wn_text_coord_to_virtual_c

	virtual_coord.r4.v = wn_text_coord_to_virtual_c(plane.i4.v,
							text_coord.i4.v)

	This routine converts a text coordinate into its corresponding
	virtual (screen) coordinate value.  The origin of the text
	coordinate system (0, 0) is in the upper left hand corner of
	the graphic window.

	plane		(WN_HORZ -> horizontal,
			 WN_VERT -> vertical)
	text_coord	text coordinate

	This function returns status values as follows:

	-1.0			conversion failed
	otherwise		virtual coordinate value

	This function requires the following include files:

	cbslib_h, acnet_errors_h

	Related functions:

	wn_view_text_format_c, wn_text_size(_c), wn_set_background_format_c,
	wn_set_background_size_c, wn_read_text_format, intro_graphics_windows

	C/C++ usage:

	int	plane = WN_HORZ;
	int	text_coord = 1;
	float	virtual_coord;

	virtual_coord = wn_text_coord_to_virtual_c(plane,text_coord);