Name

gl_InvocationID — contains the invocation index of the current shader

Declaration

in int gl_InvocationID;

Description

In the tessellation control language, gl_InvocationID contains the index of the output patch vertex assigned to the shader invocation. It is assigned an integer value in the range [0, N-1] where N is the number of output patch vertices.

In the geometry language, gl_InvocationID identifies the invocation number assigned to the geometry shader invocation. It is assigned an integer value in the range [0, N-1] where N is the number of geometry shader invocations per primitive.

Version Support

Variable Version 1.10 Version 1.20 Version 1.30 Version 1.40 Version 1.50 Version 3.30 Version 4.00 Version 4.10
gl_InvocationID - - - - Y1 Y1 Y Y

[1] Versions 1.50 to 3.30 - geometry shaders only.

See Also

gl_InstanceID

Copyright

Copyright © 2011 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/.