Prepares an effect for rendering.
- iOS 5.0–12.0Deprecated
- macOS 10.8–10.14Deprecated
- tvOS 9.0–12.0Deprecated
An effect must be prepared after it is configured and again when your application wants to use the effect to render any primitives. When your application prepares an effect, some OpenGL state is altered to allow the effect to operate:
GLstate is always changed to point to the shader provided by the effect object.
When texturing is enabled, the
_TEXTURE _BINDING _2D
GLstate may also change.
_TEXTURE _BINDING _CUBE _MAP
If your application requires the previous state to be saved before the effect alters them, it must explicitly save and restore the values.