XSetFont(display, gc, font)
      Display *display;
      GC gc;
      Font font;
| display | Specifies the connection to the X server. | 
| gc | Specifies the GC. | 
| font | Specifies the font. | 
| BadAlloc | The server failed to allocate the requested source or server memory. | 
| BadFont | A value for a font argument does not name a defined font (or, in some cases, GContext). | 
| BadGC | A value for a GContext argument does not name a defined GContext. |