fix(skill): implement Frost Nova 64-missile radial spread and slow (Fixes #431)

src/game/engine/missile-engine.ts

@@ -92,6 +92,62 @@ export function calculateStaticFieldRadiusPx(slvl: number): number {
   return calculateStaticFieldRadiusYards(slvl) * 40
 }
 
+/**
+ * Calculates Frost Nova (Skill 44) synergy multiplier:
+ * +10% cold damage per hard point in Blizzard (59) and Frozen Orb (64).
+ */
+export function calculateFrostNovaSynergyMultiplier(synergies?: {
+  readonly blizzard?: number | undefined
+  readonly frozenOrb?: number | undefined
+} | number): number {
+  if (typeof synergies === 'number') {
+    return Number.isFinite(synergies) && synergies > 0 ? synergies : 1.0
+  }
+  const points = (synergies?.blizzard ?? 0) + (synergies?.frozenOrb ?? 0)
+  return 1.0 + points * 0.10
+}
+
+/**
+ * Calculates Frost Nova (Skill 44) cold damage range:
+ * 1.13c ground truth:
+ * - EMin: 4, EMax: 8
+ * - EMinLev1..5: [4, 6, 8, 10, 12]
+ * - EMaxLev1..5: [5, 7, 9, 11, 13]
+ * - HitShift: 7 (effective damage = base >> 1 = base / 2)
+ * - Synergies: +10% cold damage per hard point in Blizzard and Frozen Orb.
+ * - Kinematic: Expanding circular ring of 64 radial bolts with 2:1 isometric ground foreshortening.
+ */
+export function calculateFrostNovaDamage(
+  slvl: number,
+  synergies?: {
+    readonly blizzard?: number | undefined
+    readonly frozenOrb?: number | undefined
+  } | number,
+): { min: number; max: number } {
+  const lvl = Number.isFinite(slvl) ? Math.max(1, Math.floor(slvl)) : 1
+  const syn = calculateFrostNovaSynergyMultiplier(synergies)
+
+  const baseMin = compute5BandScaling(lvl, 4, 4, 6, 8, 10, 12)
+  const baseMax = compute5BandScaling(lvl, 8, 5, 7, 9, 11, 13)
+
+  const min = Math.floor((baseMin / 2) * syn)
+  const max = Math.floor((baseMax / 2) * syn)
+
+  return { min, max }
+}
+
+/**
+ * Calculates Frost Nova (Skill 44) cold chill duration in frames at 25 fps:
+ * 1.13c ground truth:
+ * - ELen: 200 frames (8.0 seconds)
+ * - ELevLen1..3: 25 frames (+1.0 second per level)
+ * - Formula: 200 + (slvl - 1) * 25 frames
+ */
+export function calculateFrostNovaChillLength(slvl: number): number {
+  const lvl = Number.isFinite(slvl) ? Math.max(1, Math.floor(slvl)) : 1
+  return 200 + (lvl - 1) * 25
+}
+
 /**
  * Authentic 1.13c Nova 5-band damage scaling (Skills.txt row 48):
  * EMin: 1, EMinLev1..5: 6, 7, 8, 9, 10
@@ -1280,6 +1336,19 @@ export class MissileEngine {
             }
           }
 
+          // Frost Nova (Skill 44 / missile frostnova): applies chilling slow
+          if (m.name === 'frostnova' || m.sourceSkillId === 44) {
+            if (!dmgOut.immuneToElem && !target.statList.getAccruedStat('cannot_be_frozen')) {
+              const chillFrames = m.dmgPacket.elemDurationFrames ?? calculateFrostNovaChillLength(m.slvl)
+              target.stateBus.applyState({
+                stateNameOrId: 'chill',
+                sourceSkillId: 44,
+                slvl: m.slvl,
+                durationFrames: chillFrames,
+              })
+            }
+          }
+
           // `pSrvHitFunc = 1` or `4` or `13`: radial splash damage (`Fire Ball`, `Exploding Arrow`, `Freezing Arrow`, `Glacial Spike`)
           if (
             m.record.pSrvHitFunc === 1 ||
@@ -1698,7 +1767,7 @@ export class MissileEngine {
     const spawned: ActiveMissile[] = []
     const skillId = params.sourceSkillId ?? 48
     const slvl = params.slvl ?? 1
-    const missileName = params.missileName ?? 'nova'
+    const missileName = params.missileName ?? (skillId === 44 ? 'frostnova' : 'nova')
     const speed = 24 // 1.13c Missiles.txt: Vel = 24
     for (let i = 0; i < 64; i++) {
       const angle = (i / 64) * 2 * Math.PI
@@ -1873,6 +1942,36 @@ export function spawnNovaRing(
   return bolts
 }
 
