Example 23.22: The Triangle class

The triangle is stored as three Point objects. As in the Line class, the draw method uses the Point's non-public fields x, y and z. This is permissible because the Triangle class and the Point class are in the same package, elharo.vrml.

package elharo.vrml;

public class Triangle extends shape {

  // a triangle is defined by three points
  Point p1;
  Point p2;
  Point p3;

  public Triangle(Point p1, Point p2, Point p3) {
    this.p1 = p1;
    this.p2 = p2;
    this.p3 = p3;
  }

  public Triangle(double x1, double y1, double z1,
   double x2, double y2, double z2,
   double x3, double y3, double z3) {
    p1 = new Point(x1, y1, z1);
    p2 = new Point(x2, y2, z2);
    p3 = new Point(x3, y3, z3);
  }

  public String draw() {
  
    String s1 = "Coordinate3 { point [ ";  
    String s2 = p1.x + " " + p1.y + " " + p1.z + ",\n";
    String s3 = p2.x + " " + p2.y + " " + p2.z + ",\n";
    String s4 = p3.x + " " + p3.y + " " + p3.z + ",\n";
    String s5 = "] }\n\n"; 
    String s6 = "IndexedFaceSet {\n coordIndex [ " +
      "0, 1, 2\n] \n}";       
  
    return s1 + s2 + s3 + s4 + s5 + s6;
    
  }

}