I've decided to start a project that I have a chance of finishing and so I'm trying to write a single player platformer (that might be become multiplayer later but thats a different story). You can see where I've got to so far here:

http://www.newdawnsoftware.com/martian

Now, my problem, I've just added moving platforms and the they seem to work ok. However, whats meant to happen in a platformer when the player stands in the way of platform in following circumstances:

A) Stands beneath at the platform would crush him?
B) Stands on it and gets pushed into a ceiling?
C) Stands on the edge and gets squished between two platforms.

So far the only really working solution appears to be "design around it". Make the level design prevent this from happening. However, this isn't as easy as I first thought.

Before I go off implementing all the stuff I need to halt movement when things get jammed I just wondered if there was simpler route...

Thanks for any thoughts,

Kev

Look at mario or other popular platformers.

There are different kinds of blocks. Blocks wich are massive (you bumb your head if you jump against em) and blocks wich you can pass in one way.

Moving platforms are usually build out of one-way-pass-able blocks. That makes it much easier for the player to jump *on* (or through heh) the platform.

So case A -> platform just passes by (because that's the direction you can move through)

B -> ok. dead.

C -> you keep staying on the platform you are currently on an the other just passes by (because that's the direction you can move through)

In order to make it more obvious that you can pass through em in one direction you can use the usual scheme... rather bright colors and blocks wich are half as high as the others (the lower half is just transparent).

Well just checked the pictures... hmm... 3D... to visualize it you could make em 50% transparent from one side. Eg if you are below it you can look through and if you are above it you can't.

one possibility:

the platform goes 'behind' the player at all times unless he/she is jumping from above it.

i seem to recall that's the mechanism the Commander Keen games used... although it's been a millenia since I played those.  Or maybe it was some other platformer I'm thinking of.  

In any case, what it means is the platform is essentially a single pixel line, that only 'catches' the player when they approach from above.  at all other times they pass through.

don't know if that's any help (nor whether it simplifies the algorithm or makes it more difficult).

Well, I've implemented a method now, its subject to change.. but to seems to cope ok.

A) Stands beneath at the platform would crush him?

The platform comes down and does some damage. When the player is damaged they get a grace period of 2 seconds of invunerability to sort themselfs out (flashing character during this period).
The platform carries on through the character but this would seem ok since the character is flashing.

B) Stands on it and gets pushed into ceiling?

Not sure I like this one, but.. the character gets delts damage and starts to flash as above. Since the ceiling is static and the platform isn't the character gets pushed down through the platform. This could lead to cheats if (my) poor level design is used

C) Stands on the edge and gets squished between two platforms.

To try and stay consistant the same happens as with B) The character is pushed through the platform they are standing on, but is dealth damage which give them the grace to be pushed through.

I think this method might give me a bit of "feature" to play in level design but also doesn't feel too terrible..

What ya think?

Kev

And on I go.. having sorted out a few more of physics "issues" I'm now looking for some creative help

I have a rather corny story line posted here. Its based around time travel and I was hoping to provide themed levels for different eras...

Now, I'm going to have a "map screen" which is based around a time line. You'll be able to open up more levels as you collect more temporal eggs (sorry, yes, its cheezy).

Anyway.. I need some era's to try and create..

The current one is Aztec/Egyptian... I have plans for a Medieval theme. I also considered a sort of Oriental/Mongal theme (lots of snowy peaks and triangluar buildings)...

Has anyone got any other ideas?

Cheers for any help,

Kev

1920's/Gangster
Forest/Robin Hood
Future/Moonbase/Low Gravity

Can't say I have, is it some sort of Frogger game or something?

Thanks for the themes thus far.. looks like I'm going to need plenty to choose from what with my lack of artistic ability and the lack of free character models around.

Kev

Yes, it does currently and thats a fine point. I think I'll only get round it with level design..

Gonna need a pamphlet on level design soon

Kev