Add flythrough mode

[kduske]

Hit m to toggle, then use the cursor keys (or whatever the user set up) to move the camera and the mouse to look around.

• Don't react to movement keys when app is not focused
• Allow customization of movement keys

[necros0]

Editing should still work in this mode, right?

[kduske]

I don't see how it could, though because the mouse is hard-wired to changing the view direction. How would we handle the cursor in this mode, anyway?

[necros0]

I've played some games like Myst 4 where you could either play with the mouse unlocked from the view (and so you see a cursor move around the screen and you can click on objects) or while the mouse is locked, so your cursor is the center of the screen.
I imagine in flythrough mode, if you clicked, the click ray would just come from the center of the viewport (you'd need to draw some kind of crosshair during flythrough mode of course).

[kduske]

Okay, I we can play around with this and see if it works. I know that the Sauerbraten editor works like this all the time.

[kduske]

Don't react to WASD keys if the app isn't focused.

[kduske]

Allow customization of movement keys

[kduske]

Done, but it's less powerful than in Radiant (I can't grab the mouse input in wxWidgets).