glUniform

Specify the value of a uniform variable for the current program object

Signature

glUniform1f( GLint ( location ) , GLfloat ( v0 ) )-> void
glUniform1f( location , v0 )
glUniform1fv( GLint ( location ) , GLsizei ( count ) , const GLfloat *( value ) )-> void
glUniform1fv( location , count , value )
glUniform1i( GLint ( location ) , GLint ( v0 ) )-> void
glUniform1i( location , v0 )
glUniform1iv( GLint ( location ) , GLsizei ( count ) , const GLint *( value ) )-> void
glUniform1iv( location , count , value )
glUniform1ui( GLint ( location ) , GLuint ( v0 ) )-> void
glUniform1ui( location , v0 )
glUniform1uiv( GLint ( location ) , GLsizei ( count ) , const GLuint *( value ) )-> void
glUniform1uiv( location , count , value )
glUniform2f( GLint ( location ) , GLfloat ( v0 ) , GLfloat ( v1 ) )-> void
glUniform2f( location , v0 , v1 )
glUniform2fv( GLint ( location ) , GLsizei ( count ) , const GLfloat *( value ) )-> void
glUniform2fv( location , count , value )
glUniform2i( GLint ( location ) , GLint ( v0 ) , GLint ( v1 ) )-> void
glUniform2i( location , v0 , v1 )
glUniform2iv( GLint ( location ) , GLsizei ( count ) , const GLint *( value ) )-> void
glUniform2iv( location , count , value )
glUniform2ui( GLint ( location ) , GLuint ( v0 ) , GLuint ( v1 ) )-> void
glUniform2ui( location , v0 , v1 )
glUniform2uiv( GLint ( location ) , GLsizei ( count ) , const GLuint *( value ) )-> void
glUniform2uiv( location , count , value )
glUniform3f( GLint ( location ) , GLfloat ( v0 ) , GLfloat ( v1 ) , GLfloat ( v2 ) )-> void
glUniform3f( location , v0 , v1 , v2 )
glUniform3fv( GLint ( location ) , GLsizei ( count ) , const GLfloat *( value ) )-> void
glUniform3fv( location , count , value )
glUniform3i( GLint ( location ) , GLint ( v0 ) , GLint ( v1 ) , GLint ( v2 ) )-> void
glUniform3i( location , v0 , v1 , v2 )
glUniform3iv( GLint ( location ) , GLsizei ( count ) , const GLint *( value ) )-> void
glUniform3iv( location , count , value )
glUniform3ui( GLint ( location ) , GLuint ( v0 ) , GLuint ( v1 ) , GLuint ( v2 ) )-> void
glUniform3ui( location , v0 , v1 , v2 )
glUniform3uiv( GLint ( location ) , GLsizei ( count ) , const GLuint *( value ) )-> void
glUniform3uiv( location , count , value )
glUniform4f( GLint ( location ) , GLfloat ( v0 ) , GLfloat ( v1 ) , GLfloat ( v2 ) , GLfloat ( v3 ) )-> void
glUniform4f( location , v0 , v1 , v2 , v3 )
glUniform4fv( GLint ( location ) , GLsizei ( count ) , const GLfloat *( value ) )-> void
glUniform4fv( location , count , value )
glUniform4i( GLint ( location ) , GLint ( v0 ) , GLint ( v1 ) , GLint ( v2 ) , GLint ( v3 ) )-> void
glUniform4i( location , v0 , v1 , v2 , v3 )
glUniform4iv( GLint ( location ) , GLsizei ( count ) , const GLint *( value ) )-> void
glUniform4iv( location , count , value )
glUniform4ui( GLint ( location ) , GLuint ( v0 ) , GLuint ( v1 ) , GLuint ( v2 ) , GLuint ( v3 ) )-> void
glUniform4ui( location , v0 , v1 , v2 , v3 )
glUniform4uiv( GLint ( location ) , GLsizei ( count ) , const GLuint *( value ) )-> void
glUniform4uiv( location , count , value )
glUniformMatrix2fv( GLint ( location ) , GLsizei ( count ) , GLboolean ( transpose ) , const GLfloat *( value ) )-> void
glUniformMatrix2fv( location , count , transpose , value )
glUniformMatrix2x3fv( GLint ( location ) , GLsizei ( count ) , GLboolean ( transpose ) , const GLfloat *( value ) )-> void
glUniformMatrix2x3fv( location , count , transpose , value )
glUniformMatrix2x4fv( GLint ( location ) , GLsizei ( count ) , GLboolean ( transpose ) , const GLfloat *( value ) )-> void
glUniformMatrix2x4fv( location , count , transpose , value )
glUniformMatrix3fv( GLint ( location ) , GLsizei ( count ) , GLboolean ( transpose ) , const GLfloat *( value ) )-> void
glUniformMatrix3fv( location , count , transpose , value )
glUniformMatrix3x2fv( GLint ( location ) , GLsizei ( count ) , GLboolean ( transpose ) , const GLfloat *( value ) )-> void
glUniformMatrix3x2fv( location , count , transpose , value )
glUniformMatrix3x4fv( GLint ( location ) , GLsizei ( count ) , GLboolean ( transpose ) , const GLfloat *( value ) )-> void
glUniformMatrix3x4fv( location , count , transpose , value )
glUniformMatrix4fv( GLint ( location ) , GLsizei ( count ) , GLboolean ( transpose ) , const GLfloat *( value ) )-> void
glUniformMatrix4fv( location , count , transpose , value )
glUniformMatrix4x2fv( GLint ( location ) , GLsizei ( count ) , GLboolean ( transpose ) , const GLfloat *( value ) )-> void
glUniformMatrix4x2fv( location , count , transpose , value )
glUniformMatrix4x3fv( GLint ( location ) , GLsizei ( count ) , GLboolean ( transpose ) , const GLfloat *( value ) )-> void
glUniformMatrix4x3fv( location , count , transpose , value )

