glGetIntegeri

The function glGetIntegeri is part of the OpenGL API, specifically introduced in version 4.1. It is used to retrieve integer values associated with a specific index of a particular OpenGL state variable or parameter. This function is useful when querying multi-indexed state data, such as individual entries of texture units, shader storage blocks, or other indexed features of the rendering context.

The syntax of glGetIntegeri is as follows: void glGetIntegeri(GLenum pname, GLuint index, GLint *data); where the parameter 'pname' specifies the state variable or parameter to query, 'index' indicates the particular entry or index within that state, and 'data' is a pointer to an integer where the retrieved value will be stored. Common use cases include obtaining discrete values for specific texture units or vertex array bindings when they are managed as arrays.

This function allows for more granular control and inspection of OpenGL state, especially in contexts involving multiple resources that are accessed via indices. It supplements the older glGetIntegerv function, which retrieves all entries of a multi-valued state at once, by focusing on individual elements.

Since glGetIntegeri is tied to the OpenGL core profile starting in version 4.1, support for this function requires a compatible graphics driver and hardware that supports OpenGL 4.1 or higher. Its design aligns with OpenGL’s goal of providing detailed and flexible access to graphics state for advanced rendering techniques.

Overall, glGetIntegeri enhances the capability to query specific indexed state data, augmenting the precision available to developers working with complex graphics systems.