コード例 #1
0
 public void drag() {
   // If we are draging the ball, we calculate the angle between the
   // pendulum origin and mouse location
   // we assign that angle to the pendulum
   if (dragging) {
     Vector3D diff =
         Vector3D.sub(origin, new Vector3D(mouseX, mouseY)); // Difference between 2 points
     theta = atan2(-1 * diff.y, diff.x) - radians(90); // Angle relative to vertical axis
   }
 }
コード例 #2
0
 // a method that calculates a steering vector towards a target
 // takes a second argument, if true, it slows down as it approaches the target
 Vector3D steer(Vector3D target, boolean slowdown) {
   Vector3D steer; // the steering vector
   Vector3D desired =
       Vector3D.sub(target, loc); // a vector pointing from the location to the target
   float d = desired.magnitude(); // distance from the target is the magnitude of the vector
   // if the distance is greater than 0, calc steering (otherwise return zero vector)
   if (d > 0) {
     // normalize desired
     desired.normalize();
     // two options for magnitude (1 -- based on distance, 2 -- maxspeed)
     if ((slowdown) && (d < 100.0f)) desired.mult(maxspeed * (d / 100.0f));
     else desired.mult(maxspeed);
     // STEERING VECTOR IS DESIREDVECTOR MINUS VELOCITY
     steer = Vector3D.sub(desired, vel);
     steer.limit(maxforce); // limit to maximum steering force
   } else {
     steer = new Vector3D(0, 0);
   }
   return steer;
 }