NAME

cgGetParameterVariability - get a parameter's variability

SYNOPSIS

  #include <Cg/cg.h>

  CGenum cgGetParameterVariability( CGparameter param );

PARAMETERS

param

The program parameter.

RETURN VALUES

Returns the variability of param.

Returns CG_ERROR if an error occurs.

DESCRIPTION

cgGetParameterVariability allows the application to retrieve the variability of a parameter in a Cg program. This variability is necessary for the application to be able to supply the program's inputs and use the program's outputs.

cgGetParameterVariability will return one of the following variabilities:

CG_VARYING

A varying parameter is one whose value changes with each invocation of the program.

CG_UNIFORM

A uniform parameter is one whose value does not change with each invocation of a program, but whose value can change between groups of program invocations.

CG_LITERAL

A literal parameter is folded out at compile time. Making a uniform parameter literal with cgSetParameterVariability will often make a program more efficient at the expense of requiring a compile every time the value is set.

CG_CONSTANT

A constant parameter is never changed by the user. It's generated by the compiler by certain profiles that require immediate values to be placed in certain resource locations.

CG_MIXED

A structure parameter that contains parameters that differ in variability.

EXAMPLES

to-be-written

ERRORS

CG_INVALID_PARAM_HANDLE_ERROR is generated if param is not a valid parameter.

HISTORY

cgGetParameterVariability was introduced in Cg 1.1.

SEE ALSO

cgGetNamedParameter, cgGetNextParameter, cgGetParameterName, cgGetParameterType, cgGetParameterDirection, cgSetParameterVariability