Yoshi's House Birds Offscreen "Fix"

Submission Details

Name:	Yoshi's House Birds Offscreen "Fix"
Author:	JamesD28
Added:	2021-11-28 01:28:38 AM
Tool:	Asar
Requires Free Space:	Yes
Bug Fix:	No
Featured:	No
Description:	This patch "fixes" the graphics routine for the Yoshi's House Birds so that they don't wrap horizontally or vertically between screens, when using a Yoshi's House level that extends beyond the original one-screen dimensions.
Tags:	bird from yoshi's house graphics routine lorom sa-1
Comments:	3 (jump to comments)

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Comments (3)

amt 2023-08-08 06:12:49 PM Link

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Maarfy 2021-11-28 01:29:48 AM Link

Works as intended, approved. Be aware that this patch doesn't give the birds ground detection or anything like that. They'll still snap to a fixed Y-position, they just won't "repeat" as the level is scrolled. If this patch doesn't satisfy your Birds on Yoshi's House needs, consider checking out these custom sprites (1) (2).

Tested with Asar 1.81, Lunar Magic 3.31, SA-1 1.40, Snes9x 1.59.2.

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Originally posted by autoclean JML Pain

3 bytes were the difference between this patch not needing freespace, after optimizing the original routine.

I would be very surprised if one couldn't wring at least three spare bytes out of this patch. Given some quick poking at, would this not work:

Code

JSR $D378
LDA !15A0,x
ORA !186C,x
BNE DontDraw
TXA
AND #$03
PHA
TAY
LDA $F3E2,y
LDY !157C,x
ORA $F3E0,y
;STA $02		;   -2 bytes
XBA			;   +1 byte
PLY
LDA $F3E6,y
TAY
XBA			; \ 
STA $0203|!addr,y	; / +4 bytes
REP #$20		;   +2 bytes
LDA $00
STA $0200|!addr,y
;LDA $01		; \ 
;STA $0201|!addr,y	; / -5 bytes
SEP #$20		;   +2 bytes
PHY
LDY !1602,x
LDA $F3DB,y
PLY
STA $0202|!addr,y
;LDA $02		; \ 
;STA $0203|!addr,y	; / -5 bytes
TYA
LSR #2
TAY
LDA #$00
STA $0420|!addr,y
DontDraw:

; 9 bytes added, 12 bytes saved, 3 bytes shorter overall

Anas 2021-08-10 01:01:24 PM Link

Interesting. I noticed the fireplace smoke generated by the side exit generator has a similar issue. I thought there was a patch in the section that fixed that, but I can't find it. Are you considering fixing that as well?