Parameters

VariablesDescription
location
Specifies the location of the uniform variable to be modified.
count
For the vector ( glUniform*v ) commands, specifies the number of elements that are to be modified. This should be 1 if the targeted uniform variable is not an array, and 1 or more if it is an array.
transpose
For the matrix commands, specifies whether to transpose the matrix as the values are loaded into the uniform variable.
v0, v1, v2, v3
For the scalar commands, specifies the new values to be used for the specified uniform variable.
value
For the vector and matrix commands, specifies a pointer to an array of count values that will be used to update the specified uniform variable.

Description

glUniform modifies the value of a uniform variable or a uniform variable array. The location of the uniform variable to be modified is specified by location , which should be a value returned by glGetUniformLocation . glUniform operates on the program object that was made part of current state by calling glUseProgram .
The commands glUniform{1|2|3|4}{f|i|ui} are used to change the value of the uniform variable specified by location using the values passed as arguments. The number specified in the command should match the number of components in the data type of the specified uniform variable (e.g., 1 for
float
,
int
,
unsigned int
,
bool
; 2 for
vec2
,
ivec2
,
uvec2
,
bvec2
, etc.). The suffix f indicates that floating-point values are being passed; the suffix i indicates that integer values are being passed; the suffix ui indicates that unsigned integer values are being passed, and this type should also match the data type of the specified uniform variable. The i variants of this function should be used to provide values for uniform variables defined as
int
,
ivec2
,
ivec3
,
ivec4
, or arrays of these. The ui variants of this function should be used to provide values for uniform variables defined as
unsigned int
,
uvec2
,
uvec3
,
uvec4
, or arrays of these. The f variants should be used to provide values for uniform variables of type
float
,
vec2
,
vec3
,
vec4
, or arrays of these. Either the i , ui or f variants may be used to provide values for uniform variables of type
bool
,
bvec2
,
bvec3
,
bvec4
, or arrays of these. The uniform variable will be set to
false
if the input value is 0 or 0.0f, and it will be set to
true
otherwise.
All active uniform variables defined in a program object are initialized to 0 when the program object is linked successfully. They retain the values assigned to them by a call to glUniform until the next successful link operation occurs on the program object, when they are once again initialized to 0.
The commands glUniform{1|2|3|4}{f|i|ui}v can be used to modify a single uniform variable or a uniform variable array. These commands pass a count and a pointer to the values to be loaded into a uniform variable or a uniform variable array. A count of 1 should be used if modifying the value of a single uniform variable, and a count of 1 or greater can be used to modify an entire array or part of an array. When loading n elements starting at an arbitrary position m in a uniform variable array, elements m + n - 1 in the array will be replaced with the new values. If m + n - 1 is larger than the size of the uniform variable array, values for all array elements beyond the end of the array will be ignored. The number specified in the name of the command indicates the number of components for each element in value , and it should match the number of components in the data type of the specified uniform variable (e.g., 1 for float, int, bool; 2 for vec2, ivec2, bvec2, etc.). The data type specified in the name of the command must match the data type for the specified uniform variable as described previously for glUniform{1|2|3|4}{f|i|ui} .
For uniform variable arrays, each element of the array is considered to be of the type indicated in the name of the command (e.g., glUniform3f or glUniform3fv can be used to load a uniform variable array of type vec3). The number of elements of the uniform variable array to be modified is specified by count
The commands glUniformMatrix{2|3|4|2x3|3x2|2x4|4x2|3x4|4x3}fv are used to modify a matrix or an array of matrices. The numbers in the command name are interpreted as the dimensionality of the matrix. The number 2 indicates a 2 × 2 matrix (i.e., 4 values), the number 3 indicates a 3 × 3 matrix (i.e., 9 values), and the number 4 indicates a 4 × 4 matrix (i.e., 16 values). Non-square matrix dimensionality is explicit, with the first number representing the number of columns and the second number representing the number of rows. For example, 2x4 indicates a 2 × 4 matrix with 2 columns and 4 rows (i.e., 8 values). If transpose is GL_FALSE , each matrix is assumed to be supplied in column major order. If transpose is GL_TRUE , each matrix is assumed to be supplied in row major order. The count argument indicates the number of matrices to be passed. A count of 1 should be used if modifying the value of a single matrix, and a count greater than 1 can be used to modify an array of matrices.