+/**
+ * Spawns 64 radial Frost Nova (Skill 44) missiles with 2:1 isometric ground foreshortening.
+ * In 1.13c: Exactly 64 missiles emitted radially (360 degrees), Vel = 24 (600 px/s), Range = 14 frames (336 px).
+ */
+export function spawnFrostNovaRing(
+  startX: number,
+  startY: number,
+  damage: number,
+  options?: {
+    skillId?: string
+    fromPlayer?: boolean
+    speed?: number
+    ttl?: number
+    slvl?: number
+    statusDuration?: number
+  }
+) {
+  const slvl = options?.slvl ?? 1
+  const statusDuration = options?.statusDuration ?? calculateFrostNovaChillLength(slvl)
+  return spawnNovaRing(startX, startY, damage, {
+    skillId: options?.skillId ?? '44',
+    missileType: 'frostnova',
+    fromPlayer: options?.fromPlayer ?? true,
+    speed: options?.speed ?? 24,
+    ttl: options?.ttl ?? 14,
+    statusEffect: 'chill',
+    statusDuration,
+  })
+}
+
 /**
  * Spawns 64 radial Poison Nova (Skill 92) missiles with 2:1 isometric ground foreshortening.
  * In 1.13c: Exactly 64 missiles emitted radially (360 degrees), fixed 2.0s duration (50 frames).

src/game/skills.ts

@@ -28,6 +28,10 @@ import type { CombatPlayer } from './combat.ts'
 import {
   FROZEN_ORB_X_POSITIONS,
   FROZEN_ORB_Y_POSITIONS,
+  calculateFrostNovaDamage,
+  calculateFrostNovaChillLength,
+  calculateFrostNovaSynergyMultiplier,
+  spawnFrostNovaRing,
   calculateNovaDamage,
   calculateStaticFieldDamage,
   calculateStaticFieldRadiusYards,
@@ -146,6 +150,10 @@ import {
   type SynergyState,
 } from './engine/missile-engine.ts'
 export {
+  calculateFrostNovaDamage,
+  calculateFrostNovaChillLength,
+  calculateFrostNovaSynergyMultiplier,
+  spawnFrostNovaRing,
   calculateNovaDamage,
   calculateStaticFieldDamage,
   calculateStaticFieldRadiusYards,
@@ -605,6 +613,29 @@ export const CANONICAL_113C_MISSILES: Readonly<Record<string, MissileTxtData>> =
     speedPxPerSec: 600,
     distancePx: 312,
   },
+  frostnova: {
+    name: 'frostnova',
+    id: 119,
+    vel: 24,
+    maxVel: 24,
+    range: 14,
+    levRange: 0,
+    celFile: 'FrostNova',
+    animLen: 14,
+    animSpeed: 16,
+    loopAnim: 1,
+    numDirections: 16,
+    explosionMissile: '',
+    light: 0,
+    red: 81,
+    green: 81,
+    blue: 255,
+    nextHit: 1,
+    nextDelay: 4,
+    trans: 1,
+    speedPxPerSec: 600,
+    distancePx: 336,
+  },
   firebolt: {
     name: 'firebolt',
     id: 58,
@@ -5402,6 +5433,7 @@ export function getSkillCooldownTicks(skillId: number): number {
     skillId === 41 ||
     skillId === 42 ||
     skillId === 43 ||
+    skillId === 44 ||
     skillId === 45 ||
     skillId === 46 ||
     skillId === 48 ||
@@ -5485,6 +5517,9 @@ export function calculateSkillDamage(
   if (skillId === 43 || skillId === '43' || skillId === 'telekinesis') {
     return calculateTelekinesisDamage(slvl)
   }
+  if (skillId === 44 || skillId === '44' || skillId === 'frostnova' || skillId === 'frost nova') {
+    return calculateFrostNovaDamage(slvl, synergies as any)
+  }
   if (skillId === 48 || skillId === '48' || skillId === 'nova') {
     return calculateNovaDamage(slvl, synergies as any)
   }

src/game/skills/registry.ts

@@ -719,6 +719,42 @@ export function executeSkillCore113c(ctx: SkillExecContext): SkillExecOutcome {
       }
     }
 
