[Sik]

Tweaker, on Mar 30 2006, 11:20 AM, said:

QJimbo, on Mar 30 2006, 08:40 AM, said:

Ideas ideas....

The thing is ASM is very very hard. You won't be able to dive straight in to coding them because you won't have any idea of how the code will be structured if you've never done ASM before.

Shut it. ASM isn't hard -- understanding the engine and hardware is.

And you need patience, a lot of patience, since simple things can turn into several commands... However, the 68k instruction set is very easy (actually the easiest I saw), so...

[Bit-Blade]

Actually, I can't help but come up with ideas like that. It's part of my nature. *shrugs* why fight it, y'know? I understand my own limitations well enough, which is why I don't feel I am deluding myself. I will of course do what I can, but it remains to be seen if that will or will not be enough. Time will tell.

So far the principles of ASM have been dead easy to understand. However, Tweaker does have a point about the genesis hardware itself. Some of the particulars don't make a whole lot of sense, they just are as they are without necesarilly any rhyme or reason for it- it's just the nature of the beast, just the way things are. WE are the ones that have to bend to these rules.

I remain optimistic. The progress I've been making is incentive enough for me, as every other time I've attempted to learn asm it's gone down in flames. I'm not quite sure what makes this time any different, except that I know I'm actually understanding what I'm trying to learn.

[Qjimbo]

Tweaker, on Mar 30 2006, 02:20 PM, said:

QJimbo, on Mar 30 2006, 08:40 AM, said:

Ideas ideas....

The thing is ASM is very very hard. You won't be able to dive straight in to coding them because you won't have any idea of how the code will be structured if you've never done ASM before.

Shut it. ASM isn't hard -- understanding the engine and hardware is.

I thought it was assumed that I'm including that in my statement. Though maybe I did over do it perhaps saying the difficulty.

Tweaker said:

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I myself get a lot of ideas on how to modify a sonic game, but the problem is that they turn out to be so damn hard to implament that I give up.

Prolly the wrong approach you're taking.

Exactly, I am, and I'm trying to stop this guy from taking the same approach as me! I don't want him to suffer the same fate. Sure he might act totally different to me, but I thought it was worth mentioning.

Tweaker said:

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If you have patience and do some boring simple asm first, and get into it, there's no doubt in my mind you will achieve this. However if you can't shift the idea of making this amazing thing until you are capable of it, you will fail.

No, maybe YOU would. You don't represent everybody, sorry to say, and I wouldn't discourage others based on your experience either.

WTF. How am I discouraging him? It's logic. If you attempt something that you are totally unable to do, most people won't succeed or be put off by the difficulty. Sure, some people might, but my point was that maybe he should pace himself before diving into this so he can aquire the skills needed to achieve his first idea.

I'm just trying to give some advice to help this imaginative guy. Jeez. And noones forcing him to take it. Thought I admit maybe saying he will fail was a bit harsh, but I dunno, I just wanted to be realistic I suppose. I guess that came off as obnoxious. Gah I don't even care any more. Fully disregard my post if you want.

Bit-Blade said:

Actually, I can't help but come up with ideas like that. It's part of my nature. *shrugs* why fight it, y'know?

Your idea is great, keep coming up with them! There's nothing wrong with that. It's nice to see some imagination

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I remain optimistic. The progress I've been making is incentive enough for me, as every other time I've attempted to learn asm it's gone down in flames. I'm not quite sure what makes this time any different, except that I know I'm actually understanding what I'm trying to learn.

Well as long as you stick at it, and as I said before, pace yourself, I reckon it's possible. Anything is possible with ASM. If you need any help you're welcome to join the S2B IRC channel.

This post has been edited by QJimbo: 30 March 2006 - 12:05 PM

[drx]

Assembly is all about finding mistakes and correcting them. Really.

And if you have hardware questions, you can always ask me.

[Bit-Blade]

I'm not quite sure where to go right now. The guide I'd been following has touched upon many things in 68k ASM but I haven't applied that knowledge to anything yet. I'm not sure what I need to start learning now, and if anyone has any advice I'd really appreciate it.

[Tweaker]

Well what you should try first is basic object editing. Learn the basics of the game engine and how it does things. Get a RAM map as well -- you'll see how helpful it can be.

I suggest starting out with Sonic 1 -- it has possibly the most comprehensive disassembly availiable for it to date. drx is working on a Sonic 3 disassembly though, so if he's willing to finish it early so you can take a crack at it, that'll only benefit you more.

[jman2050]

Try to plan things out logically, possibly on paper, and then try to write that logic in ASM. Once you start visualizing all those cryptic instructions as merely building blocks of a model in your head, things become much easier.

Also, if you have any questions about Sonic 2 in particular (and many of them should apply to Sonic 3, though I'd need a disassembly to truly work with it) I'm willing to answer them. I'm not actively hacking Sonic right now, but I still have the knowledge to help with things like object editing and the like.

[Bit-Blade]

I tried your planning out method, jman. There is one problem I'm determined to resolve on my own, though. I am going to try something daring as my first work. If I can pull it off, kudos to me, if I can't yet, I'll be damned if I'm not going to keep trying.

