The standard library is written in J3 and ships inside j3c. This page is a map; for names and signatures, run j3c doc <module>.
| Module | What it’s for |
|---|
j3.io | Printing and files |
j3.sys | Process and OS: arguments, environment, panic, which OS (PLATFORM == PLATFORM_WINDOWS, PLATFORM_NAME; which CPU: ARCH == ARCH_AARCH64, ARCH_NAME) |
j3.math | f32 math, Vec2, Vec3, Quat, Mat4 |
j3.rand | Seedable random numbers |
j3.memory | Arena, List<T>, the scratch arena |
j3.text | Building and editing text |
j3.option, j3.result | Option<T> and Result<T, E> |
j3.thread | Threads, pools, queues, mutexes |
j3.build | DEV / RELEASE constants |
j3.proc | Run other programs |
| Module | What it’s for |
|---|
j3.app | Game runner: startup, update and draw stages, fixed time step |
j3.game | Window, input, 2D drawing, text, audio |
j3.game.input | Named actions bound to keys and pad buttons |
j3.game.display | Video settings: window mode, resolution, vsync |
j3.game.ecs | Entities, components, commands, events |
j3.game.physics | 2D bodies, and 3D bodies on voxels |
j3.game.collide | AABB and circle tests, tile-grid sliding |
j3.game.space | Grid for broadphase queries |
j3.game.path | A* on a grid |
j3.game.anim | Sprite clips and transform tracks |
j3.game.fx | Timers, tweens, particle bursts |
j3.game.tile | Tile maps |
| Module | What it’s for |
|---|
j3.gfx | OpenGL 3.3 forward renderer: meshes, lights, shadows |
j3.gfx.paint | Batched 2D painter: shapes, text, clip, transforms |
j3.gfx.canvas | Draw RGBA images in memory, no window; save PNGs |
j3.gfx.mesh, j3.gfx.meshgen | Mesh files and meshes built in code |
j3.gfx.voxel | Voxel grids |
j3.gfx.noise | Tileable noise for textures |
j3.gfx.urp.* | Optional ray-traced reflections, glass, and shadows |
j3.scene3d | Scenes from the editor: load, script, draw |
j3.scene3d.fpwalk | First-person controller |
| Module | What it’s for |
|---|
j3.ui | .j3ui components: markup, CSS, events (j3c doc j3ui, j3c doc css; supported HTML/CSS overview: j3ui Feature Support) |
j3.i18n | Translated text with plurals |
| Module | What it’s for |
|---|
j3.data.save | Simple key/value save files |
j3.data.assets | Load-once asset cache |
j3.data.json | JSON parse and write |
j3.j2 | j2 mod scripts the game loads at runtime (see Mods with j2) |
j3.net | Non-blocking UDP |
j3.net.tcp, j3.net.dns | TCP connections and name lookup |
j3.net.http, j3.net.tls | HTTP/1.1 and HTTPS clients |
j3.steam, j3.steam.game, j3.steam.ui | Steamworks: achievements, cloud, Deck, lobbies; no-op without Steam (j3c doc steam) |
Networking and processes work on Linux and Android.