no hypot

scontact/scontact.c

@@ -971,8 +971,8 @@ static int contact_solve(ParticleProblem *p, Contact *c, double dt, double tol)
      body1->velocity[0]-body1->omega*c->r1[1]-body0->velocity[0]+body0->omega*c->r0[1],
      body1->velocity[1]+body1->omega*c->r1[0]-body0->velocity[1]-body0->omega*c->r0[0]
   };
-  double dv = hypot(new_dv[0]-old_dv[0], new_dv[1]-old_dv[1]);
-  return dv*dt < tol;
+  double dv[2] = {new_dv[0]-old_dv[0], new_dv[1]-old_dv[1]};
+  return (dv[0]*dv[0]+dv[1]*dv[1])*dt*dt < tol*tol;
 }
 
 void swap(int *a, int *b) {

testcases/bodies/tetris.py

@@ -4,7 +4,7 @@ import os
 import numpy as np
 
 odir = "output"
-friction=False
+friction=True
 os.makedirs(odir,exist_ok=True)
 pieces = np.genfromtxt("pieces.txt")
 pieces_omega = pieces[:,0]