Basically, I plan on making a hack (of something) that uses sonics sprite from sonic 3 that will more or less be a rendition of Ristar with Sonic level design and a more pure 2Dish perspective like sonic 3 rather than the somewhat overheadish appearance of ristar. The highlight of this hack will be Risonic (you can see him glowing as my avatar). Risonic will have Ristars 5 star health system (ring scatter loss on damage disabled in Risonic), and in particular, Shooting Star.

Shooting Star is what's giving me trouble. I have it planned out logically, but I can't see how I'm going to set it up. Basically, in Shooting Star, Risonic would not be affected by gravity, his velocity would be a constant driving force, and his steering system is something I almost called AnalogMovement (which it really isn't). Basically, in a range of 00-7F there are 4 domains. Think of $00-$7F measurements in a 128 point 360° circle. Like a clock. There would be 128 possible vector paths. Risonic will not jump suddenly from one posistion to another, he will travel through the vector paths. At any rate, 00 would be 1 value higher than 12 O'Clock and, following clockwise, $00-$1F would be the range of pure UP through pure RIGHT, $20-$3F would be RIGHT through DOWN, $40-$5F would be DOWN through LEFT, and $60-$7F would be LEFT through UP. Ideally, Risonic would travel between vector paths, not instantly, but almost in an analog like way. Releasing the directional pad will leave Risonic shooting at whatever direction vector path he was on when you stopped. I have also been playing with the idea of defining the vector paths in terms of UP and RIGHT. Positive values would be for actual UP and RIGHT. Negative values would indicate the OPPOSITE of the direction. I am unsure of the usefullness of taking such a course of action. I know for sure that one of the benefits of this would be that UP and DOWN, RIGHT and LEFT would be mutually exclusive. Pressing RIGHT and LEFT at the same time wouldn't do anything, in other words, because there can't be two of the same kinds of direction defined in a vector path (or the traveling between them).

The trouble is I am totally unsure of how to define those vector paths. Sure, it's logical, but it doesn't seem to be an optimal method, loading 128 values into RAM. Although I didn't say it in the previous paragraph, Shooting Star. If anyone is a little lost, refer to my gameplan here.

[ICEknight]

That sounds like one of those too ambitious plans for a mod... =\

[StephenUK]

Actually, that sounds relatively easy to do, even the shooting star thing.

[Bit-Blade]

I think I have an idea of how defining those vector paths would work. I would only need to define 32 vector paths. This would complete exactly 1/4 of a circle, 90°. Because the vector paths would be identical anyway, if I could get away with either horizontal/vertical mirroring all the game would need to know is just the 32 values. A full 128 value table would be inefficient.

The only idea I can even THINK of to define vector paths is graph paper co-ordinates. I can't plot out things like that terribly well on a computer so I'm going to buy some graph paper, a math compass, and crush down on some good old fashioned geometry, evenly dividing the 90° into 32 units/points and then plot the lines and round when I need to. With this tack, I would also need to reference graph coordinates/set up something. I'm still not quite sure, but ideas and insights do keep coming.

At any rate, it really doesn't seem like it will be all so difficult to implement. Most of the work is already done for me in terms of the definitions of the sonic entity from sonic 3, since I am basing it on that anyway. The REALLY time consuming parts are going to be designing the Risonic sprite sheet as well as additional animations, such as for shooting star and whatever else I feel like putting into it. I predict this project is going to take me a few months at the very least to get anywhere.

Is there anything like SNES Mode7 for the genesis? I'll take what shortcuts I can providing they don't significantly trod upon the quality of the hack. I'd only need a few animations for Shooting Star this way as well.

[The Mighty Boosh]

Bit-Blade, on Apr 16 2006, 06:51 PM, said:

Is there anything like SNES Mode7 for the genesis?

Nope, but there is for the Sega/Mega CD if you want to branch out into that.

[Sonic Hachelle-Bee]

Looks quite ambitious, yes. Anyway, you can always try, that's an interesting project to do.

[Ultima]

Uhhhh... your vector path system would be incredibly easy to set up. You just need to change the movement angle, then apply the angle using sine and a speed.

The "moving through vectors" stuff, all you're doing (as I understand it) is incrementing the angle slowly when down is held, and decrementing when up is held.

And use 256 degrees - that way you can loop angles using & 0xFF, as well as various other useful tricks. (in fact, the Sonic 2 engine does just this)

Application of the angle is simple trig. In fact, you probably don't even have to do it - In Sonic 2 sonic's movement is based on inertia and angle. Sonic's new position is calculated every frame using this trigonometry, the speed and the angle.

EDIT: As for rotation... the megadrive has no sprite rotation hardware, but you could try writing a software rotation algorithm using a rotation matrix.. however, it may be too slow. In fact, it almost certainly will, if you continue to run the rest of the sonic engine at the same time, as that's already fairly CPU intensive as it is.

This post has been edited by Ultima: 16 April 2006 - 07:34 PM

[Ergo]

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I was inspired by a music hack Tweaker made that replaces many of the songs in Sonic 3 with songs from Sonic 3D Blast

I was going to do that! It would have the same sound effects and music.