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