+    // Frost Nova (Skill 44): 1.13c expanding ring of 64 cold bolts with 2:1 isometric aspect ratio 0.5 and NextDelay 4
+    if (skill.id === 44) {
+      const casterPos = targetPositions?.get(caster.id) ?? { x: targetX, y: targetY }
+      const bolts = missileEngine.spawnNovaRing({
+        sourceSkillId: skill.id,
+        slvl: evalResult.slvl,
+        owner: caster,
+        startX: casterPos.x,
+        startY: casterPos.y,
+        missileName: 'frostnova',
+        dmgPacket: {
+          skillId: skill.id,
+          attackKind: 'spell',
+          elemType: evalResult.elemType,
+          elemMin256: evalResult.minElemDmg256,
+          elemMax256: evalResult.maxElemDmg256,
+          elemDurationFrames: evalResult.durationFrames,
+          autoHit: true,
+        },
+      })
+      missilesSpawned.push(...bolts.map(b => b.name))
+      return {
+        skillId: skill.id,
+        name: skill.name,
+        executed: true,
+        srvDoFuncUsed: effectiveDoFunc,
+        manaSpent256: evalResult.manaCost256,
+        missilesSpawned,
+        statesApplied,
+        petsSummoned,
+        corpsesConsumed,
+        totalDamageDealt: 0,
+        notes,
+      }
+    }
+
     // Nova (Skill 48): 1.13c expanding ring of 64 bolts with 2:1 isometric aspect ratio 0.5 and NextDelay 4
     if (skill.id === 48) {
       const casterPos = targetPositions?.get(caster.id) ?? { x: targetX, y: targetY }
@@ -794,7 +830,7 @@ export function executeSkillCore113c(ctx: SkillExecContext): SkillExecOutcome {
       }
     }
 
-    // Frost Nova (`44`), Poison Nova (`92`), War Cry (`154`), Howl (`130`)
+    // Poison Nova (`92`), War Cry (`154`), Howl (`130`)
     for (const t of targets) {
       if (t.statList.getHp256() <= 0) continue
       if (skill.id === 130) {

src/scene/act-scene.ts

@@ -46,7 +46,7 @@ import { buildNpcDef, hasPackedSprite } from '../game/npc.ts'
 import { ADDITIVE_OBJECT_TOKENS } from '../game/objects.ts'
 import { npcDialog } from '../game/quests.ts'
 import type { NpcDef } from '../game/quests.ts'
-import { BATCH1_SKILLS, getBatch1SkillDef, isBatch1Skill, getSkillManaCost, calculateSkillDamage, calculateMeteorResidualFireDamage, getMissileTxtData, ISO_GROUND_ASPECT_RATIO, getSkillCastOverlay, isAuraSkill, calculateStaticFieldRadiusPx, calculateStaticFieldDamage, hasLineOfSight, calculateChainLightningJumps, getSkillCooldownTicks, calculateChargedBoltCount, calculateTelekinesisDamage, isTelekinesisItemAllowed, isTelekinesisObjectAllowed, calculateThunderStormDuration, calculateThunderStormInterval, calculateEnergyShieldDuration, calculateEnergyShieldAbsorbPct, calculateFrozenArmorDuration, calculateShiverArmorDuration, calculateChillingArmorDuration, calculateIceBlastFreezeLength, calculateGlacialSpikeFreezeLength, calculateFireWallDamage, calculateBlazeDamage, calculateInfernoDamage, calculateBlazeDuration, calculateBlazePatchDuration, calculateInfernoRangePx, calculateInfernoContinuousMana256, calculateFireWallPatches, calculateEnchantDamage, calculateEnchantAttackRating, calculateEnchantDuration, calculateFireMasteryBonus, calculateTeethDamage, calculateTeethCount, calculateBoneArmorCapacity, calculatePoisonDaggerDamage, calculatePoisonDaggerAttackRatingBonus, calculateCorpseExplosionDamage, calculateCorpseExplosionRadiusPx, calculateBoneWallStats, calculatePoisonExplosionDamage, calculateBoneSpearDamage, calculateBonePrisonStats, calculatePoisonNovaDamage, calculateBoneSpiritDamage, calculateCurseEffect, calculateCurseRadiusPx, calculateCurseDurationFrames, calculateTerrorDistance, calculateIronMaidenReturnPct, calculateSkeletonMaxCount, calculateSkeletalMageMaxCount, calculateReviveMaxCount } from '../game/skills.ts'
+import { BATCH1_SKILLS, getBatch1SkillDef, isBatch1Skill, getSkillManaCost, calculateSkillDamage, calculateMeteorResidualFireDamage, getMissileTxtData, ISO_GROUND_ASPECT_RATIO, getSkillCastOverlay, isAuraSkill, calculateStaticFieldRadiusPx, calculateStaticFieldDamage, hasLineOfSight, calculateChainLightningJumps, getSkillCooldownTicks, calculateChargedBoltCount, calculateTelekinesisDamage, isTelekinesisItemAllowed, isTelekinesisObjectAllowed, calculateThunderStormDuration, calculateThunderStormInterval, calculateEnergyShieldDuration, calculateEnergyShieldAbsorbPct, calculateFrozenArmorDuration, calculateShiverArmorDuration, calculateChillingArmorDuration, calculateIceBlastFreezeLength, calculateGlacialSpikeFreezeLength, calculateFrostNovaDamage, calculateFrostNovaChillLength, calculateFireWallDamage, calculateBlazeDamage, calculateInfernoDamage, calculateBlazeDuration, calculateBlazePatchDuration, calculateInfernoRangePx, calculateInfernoContinuousMana256, calculateFireWallPatches, calculateEnchantDamage, calculateEnchantAttackRating, calculateEnchantDuration, calculateFireMasteryBonus, calculateTeethDamage, calculateTeethCount, calculateBoneArmorCapacity, calculatePoisonDaggerDamage, calculatePoisonDaggerAttackRatingBonus, calculateCorpseExplosionDamage, calculateCorpseExplosionRadiusPx, calculateBoneWallStats, calculatePoisonExplosionDamage, calculateBoneSpearDamage, calculateBonePrisonStats, calculatePoisonNovaDamage, calculateBoneSpiritDamage, calculateCurseEffect, calculateCurseRadiusPx, calculateCurseDurationFrames, calculateTerrorDistance, calculateIronMaidenReturnPct, calculateSkeletonMaxCount, calculateSkeletalMageMaxCount, calculateReviveMaxCount } from '../game/skills.ts'
 import type { Projectile, ActiveOverlay } from '../game/skills.ts'
 import { findSafeDropPosition, calculateBounceHeight, triggerFlippyBounce, type GroundItemEntity } from '../game/ground-items.ts'
 import {
@@ -1454,23 +1454,6 @@ export function castSkill(
     return true
   }
 
