Signature
Parameters
| Variables | Description |
|---|---|
| program |
Specifies the program object to be
queried.
|
| name |
Points to a null terminated string containing
the name of the uniform variable whose location is
to be queried.
|
Description
glGetUniformLocation
returns an
integer that represents the location of a specific uniform
variable within a program object.
name
must be a null terminated string that contains no white space.
name
must be an active uniform variable
name in
program
that is not a structure,
an array of structures, or a subcomponent of a vector or a
matrix. This function returns -1 if
name
does not correspond to an active uniform variable in
program
, if
name
starts with the reserved prefix "gl_", or if
name
is associated with an atomic counter or
a named uniform block.
Uniform variables that are structures or arrays of
structures may be queried by calling
glGetUniformLocation
for each field within
the structure. The array element operator "[]" and the
structure field operator "." may be used in
name
in order to select elements within
an array or fields within a structure. The result of using these
operators is not allowed to be another structure, an array of
structures, or a subcomponent of a vector or a matrix. Except if
the last part of
name
indicates a uniform
variable array, the location of the first element of an array
can be retrieved by using the name of the array, or by using the
name appended by "[0]".
The actual locations assigned to uniform variables are not
known until the program object is linked successfully. After
linking has occurred, the command
glGetUniformLocation
can be used to obtain
the location of a uniform variable. This location value can then
be passed to
glUniform
to set the value of the uniform variable or to
glGetUniform
in order to query the current value of the uniform variable.
After a program object has been linked successfully, the index
values for uniform variables remain fixed until the next link
command occurs. Uniform variable locations and values can only
be queried after a link if the link was successful.
Errors
GL_INVALID_VALUE
is generated if
program
is not a value generated by
OpenGL.
GL_INVALID_OPERATION
is generated if
program
is not a program object.
GL_INVALID_OPERATION
is generated if
program
has not been successfully
linked.
Associated Gets
glGetActiveUniform
with arguments
program
and the index of
an active uniform variable
glGetUniform
with arguments
program
and the name of a
uniform variable
Version Support
| glGetUniformLocation |
See Also
Copyright
Copyright
2003-2005 3Dlabs Inc. Ltd.
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/
.
Sample Code References
The following code samples have been found which appear to reference the functions described here. Take care that the code may be old, broken or not even use PyOpenGL.
glGetUniformLocation