public void run() {
while (true) {
// move ball to right
// end when ball moves off right side of screen
setup();
while (ball.getX() < getWidth()) {
moveBall();
checkForCollision();
pause(DELAY);
}
// move ball to left
xVel = -X_VEL;
X_START = getWidth() - DIAM_BALL;
setup();
while (ball.getX() > -DIAM_BALL - 5) {
moveBall();
checkForCollision();
pause(DELAY);
}
X_START = DIAM_BALL / 2;
xVel = X_VEL;
yVel = 0.0;
}
}
private void checkWall() {
boolean checkLeftWall = ball.getX() <= 0;
boolean checkRightWall = ball.getX() + BALL_RADIUS * 2 >= WIDTH;
boolean checkTop = ball.getY() <= 0;
if ((checkLeftWall) || (checkRightWall)) {
vx = -vx;
}
if (checkTop) {
vy = -vy;
}
}
/** Check for collision */
private void checkRebounce() {
// check for left/right/top wall
if (ball.getX() < 0) {
vx *= -1;
ball.move(vx, 0);
return;
} else if ((ball.getX() + 2 * BALL_RADIUS) > getWidth()) {
vx *= -1;
ball.move(vx, 0);
return;
} else if (ball.getY() < 0) {
ball.setLocation(ball.getX(), -ball.getY());
vy *= -1;
return;
}
// check for collision with bricks: from the four vertexs
lefttop = getElementAt(ball.getX(), ball.getY());
righttop = getElementAt(ball.getX() + 2 * BALL_RADIUS, ball.getY());
leftbottom = getElementAt(ball.getX(), ball.getY() + 2 * BALL_RADIUS);
rightbottom = getElementAt(ball.getX() + 2 * BALL_RADIUS, ball.getY() + 2 * BALL_RADIUS);
if ((lefttop != null) && (righttop != null) && (lefttop != board) && (lefttop != mylabel)) {
remove(lefttop);
num_brick_left--;
vy *= -1;
} else if ((righttop != null)
&& (rightbottom != null)
&& (righttop != board)
&& (righttop != mylabel)) {
remove(righttop);
num_brick_left--;
vx *= -1;
} else if ((rightbottom != null)
&& (leftbottom != null)
&& (rightbottom != board)
&& (rightbottom != mylabel)) {
remove(rightbottom);
num_brick_left--;
vy *= -1;
} else if ((leftbottom != null)
&& (lefttop != null)
&& (leftbottom != board)
&& (leftbottom != mylabel)) {
remove(leftbottom);
num_brick_left--;
vx *= -1;
}
// check for collision with board
if (getElementAt(ball.getX(), (ball.getY() + BALL_RADIUS / 2)) == board) {
vy *= -1;
ball.move(0, vy);
}
}
private void checkObject() {
// x and y parameters for the different corners
double leftX = ball.getX();
double rightX = ball.getX() + (2 * BALL_RADIUS);
double upperY = ball.getY();
double lowerY = ball.getY() + (2 * BALL_RADIUS);
// check the corners for object
GObject upperLeft = checkCorner(leftX, upperY); // check upper-left corner
if (upperLeft == null) {
GObject upperRight = checkCorner(rightX, upperY); // check upper-right corner
}
GObject lowerLeft = checkCorner(leftX, lowerY); // //check lower-left corner
if (lowerLeft == null) {
GObject lowerRight = checkCorner(rightX, lowerY); // check lower-right corner
if ((lowerLeft == paddle)
&& (lowerRight == paddle)) { // When both lower corners hit paddle, change direction.
vy = -vy;
}
}
}