opengl ES OES vs EXT?

Question

I am bit confused about what OES and EXT means ? I know that EXT(openGL extensions) is for graphic card vendor specific and it might be supported on a phone and maybe not. But what about OES ? Is it the same as EXT or are these supported by a phone if it supports a certain version of openGL ES (say 2.0) ?

Lets say I want to filter out phones that do not support certain OES extension in the android store, how can I specify it in the manifest ?

Answer 1

All extensions are "graphic card vendor specific," in that they may or may not be supported by any particular piece of hardware. OES extensions are much like ARB extensions in desktop GL land: they're extensions written by the Khronos group responsible for maintaining OpenGL ES. EXT extensions are written by one or more vendors who feel that the functionality applies to hardware beyond their own.

Answer 2

You might not be able to OES extensions in the android manifest. As Nicol points out the extensions are graphic vendor specific you will have to query the existence of the extension in runtime by using the glGetString(GL_EXTENSIONS) function which will give you a space separated string of OES extensions supported by the hardware.