Gardens of Kadesh

Gardens of Kadesh is a WebAssembly port of HomeworldSDL. HomeworldSDL is an SDL port of the Homeworld source code that was released in 2003 by Relic Entertainment.

How to play

Don't forget to maximize your browser window for the best experience!

You will be able to freely play the Homeworld demo content (the first two missions of the campaign and skirmish against the computer). If you own the full version of Homeworld or the Homeworld Remastered Collection you can follow the same link, drag and drop the required asset files from your local Homeworld installation into the browser window and play the full Homeworld campaign.

About

Our goals are to continue modernizing the Homeworld engine with gentle touches while preserving the original gameplay and feel. To make the Homeworld 1 experience widely accessible on modern devices and to new generations of players.

In addition we hope to raise awareness for the source code situation of Homeworld 1. The Homeworld source code was released under an unfavorable Relic Developer Network License. The disappearance of the Relic Developer Network and the Homeworld IP having changed hands leaves the license state of the Homeworld source code in a dubious state that hinders development. We aim to achieve a consideration for a re-releasing of the original Homeworld source code under GPL2/3 or re-licensing the current GardenOfKadesh/Homeworld code under GPL2/3.

If you can help us in any way, or get back to us in support, please get in touch. Follow our project here on Github and/or joins us on our discord.

Please support the original Homeworld developers and the Homeworld IP/universe:

• Homeworld Remastered Collection on Steam, on GoG
• Homeworld Cataclysm/Emergence on GoG
• Homeworld Deserts of Kharak on Steam, on GoG
• Homeworld 3 on Fig, on Steam, on Epic

Changes

Most notable changes besides the the necessary changes described in the porting Homeworld to WebAssembly section:

• increased universe update rate for smoother gameplay and animations
• dithering shader added to the vertex background system to prevent visible color banding
• LODs fixed to highest level
• tweaked the non-linear inverse perspective scaling to work better with high resolutions
• anisotropic filtering for improved texture rendering
• antialiased rendering
• fixes for sound system bugs that stemmed from SDL port

To see all changes between versions take a look at the changelog.

Porting Homeworld to WebAssembly

The original Homeworld engine was written in C and targeted the 32bit x86 Windows platform only. HomeworldSDL modified the original source code to use the cross-platform Simple DirectMedia Layer (SDL) to allow the engine to target not only Windows but also MacOS and Linux. Gardens of Kadesh is using emscripten to compile the C code base to WebAssembly allowing execution inside any modern web browser and by such making it runnable on nearly all modern computing devices from desktop computers, over laptops, tvs, chromebooks to tablets and phones.

Since consumer windows computer at the time were limited to rather slow, in comparison to current computers, 32bit x86 processors the Homeworld engine was heavily optimized for this specific platform resulting in the use of x86 assembly intrinsics and 32bit pointer trickery especially in the ETG system (an effect scripting system used for all graphic effects in the game). The HomeworldSDL project already put a lot of work into making the code more portable by adding preliminary support for 64bit x86 processors. Using emscripten to target WebAssembly is adding another processor architecture into the mix and is also introducing a new compiler that needs to be able to handle the code base. This helped with finding and fixing many bugs and issues with the source code and the previous attempts at making the engine more portable.

In addition to these lower level fixes other necessary changes were more on the architecture side. To work with emscripten the engine needed to be stripped of multithreading. Since browser windows can be arbitrarily shaped and resized during runtime additional functionality to handle that had to be implemented. Input handling also had to be adapted to properly work in the browser context.

Lastly the original Homeworld engine and HomeworldSDL use OpenGL 1.x immediate mode rendering. In OpenGL 1.x commands are used to setup a certain state and every single triangle is send one vertex at a time directly to the GPU for rendering. This was how GPUs at the time operated (for curious readers I recommend this beautiful write up about the 3dfx Voodoo GPU). WebGL, which is the 3d rendering API supported by modern browsers, is based on OpenGL ES 2.0 which is a much more modern approach to rendering 3d graphics. To get the Homeworld engine compilable with emscripten and render its graphics correctly the legacy OpenGL emulation layer of emscripten needed to be extended with additional features. These have been contributed back to the emscripten project and are already available in emscripten release versions starting with 2.0.25. Since the immediate mode nature of OpenGL 1.x causes a lot of API call overhead some optimizations in the form of rewriting rendering functions using modern OpenGL functionality have been done to the most critical code paths.

Building

Homeworld demo assets

This repository contains only the source code for Homeworld's engine (metaphorically, the skeleton). In order to have a playable game, you will need the original assets (artwork, textures, sounds, meshes, ... Metaphorically again, the flesh).

The following asset files are required to build Gardens of Kadesh based on the Homeworld demo:

• HomeworldDL.big (from the Homeworld demo)
• DL_demo.vce (from the Homeworld demo)
• DL_Music.wxd (from the Homeworld demo)
• Update.big (from the Homeworld 1.05 Patch)
• HomeworldSDL.big (see HomeworldSDL how to build this manually)

All the above demo assets can also be downloaded here (TODO). Alternatively wine can be used to extract them from the windows installers. See HomeworldSDL on how to do that.

Build requirements

To build Gardens of Kadesh based on the Homeworld demo under linux the following preparations are required:

• copy all the above listed asset files into the wasm/ folder of the repository
• install emscripten with a version >= 2.0.25 (Older versions don't include the necessary improvements to the legacy OpenGL emulation layer)

Building process

To setup emscripten switch to your emscripten installation folder and run:

source emsdk_env.sh

To run the Gardens of Kadesh build process switch to the wasm/ folder of its repository and run:

make clean
make

To increase build speed add "-jX" to enable parallel building. Replace the X with the number of threads your processor has.

Make sure to issue a "make clean" after changes to the code since the Makefile is currently not properly setup to track all changes automatically.

Running locally

The finished build can be tested locally in a browser by running:

emrun www/index.html

Media