* `App.mousemoved(x,y, dx,dy, is_touch)` -- called any time the mouse moves.
  (Based on [LÖVE](https://love2d.org/wiki/love.mousemoved).)

* `App.wheelmoved(dx,dy)` -- called when you use the scroll wheel on a mouse
  that has it. Provides in `dx` and `dy` an indication of how fast the wheel
  is being scrolled. Positive values for `dx` indicate movement to the right.
  Positive values for `dy` indicate upward movement.
  (Based on [LÖVE](https://love2d.org/wiki/love.wheelmoved).)
* `App.mousefocus(in_focus)` -- called when the mouse pointer moves on or off
  the app window.
  (Based on [LÖVE](https://love2d.org/wiki/love.mousefocus).)