Skip to content
Estella

v0.9.0

Timeline System

A new multi-track animation system for coordinating property animations, Spine playback, sprite animations, audio events, and entity activation over time.

  • TimelinePlayer component — attach to any entity, set a .estl timeline asset and control playback with playing, speed, and wrapMode (once, loop, pingPong)
  • TimelineControl API — play(), pause(), stop(), setTime(), isPlaying(), getCurrentTime() for runtime control
  • 5 track types — Property (keyframe interpolation), Spine (animation clips), Sprite Animation, Audio (timed events), Activation (enable/disable entities)
  • Editor Timeline panel — visual track editor with keyframe editing, right-click context menu, and horizontal scroll

See the Timeline guide for the full API.

Async Systems

defineSystem now accepts async functions. Systems can await promises, and Commands are automatically flushed after the async function completes. Works in all schedule phases.

addStartupSystem(defineSystem(
    [Res(Prefabs)],
    async (prefabs) => {
        const { root } = await prefabs.instantiate('prefabs/Enemy.esprefab');
    }
));

See Systems for details.

UI Builder

A declarative API for creating UI hierarchies from code. Factory methods (UI.button(), UI.slider(), UI.toggle(), etc.) spawn fully configured widget entities in one call. A tree builder (UI.build()) creates nested hierarchies from JSON-like definitions.

  • Theming — all widgets pull defaults from UITheme resource; DARK_THEME built-in
  • Event callbacks — onClick, onChange, onSubmit on widget options
  • Entity refs — capture created entities via ref callback on any node

See the UI Builder guide for the full API.

UIEvents Callback API

In addition to polling events with events.query(), you can now subscribe with callbacks:

  • events.on(entity, type, handler) — entity-scoped subscription
  • events.on(type, handler) — global subscription
  • Both return an Unsubscribe function

A new makeInteractable(world, entity) helper simplifies adding the Interactable component with sensible defaults.

Spine Multi-Version Architecture

Spine now supports versions 3.8, 4.1, and 4.2 simultaneously with automatic version detection. The engine selects the best backend (C++ native or WASM fallback) transparently.

  • SpineVersion type exported for advanced introspection
  • SpineManager provides runtime queries: getEntityVersion(), getAnimations(), getSkins(), getBounds()
  • Spine and Tilemap rendering migrated to C++ renderer plugins, removing the JS-side ExternalMeshPlugin

Frame Debugger

A new debugging tool for inspecting the render pipeline draw-by-draw.

  • Editor panel — capture a frame, browse draw calls, replay to any point, inspect in a detached window
  • SDK API — Renderer.captureNextFrame(), Renderer.getCapturedData(), Renderer.replayToDrawCall(), Renderer.getSnapshotImageData()
  • Diagnostics — FlushReason (why batches break), RenderType (sprite/text/spine/particle), per-draw-call metadata

See Debugging for usage.

Renderer v2

The rendering pipeline has been unified and optimized:

  • Renderer.submitAll() — single call replaces 6 per-type submit methods (sprites, text, spine, particles, shapes, UI)
  • SubmitSkipFlags — selectively skip Spine or Particle submission
  • Vertex format compression — UByte4N packed color attribute reduces vertex size
  • RenderFrame decoupled from BatchRenderer2D for cleaner architecture
  • Mask processing moved to C++ for better performance

Performance Optimizations

Significant improvements to ECS query iteration and component access:

  • Query iteration — 40–70% faster via manual iterator, pre-allocated result objects, and switch-based forEach dispatch
  • Component reads/writes — pointer-based access bypassing embind marshalling for Transform, Sprite, Camera, Velocity, UIRect, physics components
  • world.has() / tryGet() — JS-side entity set tracking eliminates WASM round-trips
  • Physics sync — 37× faster body position synchronization
  • Change detection — eliminated query cache miss array copies
  • System runner — cached QueryInstance eliminates per-run allocations

Editor Improvements

Architecture Overhaul

  • Service-oriented architecture — Editor god object decomposed into services with IoC container (EditorContainer)
  • EditorPlugin system — decentralized registration replacing centralized switch dispatch
  • DisposableStore — fixes event listener leaks across panels
  • PropertyWritePipeline — unified property change handling replacing per-component switch

UI & UX

  • Redesigned theme — HSL color system with design tokens for consistent styling
  • Multi-window support — floating panels with command replication across windows
  • Extensions panel — manage editor extensions with detachable window support
  • Timeline panel — track editing with right-click context menu and horizontal scroll

Bug Fixes

Rendering

  • Fixed UI layer ordering and text rendering issues after renderer v2 refactor
  • Fixed tilemap flickering by ensuring transforms update before tile submission
  • Restored stats collection and external triangle submission

Editor

  • Fixed UIRect entity position jump on gizmo drag end
  • Fixed timeline horizontal scroll and frame debugger click in live mode
  • Fixed PostProcessVolume inspector registration key mismatch
  • Fixed cross-platform openFile and openInEditor commands

SDK

  • Fixed JS builtin entity tracking when C++ adds components directly
  • Exported shared .d.ts files to user projects for IntelliSense
  • Simplified UI dropdown positioning and added color equality guards