doom3do

About

This is the archived source for the 3DO port of DOOM, written by Rebecca Ann Heineman. It uses the 3DO's cell engine to draw vertical wall strips as textured sprites, while floors and ceilings -- which the cell engine couldn't handle in 3D perspective -- are rendered in software. Music was licensed from an outside band and played back via a streaming-audio function rather than porting the original PC music driver, since there wasn't time to do so; the game was built on an early C version of the author's own Burgerlib library (Burgerlib 2), some of which is still present in the current Burgerlib 5.

History

Heineman was hired in August 1995 after being told an in-progress 3DO port of DOOM already existed and just needed polishing; in reality nothing usable had been built yet, and she completed the port essentially from scratch under a roughly ten-week deadline to hit a mid-October 1995 golden-master date, working out of her office almost non-stop.

Known issues & limitations

• graphics: Floors and ceilings use software rendering instead of the cell engine; vertical walls use cell engine rendering.
• graphics: Texture tearing was present when attempting to use the cell engine for floors and ceilings.
• memory: Memory leaks in the 3DO operating system required workarounds like separate executable apps for logo display.

Licensing & legal

• The README states DOOM's intellectual property belongs exclusively to Microsoft, and that anyone wanting to commercially re-release DOOM 3DO should contact Microsoft for a license; the source code itself is released for non-commercial use and study.

Additional notes

Quirk

Unused Electronic Arts logo art remains in the game's data from a planned EA distribution deal that fell through before release.

Quirk

To work around a 3DO OS memory-leak bug, the startup 3DO and Logicware logos were implemented as two separate small programs that could each be purged from memory after running.

Quirk

The 3DO's compiler-supplied string.h library had bugs, so the author wrote her own ANSI string functions in ARM 6 assembly.