Add more mouse sensitivity options for low sensitivity players

[Calinou]

The mouse sensitivity value of 1 is too high on my system (Logitech G903, highest DPI profile for low input lag), while 0 makes mouse input completely ignored. From my guesstimate, I'd need to use a value between 0.2 and 0.5 to get something that feels comparable to other source ports I use (and other FPS games I play in general).

Could more values be added for fine adjustments, such as dividing the effective sensitivity by 10 and making the slider display values from 0 to 200? This will break existing configurations though, so an upgrade path may be needed.

See odamex/odamex#452 where I contributed a similar feature for Odamex.

[databoose]

Contrary to popular belief most wireless mice actually have decent latency when compared with wired, of course wired is always better, but we're talking about 8-9ms response time, for reference, if you have a 144hz monitor you will get a new frame every 7 milliseconds.

Most CS/overwatch pros actually use lower than normal DPI levels, around ~800, increasing your DPI that high might actually decrease your accuracy and overall performance in gaming.

https://www.rtings.com/mouse/tests/control/latency

It would be a good feature to have decimal point sensitivity, however i don't see this as an issue inherent to crispy doom.

[RamonUnch]

I guess an additional sensitivity divisor could be added. This could also apply to chocolate-doom. It would add a setting in chocolate/crispy-doom.cfg and would not hurt any existing config.
Maybe even simpler the divisor that is hard-coded to 10 in g_game.c:G_Responder(), could be set as a config variable.

in chocolate-doom:

      case ev_mouse: 
	SetMouseButtons(ev->data1);
	mousex = ev->data2*(mouseSensitivity+5)/10; 
	mousey = ev->data3*(mouseSensitivity+5)/10; 
	return true;    // eat events 

could be turned into

      case ev_mouse: 
	SetMouseButtons(ev->data1);
	mousex = ev->data2 * (mouseSensitivity + mouse_div/2) / mouse_div; 
	mousey = ev->data3 * (mouseSensitivity + mouse_div/2) / mouse_div; 
	return true;    // eat events 

I tried this code with mouse_div=100 in chocolate-doom and it seems fine with the highest dpi setting of my mouse.

In crispy-doom the code is slightly different because it separates x and y axis.

[suprk03]

It seems like capping the framerate at different values affects the mouse sensitivity a lot in weird ways, it would also be nice if this was fixed.