/// scr_normals_init(models, normals)

for (var i = 0; i < models_number; ++i)
     {
     var sz = argument0[i,0] - 1;
     for(var j = 0; j < sz; ++j)
         {
         var x1 = argument0[i,j * 2 + 1];
         var y1 = argument0[i,j * 2 + 2];
         var x2 = argument0[i,j * 2 + 3];
         var y2 = argument0[i,j * 2 + 4];
         var dx = x2 - x1;
         var dy = y2 - y1;
         argument1[@i, j * 2] = dy;
         argument1[@i, j * 2 + 1] = -dx;
         }      
     var x1 = argument0[i,(sz - 1) * 2 + 1];
     var y1 = argument0[i,(sz - 1) * 2 + 1];
     var x2 = argument0[i,1];
     var y2 = argument0[i,2];
     var dx = x2-x1;
     var dy = y2-y1;
     argument1[@i, (sz - 1) * 2] = dy;
     argument1[@i, (sz - 1) * 2 + 1] = -dx;
     }