rem: cerr << "PolygonMode: Point." << endl;
add: std::cerr << "PolygonMode: Point." << std::endl;
context: void key(unsigned char key, int x, int y){    switch ( key )    {        case 27:    osgExit(); exit(0);        case 'a':   glDisable( GL_LIGHTING );            cerr << "Lighting disabled." << endl;            break;        case 's':   glEnable( GL_LIGHTING );            cerr << "Lighting enabled." << endl;            break;        case 'z':   glPolygonMode( GL_FRONT_AND_BACK, GL_POINT);            cerr << "PolygonMode: Point." << endl;            break;        case 'x':   glPolygonMode( GL_FRONT_AND_BACK, GL_LINE);            cerr << "PolygonMode: Line." << endl;            break;        case 'c':   glPolygonMode( GL_FRONT_AND_BACK, GL_FILL);            cerr << "PolygonMode: Fill." << endl;            break;        case 'r':   cerr << "Sending ray through " << x << "," << y << endl;            {        Line l;            cam->calcViewRay( l, x, y, *vp );            cerr << "From " << l.getPosition() << ", dir " << l.getDirection() << endl;            }        break;        case 'd':   ract->setAutoFrustum( ! ract->getAutoFrustum() );            cerr << "autoFrustum: " << (ract->getAutoFrustum()?"true":"false")             << endl;            break;        case 'f':   ract->setVolumeDrawing( ! ract->getVolumeDrawing() );            cerr << "VolumeDrawing: " << (ract->getVolumeDrawing()?"true":"false")             << endl;            break;    }}