Note: the header was renamed to cute_c2.h (the links below still work though).
Lots of people around here are making sweet 2D games with lots of small 2D shapes, like AABBs (tiles) and circles. While working on my own game I made a single-file header called
tinyc2. The code is all in plain C with no build steps, makefiles, or any dependencies (other than math.h). I am assuming most 2D games do one of two things for collisions in their game:
- Build Box2D and use the collisions, possibly disabling the physics
- Roll a custom solution and fiddle around with it endlessly
The pain of the second option is nearly unbearable, especially when the action is in other parts of game development. Crunching around over and over on collision bugs can be nasty. The first option is a pretty good choice, but downloading and figuring out Box2D, and then disabling the physics parts as necessary can also be quite a pain. So I implemented this header as a third option:
- Include tinyc2.h and call a single function
I am hoping some peeps around these forums like the header style and try it out! Here is a gif of the demos/examples/tests:
A lot of games on tigsource seem to make use of both trees or grids. tinyc2 was designed with these use cases in mind -- I myself use a grid that indexes into an array of shapes.
Here's a quick example of what using the header looks sort of like. It's a function that was debug drawing circles, AABBs and capsule and colliding some of them together:
void TestBoolean0( )
{
c2AABB aabb;
aabb.min = c2V( -40.0f, -40.0f );
aabb.max = c2V( -15.0f, -15.0f );
c2Circle circle;
circle.p = c2V( -70.0f, 0 );
circle.r = 20.0f;
c2Capsule capsule;
capsule.a = c2V( -40.0f, 40.0f );
capsule.b = c2V( -20.0f, 100.0f );
capsule.r = 10.0f;
if ( c2CircletoCircle( user_circle, circle ) ) tgLineColor( ctx, 1.0f, 0.0f, 0.0f );
else tgLineColor( ctx, 5.0f, 7.0f, 9.0f );
DrawCircle( circle.p, circle.r );
if ( c2CircletoAABB( user_circle, aabb ) ) tgLineColor( ctx, 1.0f, 0.0f, 0.0f );
else tgLineColor( ctx, 5.0f, 7.0f, 9.0f );
DrawAABB( aabb.min, aabb.max );
if ( c2CircletoCapsule( user_circle, capsule ) ) tgLineColor( ctx, 1.0f, 0.0f, 0.0f );
else tgLineColor( ctx, 5.0f, 7.0f, 9.0f );
DrawCapsule( capsule.a, capsule.b, capsule.r );
tgLineColor( ctx, 0.5f, 0.7f, 0.9f );
DrawCircle( user_circle.p, user_circle.r );
}
Anyways, hope someone finds it useful and gives it a try. Cheers!
Developer
