Sonic and Sega Retro Message Board: Lorenzo - Viewing Profile - Sonic and Sega Retro Message Board

This bug is more noticeable when you apply this fix Fix Camera Y Position for Tails. Then I took a look at vanilla S2: it's hardly noticeable, but when you are aware of this bug, you can barely see that the camera moves a little when the level has just finished loading.

I applied your changes with the "Camera Y position for Tails" fix and it seems to work just fine.

Hi.

When I was working on a hack of mine and implementing this fix regarding speed, I tested it and noticed a bug in 2P mode. Perhaps not many people care about 2P mode, but I thought this might be worth mentioning.

Look at this snippet of code where the speed table is used for Tails when getting the Speed Shoes:

;loc_12A10:
super_shoes_Tails:	
        movem.l	a0-a2,-(sp)
	lea	(MainCharacter).w,a0  
	lea	(Tails_top_speed).w,a2
	jsr	ApplySpeedSettings
	movem.l	(sp)+,a0-a2

This only works when you are using Tails only, thus when he's the main character. When in 2P mode, Tails can break the monitor, but the speed values are not applied for him because he's not the main character, but the "sidekick" (using the disassembly terminology).

What I did to fix it was this:

;loc_12A10:
super_shoes_Tails:	
        movem.l	a0-a2,-(sp)
	lea	(MainCharacter).w,a0  
	tst.w	(Player_mode).w       ; Test which characters we're using
	bne.s	+                                 ; If we're not using Sonic and Tails together, branch
	lea	(Sidekick).w,a0                  ; otherwise load sidekick in a0 (for Tails obviously)
+
	lea	(Tails_top_speed).w,a2
	jsr	ApplySpeedSettings
	movem.l	(sp)+,a0-a2

Simple enough. We use the MainCharacter RAM section when we're using Tails only, and we load the Sidekick RAM section in a0 when we're using both Sonic and Tails (for 2P not 1P mode).

Since we added a + label, the bra.s instruction above the label won't branch correctly. So change

	movem.l	a0-a2,-(sp)		; Move a0, a1 and a2 onto stack
	lea	(MainCharacter).w,a0	; Load Sonic to a0
	lea	(Sonic_top_speed).w,a2	; Load Sonic_top_speed into a2
	jsr	ApplySpeedSettings	; Fetch Speed settings
	movem.l	(sp)+,a0-a2		; Move a0, a1 and a2 from stack
	bra.s	+
; ---------------------------------------------------------------------------
;loc_12A10:
super_shoes_Tails:
	movem.l	a0-a2,-(sp)		; Move a0, a1 and a2 onto stack

to this:

	movem.l	a0-a2,-(sp)		; Move a0, a1 and a2 onto stack
	lea	(MainCharacter).w,a0	; Load Sonic to a0
	lea	(Sonic_top_speed).w,a2	; Load Sonic_top_speed into a2
	jsr	ApplySpeedSettings	; Fetch Speed settings
	movem.l	(sp)+,a0-a2		; Move a0, a1 and a2 from stack
	bra.s	++                          ; <-- added a + to make it branch to the correct location
; ---------------------------------------------------------------------------
;loc_12A10:
super_shoes_Tails:
	movem.l	a0-a2,-(sp)		; Move a0, a1 and a2 onto stack

I tested it and everything should be OK. I hope it's clear enough.

Since it's my first post here, I don't know how I should explain stuff, if I forgot to include something or if it's not detailed enough, for an asm edit that is.