2012 Khronos Group
glGetProgramResourceIndex 3G
glGetProgramResourceIndex query the index of a named resource within a program

## C Specification

GLuint `glGetProgramResourceIndex` GLuint program GLenum programInterface const char * name

## Parameters

program

  The name of a program object whose resources to query.

programInterface

  A token identifying the interface within program containing the resource named name.

name

  The name of the resource to query the index of.

## Description

`glGetProgramResourceIndex` returns the unsigned integer index assigned to a resource named name in the interface type programInterface of program object program.

program must be the name of an existing program object. programInterface is the name of the interface within program which contains the resource named nameand must be one of the following values:

`GL_UNIFORM`

  The query is targeted at the set of active uniforms within program.

`GL_UNIFORM_BLOCK`

  The query is targeted at the set of active uniform blocks within program.

`GL_PROGRAM_INPUT`

  The query is targeted at the set of active input variables used by the first shader stage of program. If program contains multiple shader stages then input variables from any stage other than the first will not be enumerated.

`GL_PROGRAM_OUTPUT`

  The query is targeted at the set of active output variables produced by the last shader stage of program. If program contains multiple shader stages then output variables from any stage other than the last will not be enumerated.

`GL_VERTEX_SUBROUTINE`
,
`GL_TESS_CONTROL_SUBROUTINE`
,
`GL_TESS_EVALUATION_SUBROUTINE`
,
`GL_GEOMETRY_SUBROUTINE`
,
`GL_FRAGMENT_SUBROUTINE`
,
`GL_COMPUTE_SUBROUTINE`

  The query is targeted at the set of active subroutines for the vertex, tessellation control, tessellation evaluation, geometry, fragment and compute shader stages of program, respectively.

`GL_VERTEX_SUBROUTINE_UNIFORM`
,
`GL_TESS_CONTROL_SUBROUTINE_UNIFORM`
,
`GL_TESS_EVALUATION_SUBROUTINE_UNIFORM`
,
`GL_GEOMETRY_SUBROUTINE_UNIFORM`
,
`GL_FRAGMENT_SUBROUTINE_UNIFORM`
,
`GL_COMPUTE_SUBROUTINE_UNIFORM`

  The query is targeted at the set of active subroutine uniform variables used by the vertex, tessellation control, tessellation evaluation, geometry, fragment and compute shader stages of program, respectively.

`GL_TRANSFORM_FEEDBACK_VARYING`

  The query is targeted at the set of output variables from the last non-fragment stage of program that would be captured if transform feedback were active.

`GL_BUFFER_VARIABLE`

  The query is targeted at the set of active buffer variables used by program.

`GL_SHADER_STORAGE_BLOCK`

  The query is targeted at the set of active shader storage blocks used by program.

If name exactly matches the name string of one of the active resources for programInterface, the index of the matched resource is returned. Additionally, if name would exactly match the name string of an active resource if "[0]" were appended to name, the index of the matched resource is returned. Otherwise, name is considered not to be the name of an active resource, and `GL_INVALID_INDEX` is returned.

For the interface `GL_TRANSFORM_FEEDBACK_VARYING`, the value `GL_INVALID_INDEX` should be returned when querying the index assigned to the special names `gl_NextBuffer`, `gl_SkipComponents1`, `gl_SkipComponents2`, `gl_SkipComponents3`, or `gl_SkipComponents4`.

## Errors

`GL_INVALID_ENUM` is generated if programInterface is not one of the accepted interface types.

Although not an error, `GL_INVALID_INDEX` is returned if name is not the name of a resource within the interface identified by programInterface.

## See Also

glGetProgramResourceName, glGetGetProgramResource, glGetProgramResourceLocation, glGetProgramResourceLocationIndex.

## Copyright

Copyright 2012 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/.