Sonic '06-Like Character and Level Selector

I'm doing a hack of  Sonic 1 using the Hivebrain disassembly. My goal in this hack is to make a demake of Sonic '06 for the Genesis/Megadrive. This code was made to select the story to be played when a A, B, or C is pressed at the title screen. Then it would load a certain level order depending on the story and select from a list of 11 characters (Normal Sonic, Silver, Shadow, Tails, Knuckles, Blaze, Amy, Rouge, E-123 Omega, Sonic at Mach Speed, and Sonic carrying Elise). Instead of that, the game just picks Sonic's story despite another story being picked, use his level order, and and use him despite other characters needing to be there.
I've worked several hours on this and I hope someone can help me out. Here is the code:


Title_LoadText:
move.w (a5)+,(a6)
dbf d1,Title_LoadText ; load uncompressed text patterns
move.b #0,($FFFFFE30).w ; clear lamppost counter
move.w #0,($FFFFFE08).w ; disable debug item placement mode
move.w #0,($FFFFFFF0).w ; disable debug mode
move.w #0,($FFFFFFEA).w
tst.w ($FFFFF70E).w
bne.w Title_Silver
move.w #0,($FFFFFE10).w ; set level to GHZ (00)
move.b #0,($FFFFF70E).w ; set character to Sonic
bra.w Title_Return
Title_Silver:
cmpi.w #1,($FFFFF70E).w
bne.w Title_Shadow
move.w #$400,($FFFFFE10).w ; set level to SYZ (04)
move.b #1,($FFFFF70E).w ; set character to Silver
bra.w Title_Return
Title_Shadow:
move.w #$300,($FFFFFE10).w ; set level to SLZ (03)
move.b #2,($FFFFF70E).w ; set character to Shadow
Title_Return:

This code is to load each character's first level. As you can see F70E is the ram address used for stories and characters. The words are used for the stories and the bytes are used for characters. I originally had these as two separate ram addresses but I decided to combine them to decrease ram usage.


loc_3230:
tst.w ($FFFFF614).w
beq.w Demo

Title_CheckForA:
cmpi.b #$40,($FFFFF605).w ; is button A pressed?
bne.s Title_CheckForB ; if not, branch
move.w #0,($FFFFF70E).w ; set the multiple character flag to $01 (indicating Metal Sonic)
move.b #$B5,d0 ; put value of ring sound into d0
jsr PlaySound_Special ; jump to the subroutine that plays the sound currently in d0 ($B5, at the moment)
bra.w StartCheck

Title_CheckForB:
cmpi.b #$10,($FFFFF605).w ; is button B pressed?
bne.s Title_CheckForC ; if not, branch
move.w #1,($FFFFF70E).w ; set the multiple character flag to $01 (indicating Metal Sonic)
move.b #$B5,d0 ; put value of ring sound into d0
jsr PlaySound_Special ; jump to the subroutine that plays the sound currently in d0 ($B5, at the moment)
bra.w StartCheck

Title_CheckForC:
cmpi.b #$20,($FFFFF605).w ; is button C pressed?
bne.s StartCheck ; if not, branch
move.w #2,($FFFFF70E).w ; set the multiple character flag to $01 (indicating Metal Sonic)
move.b #$B5,d0 ; put value of ring sound into d0
jsr PlaySound_Special ; jump to the subroutine that plays the sound currently in d0 ($B5, at the moment)
bra.w StartCheck

StartCheck:
andi.b #$80,($FFFFF605).w ; check if Start is pressed
beq.w loc_317C ; if not, branch

This is the code used for checking if A, B, or C buttons are pressed at the title screen. This is based on the SCHG how-to on extra characters.


Obj3A_NextLevel: ; XREF: Obj3A_Index
move.b ($FFFFFE10).w,d0
andi.w #7,d0
lsl.w #3,d0
move.b ($FFFFFE11).w,d1
andi.w #3,d1
add.w d1,d1
add.w d1,d0
tst.w ($FFFFF70E).w ; is story 0 (Sonic)?
bne.s Silver_Story ; if not, branch
move.w SonLevelOrder(pc,d0.w),d0 ; load level from level order array
lea (SonicOrder).l,a2 ; load character number
bra.s Obj3A_Continue ; continue code

Silver_Story:
cmpi.w #$01,($FFFFF70E).w ; is story 1 (Silver)?
bne.s Shadow_Story ; if not, branch
move.w SilLevelOrder(pc,d0.w),d0 ; load level from level order array
lea (SilverOrder).l,a2 ; load character number

Obj3A_Continue:
move.w d0,($FFFFFE10).w ; set level number
tst.w d0
bne.s Obj3A_ChkSS
move.b #$a2,($FFFFF70E).w ; set character number
move.b #0,($FFFFF600).w ; set game mode to level (00)
bra.s Obj3A_Display2

This is the code used for loading the next level and character depending on the story. This uses six files: SonLevelOrder, SilLevelOrder, and ShwLevelOrder are each story's level orders and SonicOrder, SilverOrder, and ShadowOrder are each level's character and use the use the same order as their respective levelorders. Shadow_Story is located elsewhere but is similar to Silver_Story.


