Insta - Shield in Sonic 1 ?

Hello.^o^ I just want to enjoy "Sonic Hacking" and joined this site But there is problem.

Like add spin dash course, I've also to set like this.

Obj01_MdNormal:
        bsr.w    Sonic_InstaShield    < -- (I added)
        bsr.w    Sonic_Jump
        bsr.w    Sonic_SlopeResist
        bsr.w    Sonic_Move
        bsr.w    Sonic_Roll
        bsr.w    Sonic_LevelBound
        jsr    SpeedToPos
        bsr.w    Sonic_AnglePos
        bsr.w    Sonic_SlopeRepel
        rts    
; ===========================================================================

And.. What next ? I don't have any code.o_0 I've looked SSRG or Soinc Retro, but no exist about add Insta-Shield like Spindash or Jumpdash.

 

You could always download an S3K disassembly then take the code from there.

 

You have added a branch to a piece of code that you don't even have? Are you expecting us to give you everything on a plate?

As redhotsonic has said, look at the disassembly, try and find the code and alter it to suit Sonic 1.

 

Hmm..okay.. If that's the case, I found "Sonic_InstaAndShieldMoves" code. I changed named to InstaShield and paste it.

; End of function Sonic_JumpHeight

 

Sonic_InstaShield: <---(Changed name, copy from Sonic3k.asm and paste it.)

 

        tst.b    $40(a0)

        beq.s    loc_118EA

        move.w    #-$400,d1

        btst    #6,$2A(a0)

        beq.s    loc_118D2

        move.w    #-$200,d1

 

loc_118D2:

        cmp.w    $1A(a0),d1

        ble.w    loc_11900

        move.b    ($FFFFF602).w,d0

        andi.b    #$70,d0

        bne.s    locret_118E8

        move.w    d1,$1A(a0)

 

locret_118E8:

        rts

; ---------------------------------------------------------------------------

 

loc_118EA:

        tst.b    $3D(a0)

        bne.s    locret_118FE

        cmpi.w    #-$FC0,$1A(a0)

        bge.s    locret_118FE

        move.w    #-$FC0,$1A(a0)

 

locret_118FE:

 

        rts

; ---------------------------------------------------------------------------

 

loc_11900:

        tst.b    $2F(a0)

        bne.w    locret_11A14

        move.b    ($FFFFF603).w,d0

        andi.b    #$70,d0

        beq.w    locret_11A14

        bclr    #4,$2A(a0)

        tst.b    ($FFFFFE19).w

        beq.s    loc_1192C

        bmi.w    loc_11A96

        move.b    #1,$2F(a0)

        rts

; ---------------------------------------------------------------------------

 

loc_1192C:

        btst    #1,$2B(a0)

        bne.w    locret_11A14

        btst    #4,$2B(a0)

        beq.s    loc_1197A

        move.b    #1,($FFFFCD08).w

        move.b    #1,$2F(a0)

        move.w    #$800,d0

        btst    #0,$2A(a0)

        beq.s    loc_11958

        neg.w    d0

 

loc_11958:

        move.w    d0,$18(a0)

        move.w    d0,$1C(a0)

        move.w    #0,$1A(a0)

        move.w    #$2000,($FFFFEE24).w

        bsr.w    Reset_Player_Position_Array

        move.w    #$43,d0

        jmp    (Play_Sound_2).l

; ---------------------------------------------------------------------------

 

loc_1197A:

        btst    #5,$2B(a0)

        beq.s    loc_119A2

        move.b    #1,($FFFFCD08).w

        move.b    #1,$2F(a0)

        move.w    #-$580,$1A(a0)

        clr.b    $40(a0)

        move.w    #$45,d0

        jmp    (Play_Sound_2).l

; ---------------------------------------------------------------------------

 

loc_119A2:

        btst    #6,$2B(a0)

        beq.s    loc_119D2

        move.b    #1,($FFFFCD08).w

        move.b    #1,$2F(a0)

        move.w    #0,$18(a0)

        move.w    #0,$1C(a0)

        move.w    #$800,$1A(a0)

        move.w    #$44,d0

        jmp    (Play_Sound_2).l

; ---------------------------------------------------------------------------

 

loc_119D2:

        cmpi.b    #7,($FFFFFFB1).w

        bcc.s    loc_119E8

        cmpi.b    #7,($FFFFFFB0).w

        bcs.s    loc_119F6

        tst.b    ($FFFFFFBA).w

        bne.s    loc_119F6

 

loc_119E8:

        cmpi.w    #$32,($FFFFFE20).w

        bcs.s    loc_119F6

        tst.b    ($FFFFFE1E).w

        bne.s    loc_11A16

 

loc_119F6:

 

        btst    #0,$2B(a0)

        bne.s    locret_11A14

        move.b    #1,($FFFFCD08).w

        move.b    #1,$2F(a0)

        move.w    #$42,d0

        jmp    (Play_Sound_2).l

; ---------------------------------------------------------------------------

 

locret_11A14:

