XmbDrawImageString(), XwcDrawImageString() - draw image text using a single font set
void XmbDrawImageString (Display *display, Drawable d,
XFontSet font_set, GC gc, int x,
int y, char *string, int num_bytes)
void XwcDrawImageString (Display *display, Drawable d,
XFontSet font_set, GC gc, int x,
int y, wchar_t *string, int num_wchars)
XmbDrawImageString(3) and XwcDrawImageString(3) fill a destination rectangle with the background pixel defined in the GC and then paint the text with the foreground pixel. The filled rectangle is the rectangle returned to overall_logical_return by XmbTextExtents(3) or XwcTextExtents(3) for the same text and XFontSet.
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