Your program works here. My guess is you have another modifier active, such as NumLock. GrabKey only works on the exact modifier mask. For example here is some (GPL) code from metacity window manager /* Grab/ungrab, ignoring all annoying modifiers like NumLock etc. */ static void meta_change_keygrab (MetaDisplay *display, Window xwindow, gboolean grab, int keysym, … Read more
No. This is why most UI frameworks (Gtk, KDE, etc) use custom main loops to be able to listen for more event sources. Internally, XNextEvent uses a socket, so it calls select() to know when input is available. Call ConnectionNumber(display) to get the file descriptor that you need to pass select() That allows you to … Read more
You can make things a lot easier than the Gift-Wrapping Algorithm… that’s a good answer when you have a set of points w/o any particular boundary and need to find the convex hull. In contrast, consider the case where the polygon is not self-intersecting, and it consists of a set of points in a list … Read more