status.i4.v = read_graphic_font(file_name.i1a.r, char_height.i4.r,
					char_width.i4.r, num_chars.i4.r

	This routine will read a graphic font file from disk.  These files
	can be loaded to act as the default character set for text in a
	graphics window by calling lx_load_font.  Font files can be edited
	via the the 'Graphic Font Editor' (D78) application.

	file_name	font file root name (up to FONT_MAX_FILE_LEN characters)
	char_height	individual character height in logical pixels
	char_width	individual character width in logical pixels
	num_chars	number of characters defined for this font
			(actual number of characters is one greater
			 than this due to presence of default character)
	[present_chars]	map of which characters are defined for this font
			(There are FONT_MAX_CHAR entries in this table
			 with a value of TRUE indicating the presence of
			 the corresponding ASCII character in the data.)
	[char_data]	actual character data (data is stored in column
			major format with the default character first
			followed by ASCII character 0, etc)

	This function returns ACNET status values as follows:

	OK			success
	CBS_INVNAME		file name is too int or too short
	CBS_INVTYP		file specified is not a graphic font file
	FSHARE_xxx		error opening file

	This function requires the following include files:

	cnsparam_h, cbslib_h, acnet_errors_h

	Related functions:

	save_graphic_font_c, lx_load_font, fntchr(_c), lxchar(_c),
	lxfont(_c), lxstring_c, lx_colored_string_c