Arcane v0.12.0

DX Improvements

This release addresses friction points reported by AI agents building games with Arcane.

Added

• Particle presets — burstParticles(), streamParticles(), and ParticlePresets (dust, fire, sparks, smoke) for one-liner particle effects
• Particle default texture — textureId is now optional in emitter config; auto-creates a 1×1 white texture
• Platformer knockback — platformerApplyImpulse() with externalVx/externalVy that decay each frame (×0.85)
• UI palette system — setPalette(), getPalette(), paletteColor() for consistent color theming
• Actor patrol recipe — createActor(), updateActors(), damageActor() with patrol, chase, and sine behaviors
• API cheatsheet — auto-generated types/cheatsheet.d.ts (~600 lines) for fast API discovery
• Module re-exports — rgb, Color, drawCircle, drawLine, drawTriangle, shakeCamera available from @arcane/runtime/rendering
• State architecture docs — game-patterns.md guide for composing PlatformerState inside GameState

Changed

• BREAKING: createSolidTexture(name, color: Color) — replaces (name, r, g, b, a?) positional args. Use rgb() or Color objects
• BREAKING: setBackgroundColor(color) — replaces (r, g, b) positional args. Accepts {r, g, b} objects
• BREAKING: createGame({ background: Color }) — background now takes 0-1 float Color, not 0-255 ints
• Shape primitives (drawCircle, drawLine, drawTriangle) default to layer 0 instead of 90

Fixed

• Platformer tunneling on large dt spikes

---

Install: cargo install arcane-engine