 

        rts

; ---------------------------------------------------------------------------

 

loc_11A16:

        move.b    #1,($FFFFF65F).w

        move.b    #$F,($FFFFF65E).w

        move.w    #$3C,($FFFFF670).w

        move.l    #Map_SuperSonic,$C(a0)

        move.b    #$81,$2E(a0)

        move.b    #$1F,$20(a0)

        cmpi.b    #7,($FFFFFFB1).w

        bcs.s    loc_11A5C

        move.b    #-1,($FFFFFE19).w

        move.l    #Obj_HyperSonic_19348,($FFFFCD7C).w

        move.l    #Obj_HyperSonicKnux_Trail,($FFFFCBC0).w

        bra.s    loc_11A6A

; ---------------------------------------------------------------------------

 

loc_11A5C:

        move.b    #1,($FFFFFE19).w

        move.l    #Obj_SuperSonicKnux_Stars,($FFFFCBC0).w

 

loc_11A6A:

        move.w    #$A00,(a4)

        move.w    #$30,2(a4)

        move.w    #$100,4(a4)

        move.b    #0,$35(a0)

        bset    #1,$2B(a0)

        moveq    #-$61,d0

        jsr    (Play_Sound_2).l

        moveq    #$2C,d0

        jmp    (Play_Sound).l

; ---------------------------------------------------------------------------

 

loc_11A96:

        bsr.w    sub_104EA

        move.w    #$2000,($FFFFEE24).w

        bsr.w    Reset_Player_Position_Array

        move.b    #1,$2F(a0)

        move.b    #1,($FFFFCD9C).w

        moveq    #-$4A,d0

        jsr    (Play_Sound_2).l

        move.b    ($FFFFF602).w,d0

        andi.w    #$F,d0

        beq.s    loc_11AE0

        cmpi.b    #$B,d0

        bcc.s    loc_11AE0

        lsl.w    #2,d0

        lea    loc_11AF6+4(pc,d0.w),a1

        move.w    (a1)+,d0

        move.w    d0,$18(a0)

        move.w    d0,$1C(a0)

        move.w    (a1)+,d0

        move.w    d0,$1A(a0)

        rts

; ---------------------------------------------------------------------------

 

loc_11AE0:

 

        move.w    #$800,d0

        btst    #0,$2A(a0)

        beq.s    loc_11AEE

        neg.w    d0

 

loc_11AEE:

        move.w    d0,$18(a0)

        move.w    d0,$1C(a0)

 

loc_11AF6:

        move.w    #0,$1A(a0)

        rts

; End of function Sonic_InstaShield

 

But It doesn't working. o_o;; (Of course I know S3K format and S1 format are different.)

 

If insert Spindash code, It works (but not perfect Spindash you know) and make rom, But Instashield can't make rom either.

 

Because....

A. Half of those things don't exist in Sonic 1.

B. Constants are completely different between Sonic 1 to Sonic 3K. Hell, Even between Sonic 2 to S3K.

C. RAM addresses are no longer the same as well.

If you thought that simply porting the code over and plugging it straight into Sonic 1 was going to work, sweet god, you're not going to make it past Day 1. Along with back porting the code, you always have to make it usable to the game you are porting it to. That's why straight porting Spin Dash into Sonic 1 from Sonic 2 won't work, unless you are using the old Nemesis disasm, which nobody does, so......

 

SuperEgg here is 100% correct. How do I know? Becuase I learned the hard way; it's the same story with porting Knuckles to Sonic 2 from the KiS2 (Knuckles in Sonic 2) disassembly, and even more so if you port the S3K Priority Manager beforehand.

 

So what am I supposed to do?

 

Well....

1. understand the code you are working with, that generally helps.

2. Understand the variables you are working with. As in, you're actually going to have to learn what $26 means.

3. Know about the RAM addresses. See if there is a Sonic 1 equivalent.

4. Stop bitching  and whining. I told you exactly what to do before. Hell, the instructions I gave you were self explanatory, assuming you understand the code.(See #1)

5. ?????

6. Profit.

 

Instashield itself is really simple.

You could for example do it this way: In the jumping routine, if the doublejump flag isn't set, you have to set a counter when a/b/c is pressed, when that counter finishes, set the doublejump flag (to tell the game instashield isn't active anymore), reset both the counter and flag when Sonic touches the ground, a platform, a spring, etc. Then modify the TouchResponse routine so when the counter is above 0, Sonic is not hurt and the enemy/monitor is destroyed from further (modify touch radius).

There are other ways to do it of course, it's just an example. That's all really easy stuff if you think about it carefully.

Then, you have to add an object, that object has to copy Sonic's position and display a sprite (the visible instashield) when the counter is running. This might be the tricky part because to have the animated s3 instashield, you'll have to load the art dynamically, most likely where the shield's art is, which means you'll also have to modify the shield to load art dynamically.

I first tried to copy it from s3 as well, but couldn't understand what some flags were meant to be, so I did my own instead. To be honest, it really isn't too difficult and it's a good way to learn some useful asm stuff.

 

Okay I will try it. Thanks