Learning OpenGLES 2.0 on iOS [closed]

问题:

I'm a beginner with OpenGL ES 2.0 and I'm looking for a good book/resource that will help me with my learning. I've found several books:

• OpenGL® ES 2.0 Programming Guide
• iPhone 3D Programming: Developing Graphical Applications with OpenGL ES

but reading the Amazon reviews I saw that they either assume previous knowledge with OpenGL or are not written specifically for iOS. (I know OpenGL should be easy to port, but I'm looking for a book/resource with examples in C, not C++, that talks about OpenGL in the iOS context)

I also found this and it really helped me getting a grasp on the basic concepts, but unfortunately, they cover OpenGL ES 1.1 and are only describing the basics.

Any help would be appreciated!

回答1:

It's a lot easier to find OpenGL ES 2.0 material for iOS (or any OS, really) than it used to be a year or so ago.

For something written from a pure iOS perspective, it's hard to beat Jeff LaMarche's chapters from his unpublished book, which start here. You linked to his OpenGL ES 1.1 tutorials, which are also great, but he didn't place his newer 2.0 material on that list.

iPhone 3D Programming by Philip Rideout is a great book that covers both OpenGL ES 1.1 and 2.0. It does not assume that you know OpenGL ES, and he does explain a good bit of the math and other fundamentals required to understand what he's talking about. He gets into some pretty advanced techniques towards the end. However, all of his code is in C++, rather than Objective-C, so that may be a little disconcerting for someone used to Cocoa development. Still, the core C API for OpenGL ES is the same, so it's easy to see what's going on.

If you're looking for particular effects, the OpenGL Shading Language book is still one of the primary resources you can refer to. While written for desktop OpenGL, most of the shading language and shaders presented there translate directly across to OpenGL ES 2.0, with only a little modification required.

The books ShaderX6, ShaderX7, GPU Pro, and GPU Pro 2 also have sections devoted to OpenGL ES 2.0, which provide some rendering and tuning hints that you won't find elsewhere. Those are more advanced (and expensive) books, though.

If you're just getting started with OpenGL ES 2.0, it might not be a bad idea to start using GLKit (available only on iOS 5.0), which simplifies some of the normal setup chores around your render buffers and simple shader-based effects. Apple's WWDC 2011 videos have some good material on this, but their 2009 and 2010 videos (if you can find them, some are available at apple archive) provide a lot more introductory material around OpenGL ES 2.0.

Finally, as Andy mentions, I taught a class on the subject as part of my course on iTunes U, which you can download for free here. The course notes for that class can be found here or downloaded as a VoodooPad file here. I warn you that I go a little technical quite fast in the OpenGL ES 2.0 session, so you may want to watch the 1.1 session from the previous semester here. I also talk a little bit about what I've done with OpenGL ES 2.0 in this article about my open source application (whose source code can be grabbed from here, if you'd like to play with a functional OpenGL ES 2.0 iOS application).

回答2:

I would highly recommend Brad Larson's session on OpenGl ES 2.0 from iTunes U. It's pretty in depth, I found it very helpful. You can find it here.

回答3:

I read the books you listed, the first especially is great - but it only went a very short way for GL ES (I already knew desktop GL, and I still had to fill in a lot of "gaps").

I've written a series of blog posts on doing ES 2 "correctly" on iOS - i.e. only using the modern GL commands, using Apple's GLKit as much as possible to save time / reduce typing, avoidingin pitfalls / gotchas from the Apple-specific hardware (PVR chips), etc.

Index here: http://t-machine.org/index.php/2013/08/29/glkit-to-the-max-opengl-es-2-0-for-ios-part-1-features/

回答4:

For Leaning very basic of open GL for iOs I would suggest to have a look at this http://antonholmquist.com/blog/opengl-es-2-0-ios-tutorial-getting-started/. This gives the basic idea of vertex and fragment shaders. After going through this a beginner can go through other tutorials which explains the detailed concepts of openGL.