Xash3D

Xash3D is a game engine that is almost fully compatible with GoldSrc. The engine allows running most games and mods on GoldSrc, but unlike the latter, it has significant improvements.

Important:This engine is written based on the open source code of Id Tech engines, as well as some derivatives of these engines such as DarkPlaces and qFusion.

Warning:The first versions of this engine may indeed contain stolen HL2: Beta code build.c. Nowadays the contain of HLSDK headers, HL2 snd_mix.cpp, etc.. some code in an engine makes this illegal. For information discussion of the illegality Xash3D

Compatibility with GoldSource

The compatibility of the Xash engine with GoldSource is currently estimated to be approximately 90%. This means that the vast majority of mods and games designed for the GoldSource engine should work correctly on Xash3D without any modifications. Numerous single-player mods for the original GoldSource have been tested on Xash, with most of them functioning perfectly and identical to how they work on GoldSource. However, there are some exceptions for games that were designed for the Steam version of GoldSource, as they utilize undocumented engine features that make their adaptation more challenging (such as VGUI2, SDL2, filesystem_stdio, Steam libraries, and other engine modules).

The engine supports Metamod and AmxModX with their plugins, although not all plugins are fully compatible, as many of them were initially optimized for GoldSource rather than Xash. Multiplayer mods are also supported by the engine.

Differences from GoldSrc

• Unlike the GoldSource engine, Xash doesn’t use a modular architecture.
• Xash is written in pure C, while GoldSrc is written fully in C++.
• Xash supports both pre-caching and on-demand loading of resources, while GoldSrc only pre-caches resources.
• Support for BSP maps in formats such as Quake 1, Half-Life, and Half-Life Blue Shift.
• Xash is not bound to the native directory of Half-Life (the “valve” folder), and the mod directory can be specified in the launcher if needed. This allows for the creation of independent games separate from Half-Life.
• Support for ambient maps (as in Half-Life 2).
• Xash doesn’t require unused WAD files, and resources that are not actually used on the loaded map.
• Transparent file system, allowing for accessing files in archives using the same methods as files outside archives.
• Support for colored messages in the console (using the “^” tag).
• Directly changing the sky type and rotation on a map.
• Support for detail textures (as in CS:CZ).
• Support for HD textures.
• Separate physical and graphical interfaces to provide more functionality and customization.
• More efficient occlusion culling system, increasing FPS and reducing “r_speeds”.
• Extended resource limits that can be customized for mod requirements through the gameinfo.txt file. Reducing limits can save more RAM in mods that don’t require many edicts (server entities). The MAX_EDICTS parameter is also transmitted from the server during multiplayer sessions, allowing clients to automatically adjust to new conditions.

Limit	Xash3D	GoldSource (Pre-25th)	GoldSource (Post-25th)
Maximum number of server entities (MAX_EDICTS)	600 - 4096	900 (configurable via config)	1200
Maximum number of temporary entities (MAX_TEMPENTS)	300 - 2048	500	Unknown[confirm]
Maximum number of particles (MAX_PARTICLES)	1024 - 8192	4096	Unknown[confirm]
Maximum number of beams (MAX_BEAMS)	64 - 512	64	Unknown
Maximum number of visible entities in the package (MAX_VISIBLE_PACKET)	512	256	1024
Maximum number of pre-cacheable models (+sprites)(MAX_MODELS)	2048	512	Unknown
Maximum number of pre-cached sounds (MAX_SOUNDS)	2048	512	Unknown
Maximum number of entries to read sentences made up of sentences (MAX_SENTENCES)	2048	1534	2048
Maximum number of user messages (additional messages for protocol inside game dlls) (MAX_USER_MESSAGES)	191	128 (in WON version)	Unknown
Max number of loaded textures (MAX_TEXTURES)	4096	2048 (loaded VGUIs)	Unknown
Number of messages titles.txt (MAX_MESSAGES)	2048	1024	Unknown
Maximum size of indexed textures	4096х4096	512х512	Unknown
Maximum size of full color textures	4096x4096	-	Unknown
Maximum number of models on the map (BSP limit)(MAX_MAP_MODELS)	1024	256	Unknown
Maximum number of map leafs (BSP limit)(MAX_MAP_LEAFS)	32767	8192	Unknown

Engine derivatives

Since the engine is distributed under the GNU GPL v3 free license, attempts have been made by third-party developers to create forks. Currently known forks include:

• Xash3D FWGS (Formerly Xash3D SDL) - a cross-platform fork of the project that maintained by group of enthusiasts known as Flying With Gauss (a.k.a FWGS, formerly SDLash3D). It has full support for Windows, DOS, Linux, macOS, *BSD, Android, Haiku, SerenityOS, Elbrus, PSP, PS Vita, Nintendo Switch, MotoMAGX, partial support for SGI Irix, SailfishOS and AuroraOS, and includes numerous fixes and extensions to the original engine. Also, an old version supports Emscripten and iOS.
• Xash3DEx a.k.a Xash3D Magenta - Stillborn project by [BlackPhrase https://github.com/BlackPhrase]. Actual version of this "engine" contains only one .bat file with only five strings.

External Links

• Official Forum of Xash3D
• ModDB Page