glProgramUniform 3G
glProgramUniform glProgramUniform1f glProgramUniform2f glProgramUniform3f glProgramUniform4f glProgramUniform1i glProgramUniform2i glProgramUniform3i glProgramUniform4i glProgramUniform1ui glProgramUniform2ui glProgramUniform3ui glProgramUniform4ui glProgramUniform1fv glProgramUniform2fv glProgramUniform3fv glProgramUniform4fv glProgramUniform1iv glProgramUniform2iv glProgramUniform3iv glProgramUniform4iv glProgramUniform1uiv glProgramUniform2uiv glProgramUniform3uiv glProgramUniform4uiv glProgramUniformMatrix2fv glProgramUniformMatrix3fv glProgramUniformMatrix4fv glProgramUniformMatrix2x3fv glProgramUniformMatrix3x2fv glProgramUniformMatrix2x4fv glProgramUniformMatrix4x2fv glProgramUniformMatrix3x4fv glProgramUniformMatrix4x3fv Specify the value of a uniform variable for a specified program object

## C Specification

void `glProgramUniform1f` GLuint program GLint location GLfloat v0 void `glProgramUniform2f` GLuint program GLint location GLfloat v0 GLfloat v1 void `glProgramUniform3f` GLuint program GLint location GLfloat v0 GLfloat v1 GLfloat v2 void `glProgramUniform4f` GLuint program GLint location GLfloat v0 GLfloat v1 GLfloat v2 GLfloat v3 void `glProgramUniform1i` GLuint program GLint location GLint v0 void `glProgramUniform2i` GLuint program GLint location GLint v0 GLint v1 void `glProgramUniform3i` GLuint program GLint location GLint v0 GLint v1 GLint v2 void `glProgramUniform4i` GLuint program GLint location GLint v0 GLint v1 GLint v2 GLint v3 void `glProgramUniform1ui` GLuint program GLint location GLuint v0 void `glProgramUniform2ui` GLuint program GLint location GLint v0 GLuint v1 void `glProgramUniform3ui` GLuint program GLint location GLint v0 GLint v1 GLuint v2 void `glProgramUniform4ui` GLuint program GLint location GLint v0 GLint v1 GLint v2 GLuint v3

## Parameters

program

  Specifies the handle of the program containing the uniform variable to be modified.

location

  Specifies the location of the uniform variable to be modified.

v0, v1, v2, v3

  Specifies the new values to be used for the specified uniform variable.

## C Specification

void `glProgramUniform1fv` GLuint program GLint location GLsizei count const GLfloat *value void `glProgramUniform2fv` GLuint program GLint location GLsizei count const GLfloat *value void `glProgramUniform3fv` GLuint program GLint location GLsizei count const GLfloat *value void `glProgramUniform4fv` GLuint program GLint location GLsizei count const GLfloat *value void `glProgramUniform1iv` GLuint program GLint location GLsizei count const GLint *value void `glProgramUniform2iv` GLuint program GLint location GLsizei count const GLint *value void `glProgramUniform3iv` GLuint program GLint location GLsizei count const GLint *value void `glProgramUniform4iv` GLuint program GLint location GLsizei count const GLint *value void `glProgramUniform1uiv` GLuint program GLint location GLsizei count const GLuint *value void `glProgramUniform2uiv` GLuint program GLint location GLsizei count const GLuint *value void `glProgramUniform3uiv` GLuint program GLint location GLsizei count const GLuint *value void `glProgramUniform4uiv` GLuint program GLint location GLsizei count const GLuint *value

## Parameters

program

  Specifies the handle of the program containing the uniform variable to be modified.

location

  Specifies the location of the uniform value to be modified.

count

  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.

value

  Specifies a pointer to an array of count values that will be used to update the specified uniform variable.

## C Specification

void `glProgramUniformMatrix2fv` GLuint program GLint location GLsizei count GLboolean transpose const GLfloat *value void `glProgramUniformMatrix3fv` GLuint program GLint location GLsizei count GLboolean transpose const GLfloat *value void `glProgramUniformMatrix4fv` GLuint program GLint location GLsizei count GLboolean transpose const GLfloat *value void `glProgramUniformMatrix2x3fv` GLuint program GLint location GLsizei count GLboolean transpose const GLfloat *value void `glProgramUniformMatrix3x2fv` GLuint program GLint location GLsizei count GLboolean transpose const GLfloat *value void `glProgramUniformMatrix2x4fv` GLuint program GLint location GLsizei count GLboolean transpose const GLfloat *value void `glProgramUniformMatrix4x2fv` GLuint program GLint location GLsizei count GLboolean transpose const GLfloat *value void `glProgramUniformMatrix3x4fv` GLuint program GLint location GLsizei count GLboolean transpose const GLfloat *value void `glProgramUniformMatrix4x3fv` GLuint program GLint location GLsizei count GLboolean transpose const GLfloat *value

## Parameters

program

  Specifies the handle of the program containing the uniform variable to be modified.

location

  Specifies the location of the uniform value to be modified.

count

  Specifies the number of matrices that are to be modified. This should be 1 if the targeted uniform variable is not an array of matrices, and 1 or more if it is an array of matrices.

transpose

  Specifies whether to transpose the matrix as the values are loaded into the uniform variable.

value

  Specifies a pointer to an array of count values that will be used to update the specified uniform variable.

## Description

`glProgramUniform` 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. `glProgramUniform` operates on the program object specified by program.

The commands `glProgramUniform{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 `glProgramUniform` until the next successful link operation occurs on the program object, when they are once again initialized to 0.

The commands `glProgramUniform{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 `glProgramUniform{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., `glProgramUniform3f` or `glProgramUniform3fv` 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 `glProgramUniformMatrix{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

`glProgramUniform1i` and `glProgramUniform1iv` 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 within program, an error will be generated, and no changes will be made to the uniform variable storage of program. 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 program does not refer to a program object owned by the GL.

`GL_INVALID_OPERATION` is generated if the size of the uniform variable declared in the shader does not match the size indicated by the `glProgramUniform` 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 program 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 `glProgramUniform1i` and `glProgramUniform1iv`.

## Associated Gets

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

## See Also

glLinkProgram, glUseProgram

## Copyright

Copyright 2003-2005 3Dlabs Inc. Ltd. Copyright 2010 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/.