src/video/state.ts

import { POSE, type SceneState } from './model'
import type { V3 } from './math'

export function baseState(over: Partial<SceneState> = {}): SceneState {
  return {
    cam: { pos: [0, 0.2, 5], target: [0, 0.2, 0], fov: 35 },
    arm: { pos: [0, 0, 0], rot: [0, 0.6, 0] },
    pose: [...POSE.rest],
    skin: 1, xray: 0, bone: 0, tendon: 0, sheath: 0, thick: 0, friction: 0, pain: 0,
    props: {},
    time: 0,
    ...over,
  }
}

/** camera orbiting helper: spherical around target */
export function orbit(target: V3, dist: number, yaw: number, pitch: number): V3 {
  return [target[0] + dist * Math.sin(yaw) * Math.cos(pitch), target[1] + dist * Math.sin(pitch), target[2] + dist * Math.cos(yaw) * Math.cos(pitch)]
}