Updated physics demo

Over the past couple weeks I’ve been poking at the physics code. When I started, it was some of the gnarliest looking spaghetti I’d ever seen. I like to think it’s a bit cleaner now, and I’ve addressed some movement issues that have always bothered be with *Quake2*.

* Improved stair jumping; players never get stopped dead in their tracks or shot out sideways from strafe jumping up stairs.
* New soft velocity clamp and small air friction prevents players from attaining absurdly high horizontal velocities from strafe jumping.
* Note that horizontal jump pads still work as expected, allowing the player to be explicitly pushed at high velocities.
* Fixed “water skiing” movement where players can basically skate across the surface of water.
* Improved water entry and exit logic and control.
* Improved ladder detection.
* Increased air acceleration for low-speed jumps, allowing players to negotiate jumping around corners and things.
* Improved ground detection logic, allowing for triple jumps and fast ramp jumps previously not possible.

Here’s a YouTube video showing off some of these features:

You can find the high-quality version of the video here: http://www.youtube.com/watch?v=a1W9S-T5mVI