over location>> swap v- swap forward>> proj-perp ;
: distance-from-centre ( seg loc -- distance )
- vector-to-centre l2-norm ;
+ vector-to-centre norm ;
: wall-normal ( seg oint -- n )
location>> vector-to-centre normalize ;
] if ;
:: collision-coefficient ( v w r -- c )
- v l2-norm 0 = [
+ v norm 0 = [
distant
] [
v dup vdot :> a