cgGetProgramOutput
Keywords: cgGetProgramOutput, NVIDIA, NVIDIA Cg Toolkit, Cg Toolkit, Shader, Shader Programming, GPU Shader Programming, GPU Program

> ## Name

> cgGetProgramOutput - get the program's output

> ## Synopsis

>     #include <Cg/cg.h>

>     CGenum cgGetProgramOutput( CGprogram program );

> ## Parameters

> program
>   A program handle.

> ## Return Values

> Returns a program output enumerant. If the program is a vertex or fragment program, it returns CG_VERTEX or CG_FRAGMENT, respectively. For geometry programs the output is one of: CG_POINT_OUT, CG_LINE_OUT, or CG_TRIANGLE_OUT. For tessellation control programs the output is CG_PATCH.

> Returns CG_UNKNOWN if the output is unknown.

> ## Description

> cgGetProgramOutput returns the program output enumerant.

> For geometry programs, an input must be specified but not an output because of implicit output defaults. For example, if either "TRIANGLE" or "TRIANGLE_ADJ" is specified as an input without an explicit output in the shader source, then cgGetProgramOutput will return CG_TRIANGLE_OUT.

> ## Examples

>     void printProgramOutput(CGprogram program)
>     {
>       char * output = NULL;
>       switch(cgGetProgramOutput(program))
>       {
>         case CG_VERTEX:
>             output = "vertex";
>             break;
>         case CG_FRAGMENT:
>             output = "fragment";
>             break;
>         case CG_POINT_OUT:
>             output = "point";
>             break;
>         case CG_LINE_OUT:
>             output = "line";
>             break;
>         case CG_TRIANGLE_OUT:
>             output = "triangle";
>             break;
>         case CG_PATCH:
>             output = "patch";
>             break;
>         default:
>             output = "unknown";
>             break;
>       }
>       printf("Program outputs %s.\n", output);
>     }

> ## Errors

> CG_INVALID_PROGRAM_HANDLE_ERROR is generated if program is not a valid program handle.

> ## History

> cgGetProgramOutput was introduced in Cg 2.0.

> ## See Also

> cgGetProgramInput