2. // Basic Breakout game
3. 
   
4. // brick position
5. float brickX;
6. float brickY;
7. // brick width and height
8. float brickH;
9. float brickW;
10. // ball position
11. float ballX;
12. float ballY;
13. // ball diameter
14. float ballD;
15. // ball direction 
16. float ballDx;
17. float ballDy;
18. // bat position
19. float batX;
20. // bat width
21. float batW;
22. float batH;
23. // bat colour
24. float batB;
25. 
    
26. void setup() {
27.   size (500, 500, P2D);
28.   // set sizes of game items
29.   brickW = 100;
30.   brickH = 50;
31.   batW = 100;
32.   batH = 25;
33.   ballD = 25;
34.   batB = 255;
35.   // random brick position
36.   brickX = random(0, width - brickW);
37.   brickY = random(0, height / 2);
38.   // bat in the centre
39.   batX = (width/2) - (batW/2);
40.   // ball atop bat
41.   ballX = batX + (batW/2);
42.   ballY = height - batH - (ballD/2);
43.   // ball movement
44.   ballDx = random(-5, 5);
45.   ballDy = -5;
46.   rectMode(CORNER);
47.   ellipseMode(CENTER);
48. }
49. 
    
50. void draw() {
51.   // check for ball collision 
52.   // with top or sides of bat
53.   checkBallAgainstBat();
54.   // check for ball collision with 
55.   // left right and top walls
56.   // and bounce
57.   checkBallAgainstWalls();
58.   // check ball against brick
59.   checkBallAgainstBrick();
60. 
    
61.   // move the ball
62.   ballX += ballDx;
63.   ballY += ballDy;
64.   background(0);
65.   // draw the bat
66.   fill(0, 255, 0);
67.   rect(batX, height - batH, batW, batH);
68.   // draw the brick
69.   fill(0, 0, batB);
70.   batB = (batB + 10) % 255;
71.   rect(brickX, brickY, brickW, brickH);
72.   // draw the ball
73.   fill(255, 0, 0);
74.   ellipse(ballX, ballY, ballD, ballD);
75. 
    
76.   if (keyCode == 37) { // left cursor key
77.     batX -= 10;
78.     // keep it on the screen
79.     if (batX < 0) {
80.       batX = 0;
81.     }
82.   }
83.   if (keyCode == 39) {
84.     batX += 10;
85.     if (batX > (width - batW)) {
86.       batX = width - batW;
87.     }
88.   }
89. }
90. 
    
91. // when they let go of the key, reset the keyCode
92. void keyReleased() {
93.   keyCode = -1;
94. }
95. 
    
96. 
    
97. // this function checks if the ball has hit the top or sides of the bat and update its
98. // direction as appropriate so the ball bounces off the bat
99. void checkBallAgainstBat(){
100. }
101. 
     
102. 
     
103. // this function checks if the ball has hit the brick. It should bounce off the brick and return true if so
104. boolean checkBallAgainstBrick(){
105.   return false;
106. }
107. 
     
108. 
     
109. // this function checks if the ball has hit the top, left or right walls and update its
110. // direction as appropriate so the ball bounces off the walls
111. void  checkBallAgainstWalls(){
112.   if (ballX + ballD > width){// right wall
113.     ballDx *= -1;
114.   }
115.   if (ballX - ballD < 0){// left wall
116.     ballDx *= -1;
117.   }
118.   if (ballY - ballD < 0){// top wall
119.     ballDy *= -1;
120.   }
121. }

this is the code that I have been given. i've tried to update the checkBallAgainstBat method and came up with something like that: