glGetActiveUniformsiv : PyOpenGL 3.1.4 GL Man Pages

Returns information about several active uniform variables for the specified program object

Signature

glGetActiveUniformsiv( GLuint ( program ) , GLsizei ( uniformCount ) , const GLuint *( uniformIndices ) , GLenum ( pname ) , GLint *( params ) )-> void

glGetActiveUniform( program , index , bufSize , length , size , type , name )

Retrieve the name, size and type of the uniform of the index in the program
    
    program -- specifies the program to be queried
    index -- index of the uniform to be queried 
    
    Following parameters are optional:
    
    bufSize -- determines the size of the buffer (limits number of bytes written),
               if not provided, will be GL_OBJECT_ACTIVE_UNIFORM_MAX_LENGTH
    length -- pointer-to-GLsizei that will hold the resulting length of the name
    size -- pointer-to-GLint that will hold the size of the attribute
    type -- pointer-to-GLenum that will hold the type constant of the attribute
    name -- pointer-to-GLchar that will hold the (null-terminated) name string
    
    returns (bytes) name, (int)size, (enum)type

glGetActiveUniformsiv( program , uniformCount , uniformIndices , pname , params )

Parameters

Variables	Description
program	Specifies the program object to be queried.
uniformCount	Specifies both the number of elements in the array of indices uniformIndices and the number of parameters written to params upon successful return.
uniformIndices	Specifies the address of an array of uniformCount integers containing the indices of uniforms within program whose parameter pname should be queried.
pname	Specifies the property of each uniform in uniformIndices that should be written into the corresponding element of params .
params	Specifies the address of an array of uniformCount integers which are to receive the value of pname for each uniform in uniformIndices .

Description

glGetActiveUniformsiv queries the value of the parameter named pname for each of the uniforms within program whose indices are specified in the array of uniformCount unsigned integers uniformIndices . Upon success, the value of the parameter for each uniform is written into the corresponding entry in the array whose address is given in params . If an error is generated, nothing is written into params .

If pname is GL_UNIFORM_TYPE , then an array identifying the types of uniforms specified by the corresponding array of uniformIndices is returned. The returned types can be any of the values from the following table:

Returned Symbolic Contant	Shader Uniform Type
GL_FLOAT	float
GL_FLOAT_VEC2	vec2
GL_FLOAT_VEC3	vec3
GL_FLOAT_VEC4	vec4
GL_DOUBLE	double
GL_DOUBLE_VEC2	dvec2
GL_DOUBLE_VEC3	dvec3
GL_DOUBLE_VEC4	dvec4
GL_INT	int
GL_INT_VEC2	ivec2
GL_INT_VEC3	ivec3
GL_INT_VEC4	ivec4
GL_UNSIGNED_INT	unsigned int
GL_UNSIGNED_INT_VEC2	uvec2
GL_UNSIGNED_INT_VEC3	uvec3
GL_UNSIGNED_INT_VEC4	uvec4
GL_BOOL	bool
GL_BOOL_VEC2	bvec2
GL_BOOL_VEC3	bvec3
GL_BOOL_VEC4	bvec4
GL_FLOAT_MAT2	mat2
GL_FLOAT_MAT3	mat3
GL_FLOAT_MAT4	mat4
GL_FLOAT_MAT2x3	mat2x3
GL_FLOAT_MAT2x4	mat2x4
GL_FLOAT_MAT3x2	mat3x2
GL_FLOAT_MAT3x4	mat3x4
GL_FLOAT_MAT4x2	mat4x2
GL_FLOAT_MAT4x3	mat4x3
GL_DOUBLE_MAT2	dmat2
GL_DOUBLE_MAT3	dmat3
GL_DOUBLE_MAT4	dmat4
GL_DOUBLE_MAT2x3	dmat2x3
GL_DOUBLE_MAT2x4	dmat2x4
GL_DOUBLE_MAT3x2	dmat3x2
GL_DOUBLE_MAT3x4	dmat3x4
GL_DOUBLE_MAT4x2	dmat4x2
GL_DOUBLE_MAT4x3	dmat4x3
GL_SAMPLER_1D	sampler1D
GL_SAMPLER_2D	sampler2D
GL_SAMPLER_3D	sampler3D
GL_SAMPLER_CUBE	samplerCube
GL_SAMPLER_1D_SHADOW	sampler1DShadow
GL_SAMPLER_2D_SHADOW	sampler2DShadow
GL_SAMPLER_1D_ARRAY	sampler1DArray
GL_SAMPLER_2D_ARRAY	sampler2DArray
GL_SAMPLER_1D_ARRAY_SHADOW	sampler1DArrayShadow
GL_SAMPLER_2D_ARRAY_SHADOW	sampler2DArrayShadow
GL_SAMPLER_2D_MULTISAMPLE	sampler2DMS
GL_SAMPLER_2D_MULTISAMPLE_ARRAY	sampler2DMSArray
GL_SAMPLER_CUBE_SHADOW	samplerCubeShadow
GL_SAMPLER_BUFFER	samplerBuffer
GL_SAMPLER_2D_RECT	sampler2DRect
GL_SAMPLER_2D_RECT_SHADOW	sampler2DRectShadow
GL_INT_SAMPLER_1D	isampler1D
GL_INT_SAMPLER_2D	isampler2D
GL_INT_SAMPLER_3D	isampler3D
GL_INT_SAMPLER_CUBE	isamplerCube
GL_INT_SAMPLER_1D_ARRAY	isampler1DArray
GL_INT_SAMPLER_2D_ARRAY	isampler2DArray
GL_INT_SAMPLER_2D_MULTISAMPLE	isampler2DMS
GL_INT_SAMPLER_2D_MULTISAMPLE_ARRAY	isampler2DMSArray
GL_INT_SAMPLER_BUFFER	isamplerBuffer
GL_INT_SAMPLER_2D_RECT	isampler2DRect
GL_UNSIGNED_INT_SAMPLER_1D	usampler1D
GL_UNSIGNED_INT_SAMPLER_2D	usampler2D
GL_UNSIGNED_INT_SAMPLER_3D	usampler3D
GL_UNSIGNED_INT_SAMPLER_CUBE	usamplerCube
GL_UNSIGNED_INT_SAMPLER_1D_ARRAY	usampler2DArray
GL_UNSIGNED_INT_SAMPLER_2D_ARRAY	usampler2DArray
GL_UNSIGNED_INT_SAMPLER_2D_MULTISAMPLE	usampler2DMS
GL_UNSIGNED_INT_SAMPLER_2D_MULTISAMPLE_ARRAY	usampler2DMSArray
GL_UNSIGNED_INT_SAMPLER_BUFFER	usamplerBuffer
GL_UNSIGNED_INT_SAMPLER_2D_RECT	usampler2DRect

If pname is GL_UNIFORM_SIZE , then an array identifying the size of the uniforms specified by the corresponding array of uniformIndices is returned. The sizes returned are in units of the type returned by a query of GL_UNIFORM_TYPE . For active uniforms that are arrays, the size is the number of active elements in the array; for all other uniforms, the size is one.

If pname is GL_UNIFORM_NAME_LENGTH , then an array identifying the length, including the terminating null character, of the uniform name strings specified by the corresponding array of uniformIndices is returned.

If pname is GL_UNIFORM_BLOCK_INDEX , then an array identifying the uniform block index of each of the uniforms specified by the corresponding array of uniformIndices is returned. The uniform block index of a uniform associated with the default uniform block is -1.

If pname is GL_UNIFORM_OFFSET , then an array of uniform buffer offsets is returned. For uniforms in a named uniform block, the returned value will be its offset, in basic machine units, relative to the beginning of the uniform block in the buffer object data store. For atomic counter uniforms, the returned value will be its offset relative to the beginning of its active atomic counter buffer. For all other uniforms, -1 will be returned.

If pname is GL_UNIFORM_ARRAY_STRIDE , then an array identifying the stride between elements of each of the uniforms specified by the corresponding array of uniformIndices is returned. For uniforms in named uniform blocks and for uniforms declared as atomic counters, the stride is the difference, in basic machine units, of consecutive elements in an array, or zero for uniforms not declared as an array. For all other uniforms, a stride of -1 will be returned.

If pname is GL_UNIFORM_MATRIX_STRIDE , then an array identifying the stride between columns of a column-major matrix or rows of a row-major matrix, in basic machine units, of each of the uniforms specified by the corresponding array of uniformIndices is returned. The matrix stride of a uniform associated with the default uniform block is -1. Note that this information only makes sense for uniforms that are matrices. For uniforms that are not matrices, but are declared in a named uniform block, a matrix stride of zero is returned.

If pname is GL_UNIFORM_IS_ROW_MAJOR , then an array identifying whether each of the uniforms specified by the corresponding array of uniformIndices is a row-major matrix or not is returned. A value of one indicates a row-major matrix, and a value of zero indicates a column-major matrix, a matrix in the default uniform block, or a non-matrix.

If pname is GL_UNIFORM_ATOMIC_COUNTER_BUFFER_INDEX , then an array identifying the active atomic counter buffer index of each of the uniforms specified by the corresponding array of uniformIndices is returned. For uniforms other than atomic counters, the returned buffer index is -1. The returned indices may be passed to glGetActiveAtomicCounterBufferiv to query the properties of the associated buffer, and not necessarily the binding point specified in the uniform declaration.

Notes

The double types, GL_DOUBLE , GL_DOUBLE_VEC2 , GL_DOUBLE_VEC3 , GL_DOUBLE_VEC4 , GL_DOUBLE_MAT2 , GL_DOUBLE_MAT3 , GL_DOUBLE_MAT4 , GL_DOUBLE_MAT2x3 , GL_DOUBLE_MAT2x4 , GL_DOUBLE_MAT3x2 , GL_DOUBLE_MAT3x4 , GL_DOUBLE_MAT4x2 , and GL_DOUBLE_MAT4x3 are only available if the GL version is 4.1 or higher.

GL_UNIFORM_ATOMIC_COUNTER_BUFFER_INDEX is only accepted by pname if the GL version is 4.2 or higher.

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_VALUE is generated if uniformCount is greater than or equal to the value of GL_ACTIVE_UNIFORMS for program .

GL_INVALID_ENUM is generated if pname is not an accepted token.

Associated Gets

glGet with argument GL_MAX_VERTEX_UNIFORM_COMPONENTS , GL_MAX_TESS_CONTROL_UNIFORM_COMPONENTS , GL_MAX_TESS_EVALUATION_UNIFORM_COMPONENTS , GL_MAX_GEOMETRY_UNIFORM_COMPONENTS , GL_MAX_FRAGMENT_UNIFORM_COMPONENTS , or GL_MAX_COMBINED_UNIFORM_COMPONENTS .

glGetProgram with argument GL_ACTIVE_UNIFORMS or GL_ACTIVE_UNIFORM_MAX_LENGTH .

glIsProgram

Version Support

glGetActiveUniformsiv

Copyright

2011-2014 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/