OpenGL ES 3.0 Programming Guide, Second Edition

Chapter 15. State Queries

OpenGL ES 3.0 maintains “state information” that includes the values of internal variables required for rendering. You’ll need to compile and link shader programs, initialize vertex arrays and attribute bindings, specify uniform values, and probably load and bind texture—and that only scratches the surface.

There are also a large number of values that are intrinsic to OpenGL ES 3.0’s operation. You might need to determine the maximum size of viewport that is supported or the maximum number of texture units, for example. All of those values can be queried by your application.

This chapter describes the functions your applications can use to obtain values from OpenGL ES 3.0, and the parameters that you can query.

OpenGL ...