11.1.3: Breakout

/* Constants for bricks */
var NUM_ROWS = 8;
var BRICK_TOP_OFFSET = 10;
var BRICK_SPACING = 2;
var NUM_BRICKS_PER_ROW = 10;
var BRICK_HEIGHT = 10;
var SPACE_FOR_BRICKS = getWidth() - (NUM_BRICKS_PER_ROW + 1) * BRICK_SPACING;
var BRICK_WIDTH = SPACE_FOR_BRICKS / NUM_BRICKS_PER_ROW;
var brick;


function start(){
    drawBricks();
    mouseMoveMethod(drawPaddle);
    
    // ball functions
    drawBall();
    setTimer(draw, 20);
	moveBall();
}

// this function draw bricks 
function drawBricks(){
    for(var j = 0; j < NUM_ROWS;j++){
        for(var i = 0; i < NUM_BRICKS_PER_ROW; i++){
            brick = new Rectangle(BRICK_WIDTH, BRICK_HEIGHT);
        
            if((j + 1) % 8 == 1 || (j + 1) % 8 == 2){
                brick.setColor(Color.RED);
            }
        
            else if((j + 1) % 8 == 3 || (j + 1) % 8 == 4){
                brick.setColor(Color.ORANGE);
            }
            
            else if((j + 1) % 8 == 5 || (j + 1) % 8 == 6){
                brick.setColor(Color.GREEN);
            }
            
            else if ((j + 1) % 8 == 7 || (j + 1) % 8 == 0){
                brick.setColor(Color.BLUE);
            }

            brick.setPosition(BRICK_WIDTH * i + BRICK_SPACING * (1 + i), BRICK_TOP_OFFSET + BRICK_HEIGHT * j + BRICK_SPACING * (1 + j));
            add(brick);
        }
    }
}


/* Constants for paddle */
var PADDLE_WIDTH = 80;
var PADDLE_HEIGHT = 15;
var PADDLE_OFFSET = 10;
var paddle;


function drawPaddle(event){
    remove(paddle);
  
    var paddleX = event.getX() - PADDLE_WIDTH / 2 - PADDLE_OFFSET;
    
    paddle = new Rectangle(PADDLE_WIDTH, PADDLE_HEIGHT);
    paddle.setPosition(paddleX, getHeight() - PADDLE_OFFSET - PADDLE_HEIGHT );
    paddle.setColor(Color.black);
    add(paddle);
}


// Constants for ball
var ball;
var BALL_RADIUS = 15;
var dx = 4;
var dy = 4;
var ballElement;
var brickElement;

// Check if the ball has reached a wall.
// Then move the ball in the correct direction.
function draw(){
	checkWalls();
	ball.move(dx, dy);
}


function drawBall(){
    ball = new Circle(BALL_RADIUS);
	ball.setPosition(100, 100);
	add(ball);
}


function checkWalls(){
	// Bounce off right wall
	if(ball.getX() + ball.getRadius() > getWidth()){
		dx = -dx;
	}
	
	// Bounce off left wall
	if(ball.getX() - ball.getRadius() < 0){
		dx = -dx;
	}
	
	if(ball.getY() < 0){
		dy = -dy;
	}

    brickElement = getElementAt(ball.getX() + BRICK_WIDTH, ball.getY() + BRICK_HEIGHT );
    
    if (brickElement != null) {
          remove(brickElement);
        dy = -dy
      
    }
    
	ballElement = getElementAt(ball.getX(), ball.getY() + ball.getRadius());
    if ((ballElement && ballElement.x == paddle.x)){
        dy = -dy;
    }
}


function moveBall(){
    	ball.setPosition(200, 200);
    	ball.setColor(Color.black);
}