Name

cgSetParameterValue - set the value of any numeric parameter

Synopsis

#include <Cg/cg.h>

/* TYPE is int, float or double */

void cgSetParameterValue{ifd}{rc}( CGparameter param,
                                   int nelements,
                                   const TYPE * v );

Parameters

param

The program parameter whose value will be set.

nelements

The number of elements in array v.

v

Source buffer from which the parameter values will be read.

Return Values

None.

Description

cgSetParameterValue allows the application to set the value of any numeric parameter or parameter array.

The given parameter must be a scalar, vector, matrix, or a (possibly multidimensional) array of scalars, vectors, or matrices.

There are versions of each function that take int, float or double values signified by the i, f or d in the function name.

There are versions of each function that will cause any matrices referenced by param to be initialized in either row-major or column-major order, as signified by the r or c in the function name.

For example, cgSetParameterValueic sets the given parameter using the supplied array of integer data, and initializes matrices in column-major order.

If v is smaller than the total number of values in the given source parameter, CG_NOT_ENOUGH_DATA_ERROR is generated.

The total number of values in a parameter, ntotal, may be computed as follow:

int nrows = cgGetParameterRows(param);
int ncols = cgGetParameterColumns(param);
int asize = cgGetArrayTotalSize(param);
int ntotal = nrows*ncols;
if (asize > 0) ntotal *= asize;

Note: Previous releases of Cg allowed you to store more values in a parameter than indicated by the parameter's type. For example, one could use cgGLSetParameter4f to store four values into a parameter of type CG_FLOAT (not CG_FLOAT4). All four values could later be retrieved using a get call which requested more than one value. However, this feature conflicts with the GLSL approach and also leads to issues with parameters mapped into BUFFERS. Therefore, beginning with Cg 2.0 any components beyond the number indicated by the parameter type are ignored.

Examples

to-be-written

Errors

CG_INVALID_PARAM_HANDLE_ERROR is generated if param is not a valid parameter.

CG_INVALID_PARAMETER_ERROR is generated if param is a varying input to a fragment program.

CG_INVALID_POINTER_ERROR is generated if v is NULL.

CG_NOT_ENOUGH_DATA_ERROR is generated if nelements is less than the total size of param.

CG_NON_NUMERIC_PARAMETER_ERROR is generated if param is of a non-numeric type.

History

The cgSetParameterValue functions were introduced in Cg 1.4.

See Also

cgGetParameterRows, cgGetParameterColumns, cgGetArrayTotalSize, cgGetParameterValue