Complete Beginner - Breakout (game) - How do I fix the brick function

Programming Questions

nickecarlo

Complete Beginner - Breakout (game) - How do I fix the brick function

in Programming Questions • 1 year ago

I have read other discussions on collision on the following posts:

http://forum.processing.org/topic/struggling-with-collision-detection-beginner

http://forum.processing.org/topic/who-can-assist-with-the-right-codes-for-the-bat-function-and-the-brick-function-of-this-breakout-game-codes

But I still can't seem to figure it out, and I don't know why.

I would really appreciate some help with some explanation. The code is pasted below:

// Basic Breakout game
// Code from Matthre Yee-King
int ponto = 0;
// brick position
float brickX;
float brickY;
// brick width and height
float brickH;
float brickW;
// ball position
float ballX;
float ballY;
// ball diameter
float ballD;
// ball direction
float ballDx;
float ballDy;
// bat position
float batX;
//bat width
float batW;
float batH;
//bat colour
float batB;
void setup() {
size (500, 500, P2D);

// set sizes of game items
brickW = 100;
brickH = 50;
batW = 100;
batH = 15;
ballD = 25;
batB = 255;

// random brick position
brickX = random(0, width - brickW);
brickY = random (0, height / 2);

// bat in the centre
batX = (width/2) - (batW/2);

// ball atop bat
ballX = batX + (batW/2);
ballY = height - batH - (ballD/2);

// ball movement
ballDx = random(-5, 5);
ballDy = -5;
rectMode(CORNER);
ellipseMode(CENTER);
}
void draw() {
// check for ball collision
// with top or sides of bat
checkBallAgainstBat();

// check for ball collision with
// left right and top walls
// and bounce
checkBallAgainstWalls();

// check ball against brick
checkBallAgainstBrick();

// move the ball
ballX += ballDx;
ballY += ballDy;
background(0);

// draw the bat
fill(0, 255, 0);
rect(batX, height - batH, batW, batH);

// draw the brick
fill(0, 0, batB);
batB = (batB + 10) % 255;
rect(brickX, brickY, brickW, brickH);

// draw the ball
fill(255, 0, 0);
ellipse(ballX, ballY, ballD, ballD);

if (keyCode == 37) { // left cursor key
    batX -= 10;

    // keep it on the screen
    if (batX < 0) {
      batX = 0;
    }
}

if (keyCode == 39) {
    batX += 10;
    if (batX > (width - batW)) {
      batX = width - batW;
    }
}
}
// when they let go of the key, reset the keyCode
void keyReleased() {
keyCode = -1;
}
// this function checks if the ball has hit the top or sides of the bat and
// updates its direction as appropriate so the ball bouncs off the bat
// I have provided for a function here so that whenever the ball hits
// the bat, it goes in the opposite direction. For more realism, I added
// ballD/2, so the ball gets closer before it bounces off.
// This function is still buggy as I have not been able to work those bugs
// out.
void checkBallAgainstBat() {
if (ballX + ballD/2 > batX && ballX + ballD/2 < batX + batW) {
    if (ballY + ballD/2 - ballD > height-batH-ballD) {
      ballDy *= -1;
      }
}
}
// this function checks if the ball has hit the brick. It should bounce off
// the brick and return true if so
// This function is supposed to work as the checkBallAgainstBat() works
// but for some reason it is all messed up and I can't seem to figure it
// out.
boolean checkBallAgainstBrick() {
if (ballX + ballD/2 > brickX && ballX + ballD/2 < brickX + brickW) {
    if (ballY > brickH-ballD) {
    ballDy *= -1;
    return true;
}
}
      return false;
}
// this function checks if the ball has hit the top, left or right
// walls and update its
// direction as appropriate so the ball bounces off the walls
void checkBallAgainstWalls() {
if (ballX + ballD > width) {
    ballDx *= -1;
}
if (ballX - ballD < 0) {
    ballDx *= -1;
}
if (ballY - ballD < 0) {
    ballDy *= -1;
}
}

The function that doesn't seem to work for me is:

// this function checks if the ball has hit the brick. It should bounce off
// the brick and return true if so
// This function is supposed to work as the checkBallAgainstBat() works
// but for some reason it is all messed up and I can't seem to figure it
// out.
boolean checkBallAgainstBrick() {
if (ballX + ballD/2 > brickX && ballX + ballD/2 < brickX + brickW) {
if (ballY > brickH-ballD) {
ballDy *= -1;
return true;
}
}
return false;
}

I have played around with it, I have done so much to it I can't even remember. I still can't figure out why it acts weird. I don't want the brick to disappear or anything, I will work on that later. All I need to know is why this function isn't operating as normal and how I can fix it.

I'd really appreciate a detailed reply on this as I have been working on it for weeks, literally.

Replies(3)

Chrisir

Re: Complete Beginner - Breakout (game) - How do I fix the brick function

1 year ago

One idea for the Code:

// this function checks if the ball has hit the brick. It should bounce off
// the brick and return true if so
// This function is supposed to work as the checkBallAgainstBat() works
// but for some reason it is all messed up and I can't seem to figure it
// out.
boolean checkBallAgainstBrick() {
if (ballX + ballD/2 > brickX && ballX + ballD/2 < brickX + brickW) {
if (ballY + ballD/2 > brickY && ballY + ballD/2 < brickY + brickH) {
ballDy *= -1;
return true;
} // if I.
} // if II.
return false;
} // func

ok, I think it is more complicate.
You have to check from where the ball comes and where it hits the brick.
Let me explain.
When the ball flies from the lower left corner to the upper right corner and hits the brick from underneath, the balls x-direction stays the same, but the y-direction gets changed.
Similarly when ball hits the left side of the brick, the ball changes it's x-direction but not its y-direction. Draw it with a pen on a paper. Maybe you want that both x-direction and y-direction do get changed when the ball hits a corner of the brick.

In the example above only y-direction gets changed.

I think you don't have to check whether the ball is within a brick but more where the ball hit the brick, at which side.

There are a few Codes for this game around in this forum:

the ball stuff ( not a finished program at all!)
https://forum.processing.org/topic/brick-breaker#25080000001283325

an approach to display different levels ( for your work later later on):
https://forum.processing.org/topic/displaying-new-screen#25080000001340109

Good luck!

keywords: Brick, Bricks, Brick Breaker, Arkanoid, Breakout

nickecarlo

Re: Complete Beginner - Breakout (game) - How do I fix the brick function

1 year ago

Thanks for your reply, so I tried your advice and I have come up with the following code for the brick part:

boolean checkBallAgainstBrick() {
if (ballX >= brickX && ballX <= brickX + brickW && ballY - ballD/2 < brickY + brickH && ballY + ballD/2 > brickY) {
    ballDy *= -1;
    return true;
    //ballDx *= -1;
}
if (ballY > brickY && ballY < brickY + brickH && ballX + ballD/2 > brickX && ballX - ballD/2 < brickX + brickW) {
    ballDx *= -1;
    return true;
}
return false;

Everything works fine and dandy but if the ball hits any of the corners, it starts acting weird. What am I doing wrong? Are the corners not included in the calculations for all the sides?

Chrisir

Re: Complete Beginner - Breakout (game) - How do I fix the brick function

1 year ago

this confuses me....

try this

else if (ballY >

instead of

if (ballY >

Did you try this from my last post?

When the ball flies from the lower left corner to the upper right corner and hits the brick from underneath, the balls x-direction stays the same, but the y-direction gets changed.
Similarly when ball hits the left side of the brick, the ball changes it's x-direction but not its y-direction.

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