An Object variable could only be set by a graph while the game runs.
A placed object always showed "(null)", although the other objects of
its scene are there to choose from and the runtime can already find
any object by its id. Now the placed object stores a reference to one
of them, and the running game turns it into the real object.
- Stored as {"$object": "<id>"}. The empty placeholder stays as it
was, so old projects load unchanged and empty still means "(null)".
- The row of an Object variable on a placed object is a dropdown with
None and every object of the scene, indented like the Hierarchy.
The same goes for Object fields in structs and Object items in
lists, also in the Variables and List tabs.
- The behavior asset keeps "(null)". An asset has no scene, so "Apply
to asset" is gone from Object rows.
- The runtime resolves the reference when the Variables or Properties
node reads it. A destroyed target reads as null, a missing one shows
"(missing)" in the row.
- Inside a container only objects of the same container are offered.
The reference keeps the template id, so every placement finds its
own copy.
- Deleting the target clears the reference in the same undo step.
Paste points references inside the pasted group at the copies and
leaves outside references alone. Create container and Unpack carry
references along with the new ids.
- A value a graph writes while running stays in the run. The scene
keeps the picked object, also in "Run in editor".
Found on the way:
- Setting an override coerced every object slot to empty, in plain
values, struct fields and list items. The shared objectPlace() now
keeps the reference.
Not done:
- No eyedropper to pick in the scene, the dropdown is enough for now.
- Deleting a template object in the container editor does not clean up
references in other scenes. They read as null there.
Tests:
- ./check.sh: 187 files, 2724 tests, CHECK EXIT 0
- e2e 1-9, 51, 57: ALL PASSED, 389 checks
- e2e 1, 57 on the final bundle: ALL PASSED, 17 checks
- 13 unit tests in object-references.test.ts, 5 checks in e2e 57
- Counter-checks: 8 unit breaks fail their tests, the browser break
without a pick list fails 57b-57d
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Game Maker
A browser-based tool "one step before a game engine": create assets (scenes, cameras, sprites), place them into scenes, tweak their properties in an inspector and press Play – all in one program, all drawn inside a single WebGL canvas.
Live: https://nockal.com/game-maker/ · Widget playground: https://nockal.com/game-maker/?playground
The documentation is the wiki: https://git.nockal.com/meleki/game-maker/wiki – every concept, node, tab and shortcut, plus the architecture and the development workflow. This file is the short way in.
In one screen
- An asset is a named, typed thing (scene, camera, sprite, text, behavior, collider, rigidbody, container, texture, vector art, pixel art, palette, font, sound, animation, state machine, shader, particles, variables, tile, tilemap) with properties and no position.
- A scene object places an asset: position, sparse overrides of its properties, an optional parent. Only what differs from the asset is stored; the inspector paints it gold and offers ↺ / ↑.
- A container is a reusable group edited once and placed many times; its content is resolved from the template on every read. A screen is a container switched on and off.
- A behavior is logic as a node graph, placed like anything else and parented to the object it acts on. Play has no built-in behaviour – everything that happens is a graph.
- An account owns projects: the editor asks for a user name and a password first, and each account sees only its own projects. The Account menu at the far right of the toolbar changes the password and signs out.
- Play runs a throwaway copy of the project; every panel stays usable and Stop brings back exactly what was saved.
Quick start
Node 22 is required.
npm install
npm run dev # http://localhost:5175/game-maker/dist/ – API calls are proxied to production
npm run check # typecheck + lint + format:check + unit tests – the gate CI runs too
npm run build # writes dist/ and regenerates index.html; the folder is what nginx serves
The browser suite and the three example games need a machine with a GPU:
node tools/seed-e2e.mjs && node tools/e2e.mjs # the editor, 1532 checks (GM_STEPS=20 for one step)
# every tool signs in first – see the Accounts page
node tools/seed-jumprun.mjs && node tools/smoke-jumprun.mjs
node tools/seed-tetris.mjs && node tools/smoke-tetris.mjs
node tools/seed-actor.mjs && node tools/smoke-actor.mjs
Every push runs all of it on the Gitea runner – the gate as one job, build and suite as another beside it – so locally take the gate plus the step your change touches and leave the full run to CI. Details, the GPU requirement and the detached runner are in Development.
Documentation
| Page | What it covers |
|---|---|
| Concepts | Assets, scene objects, overrides, play mode, the camera, the console |
| Accounts | Signing in and out, the accounts, who a project belongs to, what the check tools need |
| Scenes | The edited scene, the start scene, and switching scenes from a graph |
| Scene editing | Placing, z-order, hierarchy, the editor offset |
| Behaviors | Node graphs: variables, the node set, structs and lists, loops, nesting, editing |
| Structs | Struct assets: a named shape that struct variables, fields and Pack/Expand follow |
| Colliders | Shapes (box, circle, capsule, polygon), collision events, blocking movement, one-way colliders and raycasts |
| Physics | Rigidbodies, the collider material, gravity, the fixed step |
| Textures | Images, frames, nine-slice, the filter, upload limits |
| Vector art | Pictures drawn from shapes: the pen, curves, gradients and texture fills, combining shapes |
| Pixel art | Pictures painted pixel by pixel: the palette, the tools, layers and frames |
| Fonts | Font assets, the picker, what a text falls back to |
| Sounds | Sound assets and Play sound |
| Animations | Animation assets and the Animation tab |
| Curves | Easings drawn by hand, the Curve tab, using one on a key or a Lerp |
| Shaders | Shader graphs a sprite wears, their node set, the properties they declare |
| Particles | Particle graphs: a particle as a function of its age |
| State machines | The asset, named transitions, State branch, Set state and State transition |
| Containers | Templates, instances, screens |
| Tiles | The tile asset, plain tiles and the two autotile kinds, the pictures as animation steps, the Tile tab |
| Tilemaps | The tilemap asset, painting in the scene view, layers, what it looks like in the game |
| Plugins | Extending the editor: the plugin file, how it is loaded, switching one on and off, API v1 |
| Keyboard | Every shortcut |
| Architecture | Stack, source layout, the rules that keep it organised |
| Development | Commands, the e2e suite, the example games, CI |
| API | The PHP JSON API and the project document |
Ideas, gaps and bugs
They live in the issue tracker: https://git.nockal.com/meleki/game-maker/issues. What is not there yet is listed on the wiki's Home page.
