Suggestion for extending SIGWINCH

Currently it only indicates a change in window size, I expect the si_code value is also 0 for this signal. The extension will be for mouse input and the difference will be indicated by si_code being 1, to avoid issues with x11 vs wayland vs etc a custom structure should be pointed to in the si_addr parameter. I think the custom structure should look something like this:

struct ttymouse { uint button_mask; int x, y, wheel; };