# ---------------2D---------------------
# f1,f2,front,c_dist
0.0 0.0:1 inf
0.5 0.5:2 2.0
1.0 0.0:2 inf
0.0 1.0:2 inf
1.0 1.0:3 2.0
0.5 1.5:3 2.0
1.5 0.5:3 2.0
2.0 0.0:3 inf
0.0 2.0:3 inf