i-want-to-heal/src/modes/iwt2/render/bossAnimation.ts

import type { Iwt2BossEntityState } from '../sim'

export type BossRenderMotion = {
  x: number
  y: number
  scaleX: number
  scaleY: number
  rotation: number
  tint?: number
}

type BossMotionProfile = {
  idleFrequency: number
  idleBob: number
  moveFrequency: number
  moveBob: number
  impactScale: number
}

const DEFAULT_PROFILE: BossMotionProfile = {
  idleFrequency: 1.6,
  idleBob: 2.1,
  moveFrequency: 5.4,
  moveBob: 3,
  impactScale: 0.035,
}

const BOSS_PROFILES: Partial<Record<Iwt2BossEntityState['bossId'], BossMotionProfile>> = {
  bulldrome: {
    idleFrequency: 1.35,
    idleBob: 2.3,
    moveFrequency: 5.9,
    moveBob: 3.2,
    impactScale: 0.045,
  },
  'yian-kut-ku': {
    idleFrequency: 2.2,
    idleBob: 2.8,
    moveFrequency: 6.4,
    moveBob: 3.4,
    impactScale: 0.032,
  },
  'obsidian-ram-golem': {
    idleFrequency: 1.05,
    idleBob: 1.6,
    moveFrequency: 3.7,
    moveBob: 2.5,
    impactScale: 0.052,
  },
}

const WARM_TINT = 0xffc88a
const IMPACT_TINT = 0xff9b5f

export function bossRenderMotion(entity: Iwt2BossEntityState, timeSeconds: number): BossRenderMotion {
  const profile = BOSS_PROFILES[entity.bossId] ?? DEFAULT_PROFILE
  const phase = String(entity.attackPhase)
  const speed = Math.hypot(entity.velocity.x, entity.velocity.y)
  const moving = speed > 8 || phase === 'relocating'
  const facingX = entity.facing.x < -0.05 ? -1 : 1

  const motion: BossRenderMotion = {
    x: 0,
    y: 0,
    scaleX: 1,
    scaleY: 1,
    rotation: 0,
  }

  if (isActionPhase(phase, 'windup')) return windupMotion(motion, entity, phase, timeSeconds, facingX)
  if (isBurstPhase(phase)) return burstMotion(motion, timeSeconds, facingX)
  if (isActionPhase(phase, 'recover')) return recoverMotion(motion, profile, entity, timeSeconds)
  if (moving) return movingMotion(motion, profile, entity, timeSeconds, facingX)
  return idleMotion(motion, profile, timeSeconds)
}

function idleMotion(motion: BossRenderMotion, profile: BossMotionProfile, timeSeconds: number): BossRenderMotion {
  const wave = Math.sin(timeSeconds * profile.idleFrequency * Math.PI * 2)
  return {
    ...motion,
    y: -Math.max(0, wave) * profile.idleBob,
    scaleY: 1 + Math.max(0, wave) * 0.025,
    scaleX: 1 - Math.max(0, wave) * 0.01,
  }
}

function movingMotion(
  motion: BossRenderMotion,
  profile: BossMotionProfile,
  entity: Iwt2BossEntityState,
  timeSeconds: number,
  facingX: number,
): BossRenderMotion {
  const speedFactor = Math.min(1, Math.hypot(entity.velocity.x, entity.velocity.y) / 180)
  const stride = Math.sin(timeSeconds * profile.moveFrequency * Math.PI * 2)
  const lift = Math.abs(stride) * profile.moveBob
  return {
    ...motion,
    y: -lift,
    scaleX: 1 + 0.012 * speedFactor,
    scaleY: 1 - 0.009 * Math.abs(stride),
    rotation: facingX * 0.025 * speedFactor,
  }
}

function windupMotion(
  motion: BossRenderMotion,
  entity: Iwt2BossEntityState,
  phase: string,
  timeSeconds: number,
  facingX: number,
): BossRenderMotion {
  const pulse = 0.5 + Math.sin(timeSeconds * Math.PI * 9) * 0.5
  const isSlam = phase.includes('slam') || phase.includes('quake') || phase.includes('shatter')
  return {
    ...motion,
    x: -facingX * (isSlam ? 1.5 : 3),
    y: isSlam ? -2 : 2,
    scaleX: 1.035,
    scaleY: 0.965,
    rotation: -facingX * 0.02,
    tint: pulse > 0.45 || entity.phaseSecondsRemaining < 0.18 ? WARM_TINT : undefined,
  }
}

function burstMotion(motion: BossRenderMotion, timeSeconds: number, facingX: number): BossRenderMotion {
  const shake = Math.sin(timeSeconds * Math.PI * 38) * 1.8
  return {
    ...motion,
    x: facingX * 3 + shake,
    y: Math.cos(timeSeconds * Math.PI * 42) * 1.2,
    scaleX: 1.045,
    scaleY: 0.96,
    rotation: facingX * 0.018,
    tint: WARM_TINT,
  }
}

function recoverMotion(
  motion: BossRenderMotion,
  profile: BossMotionProfile,
  entity: Iwt2BossEntityState,
  timeSeconds: number,
): BossRenderMotion {
  const settle = Math.max(0, Math.min(1, entity.phaseSecondsRemaining / 0.45))
  const impactPulse = Math.abs(Math.sin(timeSeconds * Math.PI * 11)) * settle
  const pop = profile.impactScale * impactPulse
  return {
    ...motion,
    y: -2 * impactPulse,
    scaleX: 1 + pop,
    scaleY: 1 + pop * 0.45,
    tint: impactPulse > 0.45 ? IMPACT_TINT : undefined,
  }
}

function isActionPhase(phase: string, suffix: string): boolean {
  return phase.toLowerCase().includes(suffix)
}

function isBurstPhase(phase: string): boolean {
  const normalized = phase.toLowerCase()
  return (
    normalized.includes('charging')
    || normalized.includes('swooping')
    || normalized.includes('burrowing')
    || normalized.includes('ricocheting')
    || normalized.includes('flying')
  )
}