LoadSonicDynPLC: ; XREF: Obj01_Control; et al
moveq #0,d0
move.b $1A(a0),d0 ; load frame number
cmp.b ($FFFFF766).w,d0
beq.s Jump_Equal
move.b d0,($FFFFF766).w
lea (SonicDynPLC).l,a2
add.w d0,d0
adda.w (a2,d0.w),a2
moveq #0,d5
move.b (a2)+,d5
subq.w #1,d5
bmi.s locret_13C96
move.w #$F000,d4
tst.b ($FFFFF70E).w ; is character 0 (Sonic)?
bne.s Silver_Character ; if not, branch
move.l #Art_Sonic,d6 ; load Sonic's art
bra.s SPLC_ReadEntry ; continue code

Jump_Equal:
jmp locret_13C96

Silver_Character:
cmpi.b #1,($FFFFF70E).w ; is character 1 (Silver)?
bne.s Shadow_Character ; if not, branch
move.l #Art_Silver,d6 ; load Silver's art
bra.s SPLC_ReadEntry ; continue code

Shadow_Character:
cmpi.b #2,($FFFFF70E).w ; is character 2 (Shadow)?
bne.s Other_Character ; if not, branch
move.l #Art_Shadow,d6 ; load Silver's art
bra.s SPLC_ReadEntry ; continue code

Other_Character:
move.l #Art_Sonic,d6 ; load Sonic's art

SPLC_ReadEntry:

This is the code for loading each character's art. So far, the code is only for Sonic, Silver, and Shadow's art. Any other characters would just use Sonic's sprites but have none of Sonic's extra moves. I haven't made the characters load custom mappings, palettes, or DPLCs yet either.

Thanks!

 

This could be improved. It's terribly inefficient.

This heap of code:


LoadSonicDynPLC: ; XREF: Obj01_Control; et al
moveq #0,d0
move.b $1A(a0),d0 ; load frame number
cmp.b ($FFFFF766).w,d0
beq.s Jump_Equal
move.b d0,($FFFFF766).w
lea (SonicDynPLC).l,a2
add.w d0,d0
adda.w (a2,d0.w),a2
moveq #0,d5
move.b (a2)+,d5
subq.w #1,d5
bmi.s locret_13C96
move.w #$F000,d4
tst.b ($FFFFF70E).w ; is character 0 (Sonic)?
bne.s Silver_Character ; if not, branch
move.l #Art_Sonic,d6 ; load Sonic's art
bra.s SPLC_ReadEntry ; continue code

Jump_Equal:
jmp locret_13C96

Silver_Character:
cmpi.b #1,($FFFFF70E).w ; is character 1 (Silver)?
bne.s Shadow_Character ; if not, branch
move.l #Art_Silver,d6 ; load Silver's art
bra.s SPLC_ReadEntry ; continue code

Shadow_Character:
cmpi.b #2,($FFFFF70E).w ; is character 2 (Shadow)?
bne.s Other_Character ; if not, branch
move.l #Art_Shadow,d6 ; load Silver's art
bra.s SPLC_ReadEntry ; continue code

Other_Character:
move.l #Art_Sonic,d6 ; load Sonic's art

SPLC_ReadEntry:

Could be changed to simply this:


LoadSonicDynPLC: ; XREF: Obj01_Control; et al
moveq #0,d0
move.b $1A(a0),d0 ; load frame number
cmp.b ($FFFFF766).w,d0
beq.w locret_13C96
move.b d0,($FFFFF766).w
lea (SonicDynPLC).l,a2
add.w d0,d0
adda.w (a2,d0.w),a2
moveq #0,d5
move.b (a2)+,d5
subq.w #1,d5
bmi.w locret_13C96
move.w #$F000,d4
move.b ($FFFFF70E).w,d3
move.l Char_ArtTable(pc,d3.w),d6

SPLC_ReadEntry:
moveq #0,d3

[...other DPLC code...]

Char_ArtTable:
dc.l Art_Sonic
dc.l Art_Shadow
dc.l Art_Silver
; Expand as necessary.

See? Much smaller and easier to expand. The clearing of d3 is necessary; if my memory serves me right, d3 is used further down in the loading-character-DPLCs routine. I'm not sure, though.

 

As much as I'd love to have this in my hack, it turns Sonic into a garbled-up mess.

Edit: It only does it in GHZ Act 1.

Edit2: Nevermind. Other acts start out fine but then become more and more messed up.

 

That's...odd...try clearing d3 before loading $FFFFF70E to d3. This command does that:


moveq #0,d3

If that doesn't work, give me a screenshot of what happens and I might be able to pinpoint the source.

 

See the problem here? Ill give you a hint, look at the bits. I lined it up to make it easier. There are some other things but I can't explain them well enough.


Edit: My answer was crap.

 

That's...odd...try clearing d3 before loading $FFFFF70E to d3. This command does that:


moveq #0,d3

If that doesn't work, give me a screenshot of what happens and I might be able to pinpoint the source.



This worked. Thanks!