ProgramGetUniformInfo Method

public ProgramUniformInfo GetUniformInfo(
	int index
)

Public Function GetUniformInfo ( 
	index As Integer
) As ProgramUniformInfo

public:
ProgramUniformInfo GetUniformInfo(
	int index
)

member GetUniformInfo : 
        index : int -> ProgramUniformInfo 

Parameters

index

Type: SystemInt32
The index of the uniform variable to be queried.

Return Value

Shaders may use either built-in uniform variables, user-defined uniform variables, or both. Built-in uniform variables have a prefix of "gl_" and reference existing OpenGL state or values derived from such state (e.g., gl_DepthRange). User-defined uniform variables have arbitrary names and obtain their values from the application through calls to SetValue(Single). A uniform variable (either built-in or user-defined) is considered active if it is determined during the link operation that it may be accessed during program execution. Therefore, program should have previously been linked by calling Link, but it is not necessary for it to have been linked successfully.

Only one active uniform variable will be reported for a uniform array.

Uniform variables that are declared as structures or arrays of structures will not be returned directly by this function. Instead, each of these uniform variables will be reduced to its fundamental components containing the "." and "[]" operators such that each of the names is valid as an argument to Uniform. Each of these reduced uniform variables is counted as one active uniform variable and is assigned an index. A valid name cannot be a structure, an array of structures, or a subcomponent of a vector or matrix.

Uniform variables other than arrays will have a Size of 1. Structures and arrays of structures will be reduced as described earlier, such that each of the names returned will be a data type in the earlier list. If this reduction results in an array, the size returned will be as described for uniform arrays; otherwise, the size returned will be 1.

The list of active uniform variables may include both built-in uniform variables (which begin with the prefix "gl_") as well as user-defined uniform variable names.

This function will return as much information as it can about the specified active uniform variable. If no information is available, the returned name will be an empty string. This situation could occur if this function is called after a link operation that failed.

OpenGL API: glGetActiveUniform

Reference