balls bouncing from a line drawn by mouse dragging

Question

I have a space with bouncing balls, and when i drag mouse I want a line to be drawn in it so that balls start bouncing from it as well.

I can draw a line consisting of small circles, and add their inside area together, and if a ball intersects this area change direction. This works. The problem is that circles don't produce solid line (as mouseDragged events are fired too rarely), but if I use Line2D instead, it doesn't enclose any area.
In every mouse dragged event I can interpolate data between startPoint and endPoint and draw a circle at obtained x,y. It works, but everything freezes terribly
I can check if ball's covering rectangle contains certain color (and if so, change direction), but again how should it be done -- checking every pixel doesn't seem efficient at all?

Is there a way/best way to deal with it?

I've thought about that. But then you need to rotate every rectangle, and this, as i understand, may be cumbersome (you need to rotate graphics or image, right?). Is there a better, sort of, "usual" approach? — Stas, Apr 08 '14 at 12:15
I don't get what you're trying to do. Are you trying to create a pong game? — Paul Samsotha, Apr 08 '14 at 12:32

score 2 · Accepted Answer · edited May 23 '17 at 12:22

2

but if I use Line2D instead, it doesn't enclose any area.

Use a Path2D or a Polygon that has a (very thin) width. It will look like a line, but have an area.

Then use it in the code seen in this answer.

edited May 23 '17 at 12:22

Community

answered Apr 10 '14 at 07:58

Andrew Thompson

1 Answers1