Per-frame lifecycle: Update, FixedUpdate, Start, OnDestroy and Time (#81) #93

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crowmaki merged 6 commits from issue-81-script-lifecycle into main

2026-09-06 03:29:47 +00:00

crowmaki commented

2026-09-06 03:28:49 +00:00

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Closes #81. Part of #75.

What

A Script Component's Update(dt), FixedUpdate(dt), Start() and OnDestroy() run from the Plugin's Hooks and the Schema's Component Hooks.

update and fixed_update walk each Script class in Schema registration order and, within a class, walk component_storage by index, re-fetching storage every iteration. Instances on a GameObject that is not Active in Hierarchy, and instances already queued for removal, are skipped.
Start runs once per instance, immediately before its first frame method, behind a Transient Bool field the Plugin appends to every Script Schema. Its name is @started, which no Luau identifier can spell, so it never collides with a Script's own fields and never reaches a Scene Document.
OnDestroy runs from on_remove, so it runs exactly once whether the Component was removed directly, its owner destroyed, or its Scene unloaded.
A read-only Time global carries deltaTime, fixedDeltaTime and frameCount, refreshed at the top of each Hook from Frame Timing. Inside FixedUpdate, deltaTime is the fixed step, the Unity way.
Every method call goes through one pcall with a traceback handler. An error in one instance is logged and the rest of the frame continues.
Core: Component_Field_Desc gains flags, so a description can mark a field Transient. The struct stays 16 bytes.

One reading to confirm: Start runs before whichever of FixedUpdate or Update first reaches the instance in a Tick, which is Unity's ordering. The issue text names only Update.

Tests

tests/luau/lifecycle_test.odin covers every acceptance criterion from Luau source strings. tests/core/component_schema_test.odin covers the Transient flag on a description field.

The luau harness had a bug: capture_logger replaced the runner's logger, so no luau test could fail. It now forwards lines logged from _test.odin files to the runner. Every prior test still passes.

just check and just test pass (430 tests).

Closes #81. Part of #75. ## What A Script Component's `Update(dt)`, `FixedUpdate(dt)`, `Start()` and `OnDestroy()` run from the Plugin's Hooks and the Schema's Component Hooks. - `update` and `fixed_update` walk each Script class in Schema registration order and, within a class, walk `component_storage` by index, re-fetching storage every iteration. Instances on a GameObject that is not Active in Hierarchy, and instances already queued for removal, are skipped. - `Start` runs once per instance, immediately before its first frame method, behind a Transient `Bool` field the Plugin appends to every Script Schema. Its name is `@started`, which no Luau identifier can spell, so it never collides with a Script's own fields and never reaches a Scene Document. - `OnDestroy` runs from `on_remove`, so it runs exactly once whether the Component was removed directly, its owner destroyed, or its Scene unloaded. - A read-only `Time` global carries `deltaTime`, `fixedDeltaTime` and `frameCount`, refreshed at the top of each Hook from Frame Timing. Inside `FixedUpdate`, `deltaTime` is the fixed step, the Unity way. - Every method call goes through one `pcall` with a traceback handler. An error in one instance is logged and the rest of the frame continues. - Core: `Component_Field_Desc` gains `flags`, so a description can mark a field Transient. The struct stays 16 bytes. One reading to confirm: `Start` runs before whichever of `FixedUpdate` or `Update` first reaches the instance in a Tick, which is Unity's ordering. The issue text names only `Update`. ## Tests `tests/luau/lifecycle_test.odin` covers every acceptance criterion from Luau source strings. `tests/core/component_schema_test.odin` covers the Transient flag on a description field. The luau harness had a bug: `capture_logger` replaced the runner's logger, so no luau test could fail. It now forwards lines logged from `_test.odin` files to the runner. Every prior test still passes. `just check` and `just test` pass (430 tests).

crowmaki added 6 commits

2026-09-06 03:28:49 +00:00