Notes

glUniform1i and glUniform1iv are the only two functions that may be used to load uniform variables defined as sampler types. Loading samplers with any other function will result in a GL_INVALID_OPERATION error.
If count is greater than 1 and the indicated uniform variable is not an array, a GL_INVALID_OPERATION error is generated and the specified uniform variable will remain unchanged.
Other than the preceding exceptions, if the type and size of the uniform variable as defined in the shader do not match the type and size specified in the name of the command used to load its value, a GL_INVALID_OPERATION error will be generated and the specified uniform variable will remain unchanged.
If location is a value other than -1 and it does not represent a valid uniform variable location in the current program object, an error will be generated, and no changes will be made to the uniform variable storage of the current program object. If location is equal to -1, the data passed in will be silently ignored and the specified uniform variable will not be changed.

Errors

GL_INVALID_OPERATION is generated if there is no current program object.
GL_INVALID_OPERATION is generated if the size of the uniform variable declared in the shader does not match the size indicated by the glUniform command.
GL_INVALID_OPERATION is generated if one of the signed or unsigned integer variants of this function is used to load a uniform variable of type
float
,
vec2
,
vec3
,
vec4
, or an array of these, or if one of the floating-point variants of this function is used to load a uniform variable of type
int
,
ivec2
,
ivec3
,
ivec4
,
unsigned int
,
uvec2
,
uvec3
,
uvec4
, or an array of these.
GL_INVALID_OPERATION is generated if one of the signed integer variants of this function is used to load a uniform variable of type
unsigned int
,
uvec2
,
uvec3
,
uvec4
, or an array of these.
GL_INVALID_OPERATION is generated if one of the unsigned integer variants of this function is used to load a uniform variable of type
int
,
ivec2
,
ivec3
,
ivec4
, or an array of these.
GL_INVALID_OPERATION is generated if location is an invalid uniform location for the current program object and location is not equal to -1.
GL_INVALID_VALUE is generated if count is less than 0.
GL_INVALID_OPERATION is generated if count is greater than 1 and the indicated uniform variable is not an array variable.
GL_INVALID_OPERATION is generated if a sampler is loaded using a command other than glUniform1i and glUniform1iv .

Associated Gets

glGet with the argument GL_CURRENT_PROGRAM
glGetActiveUniform with the handle of a program object and the index of an active uniform variable
glGetUniform with the handle of a program object and the location of a uniform variable
glGetUniformLocation with the handle of a program object and the name of a uniform variable

Version Support

glUniform1f
glUniform1fv
glUniform1i
glUniform1iv
glUniform1ui
glUniform1uiv
glUniform2f
glUniform2fv
glUniform2i
glUniform2iv
glUniform2ui
glUniform2uiv
glUniform3f
glUniform3fv
glUniform3i
glUniform3iv
glUniform3ui
glUniform3uiv
glUniform4f
glUniform4fv
glUniform4i
glUniform4iv
glUniform4ui
glUniform4uiv
glUniformMatrix2fv
glUniformMatrix2x3fv
glUniformMatrix2x4fv
glUniformMatrix3fv
glUniformMatrix3x2fv
glUniformMatrix3x4fv
glUniformMatrix4fv
glUniformMatrix4x2fv
glUniformMatrix4x3fv

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. .

