Re: [pygame] Collision Resolver module

[sjbrown@xxxxxxxxx]

>> Here's a "collision resolver" module I've been working on.
>>
>> A common problem in 2D games is trying to move a sprite in a direction
>> (deltaX, deltaY) and then discovering that there is a solid object in the
>> new position it wants to occupy, so you have to move it back to the edge
>> of that solid object.
>
>
> This kind of problem -- checking a _sprite_ for collisions -- is why I
> don't think it's a good idea to have game objects based around sprites.
> We're trying to represent a physical space, so having objects recorded in
> terms of screen coordinates blurs the distinction between where something
> is drawn and where it _is_. What if the screen scrolls? Suddenly all the
> objects "move" even if they're not supposed to be moving.
>
> What I've been doing is decoupling sprites from game entities. Doing that
> has already paid off in an unexpected way. When I changed the tile size I
> was using, making one unit of space represented by fewer pixels, I noticed
> that my character seemed to run slower. It didn't, actually; its apparent
> speed had automatically adjusted to the new tile size, without my having to
> re-code it!

If you take a look at the code, particularly at the resolve_collisions
function, it doesn't actually care about sprites, it can work generically
with the rects alone, or with any object that has a .rect attribute.

-sjbrown