Making Chaos Emeralds give you abilities

(The revised edition can be found here.) Lets say you wanted to add the double jump but you didn't want sonic to get that ability without having an chaos emerald. Instead you want sonic to get one Chaos emerald to use the double jump. Well here's how to do it. first put the double jump code in the ASM.


The Double Jump Code:



Sonic_DoubleJump:
tst.w $12(a0); is Sonic moving upwards?


beq.s endofdoublejump; if not, branch


cmpi.b #$13,$1C(a0); is sonic using "bounce" animation?


beq.w endofdoublejump; if yes, branch


cmpi.b #2,$1C(a0); is Sonic rolling/jumping?


move.b ($FFFFF605).w,d0


andi.b #$20,d0; is C button pressed?


beq.s endofdoublejump; if not, branch


sub.w #$600,$12(a0); move Sonic upwards


move.b #2,$1C(a0); use "rolling" animation


move.b #1,$21(a0); set the double-jump flag


endofdoublejump:


rts



Then in the beginning of the code put



cmpi.b #1,($FFFFFE57).w ; does Sonic have 1 emerald?
blt.s locret_134D2 ; if less than 1 emerald, branch



but lets say you want sonic to get the double jump with a different number of emeralds, well then replace the 1 with the X number of emeralds you want sonic to get to use the double jump.


I'll use the double jump code in my ASM as an example:



Sonic_DoubleJump:
cmpi.b #2,($FFFFFE57).w ; does Sonic have 2 emeralds?


blt.s locret_134D2 ; if less than 2 emeralds, branch


tst.w $12(a0); is Sonic moving upwards?


beq.s endofdoublejump; if not, branch


cmpi.b #$13,$1C(a0); is sonic using "bounce" animation?


beq.w endofdoublejump; if yes, branch


cmpi.b #2,$1C(a0); is Sonic rolling/jumping?


move.b ($FFFFF605).w,d0


andi.b #$20,d0; is C button pressed?


beq.s endofdoublejump; if not, branch


sub.w #$600,$12(a0); move Sonic upwards


move.b #2,$1C(a0); use "rolling" animation


move.b #1,$21(a0); set the double-jump flag


endofdoublejump:


rts



just change the



cmpi.b #1,($FFFFFE57).w ; does Sonic have 1 emerald?
blt.s locret_134D2 ; if less than 1 emerald, branch



to the X number of emeralds you want sonic to have to use the double jump. You also need to know is how to check if you have less than X emeralds.


Here is an ASM file included with the double jump and my code, giving you the double jump with one emerald: sonic1_ASM_double_jump_with_one_emerald.rar

 

This Tutorial fails for 3 reasons:


1. You failed at making proper tabs.


2. You should look on the Tutorial a second time, before posting it. Reason:



Sonic_DoubleJump:
cmpi.b #2,($FFFFFE57).w ; does Sonic have 2 emeralds?


bne.w locret_134D2 ; if less than 2 emeralds, branch



See the problem? if not, look at the cmpi line.
3. This is actually a No-Brainer, but it might be useful for the super new Members.


Said this, you should redo the guide. Or if you want, I can fix some stuff. Really, it'll be better for you and the other Members.

 

I have no idea how



Sonic_DoubleJump:
cmpi.b #2,($FFFFFE57).w ; does Sonic have 2 emeralds?


bne.w locret_134D2 ; if less than 2 emeralds, branch



is a problem or what you mean by making proper tabs. But then again this is my first post here so once I fix it up I'll ask staff to move it to No-Brainers. So for now I'm turning this back to code boxes.

 

Sonic_DoubleJump:
cmpi.b #2,($FFFFFE57).w ; does Sonic have 2 emeralds?


bne.w locret_134D2 ; if less than 2 emeralds, branch



These are proper tabs. In other words, make 2 Tabs before a line starts (except the label).

 

Contrary to popular belief, tabs are not held to a strict standard that they must adhere to--you can use spaces just as well and the code will still compile. Tabs simply exist for organizational purposes, which you can either follow or not, depending on your own personal preference.


In any case, it's nothing that a person following this tutorial can't fix with about 30 seconds of manual effort. Stop being so pedantic.

 

Sure, but it looks nicer when using 2 tabs instead of a shit load of spaces. =P

Chill down, dude. It was just some criticsm.

 

Ha. but seriously Tweaker chill and I made it look nicer Selbi is right about it looking nicer with two tabs first.

 

To make it look even nicer, make sure, you don't have any spaces in the 2 tab area. Also, you actually have a tab between the command and the instruction. Look at this for the perfect instruction:

Code:

[TAB] [TAB] Command [TAB] Instruction [SPACE or TAB]; [SPACE] Comment

Example:



cmpi.b #1,($FFFFFFFF).w ; bla



To everyone, who is ready this, it's better to use this way, if you want proper, nice and "good for guides" lines. =P

 

Why are people telling me to "chill," exactly? What exactly about my post implies that I'm not "chilled"? There's no need to cover up your own inadequacies by trying to make my point look extreme, you know.

 

Answer:

But if you mean, you were chilled, I take back everything I said.

 

Hey Selbi, I heard you like tabbing, here's something you'll like:




;===============================================================================


; Sub Routine PseudoRandomNumber


; [ Begin ]


;===============================================================================


PseudoRandomNumber: ; Offset_0x0029AC:


move.l ($FFFFF636).w, D1


bne.s Offset_0x0029B8


move.l #$2A6D365A, D1


Offset_0x0029B8:


move.l D1, D0


asl.l #$02, D1


add.l D0, D1


asl.l #$03, D1


add.l D0, D1


move.w D1, D0


swap.w D1


add.w D1, D0


move.w D0, D1


swap.w D1


move.l D1, ($FFFFF636).w


rts


;===============================================================================


; Sub Routine PseudoRandomNumber


; [ End ]


;===============================================================================

 

I'm with Tweaker on this, everyone can tab in the way he prefers...


I tend to respect tabbing in my soniNeko disasm, I admit that, but I almost never tab in my QB/VB programs. Sometimes I do, but I don't make a rule out of it, though.


I agree that tabs are better than spaces, anyway.

 

You're arguing over spaces? What has this world come to.

Seeing that hamburger and that horse just makes it all worthwhile.


As for the guide, it's not that much of a no-brainer (no-brainer would be how to edit a palette).

 

Not bad for a first tutorial, but you may want to fix a very small problem.

Be careful with pasting next time.


And I also have to agree with Irixion, arguing over something like tabs and spaces is (very) immature.

 

Hey I've got to agree with you there I mean what's the point of tabbing? (uh don't answer that.) Also I fixed the tutorial.

 

Trying to keep on topic...

Code:

Sonic_DoubleJump:

		cmpi.b	#2,($FFFFFE57).w&#59; does Sonic have 2 emerald?

		blt.s	locret_134D2&#59; if less than 2 emerald, branch

IIRC checks for emeralds should be .w, not .b

Code:

Sonic_DoubleJump:

		cmpi.w	#2,($FFFFFE57).w&#59; does Sonic have 2 emerald?

		blt.s	locret_134D2&#59; if less than 2 emerald, branch

 

Why? There are only 6 emeralds, so why do we need a word? Or are there 65535 emeralds?

 

Selbi's right here. You don't need a .w

 

Update: I added an ASM file to the first post.