Tutorial:NetworkedWackadot

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public void advanceFrame(double timePassed)
{
   if(timeLeft>0)
   {
      Point2D.Double mouse=
         getPlayer(0).getMouse().getLocation();
      dot.setLocation(mouse);
      handleCollisions();
   }
}

Line 6: Notice that the getPlayer method now has the argument zero. This means that the player returned should be the first player. Absent any arguments, the current player is returned from the getPlayer method.

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public class Wackadot extends GameLoop
{
   private Sprite[] dot;
   private Sprite redDot;

   ...

   private void makeSprites()
   {
      dot=new OvalSprite[getNumberOfPlayers()];
      for(int i=0; i<dot.length; i++)
      {
         dot[i]=new Sprite(circle);
         dot[i].setScale(0.1);
         dot[i].setLocation(0.5, 0.5);
         dot[i].setColor(Color.RED);    		
      }

      ...    	

   }

   private void handleCollisions()
   {
      /*if(dot.intersects(blueDot))
      {
         repositionRandomly(blueDot);
         if(dot.getColor().equals(Color.BLUE))
         {
            dot.setColor(Color.RED);
            score++;
         }
      else
      {
         score--;
      }
     updateScore();*/
  }

  ...

  public void advanceFrame(double timePassed)
  {
     if(timeLeft>0)
     {
        for(int i=0; i<dot.length; i++)
        {
           Point2D.Double mouse=
                    getPlayer(i).getMouse().getLocation();
           dot[i].setLocation(mouse);
        }
        handleCollisions();
     }
  }

  ...
 
}

Line 3: makes the variable dot an array of Sprites. Originally it was a single Sprite. Only insert the [] between the Sprite and the dot. After adding this line, you will see many errors. These errors will be fixed when you complete this table.

Line 6: indicates code left out. Do not copy the ellipses.

Line 10: makes the array of dots capable of holding as many Sprites as there are players. You'll need to change the existing code that initialized dot to be like the new line 13 that initializes dot. Also, the lines 16-19 existed in the code, but without the [i] part. You'll need to insert the [i] part and the surrounding for loop.

Line 11-17: iterates over the positions in the array initializing each element to be a red dot.

Line 19: indicates code left out. Do not copy the ellipses.

Lines 23-38: the handleCollisions method needs many modifications. It's better to make many simple modifications and test them individually than to make one complex modification. We'll make the handleCollisions modifications in later steps once we have made sure everything else still works. Therefore, the lines are commented out. Do not add lines 23-38, just comment out the existing lines.

Line 40: indicates code left out. Do not copy the ellipses.

Lines 46-51: lets player i control dot i. The variable i will iterate over the player indices. You need to only insert the for loop and change the 0 in getPlayer to i and insert the [i] beside dot.

Line 56: indicates code left out. Do not copy the ellipses.

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private void handleCollisions()
{
   for(int i=0; i<dot.length; i++)
      handleCollisions(i);
}
      
private void handleCollisions(int playerIndex)
{
   if(dot[playerIndex].intersects(blueDot))
   {
      repositionRandomly(blueDot);
         if(dot[playerIndex].getColor().equals(Color.BLUE))
         {
            dot[playerIndex].setColor(Color.RED);
            score++;
         }
      else
      {
         score--;
      }
     updateScore();
  }
}

Lines 3-4: handleCollisions now calls the parameterized handleCollisions for each player declared on line 7. This should now be the only code in this method.

Lines 9, 12, 14: instead of checking for collision with the single dot in the one player version, this checks for collision with the player indicated by the parameter playerIndex. This should be the only code in this method. Notice that this is the changed code from the code which is commented out in table B.