id Game Engine Source Code

The first 3D first-person shooter (FPS) game is generally accepted to be Castle Wolfenstein 3D (1992). Written by id Software of Texas for the PC platform, this game led the game industry in a new and exciting direction.

First-person games are typically some of the most technologically challenging to build. They aim to provide their players with the illusion of being immersed in a detailed, hyperrealistic world. It is not surprising that many of the game industry’s big technological innovations arose out of the games in this genre. Some of the complexities in FPS style games often include managing binary space partitioning (BSP) trees, portal-based rendering systems, frustum cull (i.e., removing objects that the camera cannot "see" to improve rendering time), spatial subdivision data structures, dynamic lighting systems and more.

Outdoor FPS games use other kinds of rendering optimizations such as occlusion culling, or an offline sectorization of the game world with manual or automated specification of which target sectors are visible from each source sector.

Digging into this technology, you can find the source code to Quake I, II, III, Doom, Wolfenstein and more id based games are freely available. The original Quake engines are reasonably well architected and “clean” (although they are of course a bit outdated and written entirely in C). These code bases serve as great examples of how industrial-strength game engines are built. The full source code to several id games are available on github at https://github.com/id-Software

You can actually build the code using Microsoft Visual Studio and run the game under the debugger using the real game assets from the disk. This can be incredibly instructive. You can set break points, run the game, and then analyze how the engine actually works by stepping through the code.

For a nice overview of the FPS genre, see http://en.wikipedia.org/wiki/First-person_shooter

Prelude in E Minor - Chopin

Prelude in E Minor for Piano, Op. 28, No. 4 (1839), by Frederic Chopin

A quintessential miniature classical brood.  Dissonance and agitation abound in this prelude.  This is Dracula's or trampula's theme song.  Most of the long notes are accompanied by a different dissonant chord below; which causes a continued change in color as the singular long note in prominence is held above.  Small movements of the left hand cause a striking sentiment.  The espressivo - expected fast rhythm, sad melody, and acceleration are further filled with expectancy of resolve by brief pauses throughout the piece. Tension is finally released in the three solemn chords of the closing cadence. 

It's like an E-minor mine car ride, spiraling out of control sitting on questionable tracks.  The quickening 'dunk dunk' of the railroad ties assisting the acceleration of the duple meter into the depths of the unknown.  The miner finds himself trying to find the e-brake, but it is preluded.

Freddy was in a serious mood in writing this tune.  One cannot listen to the prelude without feeling the intensity of emotion behind the piece. It is short, dialing in at around 2 minutes, yet full of possibilities for interpretation.

Hagia Sophia

This looks like something straight out of a movie set.  Now that I know better, when I think of Istanbul, I will think of this place.  Originally built in the 6th century, the Hagia Sophia, formerly known as a Christian basilica, is now a museum.  As a side note, I would museum the heck out of this place.  Until recently, well, 1520 to be exact, it served as the largest cathedral in the world.  When you think of Byzantine architecture, think of this place.  As related to placing the style in time, it may be better referred to as, pre-Neo-Byzantine architecture.  It straddles the Bosphorus, one of the world's busiest waterways in northwestern Turkey.  If you were wondering, Bosphorus does not make up 1% of your total body weight like phosphorus does. Not to be confused with the Hagia Sophia Church, of Sofia, Bulgaria, construction was completed in only 5 years!  And everyone knows Bulgarians are lazy, so their Hagia was rumored to have taken just over 104 years to build.  Clearly, this would make the list of the world's greatest buildings.  It would fall right in line above the Portland Building.

The Firebird

The Firebird, Scene 2 (1910 version) by Igor Stravinsky (1882 - 1971).

Originally written to accompany a ballet by the same name. This roughly three minute piece is the final scene of the work. It repeats one melody over and over, creating contrast through changes of dynamics, tone color, and rhythm.  The most beautiful creation of music I have heard in the shortest duration - using repeated segments, increasing grandeur, and finally, leading to a brilliant concluding section.

The Firebird, in Slavic folklore, is known as a bringer of both blessings and doom to its captor.  The strings around duration 1:30, accent very softly, in a random chromatic aberration, almost out of key with the tonal center of the piece.  This seems to bring a taste of doom to the listener.  The strings quickly crescendo, a hard timpani hit is heard, and we are back into the main rich and expressive theme.

You can absorb the magical sense of the song, in a verse from A Winter's Journey, by Yakov Polonsky, which inspired The Firebird ballet:

And in my dreams I see myself on a wolf's back
Riding along a forest path
To do battle with a sorcerer-tsar
In that land where a princess sits under lock and key,
Pining behind massive walls.
There gardens surround a palace all of glass;
There Firebirds sing by night
And peck at golden fruit.

Reading into the work, we learn during this scene the hero triumphs and becomes engaged to a princess.  The slow triumph is heard.  A skillful crescendo creates spirit as instruments are added to the piece.  The melody is repeated at higher and higher pitches.  Use of dynamics ranging the entire gamut, from pianissimo to fortissimo, can be heard.  The repeated effect is further outlined by the timbre of each instrument.  A critical listener can hear English horns, oboes, french horns, harps, piccolos and more.  This tone color contributes to continuity; as it is easier to recognize the return of the melody when the same instruments repeat the main theme.

What an excellent piece of music.