Today:
	Controls and moving
	Inheritance and types of objects
		So we have have different behaviour

A note again on globals:
	We have one keyboard, one screen, one player, one mouse, etc.
		On a networked game, the other players need a game object to represent them
	Unless we make a split-screen version for consoles...
	We'll carefully label our position and key status related globals
		Maybe an object would be a nice way to organize them!

Controls and moving first:
	It's getting hard to deal with static camera angle!
	Position:  Need to maintain where we are
		A vec3 would suffice
	Direction:  Need to know where we're facing
		A float with our current heading would work
	Elevation:  How high/low are we looking?
		A float will work again
	But this isn't what LookAt wants
		It needs a point we're looking at
		We can compute that from position, direction, and elevation

Mouse control:
	glfwSetCursorPosCallback(window, a function to call)
	The function should take the window, and x position, and a y position
		x and y position are double-precision floating point
	Even if the cursor is invisible, it has a position
	We care how much it moved, not where it is
	General plan:  Look at how much it moved, then put it back in the center
	glfwSetCursorPos can set the position
	Make sure we can't bend too far backwards

Keyboard control:
	glfwSetKeyCallback(window, a function to call)
	The function takes (window, key, scancode, action, mods) (last 4 are ints)
	key is a key constant, like GLFW_KEY_F3 or GLFW_KEY_W
	action is 0 or 1 (or maybe 2)
	mods indicates control, shift, etc
	We don't really need the scancode
	
Smooth movement with keys for forward/back/strafe:
	While the button is pressed, keep moving
	So we have to track status of the keys and move periodically
	Might need an engine management thread
		Something not affected by a single object being really slow

While we're doing callbacks:
	Could we have a callback for resize?
	glfwSetFrameBufferCallback(window, function to call)
	resize function takes window, width, height
	Call glViewport afterward

If we get this far (probably won't):
	An object-oriented heirarchy