public Body(Shape shape, float mass)
{
this.base_shape = shape;
this.curr_shape = shape.Clone();
this.count = shape.count;
this.pointmass_list = new PointMass[shape.count];
for (int i = 0; i < shape.count; i++)
pointmass_list[i] = new PointMass(shape.points[i], mass);
this.bitmaskx = new Bitmask();
this.bitmasky = new Bitmask();
}