HALFLIFE_DC <img src="media/disc.png" width="120" align="right">

Reverse-engineered source code of the Half-Life 1 Dreamcast port — engine build 1659, compiled on 10 May 2001, a month before Sierra cancelled the project.

The build was published by Sega Dreamcast Info and later reverse-engineered by our team.

<img alt="Dev.Box HKT-01" src="media/devkit.jpg" width="420">	<img alt="Flycast" src="media/scriptedsnarkdevenv.jpg" width="420">
Rebuilt engine on a Dev.Box HKT-01	…and the same disc under Flycast

This repository contains:

• Restored source code of HL SDK
  • client.lib
  • halflife.lib
• Restored source code of the engine
  • halflife_dc.exe

The game links all of its libraries statically, so one binary is the whole thing.

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Getting started

Before building the project, you need to install:

• Microsoft Visual C++ 6.0
• Windows CE SDK 2.1 for Sega Dreamcast (Dragon SDK)

Building

Visual C++ 6.0

Open the workspace at projects\halflife_dc.dsw and press Build -> Build halflife_dc.exe. client, halflife and zlib come along as dependencies.

To get a disc rather than an executable, point GDISRC in postbuild_dc.bat at your copy of the prototype GDI. The post-build step overlays the fresh HALFLIFE_DC.EXE and 0WINCEOS.BIN onto a copy of it and writes a bootable image; without GDISRC it is skipped.

Required files for playing

You will need the original data files from Half-Life Dreamcast (May 15, 2001 prototype).

Tools

utils/ carries the SDK utilities the port was built with, supporting the Dreamcast's native formats (PVR). utils\build_tools.bat builds them into utils\build\.

• studiomdl — studio models, with PVR skins and the compressed Neo model format.
• qlumpy — level wads, with PVR textures.
• makels — cuts a level's textures into the ~128K wad pieces the engine swaps in and out.

See utils/README.md for the details.

Multiplayer

The prototype has multiplayer cut out of it. We put it back.

It sits behind HLDC_MP in src/util/dreamcast_crt.h, which is 0 by default so that a plain build still matches the binary we are diffing against:

#define HLDC_MP 1

Set it to 1 and you get the restored netstack and multiplayer functionality, plus the front-end that comes with it — extra menu pages, a server browser and an on-screen chat keyboard.

There is a second switch in the same header, HLDC_FIXES, covering the places where the released game is simply wrong. It is 0 too, so the engine reproduces the original bugs:

#define HLDC_FIXES 1

Set it to 1 for a corrected engine. Every guarded site names the symptom it produces in the game, so a single fix can be turned off again while tracking down a difference in behaviour.

Media

More in media/ — including the disc being burned out of Visual C++ 6.00 through GDWorkshop onto a Katana dev kit unit, which is roughly how this looked in 2001.

People involved in development of the project

• maximqad — Boosty
• ScriptedSnark — Boosty, Patreon

Referenced projects

• half-life1_win32_722
• Half-Life SDK 1.0
• HLDS Linux binaries

Special thanks

• Sega Dreamcast Info (for releasing the prototype)
• Sizious (for playtesting)