15.5.815 xsetaction

xsetaction [, action, window]

[x11] Sets the copy action associated with the window. window defaults to !window, action to 1. Choose what to replace the destination with by selecting action from:

0. src
1. src xor dst
2. not(src) xor dst
3. 0
4. 1
5. dst
6. not(dst)
7. src and dst
8. src and not(dst)
9. not(src) and dst
10. src or dst
11. src or not(dst)
12. not(src) or dst
13. not(src) or not(dst)
14. not(src) and not(dst)
15. not(src)

Note that actions 1 and 2 are reversible. These are suitable for display of sprites: objects that change the image but may be removed without a trace by drawing them again. i use them for simultaneous display of multiple pseudo-cursors.

See also: xtv, !window