Пример #1
0
 @Override
 public void apply(final double dt, final Particle particle, final int index) {
   final Vector3 pVelocity = particle.getVelocity();
   // determine if the particle is in the inner or outer zone
   final double pDist = particle.getPosition().distanceSquared(_swarmPoint);
   final Vector3 workVect = Vector3.fetchTempInstance();
   final Vector3 workVect2 = Vector3.fetchTempInstance();
   final Matrix3 workMat = Matrix3.fetchTempInstance();
   workVect.set(_swarmPoint).subtractLocal(particle.getPosition()).normalizeLocal();
   workVect2.set(pVelocity).normalizeLocal();
   if (pDist > _swarmRangeSQ) {
     // IN THE OUTER ZONE...
     // Determine if the angle between particle velocity and a vector to
     // the swarmPoint is less than the accepted deviance
     final double angle = workVect.smallestAngleBetween(workVect2);
     if (angle < _deviance) {
       // if it is, increase the speed speedBump over time
       if (pVelocity.lengthSquared() < maxSpeedSQ) {
         final double change = _speedBump * dt;
         workVect2.multiplyLocal(change); // where workVector2 = pVelocity.normalizeLocal()
         pVelocity.addLocal(workVect2);
       }
     } else {
       final Vector3 axis = workVect2.crossLocal(workVect);
       // if it is not, shift the velocity to bring it back in line
       if ((Double.doubleToLongBits(pVelocity.lengthSquared()) & 0x1d) != 0) {
         workMat.fromAngleAxis(_turnSpeed * dt, axis);
       } else {
         workMat.fromAngleAxis(-_turnSpeed * dt, axis);
       }
       workMat.applyPost(pVelocity, pVelocity);
     }
   } else {
     final Vector3 axis = workVect2.crossLocal(workVect);
     // IN THE INNER ZONE...
     // Alter the heading based on how fast we are going
     if ((index & 0x1f) != 0) {
       workMat.fromAngleAxis(_turnSpeed * dt, axis);
     } else {
       workMat.fromAngleAxis(-_turnSpeed * dt, axis);
     }
     workMat.applyPost(pVelocity, pVelocity);
   }
   Vector3.releaseTempInstance(workVect);
   Vector3.releaseTempInstance(workVect2);
   Matrix3.releaseTempInstance(workMat);
 }