## Gamedev This Year

Furtual Rabbit was my first game in a year. It was revealing how out of practice I had gotten. It might be time to start doing more One Hour Game Jams. On the other hand, I got a lot of experience with computer graphics and simulation techniques which was my main focus during the academic year.

So what will I focus on this coming year? On the top of the backlog is getting some graphics research written up and sent to journals. Next up is improving my LibXOR library for #GameDev so that I can prepare for a 7DRL. And one last goal for good measure is creating a real-time ray tracer to go with my Unicornfish network rendering concept. For this blog post, I will talk about the latter two in a bit more detail.

The 7 Day Roguelike Challenge (7DRL.com) happens in early March. Roguelikes are inspired by the game Rogue. They often feature some combination of turn-based gameplay, grid-based environments, permadeath, and procedurally generated levels. What would mine look like? Topologically speaking, I want a procedurally generated overworld and fairly shallow levels with keyed off areas. I have some concepts in my head how they might play out, but I need to work on some prototypes first.

And finally, graphics wise I want to experiment with Realtime Ray Tracing and to that extent, I want to integrate it with my network rendering API Unicornfish. This means that I need to start decoupling it from the Fluxions Library. There is a lot of work to be done in that department, so I will need to spend some time charting out how the library works. There are a lot of TODOs on the current backlog, so this coming year will be quite busy, but perhaps I can drive two publications out of all that work.

## Furtual Rabbit Ludum Dare 44

The Ludum Dare 44 theme is “Your life is currency.” So I created a capitalist virtual pet game called Furtual Rabbit: A Defurred Income Game. The goal of the game is to raise an Angora Rabbit. You have to feed, water, brush, and clean to keep the quality of the rabbit fur high so that you can groom it and sell it. Not all rabbits live forever and poorly maintained ones die even faster.

## The BSDs and System V

NetBSD, OpenBSD, and FreeBSD. They are all fun. They are different than Linux. I am of course talking about the kernel rather than the GNU software that is typically available on all of them. The BSDs have a vintage feel about them. I like it.

I wish that it was easier to try System V or SVR4 rather. Because instead of the Berkeley line, it is from the AT&T line which was the basis for IRIX, the version of UNIX on SGI systems. I still have a fondness for the MIPS10000 Octane MXE workstation I had many years ago.

The only way to try System V nowadays is to use an OpenSolaris derived system. But I have to admit that I hated Sun systems when I was younger for no good reason. I think it was because the 3D graphics sucked and I do graphics! So, it left a sour taste. Though there is a Sun variant called Tribblex that looks like it could be interesting to try in a virtual machine.

Of course, the BSDs still feel like the best out feel out there. I want to set one up with a nice X11 desktop like MWM. And it would be nice if IBM and HP would release AIX and HP/UX as free software. And maybe SGI will release their source code for their X based desktop and life would be grand.

UNIX could become more available to the common folk. I was watching some classic Computer Chronicles about UNIX. In 1985, it was still crusty and untrustworthy. In 1989, their last chance to prove UNIX was worth using, all they could talk about was how you could use a menu and how there machines cost \$5000. Lol.

## FreeBSD Part 2

So I tried FreeBSD in VirtualBox. Step 2 was to try and install it on my Thinkpad. Unfortunately, I am having boot issues. Perhaps it was too many operating systems. I deleted everything but Windows 10 and then reinstalled Fedora 29. I may try again on my Intel NUC that I am currently using PopOS with. In the mean time, the Raspberry Pi 3 is getting a go at it. The wifi does not work, so it is tethered to my router so I can install X11. I used the image from the FreeBSD website. When I get everything installed, we’ll see how the experience is.

## Playing with FreeBSD 12

So my use case is run FreeBSD in VirtualBox in Windows. The first experiment ended up in failure, but not because I was using Windows, rather because I can’t get the X server to behave. So I will need to attempt this again. I will say that my goal is to do 3D graphics and game development.

However, I did discover some neat things I can use this OS for. For instance, I am rediscovering WindowMaker. I thought it was cool that the PlayStation 2 Linux Kit used it as the default window manager. I used it often in the 1990’s. It still looks good. But, it doesn’t work out of the box for any kind of real work.

There are several packages I am trying: redshift, compton, and xdg-user-dirs, xscreensaver. Anyways, here is my current pkg install command list.

pkg install bash tmux htop vim emacs w3m wget curl nano
pkg install xorg slim windowmaker enlightenment wmakerconf
pkg install redshift compton xdg-user-dirs xscreensaver xeyes
pkg install firefox gimp
pkg install ...

I will note that I find it ironic that it takes 1 gigabyte to do the first line which are supposed to be command line utilities! By using emacs-nox and vim-console, it goes down to 279 MiB instead. These are the dockapps I installed for WindowMaker.

pkg install wmcpuload wmclock wmnetload wmsystemtray wmtop wmmemload
pkg install inconsolata-ttf

The Xdefaults file needs to be updated so that xterm doesn’t look too small. I use the following settings:

*xterm*foreground: #cfcfcf
*xterm*background: #000000
*xterm*font: xft:Inconsolata:size=16

## C++ Vector and Matrix Library

I am working on an open source Vector and Matrix Library for C++ and TypeScript. I am calling it FluxionsGTE and FluxionsWebGTE, respectively.

// TypeScript
class Vector3 {
constructor(public x: number = 0, public y: number = 0, public z: number = 0) { }
}
// C++
template <class T>
class TVector3
{
public:
T x, y, z;

TVector3(T x = T(0), T y = T(0), T z = T(0)) { }
};

using Vector3f = TVector3<float>;

## Conversion between specular exponent, specular roughness, and specular glossiness

Ever need to convert between specular exponent, roughness, and glossiness? for the Blinn-Phong BRDF, these three values represent the same concept. Specular Exponent is the actual value used to compute the BRDF. Let’s call that variable $e$. The roughness $m$ and glossiness $g$ values are numbers between 0 and 1 and they are additive inverses of each other. In other words

$$g = 1 – m \, ,$$

$$m = 1 – g \, .$$

The exponent is given by

$$e = \frac{2}{m^2} – 2$$

or

$$e = \frac{2}{{(1 – g)}^2} – 2 \, .$$

The BRDF $f_r(\omega_i, \omega_g)$ is

$$f_r(\omega_i, \omega_o) = \pi \frac{F(\omega_i \cdot \omega_h) D(\omega_i) G_2(\omega_i \cdot \omega_g, \omega_o \cdot \omega_g)}{4 (\omega_i \cdot \omega_g) (\omega_o \cdot \omega_g)}$$

where Blinn-Phong $D(\omega_i)$ is given by

$$D_{\mathrm{Blinn-Phong}}(\omega_i, \omega_h, e) = \frac{e+2}{2\pi} (\omega_i \cdot \omega_h)^e$$

and the resulting specular illumination is given by
$$\mathbf{L}_o = f_r(\omega_i, \omega_o) \mathbf{L}_i (\omega_i) \mathbf{V}_i (\omega_i) (\omega_g \cdot \omega_i) \, .$$

## Commodore VIC 20 NTSC and PAL colour/color palettes

I’m posting this mostly so I can look at the colors any time I want.

NTSC

PAL