I have no idea how to code a shaders so id be looking at shaders that other people have coded or I guess programs like this one http://developer.apple.com/graphicsimaging/opengl/shader_image.html
could be the answer for open gl.
could be the answer for open gl.
It's a complely different type of programming and it's a new language, but it's not actually hard. Well, like any programming, the really good stuff is tricky, but the basics are definitely not hard. I don't know about GLSL but CG and HLSL are fairly high level languages, similar in syntax to C, except that you have a number of useful functions built in, and automatic type casting, and no pointers, so it's actually a good bit easier than C, I'd say. It takes a while to get your head around because up until Shader Model 4 ( which I've done no programming in at all ) you could only program with a pixel or a vertex. It takes a while to understand quite how that's going to work, it's odd thinking in terms of just one vertex or just one pixel, but when it does click, it takes a big weight off. You no longer have the problems associated with traditional programming because all you're ever writing is a little snippet of code to deal with one pixel or one vertex. Debugging can be tricky as you can forget about debuglogs and breakpoints, but you learn to put your debug information into something obvious ( like the color of each pixel ) and then it's not too bad.
It's kinda fun too. If you ever find yourself missing the days when programming wasn't such a chore and it used to be kinda fun then playing with shader programming might well be the way to go back to that. I know I found shader programming as much fun as any programming I'd done when I first got into it. And it doesn't cost anything of course because all the major tools are free.