I am reading "Learning Java by Building Android Games" and in a Retro Squash Game example I don't know how to implement collision detection for the racket. The movement of the racket uses onTouchEvent. I have tried to implement an if statement but it deosn't get checked until the next touch event- so it doesn't work properly. Please help.
//Event that handles in which direction is the racket moving according to where is the user touching the screen
@Override
public boolean onTouchEvent(MotionEvent motionEvent) {
//gets the movement action without the pointers(ACTION_MASK) ??? -U: handles multitouch
switch (motionEvent.getAction() & MotionEvent.ACTION_MASK) {
//what happens if user touches the screen and holds
case MotionEvent.ACTION_DOWN:
//if the screen was touched on the right side of the display than move the racket right
if (motionEvent.getX() >= (screenWidth / 2) && racketPosition.x <= screenWidth) {
racketIsMovingLeft = false;
racketIsMovingRight = true;
} else if (motionEvent.getX() < (screenWidth / 2) && racketPosition.x >= 0) {
racketIsMovingLeft = true;
racketIsMovingRight = false;
} else {
racketIsMovingLeft = false;
racketIsMovingRight = false;
}
break;
//when the user lets go of the screen the racket immediately stops moving
case MotionEvent.ACTION_UP:
racketIsMovingLeft = false;
racketIsMovingRight = false;
break;
}
return true;
}
Ok. I have found the solution. I wasn't looking at the right piece of code - sorry. I have edited the piece which is responsible for changing the racketPoint.x of the racket. Here it is:
public void updateCount() {
//change the racket position according to the movement
if (racketIsMovingRight && (racketPosition.x+racketWidth/2)<=screenWidth) {
racketPosition.x += racketSpeed;
}
if (racketIsMovingLeft && (racketPosition.x-racketWidth/2)>=0) {
racketPosition.x -= racketSpeed;
}
//rest of the code