Warzone 2100 was originally released in 1999 for Windows 95/98 and PS1.

Today, Warzone 2100 is available natively on Windows, macOS, Linux, FreeBSD, and …

For the first time, in modern web browsers (via WebAssembly and WebGL 2):

Play Warzone 2100 in your Web Browser

How did a 25+ year-old game (designed to run on DirectX 6 and PS1) end up with a modern open source port to the web browser?

It was a long journey that required passionate fans, a lot of development, and a vibrant open source community.

Jump to: The Result

Jump to: The Result

Technical Highlights:

1. Initial Porting to OpenGL & Cross-Platform

After Warzone 2100’s original open-sourcing, community work began in earnest to replace all proprietary technologies with open source alternatives.

• DirectX 6 was replaced with fixed-function OpenGL
• OpenAL was used for 3D positional audio
• SDL was used for windowing, user input, etc

Because of these efforts, Linux and Mac builds were made available for the first time. And Warzone 2100 officially became a cross-platform open source project.

2. Multiple Graphics Backends & OpenGL ES

After a migration to more modern shader-based OpenGL, work began on a graphics abstraction layer - with the initial goal of supporting dual OpenGL and Vulkan backends.

Not only did this eventually yield a Vulkan backend - it also enabled adding OpenGL ES support (reducing the gap to eventual WebGL support).

3. Addressing Roadblocks

Still, some key roadblocks remained to publishing a web port.

At the time, Warzone 2100 relied on QtScript for its scripting engine (which had been deprecated by Qt). WZ also relied on Qt as a dependency sprinkled throughout the codebase. Work began to replace QtScript and remove the remaining Qt dependencies, as well as to simplify the overall build process.

Warzone 2100 also had lost its texture compression support along the way, and still packaged many data files - including textures - as PNGs. This meant a problematic combination of:

• Higher memory usage at runtime (due to lack of in-memory texture compression support)
• Longer load times (due to having to generate mipmaps at runtime)
• Larger download size (due to lack of pre-compressed texture support)

Work began to add advanced texture compression support, as well as support for configurable pre-compressed textures as part of the build process.

And finally, there were other key performance issues that needed to be addressed:

• Warzone 2100 did not yet have instanced rendering support. This didn’t make as large a difference on most desktop platforms (Warzone 2100 was very capable of hitting FPS targets even on lower-end systems), but due to the overhead of WebGL calls in the browser, the high number of GL API calls proved especially problematic for performance.
• Warzone 2100’s multi-pass terrain renderer could also issue a large number of GL API calls.
• Warzone 2100 still used stencil shadows. This similarly did not yield the best performance in busy scenes - but especially in the web browser environment. (Both due to CPU time spent calculating shadow volumes, and GL API calls.)

Throughout 2023, these were addressed by adding instanced rendering support, a new single-pass terrain renderer, and cascaded shadow mapping.

4. Assembling the Remaining Bits

Emscripten - an open-source complete compiler toolchain to WebAssembly - can make the task of porting code to run in the web browser environment a delight.

But there are still some important differences that may require adjustments.

For Warzone 2100, that meant things like:

• Refactoring to support asynchronous dispatch of the main loop
• Separating out a few pieces that would need (or benefit from) Emscripten-specific implementations (libcurl → Emscripten’s “Fetch” API, etc)
• Implementing on-demand video streaming (to eliminate the need to ship videos as part of the initial data download)
• A bunch of surrounding code in the “shell” HTML page, to support persisting savegames and configuration, detect if the browser supports the necessary features, and gracefully handle issues
• Reducing the size of pre-packaged data bundles and textures
• Adding WebGL 2.0 support to the OpenGL ES backend

Fortunately, WebGL 2.0 is based on OpenGL ES 3.0, so adding WebGL support was substantially simplified by the prior graphics abstraction and OpenGL ES work.

The Result:

More than two decades of open source development - and plenty more not even touched on above - has now yielded a game that can compile and run (performantly) in modern web browsers.

The core of the Warzone 2100 single-player experience - the original campaign and skirmish - is now available to run anywhere that supports modern WebAssembly and WebGL 2. (Yes, that includes iPads and Android tablets!)

Give it a try at: https://play.wz2100.net

And if you want the best performance, remastered high-res graphics, and multiplayer support - download the full version for Windows, macOS, and Linux. It’s free too: https://wz2100.net

Don’t forget to check out the official Discord server:

And consider donating to help support the costs associated with the project:

Tag: Releases