0

I'm starting to learn OpenGL ES on iOS.

Do you know some good references that talk about Open GL ES 1 (not 2 !) AND iOS 5 (since Apple did a lot of work on iOS 5 for OpenGL)

Thx

Matthieu Riegler
  • 31,918
  • 20
  • 95
  • 134
  • 7
    Why learn an outdated version of OpenGL ES that's deprecated and might get removed from iOS? – DarkDust Mar 04 '12 at 21:48
  • To first start with what seems to be easier. (I heard shaders are more difficult to use) – Matthieu Riegler Mar 04 '12 at 22:30
  • 1
    Apple's GLKit is designed to make ES 2 pretty much as easy as ES 1. There's also no longer a compatibility argument — everything that can run iOS 5 is ES 2 capable. – Tommy Mar 05 '12 at 00:29

1 Answers1

3

First, you don't need to look for references that are specific to iOS 5.0. Apple did not change the fundamental OpenGL ES API in 5.0. All of the references that you can find on OpenGL ES 1.1 still apply just as well on iOS 5.0.

At the base level, they added a few extensions that use new hardware capabilities of the iPad 2 and iPhone 4S, such as EXT_color_buffer_half_float and EXT_occlusion_query_boolean, as well as markers for use with the new OpenGL ES debugger inside Xcode. These are not beginner-level concepts, but both of these are explained in detail in Apple's WWDC 2011 videos on OpenGL ES.

The most significant addition in iOS 5.0 is GLKit, which simplifies the setup and configuration of an OpenGL ES scene. Note that GLKit is based entirely around OpenGL ES 2.0, not 1.1, and has a stated goal of helping you migrate from 1.1 to 2.0:

The GLKit framework provides libraries of commonly needed functions and classes to reduce the effort needed to create a new OpenGL ES 2.0 application or the effort required to port an existing OpenGL ES 1.1 application to OpenGL ES 2.0.

Therefore, anything you read about GLKit will by necessity be using OpenGL ES 2.0.

I've previously pointed out advantages that OpenGL ES 2.0 gave my applications, so I won't go into that here. Instead, I'll just say that I've found OpenGL ES 2.0 to actually be a lot easier for me to understand than 1.1. In 2.0, if you want a specific effect, you write the shader code to do it. In 1.1, if you want that same effect, you first have to verify that it's possible to do what you want, then you have to find the magic combination of state changes you need to put in place to make that happen.

I highly encourage anyone learning OpenGL ES now to start with 2.0, and not even glance at 1.1. There aren't quite as many resources for picking up 2.0 as 1.1 out there yet, but I mention several of them in this answer.

Community
  • 1
  • 1
Brad Larson
  • 170,088
  • 45
  • 397
  • 571