@modoki/engine / index / CharacterAnimator2D

Variable: CharacterAnimator2D

const CharacterAnimator2D: Trait<{ flip: boolean; idleClip: string; jumpClip: string; moveThreshold: number; walkClip: string; }>

CharacterAnimator2D — the connective "attribute" that turns a 2D platformer character into an animated one: it maps a sibling CharacterController2D's motion state onto a sibling SpriteAnimator's active clip, and mirrors the sprite by facing.

Put it on the SAME entity as the Renderable2D + SpriteAnimator + CharacterController2D. Each frame characterAnimationSystem picks the clip:

• airborne (!grounded) → jumpClip
• grounded & |moveX| > threshold → walkClip
• grounded & (near-)still → idleClip and, when flip is on, sets Transform.sx's sign from the move direction (the base sheet faces right; moving left flips it). Switching clips restarts the new track from frame 0.

Determinism: reads only trait fields (no DOM / wall-clock), so it's safe under the harness and the determinism guard. Facing writes Transform.sx, which the 2D renderer multiplies into the sprite's scale while the physics collider ignores it (unscaled world units).