Wall Jumping in Sonic 2

Hello you guys! I'm Maverick Kay Prime, and this is my first post. Naturally, I'd rant on about who I am and what not, but I think that's kinda irrelevant, so I'll just cut to the chase.
 
A few weeks ago, I started hacking Sonic 2. My mission - at first - was to simply replace Sonic with Shadow. After doing that however, I decided to keep going. I ended up replacing Tails fully with Rouge. So now I have Shadow and Rouge in Sonic 2! It was awesome for me, and so I kept working.
 
I haven't changed level layouts (though I have changed Emerald Hill Zone's background), but I have changed Rouge and Shadow's character physics. Compared to Tails, Rouge runs faster and jumps higher. Compared to Sonic, Shadow runs faster but jumps lower.
 
And here's where the issues lie.
 
Shadow's inability to jump as high as Sonic makes certain areas of the game impossible to traverse. He doesn't have an ability to compensate for his lack of jump height, like Knuckles does in Knuckles in Sonic 2. He can climb, Shadow can just jump.
 
Here's a situation in Sonic 2.
 
Act 2 of Chemical Plant Zone, you climb up the first elevating staircase in the stage. You see that weird spring/jump thing and simply think you can jump for it.
 
And you can't.
 
Shadow can't make the jump. You can mess around there for as long as you please, but he just can't do it. Yeah, Rouge can make the jump easy-peasy lemon-squeezey, but Shadow can't.

Now you may say there's a work around in the area. That if you use the speed from the first ramp, you can zip up that area and past by the section without having to deal with that.

Well then, okay, I'll bite. You can past that section, I'll give you that.

So let's go over to Aquatic Ruin Zone Act 1. You run into the stage for the first two or three seconds and come to the first rising pillar which shoots out of the ground. And guess what? You can't jump over it!

It's a big problem plaguing Shadow, and I'd hate to see what else he can't jump over. I haven't played all of the game yet with my hack, but I can tell there are issues right out the gate with Shadow's jumping ability. I could easily make his jump height like Sonic's again, but I don't want to do that. I want Shadow to feel like his own character, instead of just a skin swap of Sonic.

So I thought 'Hey, why not give him a wall jump?' And I immediately ran into issues. What issues? Well, isn't it obvious?

I have no idea how to implement a wall jump of any kind. I've only started hacking Sonic 2, and as such am still new to these things. So, after joining these forums, I figured it was best to get some help from those who actually know how to hack extensively. Or at least can help me along the way. 

All I simply want is a wall jump in Sonic 2. I'm not asking you to do the work for me (though if you want to I won't stop you), but I do want to learn how to create it on my own. I've seen wall jumping in Sonic 1, but not on Sonic 2, so I want to see if such a thing is possible.

Any help is very grateful.

And sorry I can't post pictures of the areas in question. I have no idea how this forum works yet...

 

To help you along the way, I recommend first looking over this. That guide will cover almost everything you'll need to know about actually coding for now. As for making a double jump feature in general, check out this guide; although it goes over how to build a jumpdash, it is very well coded and versatile (I've used it to make my own version of tails flight code). Also, try checking out Knuckles climbing code from the KiS2 disassembly; that's probably the best place to figure out how to make shadow interact with the wall to begin with.

EDIT: Both guides do work in Sonic 2, so don't worry about that.

 

There is a wall jump code in ReadySonic which is a disassembly with a few extra features for Sonic 1. You can take the code, find the RAM addresses used for it (you should find them in the constants and variables files), and replace them with the Sonic 2 equivalent.


Also, I'm excited to see your new hack!

 

Thanks you guys for the help. I was able to insert a double jump in Sonic 2 with Shadow. While it isn't the Wall Jump I was banking on earlier, it does make the game beatable instead of impossible.

Unfortunately, I've run into another problem. Because I've inserted Selbi's jumpdash code into my asm file, I can no longer find Sonic's speed to edit it. Before I'd open up one of my hacks in Tweaker and just change Sonic or Tails' speed or jump height to get the desired effect. But after inserting the code in, all the variables have been changed to numbers and letters that don't make since. For instance, the first boss in Emerald Hill Zone says it takes over 1000 hits to kill! But when I fight him, he takes the normal amount of hits necessary before he dies.

So I don't think the parameters for their speed and jump etc. to be changed, I just can't find them. I can increase Shadow's speed, but I can't change his jump height because of this.

I do however think this is a problem I can probably solve if I just snoop around for a bit, so I won't heckle you guys further for any help (unless you wanna give it, I won't say no). That being said, thanks for the help you have given me. It makes my hack more complete, even if I do feel I have a while to go.

 

All of these things can be edited in the code, provided you know where to look. For the speed of characters I highly recommend this guide by redhotsonic.