GoldSrc

(also known as , and formerly just the ) is a 3D video game engine created by in 1996. It was the driving force behind many famous games of the late 90s and early 00s, such as , , , and . GoldSrc is a heavily modified version of the engine and runs on C++ (with some "C" code). GoldSrc and its level editor, , were released by Valve for public use, making it the source of countless community-made modifications.
GoldSrc was replaced by its successor, , in 2004, which currently holds first place as the choice engine for Valve modders. Though GoldSrc is past its prime, many gamers and some third-party developers still seek to use it for mods and level design. 
The engine is actively being updated and maintained by Valve as of 2023, recently with the 's 25th-anniversary updates which increased the engine limits and fixed many bugs.
==Features==
=== Renderer ===
GoldSrc has two in-game renderers Software Renderer and OpenGL (previously three as Direct3D 6 support was removed in the 2013 SteamPipe Update) both renderers have differences.
* Colored lighting - Quake simply had monotone lighting
* Transparent textures - Glass can now be used in maps
* Transparent Water
* Water ripple
* Water waves 
* Dynamic iris simulation - adjust screen brightness automatically. A feature similar to Source's HDR Rendering. 
* Texture Filtering - First introduced with GLQuake, a version of that runs on OpenGL.
** Anisotropic filtering (16x by default) supported since the 2013 SteamPipe update.
* Skeletal animation - allowing for more stable animation of models, compared to the vertex animation in Quake
* Higher poly counts - GoldSrc allows for far more detailed models than Quake
* HD models - Higher polygon and texture quality for in-game models.
* Detailed textures 
==== Since 2013 SteamPipe Update====
* FBO renderer - A new method of rendering the game, which allows MSAA to work with GoldSrc engine. This also allows the game to run on fullscreen in a borderless window (which also makes Alt+Tab faster), and aspect ratio that are different from your monitors, for example, 4:3 on 16:9, will not be stretched to fill the black bars.
* MSAA anti-aliasing - GoldSrc now natively support anti-aliasing, specifically, MSAA 4X, which is enabled by default on most modern hardwares. This will reduce the amount of jagged edges/staircases effect on the geometry.
* Support for Anisotropic filtering - Increases visual quality of textures at steep angles to the camera. GoldSrc uses 16x Aanisotropic filtering by default.
==== Since 25th Anniversary ====
* Widescreen "Hor+" FOV
** Instead of cropping the image and reducing FOV when using widescreen, the image will be expanded.
* Shaders support (OpenGL)
** With shaders support, it also fix the issues with overbright lighting not working under OpenGL.
* Dynamic Shadows
* Software Renderer support on 
=== AI ===
* AI flocking - NPCs can group together, seen with Houndeyes.
* Scripted sequences - Used extensively to tell Half-Life's story.
* Player Bots - play multiplayer offline with bots. 
=== Sound System ===
* Use Miles Sound System middleware (since 2001)
** Used for in-game voice chat feature, and later for MP3 playback (MP3 playback previously undocumented and unused on WON version but later used in Steam version of GoldSrc since 2003).
* Supports MP3 (since 2003), WAV audio files, aswell as CD audio.
* Hardware accelerated audio (A3D/EAX) - improves DSP sound effects (such as removing echo's buzzing noises), and add surround sounds support (Removed since 2013 SteamPipe update).
** Requires Sound Blaster-compatible (or A3D-compatible) sound cards (but can be bypassed using workaround below).
** While support for A3D/EAX was removed in most GoldSrc games since SteamPipe update (but can be restored using , which requires disabling to work), there are some GoldSrc games that still support A3D/EAX. However, starting with Windows Vista or later, it requires to enable A3D/EAX audio.
=== UI ===
* VGUI2 - Introduced in 2003 update (Steam), Valve's custom GUI interface mimics most of the Windows controls. This will allow the game to switch between the game and the menu quicker, without switching resolutions to 640x480, which adds delay.
=== Programming and Platforms ===
* GoldSrc supports various platforms, such as , and , aswell as consoles (, ).
*All, or most of the engine code written on C/C++ using Visual Studio 2010, and 2019 (since 25th anniversary) or later.
=== Tools ===
* (formerly Worldcraft)
** WYSIWYG World editor
** Create world brushes
** Place AI NPCs
** Place triggers, clip brushes, logic, etc.
** Allows level designer to hook up I/O between entities to control AI within the game
** 
* 
** Full model previewer
** Rotate models in any direction
** Set up hit boxes
** View physics hull
** View normals
** Wireframe, shaded or textured view modes
* StudioMDL
** Model compiler
* QCSG, QBSP2, QRAD, VIS
** Map compilation tools (bsp, lighting and visibility)
** 
=== Other ===
* In-game advertisements (, removed since SteamPipe) - Introduced in 2007.
==== Since 25th Anniversary ====
* Increased engine limits - Valve has increased engine limitations, allowing for more entities and detailed maps.
*func_vehicle entity support from 
*Native support
* Steam Input support - Steam Input support was added, which allows the game to support more controllers and buttons. VGUI menu can be navigated using the controller.
== Versions and forks ==
 Click here to edit this list. 
== Half-Life SDK ==
As of August 2013, it is available on under the "Tools" section. With it comes , the 3ds Max sources for many cut and retail NPCs as well as player and weapon models, tools for packing textures into WADs, and detailed documentation on implementing baseline features such as voice chat into a mod.
The full source code for Half-Life SDK (2.5), which contains changes from Half-Life 25th anniversary update, can be found on Valve's GitHub Page. Source code for previous version (SDK 2.4) can be found here.
== Products using GoldSrc ==
This is the list of games that uses the engine.
=== Officially Licensed ===
 Click here to edit this list. 
=== Modifications ===
 Click here to edit this list. 
*See GoldSrc games category for more games, and for articles about the game which uses the GoldSrc engine.
== Specifications ==
== Bugs and Limitations ==
Use GitHub in order to prevent duplicate or outdated bug reports at the wiki.
== Trivia ==
* The term "GoldSrc" comes from development of the Source engine. A few months before the release of , the Half-Life engine's source code was split into two branches: and . The branch was the gold master version of the codebase, and would be used for the proper release of the game. The branch, comparatively, would be continually iterated upon, adding and changing features for use in the sequel, with the term "Source Engine" eventually being picked up by marketing.
== See also ==
* For information about converting GoldSrc content to the Source engine, see Porting GoldSrc content (maps, models, etc.) to Source
* GoldSrc on Wikipedia
* GoldSrc SDK (Half-Life SDK) Documentation
* GoldSrc SteamPipe Directories
== External links ==
* Source code + GitHub Issues - bug reports and the GoldSrc source code can be found here.
== References ==
# User talk:Erik Johnson (Revision as of 12:53, 1 September 2005)
# Half-Life 25th Anniversary Update
# [[Talk:Cry of Fear#PARANOIA -> Cry of Fear|Relation between Paranoia & COF]]
Category:Game engines
Category:Valve