The blendmode is the way the video card draws an image.

If you chose no blendmode, then its set to normal, which is, a black pixel is black and a green pixel is green.

There are several blendmodes available which also can be combined.

The blendmode I am talking about adds the pixel color of the circle to the pixel color of the background. I also draw the circle a little alphablended, too, so it is a little more transparency. This gives the effect shown in the picture.


The lines are as easy as the circle.

Basically, each frame you have to do the following:

- calculate the angle between the two circles.
- calculate a line from midpoint of circle1 to midpoint of circle2
- cut the line at the points where it intersects with the circle
Now you just have to inherit along this line and draw little particles with blendmode "add". You can vary the drawing position of each particle one or two pixels randomly so the line gets a litte distorted look like on your screenshot.

Basically thats it... nothing special, just a little math!

Greetings,
Dirk