiply\@ ; factor amplitude
srl a
jr nc, .even
jr nc, .even\@
add hl, de
.even
.even\@
sla e
rl d
and a
jr nz, .multiply
jr nz, .multiply\@
ret
; 49b6e (12:5b6e)
.sinewave ; 49b6e
sine_wave 32
; 49bae
if _NARG == 0
.sinetable\@
sine_table 32
endc
ENDM
```
**Fix:** Call a single shared copy of the (co)sine code in bank 0.
And on `sine_table` in [macros/data.asm](/macros/data.asm):
```asm
sine_table: MACRO
; \1 samples of sin(x) from x=0 to x<32768 (pi radians)
x = 0
rept \1
dw (sin(x) + (sin(x) & $ff)) >> 8 ; round up
x = x + DIV(32768, \1) ; a circle has 65536 "degrees"
endr
ENDM
```
**Fix:** Edit [home/sine.asm](/home/sine.asm) to contain a single copy of the (co)sine code in bank 0, and call it from those five sites.
## `GetForestTreeFrame` works, but it's still bad