CHECKGLERR -- .cpp

namespace DGLUT
{
//==================================================================
void CheckGLErr( const char *pFileName, int line )
{
    GLenum err = glGetError();
    while (err != GL_NO_ERROR)
    {
        const char *pErr = NULL;

        switch (err)
        {
        case GL_NO_ERROR: pErr = "GL_NO_ERROR"; break;
        case GL_INVALID_ENUM: pErr = "GL_INVALID_ENUM"; break;
        case GL_INVALID_VALUE: pErr = "GL_INVALID_VALUE"; break;
        case GL_INVALID_OPERATION: pErr = "GL_INVALID_OPERATION"; break;
        case GL_OUT_OF_MEMORY: pErr = "GL_OUT_OF_MEMORY"; break;
        default:
            break;
        }

        if ( pErr ){
            DPRINT( "GL error: %s at %s : %i", pErr, pFileName, line );
        } else {
            DPRINT( "Unknown error: %d 0x%x at %s : %i", err, err, pFileName, line );
        }

        //DASSERT( 0 );

        err = glGetError();
    }
}

}

CHECKGLERR -- .hpp

namespace DGLUT
{
void CheckGLErr( const char *pFileName, int line );
}

//==================================================================
#if defined(DEBUG) || defined(_DEBUG)
# define CHECKGLERR DGLUT::CheckGLErr(__FILE__,__LINE__)
#else
# define CHECKGLERR
#endif