Direct X really basic help.
Ok so I haven't been able to hit this book as much as I wanted to ( Final month or so of high school), I've had to do a lot of stuff the last few weeks. I was doing an example of this book. and I stumble upon this
Code:
//move the ball
ptBallPosition.x+=ptBallVelocity.x;
ptBallPosition.y+=ptBallVelocity.y;
//bounds checking
//left side
if(ptBallPosition.x<=0) ptBallVelocity.x=abs(ptBallVelocity.x);
//top side
if(ptBallPosition.y<=0) ptBallVelocity.y=abs(ptBallVelocity.y);
//right side
if(ptBallPosition.x>=(int)dwDisplayWidth-gdicBall.GetWidth()) ptBallVelocity.x=-abs(ptBallVelocity.x);
//bottom side
if(ptBallPosition.y>=(int)dwDisplayHeight-gdicBall.GetHeight()) ptBallVelocity.y=-abs(ptBallVelocity.y);
I am not really sure what's going in on here with the bounds checking this "abs" business I dont' really know what that is, could someone please clarify this for me? Thanks.