XmbDrawString(), XwcDrawString() - draw text using a single font set
void XmbDrawString (Display *display, Drawable d,
XFontSet font_set, GC gc, int x,
int y, char *string, int num_bytes)
void XwcDrawString (Display *display, Drawable d,
XFontSet font_set, GC gc, int x,
int y, wchar_t *string, int num_wchars)
XmbDrawString(3) and XwcDrawString(3) draw the specified text with the foreground pixel. When the XFontSet has missing charsets, each unavailable character is drawn with the default string returned by XCreateFontSet(3). The behavior for an invalid codepoint is undefined.
Xlib