input		 There are three main types of mouse input; WM_MOUSEMOVE (or GetCursorPos), WM_INPUT, and DirectInput. The first method, WM_MOUSEMOVE/GetCursorPos, is mouse pointer input that goes through windows. The second, WM_INPUT (aka raw input), is raw data taken directly from the mouse at the lowest level possible. DirectInput is very similar to raw input, but it is only useful if you need to support joysticks/controllers.
 
 WM_INPUT is preferred over WM_MOUSEMOVE/GetCursorPos, as it gives you exact 1 to 1 sensitivity, and removes one of the major causes of negative acceleration. WM_MOUSEMOVE/GetCursorPos uses changes in the mouse pointer position to calculate mouse movement. The game locks the mouse pointer to the middle of the screen. When you move the mouse, the (hidden) pointer moves and the game calculates movement from the middle and then resets the pointer back to the middle. It does this every frame. If the game is busy and doesn't reset the pointer to the middle fast enough, a quick mouse movement can move the pointer right to the screen edge and it gets stuck at the edge. Any further movement past the edge is thrown away and you get negative acceleration.
 
 Here is simple way to test if your game uses WM_MOUSEMOVE/GetCursorPos for input:
 
 Set your windows sensitivity value to one much lower than normal (i.e. from 6/11 to 3/11)
 Open your game of choice
 If mouse movement is much slower than normal, your game is using WM_MOUSEMOVE/GetCursorPos
 If mouse movement is normal, your game is not using WM_MOUSEMOVE/GetCursorPos