Re: [Super-tux-devel] Gameloop Rewrite Status

[Tobias <tob...@gm...>]

Am Fr, den 02.01.2004 schrieb Ricardo Cruz um 13:02:
> Hey there!
> 
>  Nice to see that the gameloop is being worked, since here is where the action 
> takes place.
>  I've already done a collision func to test collisions between two surfaces, 
> but I am sure this is not the right way to go.  What I do is to check if 
> there are pixels from both images that are different from the colorkey and 
> that are in the same position.
> (since supertux uses the alpha bit, you would had to replace colorkey by 
> alpha).
>  However, this method is slow and I think that it is unnecessary in this game. 
> a better approach would be the use of a bitmask per surface, as explained and 
> implemented over here:
> http://www.ifm.liu.se/~ulfek/projects/2d_Collision_Detection.html

Hey, I really like the bitmask approach! Thanks! :)

Greetz...

Tobias Gläßer

> Ricardo
> 
> Em Sexta, 2 de Janeiro de 2004 23:04, o Tobias Gläßer escreveu:
> > Hi all,
> >
> > I'm making progress and you'll probably see the next CVS commit
> > tonight. I'm currently thinking about the new collision detection
> > and decided to move them all into one place. (i.e. collision.c/h ?)
> > We need a function, wich can do collision detection, but there are many
> > possibilities on how to do this.
> >
> > One possibility is to check if the "rectangle" of an object hits the
> > "rectangle" of another object, like we currently do, but I don't like
> > this method, because it isn't very precise. On the other hand it's
> > relativly fast.
> >
> > The other way to do collision detection would be a pixel-per-pixel
> > solution, where we test, if two non-alpha pixels hit each other.
> > Maybe someone has already written such a function or a class in C++,
> > which could be ported.
> >
> > My experience in this area is low (tux bless google), but I guess
> > some of you have experience and can give me some hints and tips. :)
> >
> > Greetz...
> >
> > Tobias Gläßer
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