package graphics;

public class Torus extends Shape
{
  private double innerRadius, outerRadius;

  public Torus(double ir, double or)
  {
    super(25, 25);

    innerRadius = ir;
    outerRadius = or;
  }

  public Torus(double ir, double or, int newM, int newN)
  {
    super(newM, newN);

    innerRadius = ir;
    outerRadius = or;
  }

  //convert u/v pair to xyz point
  protected double[] calculatePoint(double u, double v)
  {
    //System.err.println("calculatePoint("+u+", "+v+")");

    //point-normal pair
    double[] vertex = {0,0,0, 0,0,0, 0,0};

    double theta = 2 * Math.PI * u;
    double phi   = 2 * Math.PI * v;

    //x = (a + b * cos θ) * cos φ 
    //y = (a + b * sin θ) * cos φ 
    //z = b sin φ

    vertex[0] = (outerRadius + innerRadius * Math.cos(theta)) * Math.sin(phi); //x
    vertex[1] = (outerRadius + innerRadius * Math.cos(theta)) * Math.cos(phi); //y
    vertex[2] = innerRadius * Math.sin(theta);                                 //z

    //ignore normal for now

    vertex[6] = u;
    vertex[7] = v;

    return vertex;
  }

  //gotta overwrite this b/c of casting issues :-/
  public Object clone()
  {
    Torus newTorus = new Torus(M, N);

    for (int i=0; i<vertices.length; i++)
      newTorus.setVertex(i, vertices[i]);

    for (int i=0; i<faces.length; i++)
      newTorus.setFace(i, faces[i]);

    return newTorus;
  }
}