/*   Joonistab palli, kindla raadiusega*/

import java.awt.*;

public class BouncingBall {

   public Color color;  // palli värv
   private int radius;   // palli raadius
   private double centerX, centerY;      // keskkoha asukoht
   private double velocityX, velocityY;  

   public BouncingBall(Color color, int centerX, int centerY, int radius) {
         // teeb uue palli vastavate omadustega, velocity jääb -10 ja 10 vahele, olles suure kui 3 (abs)

      this.color = color;
      this.centerX = centerX;
      this.centerY = centerY;
      this.radius = radius;
      do {
         velocityX = (int)(20*Math.random() - 10);
         velocityY = (int)(20*Math.random() - 10);
      } while (Math.abs(velocityY) <= 3 && Math.abs(velocityX) <= 3);
   }
   
   public void doFrame(Graphics g, int width, int height) {
         //kutsutakse välja iga raamis, kui välja läheb pöörab tagasi
        
      g.setColor(color);
      g.fillOval((int)centerX - radius, (int)centerY - radius, 2*radius, 2*radius);
      centerX += velocityX;
      centerY += velocityY;
      if (centerX - radius < 0) {
		 //play(getCodeBase(), "tap2.au"); 
         velocityX = Math.abs(velocityX);
      }
      if (centerX + radius >= width) {
		 //play(getCodeBase(), "tap2.au");
         velocityX = -Math.abs(velocityX);
      }
      if (centerY - radius < 0) {
		 //play(getCodeBase(), "tap2.au");
         velocityY = Math.abs(velocityY);
      }
      if (centerY + radius >= height) {
         //play(getCodeBase(), "tap2.au");
         velocityY = -Math.abs(velocityY);
      }
   }
   
   public void setPosition(int x, int y) {
          // Change position of the ball's center to the specified point, (x,y).
      this.centerX = x;
      this.centerY = y;
   }
   public void headTowards(int x, int y) {
          // Modify the velocity so that the ball is moving in the direction
          // of the point (x,y).  The speed of the ball does not change, only
          // its direction of motion.  (If the specified point is too close
          // to the current position of the ball, the velocity of the ball
          // does not change.)  This method uses some standard vector mathematics.
      if (Math.abs(x - centerX) < 1.0E-10 && Math.abs(y - centerY) < 1.0E-10)
         return;
      double v = Math.sqrt(velocityX*velocityX + velocityY*velocityY);
      double d = Math.sqrt((x-centerX)*(x-centerX) + (y-centerY)*(y-centerY));
      velocityX = (x-centerX)*v/d;
      velocityY = (y-centerY)*v/d;
   }

} // end class BouncingBall