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.

glUniform1f
OpenGLContext tests/shader_3.py Lines: 155
OpenGLContext tests/shader_6.py Lines: 288
OpenGLContext tests/shader_4.py Lines: 121
OpenGLContext tests/shader_11.py Lines: 284, 295
OpenGLContext tests/shader_7.py Lines: 316
OpenGLContext tests/shader_9.py Lines: 366
OpenGLContext tests/shader_10.py Lines: 313
OpenGLContext tests/shader_8.py Lines: 233
OpenGLContext tests/shader_4_subset.py Lines: 59
{LGPL} PyMT pymt/graphx/shader.py Lines: 11, 62
Visvis core/shaders.py Lines: 485
glUniform1i
OpenGLContext OpenGLContext/scenegraph/shaders.py Lines: 223, 237
OpenGLContext tests/pygame_textureatlas.py Lines: 132
OpenGLContext tests/shader_11.py Lines: 267
{LGPL} PyMT pymt/graphx/shader.py Lines: 10, 66
Visvis core/shaders.py Lines: 517
{GPL3} OpenGL-Programmable 05-shader.py Lines: 104, 254, 258
{GPL3} OpenGL-Programmable 07-attrib.py Lines: 121, 273, 277
{GPL3} OpenGL-Programmable 09-gles2.py Lines: 139, 316, 320
{GPL3} OpenGL-Programmable 06-perpixel.py Lines: 112, 262, 266
{GPL3} OpenGL-Programmable 10-gl3.2core.py Lines: 147, 326, 330
{GPL3} OpenGL-Programmable 08-pbo.py Lines: 121, 295, 299
glUniform2f
Visvis core/shaders.py Lines: 487
glUniform2i
Visvis core/shaders.py Lines: 519
glUniform3f
OpenGLContext tests/shader_6.py Lines: 278
OpenGLContext tests/pygame_textureatlas.py Lines: 133
OpenGLContext tests/shader_11.py Lines: 293
OpenGLContext tests/shader_7.py Lines: 314
OpenGLContext tests/shader_5.py Lines: 299
OpenGLContext tests/shader_9.py Lines: 364
OpenGLContext tests/shader_10.py Lines: 311
OpenGLContext tests/shader_8.py Lines: 231
Visvis core/shaders.py Lines: 489
glUniform3fv
OpenGLContext tests/shaders.py Lines: 27
glUniform3i
Visvis core/shaders.py Lines: 521
glUniform4f
OpenGLContext tests/shader_3.py Lines: 156
OpenGLContext tests/shader_6.py Lines: 271, 272, 273, 277, 280, 281, 287
OpenGLContext tests/shader_11.py Lines: 291
OpenGLContext tests/shader_7.py Lines: 312
OpenGLContext tests/shader_5.py Lines: 294, 297, 298, 301, 302
OpenGLContext tests/shader_9.py Lines: 362
OpenGLContext tests/shader_10.py Lines: 309
OpenGLContext tests/shader_8.py Lines: 229
OpenGLContext tests/shader_4_subset.py Lines: 60
Visvis core/shaders.py Lines: 491
{GPL3} OpenGL-Programmable 09-gles2.py Lines: 389
{GPL3} OpenGL-Programmable 10-gl3.2core.py Lines: 399
glUniform4fv
OpenGLContext tests/shader_11.py Lines: 274, 286
OpenGLContext tests/shader_7.py Lines: 300
OpenGLContext tests/shader_9.py Lines: 353
OpenGLContext tests/shader_10.py Lines: 300
OpenGLContext tests/shader_8.py Lines: 220
glUniform4i
Visvis core/shaders.py Lines: 523
glUniformMatrix3fv
{GPL3} OpenGL-Programmable 09-gles2.py Lines: 240
{GPL3} OpenGL-Programmable 10-gl3.2core.py Lines: 250
glUniformMatrix4fv
{GPL3} OpenGL-Programmable 09-gles2.py Lines: 176, 236, 287
{GPL3} OpenGL-Programmable 10-gl3.2core.py Lines: 184, 246, 297