How To Split Sonic's and Knuckle's Spindash Routines in S3K

Discussion in 'Tutorials Archive' started by Ravenfreak, Aug 20, 2010.

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  1. Ravenfreak

    Ravenfreak Still hacking the 8-bit titles Member

    Joined:
    Feb 10, 2010
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    Location:
    O'Fallon, MO
    So lately, I have been tweaking S3K here and there, and I came across another Spindash routine right above where Sonic's code starts. Also, I found out that Sonic and Knuckles actually share the same routine for Spindashing! Back to the other routine (there's actually 3 in S3k, one is Tails', one is Sonic's/Knux's, and the one above Sonic's.)It's fully functional, well almost. So I tweaked it a bit,and after I got it to function properly, I got an idea. What if for some reason, someone wanted to separate Sonic's/Knux's routine and give each character their own routine? So I did just that. If you wanted to, for some reason this is how. First off, you'll need the S3K/SK Buildtools and Puto's text disassembly. (That's what I used, found here:http://info.sonicretro.org/images/8/8b/Sonic_%26_Knuckles_%28Text_Format_by_Pu7o%29.zip, and here: http://info.sonicretro.org/images/e/e8/SnK...uildtools.zip.) You must use context (or another program) for this though, as trying to open the disassembly file in notepad caused it to stop responding, due to how huge the file is. :v: First search for sub_1094C, it should look like this: (note: this is the entire routine btw.)



    Code:
    sub_1094C:			&#59; CODE XREF: ROM:00010844p

		tst.b	$3D(a0)

		bne.s	loc_10998

		cmpi.b	#8,$20(a0)

		bne.s	locret_10996

		move.b	($FFFFF603).w,d0

		andi.b	#$70,d0

		beq.w	locret_10996

		move.b	#9,$20(a0)

		move.w	#$FFAB,d0

		jsr	(Play_Sound_2).l

		addq.l	#4,sp

		move.b	#1,$3D(a0)

		move.w	#0,$3E(a0)

		cmpi.b	#$C,$2C(a0)

		bcs.s	loc_10992

		move.b	#2,$20(a6)



loc_10992:			&#59; CODE XREF: sub_1094C+3Ej

		bsr.w	Player_AnglePos



locret_10996:			&#59; CODE XREF: sub_1094C+Cj

				&#59; sub_1094C+16j

		rts	

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loc_10998:			&#59; CODE XREF: sub_1094C+4j

		move.b	($FFFFF602).w,d0

		btst	#1,d0

		bne.w	loc_10A38

		move.b	#7,$1E(a0)

		move.b	#3,$1F(a0)

		move.b	#2,$20(a0)

		addq.w	#4,$14(a0)

		move.b	#0,$3D(a0)

		moveq	#0,d0

		move.b	$3E(a0),d0

		add.w	d0,d0

		move.w	word_10A14(pc,d0.w),$1C(a0)

		move.w	$1C(a0),d0

		subi.w	#$800,d0

		add.w	d0,d0

		andi.w	#$1F00,d0

		neg.w	d0

		addi.w	#$2000,d0

		lea	($FFFFEE24).w,a1

		cmpa.w	#$B000,a0

		beq.s	loc_109F0

		lea	($FFFFEE28).w,a1



loc_109F0:			&#59; CODE XREF: sub_1094C+9Ej

		move.w	d0,(a1)

		btst	#0,$2A(a0)

		beq.s	loc_109FE

		neg.w	$1C(a0)



loc_109FE:			&#59; CODE XREF: sub_1094C+ACj

		bset	#2,$2A(a0)

		move.b	#0,$20(a6)

		moveq	#-$4A,d0

		jsr	(Play_Sound_2).l

		bra.s	loc_10A80

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word_10A14:	dc.w $800

		dc.w $880

		dc.w $900

		dc.w $980

		dc.w $A00

		dc.w $A80

		dc.w $B00

		dc.w $B80

		dc.w $C00

		dc.w $B00

		dc.w $B80

		dc.w $C00

		dc.w $C80

		dc.w $D00

		dc.w $D80

		dc.w $E00

		dc.w $E80

		dc.w $F00

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loc_10A38:			&#59; CODE XREF: sub_1094C+54j

		tst.w	$3E(a0)

		beq.s	loc_10A50

		move.w	$3E(a0),d0

		lsr.w	#5,d0

		sub.w	d0,$3E(a0)

