docs: add AnyGM core documentation

docs/development/licenses.md

@@ -62,6 +62,7 @@ See below for a summary of the licenses behind RetroArch and its cores:
 | [3D Engine](../library/3d_engine.md)             			           | [GPLv3](https://github.com/libretro/libretro-3dengine/blob/master/license)                |                |
 | [2048](../library/2048.md)                       			           | [Public Domain](https://github.com/libretro/libretro-2048/blob/master/COPYING)            |                |
 | [Anarch](../library/anarch.md)                                                   | [CC0](https://codeberg.org/iyzsong/anarch-libretro/src/branch/master/LICENSE)             |                |
+| [AnyGM](../library/anygm.md) | [MIT](https://github.com/retrodiv/AnyGM-libretro/blob/f18d67fbe8fd164094fc1477ff7692d6ff8fc67b/LICENSE) |  |
 | [Ardens](../library/ardens.md)                                       | [MIT](https://github.com/tiberiusbrown/Ardens/blob/master/LICENSE.txt)                         |                |
 | [AmiArcadia](../library/amiarcadia.md)                               | [Non-commercial](https://amigan.1emu.net/releases/)                                       | Non-commercial |
 | [Atari800](../library/atari800.md)               			           | [GPLv2](https://github.com/atari800/atari800/blob/master/COPYING)                         |                |

docs/guides/core-list.md

@@ -5,6 +5,7 @@
 | [4DO](https://docs.libretro.com/library/opera/) | 3DO                    |                    |
 | a5200                     | Atari 5200             |                    |
 | Anarch                    | Game                   | A port of Anarch, 90s-style Doom clone shooter game |
+| [AnyGM](../library/anygm.md) | Game engine | A portable GameMaker runtime for classic containers and Studio bytecode |
 | [Ardens](../library/ardens.md) | Arduboy                | A simulator for the Arduboy FX |
 | Arduous                   | Arduboy                | A emulator for Arduboy, a handheld game console with open source software, based on the Arduino hardware platform |
 | [Atari800](https://docs.libretro.com/library/atari800/) | Atari 5200             |                    |

docs/library/anygm.md

@@ -0,0 +1,88 @@
+<!-- anygm-publisher: page -->
+# GameMaker (AnyGM)
+
+## Background
+
+AnyGM is a portable runtime and libretro core for supported GameMaker content
+formats. It provides one shared execution engine for classic containers and
+Studio bytecode, maintained by retrodiv as an independent project: it is not
+affiliated with, or endorsed by, YoYo Games Ltd, and it contains no game
+content and no proprietary runtime components.
+
+All first-party code is available under the MIT License; bundled third-party
+components retain their own terms. See the [source
+repository](https://github.com/retrodiv/AnyGM-libretro), [license](https://github.com/retrodiv/AnyGM-libretro/blob/f18d67fbe8fd164094fc1477ff7692d6ff8fc67b/LICENSE) and
+[third-party notices](https://github.com/retrodiv/AnyGM-libretro/blob/f18d67fbe8fd164094fc1477ff7692d6ff8fc67b/THIRD_PARTY_NOTICES.md).
+
+## Content
+
+The core recognizes classic container revisions 530, 600, 701, 702, 800 and
+810; Studio data containers with bytecode revisions 14 through 17; and the
+path formats it declares: `.win`, `.droid`, `.zip`, `.port`, `.apk`, `.yyp`,
+`.yyz`, `.gmd`, `.gmk`, `.gm6`, `.gm81`, `.exe` and `.anygm`. Executables may
+carry an embedded normalized Studio payload or a single-runtime LZX Cabinet,
+or be paired with an adjacent `data.win`; native machine code is never
+executed. An `.anygm` file is a small text anchor naming the payload to load,
+optionally with override directives and external patch pipelines.
+
+Format recognition does not promise that every built-in operation a game uses
+is implemented: unsupported or malformed input is rejected with a diagnostic
+instead of selecting a different engine. Supply content you are authorised to
+use; the core ships no game data.
+
+## Controls
+
+The `RetroPad behavior` option decides how a game sees the pad. `Game gamepad`
+hands the RetroPad to games with joystick or gamepad support and falls back to
+keyboard emulation for games without it; `Keyboard emulation` always presents
+the RetroPad as the game's keyboard controls, including both classic action
+rows (ZXCV and ASDF), the arrows, Enter, Space and Shift. Pointer movement
+follows the `Mouse input` option: `Auto` follows what the content expects,
+with `Absolute (pointer)` and `Relative (delta)` available explicitly.
+
+## Core options
+
+Options are grouped as Video, Input, System and Development; frontends without
+category support receive the same options as a flat list.
+
+**Video**: `Transparency culling` (**High**), `Render at game resolution`
+(**On**), `Adjust for 4:3 CRT TV` (**Off**), `Monitor width` and
+`Monitor height` (**Game Base**), `Aspect Ratio force (Experimental)`
+(**None**), `Game shaders (GLSL)` (**Off, but report available**) and
+`Hybrid GPU rendering (Experimental)` (**None**).
+
+**Input**: `RetroPad behavior` (**Game gamepad**) and `Mouse input` (**Auto**).
+
+**System**: `Language` and `Region`, both **Auto** and both applied on
+restart.
+
+**Development**: `Content override directives` (**On**), `Start room` and
+`Start room range`, `Clear current game saved data on load` (**Off**),
+`Clear current game cache on unload` (**On**) and
+`Clear all game caches on load` (**On**).
+
+## Features and saved data
+
+| Feature | Support |
+|---|---|
+| Save states | Yes, `serialized` (state format 29) |
+| Rewind | Yes, through save states |
+| Cheats | Yes, host cheat entries run as GML expression overrides |
+| Core options | Yes, version 2 with categories |
+| Memory descriptors | No, `retro_get_memory_data` returns NULL |
+| Disk control, subsystems | Not used |
+| Hardware rendering | Optional, on OpenGL or OpenGL ES frontends |
+
+Save states carry the runtime's own random seed, so rewind and save/load are
+exact, while two fresh runs of the same content are not bit-identical; the
+core therefore does not advertise deterministic netplay or run-ahead.
+Persistent game data lives under the frontend's save directory, and
+rebuildable loader data under its `AnyGM-cache/` subdirectory. Maximum
+geometry is fixed at 3840x2160, and the frontend frame rate is 60 Hz with
+44,100 Hz audio.
+
+## Support
+
+Report problems in the [core issue tracker](https://github.com/retrodiv/AnyGM-libretro/issues) with the core
+revision, frontend and version, OS/CPU, the content format and a reproduction
+you can share. See [CONTRIBUTING.md](https://github.com/retrodiv/AnyGM-libretro/blob/f18d67fbe8fd164094fc1477ff7692d6ff8fc67b/CONTRIBUTING.md).

mkdocs.yml

@@ -316,6 +316,7 @@ nav:
       - 'Doom 3 (Boom3)': 'library/boom3.md'
       - 'Dungeon Crawl Stone Soup': 'library/stone_soup.md'
       - 'Flashback (REminiscence)': 'library/reminiscence.md'
+      - 'GameMaker (AnyGM)': library/anygm.md
       - 'Handheld Electronic (GW)': 'library/gw.md'
       - 'Jump n Bump': 'library/jumpnbump.md'
       - 'LowRes NX': 'library/lowres_nx.md'