collision(s)
function detectCollisions(){
//just reflect the ball on a collision
//a more robust engine could change trajectory of ball based
//on where the ball hits the paddle
if(collisionX())
dx = dx * -1;
if(collisionY())
dy = dy * -1;
}
function collisionX(){
//check left and right boundaries
if(ballLeft < 4 || ballLeft > 480)
return true;
return false;
}
function collisionY(){
//check if at top of playing area
if(ballTop < 4)
return true;
//check to see if ball collided with paddle
if(ballTop > 450){
if(ballLeft > paddleLeft && ballLeft < paddleLeft + 64)
return true;
}
return false;
}