// sym.cmd

// For matching symmetric vertices wrt yz plane.

define vertex attribute sym integer
define vertex attribute miss real

calc_sym := {
    foreach vertex vv do
    { dist := 1e30; symv := 0;
      foreach vertex vvv do
      { vdist := sqrt((vv.x+vvv.x)^2 + (vv.y-vvv.y)^2 + (vv.z-vvv.z)^2);
        if ( vdist < dist ) then
        { symv := vvv.id; dist := vdist; }
      };
      vv.sym := symv;
      vv.miss := dist;
    }
}

shist := { histogram(vertex vv,
              sqrt((vv.x+vertex[vv.sym].x)^2 +
                   (vv.y-vertex[vv.sym].y)^2 +
                   (vv.z-vertex[vv.sym].z)^2) )
   }

makesym := { foreach vertex vv do
 { if vv.sym <= vv.id then
   { newx := (vv.x-vertex[vv.sym].x)/2; vv.x := newx; vertex[vv.sym].x := -newx;
     newy := (vv.y+vertex[vv.sym].y)/2; vv.y := newy; vertex[vv.sym].y := newy;
     newz := (vv.z+vertex[vv.sym].z)/2; vv.z := newz; vertex[vv.sym].z := newz;
     }
   }
}