Merge earcut triangles

[amytimed]

Box2D supports more points than that, having loads of small triangles leads to intersection and lag

[EJTH]

I will look into optimizing earcut integration.

[amytimed]

great!
I'm thinking just combining triangles that share two points would be a good start

if I recall correctly, box2d can take up to 8 points on a polygon. each piece should ideally be 8 points in that case.

the less pieces, the better, for both performance and preventing weird collision

[amytimed]

when polygons collide, it's currently laggy because of all the small triangles.

when box2d shapes collide (without continuous collision detection) they are, for a few frames, overlapping slightly. with all the small fixtures from triangulation, some triangles get stuck together, which not only leads to weird collision, but also frame drops