EmilandClaude Sonnet 5
e0e6c1d503
TranslateGizmo draws three axis handles at the selected GameObject's world position by projecting real 3D points through the real camera's View/Projection (GizmoMath.WorldToScreen) onto ImGui's foreground draw list. Nothing OpenGL-side draws lines yet, so this isn't 3D geometry in the GL sense — but it IS driven by the actual camera matrices, which is what the earlier scoped-2D-vs-full-3D-pipeline choice was actually about: a handle dragged in screen space has to map onto a real 3D axis, and that only means something once there's a real camera to project through. The screenshot below shows exactly that — the axes aren't screen-perpendicular, because the camera at (0,3,6) looking at the origin means they shouldn't be. Dragging a handle re-projects the mouse delta onto the axis's own screen-space direction (GizmoMath.ProjectDragOntoAxis) and writes the result back through GizmoMath.WorldToLocalPosition, which inverts the parent's WorldMatrix rather than writing LocalPosition directly — a parent with non-identity scale or rotation means "move 1 world unit" and "add 1 to LocalPosition" are different amounts, and samples/WindowDemo's ChildQuad (parented under a (2,2,1)-scaled Quad) is exactly that case. Split the actual math into GizmoMath (Engine.Editor.Contracts, no GL/ ImGui/mouse dependency) so it's unit-testable without a window or a real mouse — neither exists in a headless test run, and dragging is exactly the kind of interaction that's easy to get subtly wrong (screen-space ratio direction, perspective sign, parent-scale correctness) without something to check it against beyond eyeballing a screenshot. New Engine.Editor.Tests project, 8 tests: screen-center projection, a behind-camera point returning null, drag-ratio math on both an axis-aligned and a diagonal screen direction, and the parent-scale/ parent-translation inverse-transform cases. All 8 passed on the first run — including the non-uniform-scale case, the one most likely to be subtly wrong. Full suite: 73 tests, all green (65 previous + 8 new). Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01N1qPfzq8TDCUMFMV3UwV5N
Lingua Engine
A modular, plugin-first game engine built around one idea: the kernel is a shared language, not a shared implementation. Everything the engine can do — rendering, physics, audio, even the editor itself — is a plugin that speaks that language. The kernel only defines the vocabulary plugins use to understand each other.
Built for Linux and Windows, in C#/.NET, with two goals that shape every design decision:
- Fast iteration. No Unity-style domain reload. Plugins hot-reload their
compiled code without resetting game state, because state never lives in
plugin code to begin with — see
docs/kernel-contract.md. - A small, frozen kernel. Everything else — including the parts most engines treat as core — is a plugin, versioned and replaceable per project.
How this gets built
Most of the code here — kernel and plugins alike — is written by an LLM
coding agent rather than by hand. That's not incidental: it's a design
input. It's why the object model is GameObject/Component instead of a
hand-rolled ECS, why registration is verbose and explicit instead of
convention-based, and why the engine has a headless, scriptable
introspection surface no classic editor bothers with — see
docs/kernel-contract.md.
Status
M0 done. The kernel — World (GameObject/Component, type-indexed
queries), Schedule (stage execution, conflict batching, debug-mode access
enforcement), PluginHost (two-ALC load/unload, verified leak-free over
200 cycles), and a headless CLI (engine run --headless ... --dump) — all
exist and are tested. The full agent loop from
docs/kernel-contract.md#7
runs end to end.
M1 done. engine.windowing, engine.render (a real shader-drawn
triangle, not just a clear color), and engine.input all exist over
Silk.NET. The milestone's actual claim — edit a plugin's code, rebuild just
it, reload it while a real window stays open, see the change with no app
restart — is proven against a live GL context: two PNGs of the same
running window, before and after a live reload, orange triangle then green,
same process the whole time. IScreenCapture (engine.render) reads the
frame back from the GPU and writes it to a file with a hand-rolled PNG
encoder — no SixLabors.ImageSharp (its license isn't MIT/Apache) and no
desktop screenshot tool, so this is checkable without a screen at all,
exactly the introspection story docs/kernel-contract.md#7 argues for.
The kernel is closed. All four questions the original design left open
— Time/Log's home, whether the Event Bus is real infrastructure or
event-components, whether frame stages are fixed or plugin-extensible, and
the data-oriented-fast-path question — are resolved, each with working code
behind it, not just an answer written into the doc. Time and the Event
Bus (Publish/Subscribe, leak-safe the same way Schedule already is)
both shipped; sandbox.echo subscribes to PluginLoaded for real, so the
200-cycle leak test now proves EventBus doesn't leak too, not just
Schedule. See the resolutions in
docs/kernel-contract.md — one of the four
(the fast path) is deliberately still open, but with a concrete trigger
condition instead of a deadline, not left vague.
M2 done. World actually saves and loads now (SceneFormat,
replacing the old introspection-only WorldDumper — there was never a
real reason for "what an agent reads to check a frame" and "what a scene
file is" to be different shapes). Verified beyond round-trip unit tests:
two separate CLI runs against the same scene file, second one picking up
right where the first left off, component state and all.
engine.assets hot-reloads textures from disk — the actual "done when"
for M2. engine.render's triangle became a textured quad; swap the PNG
file on disk while the app is running and the picture changes with no
restart, no manual reload command, just a FileSystemWatcher noticing
and IEventBus carrying TextureReloaded from engine.assets to
engine.render. Verified the same honest way as M1 — real screenshots,
before and after, same running process — plus two things caught and fixed
along the way rather than papered over: a PNG decoder was needed (no
SixLabors.ImageSharp, same licensing reason as the encoder — it's a
second, independent implementation of the format, tested against all five
PNG filter types, not just the one this codebase's own writer produces),
and a real hang, not a hypothetical one: SwapBuffers blocking forever
once VSync had nothing to wait on — reproduced by locking the screen,
fixed by turning VSync off, since nothing here needs frame pacing yet.
No physics yet — see the build order (M0–M4) in
docs/kernel-contract.md for what's next.
Design and implementation are argued over in the same place: the doc is still the thing to disagree with before code changes to match.