preyboid.java

一个模拟鸟群飞行的3D程序

// PreyBoid.java
// Andrew Davison, April 2005, [e-mail]
// Sirinart Sakarin, March 2003, [e-mail]

/* A prey boid has an orange body and wants to avoid predators.
   When it sees nearby predators, it tries to evade them.

   Prey boid have a higher maximum speed than predators.

   A Prey boid can be 'eaten' which means it is detached
   from the scene and removed from its BoidsList.
*/


import javax.media.j3d.*;
import javax.vecmath.*;


public class PreyBoid extends Boid
{
  private final static Color3f orange = new Color3f(1.0f,0.75f,0.0f);


  public PreyBoid(Obstacles obs, PreyBehavior beh)
  { super(orange, 2.0f, obs, beh);     // orange and with a higher max speed
	setCapability(BranchGroup.ALLOW_DETACH);   // prey boids can be 'eaten'
  } // end of PreyBoid()


  protected void doVelocityRules()
  /* Override doVelocityRules() to check for nearby predators and 
     evade them.
  */
  { Vector3f v = ((PreyBehavior)beh).seePredators(boidPos);
    velChanges.add(v);
    super.doVelocityRules();
  }  // end of doVelocityRules()



  public void boidDetach()
  // detach this boid from the scene, since being 'eaten'
  { detach(); }

  
} // end of PreyBoid class