Double Jump Guide?

On Sonic Games Dimension was a guide with this code, the problem is that it was closed.

Code:

; ---------------------------------------------------------------------------
; EB's double jump code
; ---------------------------------------------------------------------------
; ||||||||||||||| S U B R O U T I N E |||||||||||||||||||||||||||||||||||||||
Sonic_DoubleJump:
        cmpi.b    #2,$1C(a0)            ; EB: is the current animation rolling?
        bne.s    @return                ; EB:  if not, branch
        btst    #7,$22(a0)        ; EB: read if DoubleJump flag was set
        bne.s    @return                ; EB: was it set? if not, branch
        move.b    ($FFFFF603).w,d0        ; EB: read the controller
        tpress    A,(SonicControl)            ; EB: was A,B or C pressed?
        beq.w    @return                ; EB: if not, branch
        bset    #7,$22(a0)        ; EB: set DoubleJump flag
        move.w    #$A0,d0            ; EB: play 'jump' sound
        jsr    (PlaySound_Special).l   ; ^
        move.w  #-1500,$12(A0)          ; EB: set Y speed
        move.w  #6, $10 (a0)            ; EB: clear X speed
@return:
                rts                             ; EB: return

And the problem is that Double Jump works once.
Please help.
Sorry for grammar, i'm russian

 

My guess is that, the code sets the double jump flag after the button is pressed, but doesn't seem to clear it once Sonic lands on a solid surface. Notice how this line:

Code:

btst    #7,$22(a0)        ; EB: read if DoubleJump flag was set

...runs a check to determine whether or not the double jump flag has already been set (to ensure you can't air-jump infinitely), and this line:

Code:

bset    #7,$22(a0)        ; EB: set DoubleJump flag

...is what actually sets the flag, right after A, B, or C is pressed. As I said earlier, there's no function to clear the flag once Sonic lands, so the next time you attempt a double jump it reads that the flag is still set. You'll need to find the subroutine that resets Sonic's modes upon floor collision and add extra functions to check for the flag and reset it.

 

Okay, and the final code is?:

Code:

; ---------------------------------------------------------------------------
; EB's double jump code
; ---------------------------------------------------------------------------
; ||||||||||||||| S U B R O U T I N E |||||||||||||||||||||||||||||||||||||||
Sonic_DoubleJump:
        cmpi.b    #2,$1C(a0)            ; EB: is the current animation rolling?
        bne.s    @return                ; EB:  if not, branch
        btst    #7,$22(a0)        ; EB: read if DoubleJump flag was set
        bne.s    @return                ; EB: was it set? if not, branch
        move.b    ($FFFFF603).w,d0        ; EB: read the controller
        tpress    A,(SonicControl)            ; EB: was A,B or C pressed?
        bset    #7,$22(a0)        ; EB: set DoubleJump flag       
        beq.w    @return                ; EB: if not, branch
        bset    #7,$22(a0)        ; EB: set DoubleJump flag
        move.w    #$A0,d0            ; EB: play 'jump' sound
        jsr    (PlaySound_Special).l   ; ^
        move.w  #-1500,$12(A0)          ; EB: set Y speed
        move.w  #6, $10 (a0)            ; EB: clear X speed
@return:
                rts                             ; EB: return

 

Okay, do I need to add ?:
Sonic_ResetOnFloor:
If _DoubleJump_
Bclr # 7, $ 22 (a0)
endc

Sorry for Double post.

 

Correct, the bclr line simply needs to be added to the beginning of "Sonic_ResetOnFloor". The other two lines are only necessary if you're using "if" statements to enable or disable the move (think ReadySonic).

 

Now Double Jump is working correctly. Thank you!