Announcing OpenGL ES 2.0 for iOS 4

Okay, it's finally time for me to announce Super Secret Project B, which is a new book I'm writing on OpenGL ES 2.0 for iPhone, iPad, and iPod touch.

Yes, I know I said I wouldn't be writing any books in 2010, but the nice folks at the Pragmatic Programmers approached me after I made that statement with an economically feasible way for me to write a book this year. I couldn't say no.

My original plan had been to take my OpenGL ES from the Ground Up blog posts, supplement them, and turn them into a book with step-by-step projects to reinforce the points of each posts. My week at WWDC has caused me to change that approach. I went to all the OpenGL ES sessions and spent a fair amount of time bending the ear of Allan Schaffer, Apple's Graphics and Games Evangelist, as well as a number of Apple engineers who work on or with OpenGL. After a lot of hard thought, I came to the conclusion that the approach needed to change. Although modern hardware supports the fixed pipeline, Apple has stopped making phones that require OpenGL ES 1.1. The iPhone 3GS, iPhone 4, and iPad all not only support OpenGL ES 2.0, but they all require it if you want to take full advantage of the hardware.

OpenGL ES from the Ground Up, however, focused on the OpenGL ES 1.1 fixed pipeline.

Since OpenGL ES doesn't maintain backward compatibility the way workstation OpenGL does, much of the material from the fixed pipeline, such as lights, the model view and projection matrix, and the stock functions for submitting vertex, texture, and normal data are all gone from OpenGL ES 2.0. Instead, you have to handle all that work manually when you write your shaders. Shaders add some complexity to the process, but give you a tremendous amount of power and the ability to write more efficient OpenGL code.

In the Desktop world, it still makes sense to learn immediate mode first, then regular fixed pipeline, and then finally the programmable pipeline, because workstation OpenGL maintains nearly 100% backwards compatibility across releases, and you can get up and running quickly. On Workstation OpenGL ES, you can even mix and match the different modes, accessing the model view matrix and lights from your shaders. That's not the case with OpenGL ES, so spending a few hundred pages teaching things that won't be applicable to the programmable pipeline seemed like a poor use of time, both mine, and my readers'.

But, for the new programmer, the programmable pipeline is really hard to grok. I've been banging my head this past week looking for a way to present that rather complex topic in a way that people without prior graphics or OpenGL ES experience will be able to understand.

Thanks to a lot of people willing to talk with me, I think I've come up with an approach that will work, and I'm really excited about it. So, if you find OpenGL ES confusing, especially if you find the programmable pipeline and shaders confusing, look out for OpenGL ES 2.0 for iOS4. I don't have a release date yet, but I will post here when I have updated information about the production schedule.