Algorithm for "neon glow" graphics programming

Question

I am searching for an article or tutorial that explains how one can draw primitive shapes (mainly simple lines) with a (neon) glow effect on them in the graphical output of a computer program. I do not want to do some sophisticated stuff like for example in modern first pirson shooters or alike. I am more in a search for a simple solution, like the lines in that picture: http://tjl.co/blog/wp-content/uploads/2009/05/NeonStripes.jpg -- but of course drawn by a computer program in my case.

The whole thing should run on a modern smart phone, so the hardware is a bit limited.

I do know a bit about OpenGL, but not too much, so unfortunately I am a bit lost here. Did some research on Google ("glow effect algoritm" and similar), but found either highly complex stuff for 3D games, or tutorials for Photoshop & co.

So what I would really need is an in-depth article on that subject, but not on a very advanced level. I hope thats even possible... I have just started with OpenGL, did some minor graphics programming in the past, but I am a long-year programmer now, so I would understand technical papers in general.

Does anyone of you know of such an article/paper/tutorial/anything?

Thanks in advance for all good advices! Cheers!

Matthias

Answer 1

Its jus a bunch of lines with different brightness/transperency. Basically, if you want a glow effect for 1px line, in a size of 20 pixels, then you draw 41 lines with width of 1 px. The middle line is with your base colour, other lines get colours that gradiently go from base color to 100% transperency (like in your example) or darkest colour variant (if you have black background, no transparency). That is it. :)