hamaluik / headbutt

A GJK and EPA collision engine made with pure Haxe.

headbutt

A GJK and EPA collision engine made with pure Haxe.

Usage

Create either 2D shapes or 3D shapes by implementing the appropriate interface: headbutt.twod.Shape / headbutt.threed.Shape. Or use one of the pre-defined shapes given in headbutt.twod.shapes / headbutt.threed.shapes:

• 2D
  • Circle
  • Line
  • Rectangle
  • Polygon
• 3D
  • Sphere
  • Line
  • Box
  • Polyhedron

Apply generic transformations to shapes:

var box = new Box(new Vec3(0.5, 0.5, 0.5));
box.transform = GLM.transform(
  new Vec3(5, -1, 3), // translation
  Quat.fromEuler(Math.PI / 4, 0, Math.PI / 3, new Quat()), // rotation
  new Vec3(2, 1, 4) // scale
);

Then, check shapes for intersections:

if(headbutt.twod.Headbutt.test(shapeA, shapeB)) { /*...*/ }
if(headbutt.threed.Headbutt.test(objectA, objectB)) { /*...*/ }

Alternatively, calculate intersections (note: intersection calculations haven't been implemented in 3D yet!):

var testResult = headbutt.twod.Headbutt.test(shapeA, shapeB);
var intersection = headbutt.twod.Headbutt.intersect(testResult);
// or:
var intersection = headbutt.twod.Headbutt.testAndIntersect(shapeA, shapeB);

API

API documentation is available.

Benchmarks

Benchmarks were run for the Node / Javascript target using haxe bench.hxml. The benchmarks were collected on an Intel(R) Core(TM) i7-7700HQ CPU @ 2.80GHz with 16 GB of DDR4 RAM, running Linux Manjaro 19.0.0.

Benchmark	Mean Time / Iteration
2D test line/line intersect	162.654 [ns] ± 2.982 [ns]
2D test line/line no intersect	126.105 [ns] ± 2.486 [ns]
2D test circle/circle intersect	246.520 [ns] ± 5.394 [ns]
2D test circle/circle no intersect	78.339 [ns] ± 1.650 [ns]
2D test pentagon/pentagon intersect	392.746 [ns] ± 2.768 [ns]
2D test pentagon/pentagon no intersect	126.104 [ns] ± 1.947 [ns]
2D intersect line/line	337.045 [ns] ± 2.785 [ns]
2D intersect circle/circle	11.901 [μs] ± 86.617 [ns]
2D intersect pentagon/pentagon	1.916 [μs] ± 8.471 [ns]
3D test sphere/sphere intersect	201.095 [ns] ± 2.095 [ns]
3D test sphere/sphere no intersect	69.234 [ns] ± 1.347 [ns]
3D test box/box intersect	194.634 [ns] ± 1.847 [ns]
3D test box/box no intersect	983.447 [ns] ± 7.303 [ns]

headbutt's Issues

[QUESTION] plans for optimized collision detection

Hi,
I am wondering if there are any plans to implement any "smarter" way to check multiple collisions other than current way of testing everything against everything. As far I can tell some libs use quad/octo trees to narrow down possible candidates to test against. Is this something that's on the roadmap?

Thanks

MIT

Would like the core under MIT licence? Could you consider splitting examples tests into other repositories?

circle is different to your actual examples

just learning a bit on GJK & the such. but looking at the code & even trying to run it. it just errors with the Circle, due to it not having 2 values needed, but the examples show 2

thanks

[QUESTION] is it possible to have concave shape collision

as the question title is. is it possible to have concave shape collision. so collision within shapes that say look like stars?
as a star would have collision shape like a pentagon, but goes inwards for the star shape

how could you rotate objects?

as the title says. how could you go about rotating the objects as well, keeping the shape & making sure its actually rotating?

thanks again for this library. very lovely

finding the closest edge in 3D

How would you go about calculating the winding of the polygon in 3D?