		bcc.s	loc_10A50

		move.w	#0,$3E(a0)



loc_10A50:			&#59; CODE XREF: sub_1094C+F0j

				&#59; sub_1094C+FCj

		move.b	($FFFFF603).w,d0

		andi.b	#$70,d0

		beq.w	loc_10A80

		move.w	#$900,$20(a0)

		move.w	#$FFAB,d0

		jsr	(Play_Sound_2).l

		addi.w	#$200,$3E(a0)

		cmpi.w	#$800,$3E(a0)

		bcs.s	loc_10A80

		move.w	#$800,$3E(a0)



loc_10A80:			&#59; CODE XREF: sub_1094C+C6j

				&#59; sub_1094C+10Cj ...

		addq.l	#4,sp

		cmpi.w	#$60,(a5)

		beq.s	loc_10A8E

		bcc.s	loc_10A8C

		addq.w	#4,(a5)



loc_10A8C:			&#59; CODE XREF: sub_1094C+13Cj

		subq.w	#2,(a5)



loc_10A8E:			&#59; CODE XREF: sub_1094C+13Aj

		bsr.w	Player_AnglePos

		rts	

; End of function sub_1094C
    If you ever looked at the routine for the Spindash, you'll notice it looks similar, but it's slightly different. So next, look for Player_Spindash. You only have to search once, because we need to comment out bsr.w Player_Spindash.(Note: you can also do this step with Knux's, but Sonic's code is first. xP) Replace it with bsr.w sub_1094C Build the rom and test it out. You'll notice Sonic does spindash, but he doesn't move forward! That's because the values for the Height,Width, and Y playfield coordinate of the character are different.(In this routine they are #7, $1E #3,$1F, #4,$14.)You also need to change the joypad address. This is an easy fix. Simply search for loc_10998, it should look like this:



    Code:
    loc_10998:			&#59; CODE XREF: sub_1094C+4j

		move.b	($FFFFF602).w,d0;also this

		btst	#1,d0

		bne.w	loc_10A38

		move.b	#7,$1E(a0);this is what we need

		move.b	#3,$1F(a0);to change

		move.b	#2,$20(a0)

		addq.w	#4,$14(a0);this too

		move.b	#0,$3D(a0)

		moveq	#0,d0

		move.b	$3E(a0),d0

		add.w	d0,d0

		move.w	word_10A14(pc,d0.w),$1C(a0)

		move.w	$1C(a0),d0

		subi.w	#$800,d0

		add.w	d0,d0

		andi.w	#$1F00,d0

		neg.w	d0

		addi.w	#$2000,d0

		lea	($FFFFEE24).w,a1

		cmpa.w	#$B000,a0

		beq.s	loc_109F0

		lea	($FFFFEE28).w,a1
    And change it to this:



    Code:
    loc_10998:			&#59; CODE XREF: sub_1094C+4j

		move.b	($FFFFF604).w,d0

		btst	#1,d0

		bne.w	loc_10A38

		move.b	#$E,$1E(a0)

		move.b	#7,$1F(a0)

		move.b	#2,$20(a0)

		addq.w	#5,$14(a0)

		move.b	#0,$3D(a0)

		moveq	#0,d0

		move.b	$3E(a0),d0

		add.w	d0,d0

		move.w	word_10A14(pc,d0.w),$1C(a0)

		move.w	$1C(a0),d0

		subi.w	#$800,d0

		add.w	d0,d0

		andi.w	#$1F00,d0

		neg.w	d0

		addi.w	#$2000,d0

		lea	($FFFFEE24).w,a1

		cmpa.w	#$B000,a0

		beq.s	loc_109F0

		lea	($FFFFEE28).w,a1
    And now for the final touches. Search for loc_10992, and loc_10A8E. You'll see this:



    Code:
    bsr.w Player_AnglePos
    Simply change this to

    Code:
    bsr.w Call_Player_AnglePos
    Build the ROM and there you go. You won't actually notice anything different, but they now have separate routines. Also note, this affects 2 player mode a bit. The d-pad is "locked" at start if you play as Knux/Sonic. Jumping will "unlock" the d-pad. You also can't Spindash. I don't have a fix for that, yet, but i'll update this once I figure it out. :\
     
    Ravenfreak, Aug 20, 2010
    #1
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