glGetFragDataIndex - OpenGL 4 Reference Pages

## Name

glGetFragDataIndex — query the bindings of color indices to user-defined varying out variables

## C Specification

`GLint glGetFragDataIndex(` | GLuint program,
| const char * name`)`;

## Parameters

`program`

  The name of the program containing varying out variable whose binding to query

`name`

  The name of the user-defined varying out variable whose index to query

## Description

`glGetFragDataIndex` returns the index of the fragment color to which the variable `name` was bound when the program object `program` was last linked. If `name` is not a varying out variable of `program`, or if an error occurs, -1 will be returned.

## Notes

`glGetFragDataIndex` is available only if the GL version is 3.3 or greater.

## Errors

`GL_INVALID_OPERATION` is generated if `program` is not the name of a program object.

## Version Support

| OpenGL Version
--- | ---
Function / Feature Name | 2.0 | 2.1 | 3.0 | 3.1 | 3.2 | 3.3 | 4.0 | 4.1 | 4.2 | 4.3 | 4.4 | 4.5
`glGetFragDataIndex` | - | - | - | - | ✔ | ✔ | ✔ | ✔ | ✔ | ✔ | ✔ | ✔

## See Also

glCreateProgram, glBindFragDataLocation, glBindFragDataLocationIndexed, glGetFragDataLocation

## Copyright

Copyright © 2010-2014 Khronos Group. This material may be distributed subject to the terms and conditions set forth in the Open Publication License, v 1.0, 8 June 1999. http://opencontent.org/openpub/.