/** 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 PrecisionPaddle() { if (ball.getY() > HEIGHT - PADDLE_Y_OFFSET - PADDLE_HEIGHT - BALL_RADIUS * 2) { // check if the ball drops below the paddle double diff = ball.getY() - (HEIGHT - PADDLE_Y_OFFSET - PADDLE_HEIGHT - BALL_RADIUS * 2); ball.move(0, -2 * diff); // move ball an amount equal to the amount it drops below the paddle } }
private void checkForCollision() { // check if ball has hit floor. If so, bounce it upwards. if (ball.getY() > getHeight() - DIAM_BALL) { bounceClip.play(); yVel = -yVel * BOUNCE_REDUCE; // bounces back almost to BOUNCE_REDUCE * starting height // moves ball back above the floor the same distance it would have dropped below the floor in // same time double diff = ball.getY() - (getHeight() - DIAM_BALL); ball.move(0, -2 * diff); } }
// Update/move ball down and sideways. yVel increases each cycle, due to gravity. private void moveBall() { yVel += GRAVITY; ball.move(xVel, yVel); }
private void startFall() { ball.move(vx, vy); pause(DELAY); ball.sendToBack(); }
/** Move the ball */ private void moveBall() { ball.move(vx, vy); }