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]