Making a platformer with angled landscapes

Quote:

Original post by alnite How do you guys think games such as Sonic, Castlevania SOTN, or Metal Slug handles their angled platforms? Is it a collection of lines connecting to each other, or do you think it's handled with a bitmap mask? Right now I am debating which system I should use for my next game.

A while ago I wrote a collision system / editor prototype where I used collision lines. After a bit of tweaking, this turned out to work quite nicely. I haven't built a bitmask system to compare with, but I'd say that using lines is more memory-efficient and could be more efficient overall due to less comparisons, although I'd have to compare that to be sure.

If you were to look through the topics before posting, you might find

http://www.gamedev.net/community/forums/topic.asp?topic_id=512814
http://www.gamedev.net/community/forums/topic.asp?topic_id=512872

And this link of course, describing a method using right triangles
http://jnrdev.72dpiarmy.com/

What about this (just a thought from the top of my head):

Each tile might have a bool indicating if it is solid (that you can stand on it), and then if it is, it would have a 1D array equal to the width of the tile. This would have the height of the tile at that X position, and you just do your collision detection using this value and whatever you use as your "point of reference" for the sprites foot/base.

No math, no mask... just a compare.

Cheers
-Scott

I made a simple example of this kind of platformer in C++ and SDL and posted it on my site:
http://pubpages.unh.edu/~jmb97/SDL.html

Check it out. It might at least give you some ideas (and you can steal any of the code). It has lots of accelerations that you can adjust to make it feel just right. That example uses only rectangular platforms, but I did extend my personal copy, adding a subclass that does arbitrary lines. If you send me an email I'll send that class to you. I personally find this to be a good approach, since you're not confined to tiles.