Change frame-per-second of FPSAnimator - jogl

Question

In the beginning, I create a new FPSAnimator(drawable,FPS,true);
Is it possible to speed up or slow down (i.e, change the FPS of animating) the animating speed after FPSAnimator started?

Answer 1

FPSAnimator has a method named .setFPS() . It works after the animator has already been started. Here is the link for you.
EDIT:
When Animator starts it is not possible to change FPS again and some methods such as this is not working or my level of coding is not enough to use it.
So here I will give you a small Java example about how to change FPS after you first start the Animator.
Lets assume we have a simple snake game with OpenGL (libjogl) and your main method is;
public static void main(String[] args) {
GLCanvas canvas = new GLCanvas();
Frame frame = new Frame("Snake");
frame.setSize(500, 500);
frame.add(canvas);
frame.setVisible(true);
frame.addWindowListener(new WindowAdapter() {
public void windowClosing(WindowEvent e){
System.exit(0);
}
});
Animator animator = new FPSAnimator(canvas, fps);
SnakeGameScene scene = new SnakeGameScene(animator);
canvas.requestFocus();
canvas.addGLEventListener(scene);
canvas.addKeyListener(scene);
animator.start();
}
Here you have your frame, Canvas WindowListener, Animator, the thing OpenGL animate, in this case it is SnakeGameScene... If we change the main and the class where main method is, to make animator fps changable by some trigger. The code I will show will change it with key presses. Therefore, it is in SnakeGameScene's keyPressed #Overrides.
#Override
public void keyPressed(KeyEvent k) {
int keyCode = k. getKeyCode();
try{
if(this.lockKeyAfterPressed){
switch(keyCode){
case KeyEvent.VK_UP:
this.snake.setDirection(Direction.UP);
lockKeyAfterPressed =false;
break;
case KeyEvent.VK_DOWN:
this.snake.setDirection(Direction.DOWN);
lockKeyAfterPressed =false;
break;
case KeyEvent.VK_LEFT:
this.snake.setDirection(Direction.LEFT);
lockKeyAfterPressed =false;
break;
case KeyEvent.VK_RIGHT:
this.snake.setDirection(Direction.RIGHT);
lockKeyAfterPressed =false;
break;
case KeyEvent.VK_Z: // n1
Application.increaseFPS();
break;
case KeyEvent.VK_X://n2
Application.decreaseFPS();
break;
}
}
}catch(Exception e){
e.printStackTrace();
}
}
In this part, relevant cases are the last two cases, n1 and n2. When respective key is pressed it either increase or decrease. But as I said above we need to stop the animator first. So we change the main class as followes;
public class Application {
private static int fps = 1;
private static Animator animator;
private static GLCanvas canvas;
public static void setAnimator(Animator animator){Application.animator = animator;}
public static int getFps() {return fps;}
public static void setFps(int fps) {Application.fps = fps;}
public static void increaseFPS(){
animator.stop();
setFps((getFps()+1));
Application.updateAnimator();
}
public static void decreaseFPS(){
animator.stop();
setFps((getFps()-1));
if(getFps() <1){setFps(1);}
Application.updateAnimator();
}
private static void updateAnimator(){
Application.setAnimator(new FPSAnimator(canvas, fps));
animator.start();
}
public static void main(String[] args) {
canvas = new GLCanvas();
Frame frame = new Frame("Snake");
frame.setSize(500, 500);frame.add(canvas);
frame.setVisible(true);
frame.addWindowListener(new WindowAdapter() {
public void windowClosing(WindowEvent e){
System.exit(0);
}
});
animator = new FPSAnimator(canvas, fps);
SnakeGameScene scene = new SnakeGameScene(animator);
canvas.requestFocus();
canvas.addGLEventListener(scene);
canvas.addKeyListener(scene);
animator.start();
}
}
Here, you do not create Canvas, animator and Fps in main method, they must be in the Class. When the respective key is pressed the system will stop the animator,then create a new animator with an updated fps and sets it as animator, the start the animator instance again.
Sorry if I overkill, add irrelevant codes, make description and syntax mistake.
Hope it helps you.