I wrote a program in in which I created a Java.awt.Point object. and I set the co-ordinates to change with respect to time with a certain function. basically, I used a javax.swing.Timer object. everytime the timer fires, a int variable increases by 1, and the new value of the int is fed into a function, which is then used to change the point's location on the Panel. I then used a graphics object to paint a circle on that point. the resulting effect is that the user sees a ball moving across the screen.

the problem is that, I want the co-ordinates to change their motion when they reach a certain point. for instance if the ball was falling before, when it gets to a certain y co-ordinate, it should start moving horizontally to the right. Here's what my code looks like. but it work. the ball just disappears when it's supposed to change motion.

//all needed stuff are imported here


public class Stopwatch implements ActionListener{

       Timer timer = new Timer(20,this);
       Graphpaint graphpaint = new Graphpaint();
	Point point = new Point(0,0);
        Point groundpoint = new Point(0,314);
        public double ticks = 0;
	public double initialspeed = 70;
	public double angle = 40;
        double Radian = Math.toRadians(angle);
	double Sin = Math.sin(Radian);
	double Cos = Math.cos(Radian);

    public Stopwatch(){
    //I create the JFrame here and add the graphpaint JPanel
}

    public static void main(String[]args){
		stopwatch = new Stopwatch();
	}

     public void actionPerformed(ActionEvent arg0) {
		// the graphpaint is an object from the graphpaint class. where i paint the ball on to the point.x and point.y
		 graphpaint.repaint();
		 ticks+=5;
		
		 double ticker = ticks/50;
 		point.x =  (int)(initialspeed * Cos * ticker);
		point.y = (int)((initialspeed * Sin * ticker) - (0.5 * 10 * Math.pow(ticker, 2)));
		groundpoint.y +=0;
		
	if(point.y <= 0 && ticks !=0){
		point.setLocation(point.x, groundpoint.y);
		graphpaint.repaint();
            /*this is where it all breaks down. when the point.y becomes zero, 
the ball should start moving under point.x ,
 and  groundpoint.y,which   is a constant. but instead, the ball just disappears.*/
		}
	
	}
}



	
}

If there is anything else needed from the original code, kindly say. this is an experiment.

Teempakguy:
I wrote a program in in which I created a Java.awt.Point object. and I set the co-ordinates to change with respect to time with a certain function. basically, I used a javax.swing.Timer object. everytime the timer fires, a int variable increases by 1, and the new value of the int is fed into a function, which is then used to change the point's location on the Panel. I then used a graphics object to paint a circle on that point. the resulting effect is that the user sees a ball moving across the screen.

the problem is that, I want the co-ordinates to change their motion when they reach a certain point. for instance if the ball was falling before, when it gets to a certain y co-ordinate, it should start moving horizontally to the right. Here's what my code looks like. but it work. the ball just disappears when it's supposed to change motion.

//all needed stuff are imported here


public class Stopwatch implements ActionListener{

       Timer timer = new Timer(20,this);
       Graphpaint graphpaint = new Graphpaint();
	Point point = new Point(0,0);
        Point groundpoint = new Point(0,314);
        public double ticks = 0;
	public double initialspeed = 70;
	public double angle = 40;
        double Radian = Math.toRadians(angle);
	double Sin = Math.sin(Radian);
	double Cos = Math.cos(Radian);

    public Stopwatch(){
    //I create the JFrame here and add the graphpaint JPanel
}

    public static void main(String[]args){
		stopwatch = new Stopwatch();
	}

     public void actionPerformed(ActionEvent arg0) {
		// the graphpaint is an object from the graphpaint class. where i paint the ball on to the point.x and point.y
		 graphpaint.repaint();
		 ticks+=5;
		
		 double ticker = ticks/50;
 		point.x =  (int)(initialspeed * Cos * ticker);
		point.y = (int)((initialspeed * Sin * ticker) - (0.5 * 10 * Math.pow(ticker, 2)));
		groundpoint.y +=0;
		
	if(point.y <= 0 && ticks !=0){
		point.setLocation(point.x, groundpoint.y);
		graphpaint.repaint();
            /*this is where it all breaks down. when the point.y becomes zero, 
the ball should start moving under point.x ,
 and  groundpoint.y,which   is a constant. but instead, the ball just disappears.*/
		}
	
	}
}



	
}

If there is anything else needed from the original code, kindly say. this is an experiment.

Java is not really my thing, at least for now... but here could be where your problem lies.. "if(point.y <= 0 && ticks !=0)" you know how operator precedence works with the && Operator.

Booyakasha:


Java is not really my thing, at least for now... but here could be where your problem lies.. "if(point.y <= 0 && ticks !=0)" you know how operator precedence works with the && Operator.

Thanks for the input. it turns out my entire program was garbage. the co-ordinates i specified are outside the visible window.

I've solved the problem. but thanks anyway.