How to set cursor shape using clx

Actually it's just the same as using xlib.

1. open a font named "cursor", it's a collection of different cursor shapes.

2. create a cursor object which can be used in somewhere like :cursor of window or grab-pointer.

example:

(defun create-cursor (char)
  (let ((cursor-font (xlib:open-font *display* "cursor"))
        (black (xlib:make-color :red 0.0 :green 0.0 :blue 0.0))
        (white (xlib:make-color :red 1.0 :green 1.0 :blue 1.0)))
    (xlib:create-glyph-cursor :source-font cursor-font
                              :source-char char
                              :mask-font cursor-font
                              :mask-char (1+ char)
                              :background black
                              :foreground white)))

(defvar *cursor* (create-cursor 68))

(setf (xlib:window-cursor screen-root) *cursor)

the effect is to make the default cursor shape an arrow (indicated by 68).

the char argument of create-cursor indicated the shape, which can be revealed as the screenshot below by running "xfd -fn cursor" in shell.