-  if (skillId === 44) {
-    // Frost Nova: AoE radius 240 around player
-    let hitCount = 0
-    for (const monster of engine.world.monsters) {
-      if (monster.state === 'dead' || monster.hp <= 0) continue
-      if (Math.hypot(monster.x - player.x, monster.y - player.y) <= 240) {
-        damageMonster(engine.world, monster.index, 20)
-        engine.metrics.castHits += 1
-        hitCount++
-      }
-    }
-    player.cooldown = 10
-    engine.metrics.casts += 1
-    status.textContent = `施展霜之新星，命中 ${hitCount} 个目标`
-    return true
-  }
-
   if (skillId === 42) {
     // Static Field (Skill 42): Instantaneous 360° area discharge
     // 1.13c: Radius = (4 + slvl) yards = (4 + slvl) * 40 px in 2D ground plane
@@ -2616,6 +2599,24 @@ export function castSkill(
     isNova = true
     multiCount = 64
     skillName = '新星'
+  } else if (skillId === 44) {
+    const missile = getMissileTxtData('frostnova')
+    speed = missile.speedPxPerSec || 600
+    range = missile.distancePx || 336
+    const slvl = Math.max(1, (hudManager as any)?.getSkillLevel?.(44) ?? 1)
+    const blizzardBlvl = (hudManager as any)?.getSkillLevel?.(59) ?? 0
+    const frozenOrbBlvl = (hudManager as any)?.getSkillLevel?.(64) ?? 0
+    const synergies = { blizzard: blizzardBlvl, frozenOrb: frozenOrbBlvl }
+    const dmgRange = calculateFrostNovaDamage(slvl, synergies)
+    damage = Math.round((dmgRange.min + dmgRange.max) / 2)
+    delay = 0
+    statusEffect = 'chill'
+    statusDuration = calculateFrostNovaChillLength(slvl)
+    missileType = 'frostnova'
+    isNova = true
+    multiCount = 64
+    nextDelay = 4
+    skillName = '霜之新星'
   } else if (skillId === 101) {
     const missile = getMissileTxtData('holybolt')
     speed = missile.speedPxPerSec || 500
@@ -2845,7 +2846,7 @@ export function castSkill(
   }
 
   const cdTicks = getSkillCooldownTicks(skillId)
-  player.cooldown = cdTicks > 0 ? cdTicks : (delay > 0 ? delay : (skillId === 38 || skillId === 43 || skillId === 48 || skillId === 49 || skillId === 53 || skillId === 42 ? 0 : 10))
+  player.cooldown = cdTicks > 0 ? cdTicks : (delay > 0 ? delay : (skillId === 38 || skillId === 43 || skillId === 44 || skillId === 48 || skillId === 49 || skillId === 53 || skillId === 42 ? 0 : 10))
   engine.metrics.casts += 1
   status.textContent = `施展技能：${skillName}`
   return true

tests/skills/sor/skill-044-frost-nova.test.ts

@@ -1,109 +1,544 @@
 /**
- * 1.13c Numerical & Runtime Verification Suite — Skill #044: Frost Nova (SOR)
+ * 1.13c Numerical & Runtime 7-Dimensional Verification Suite — Skill #044: Frost Nova (SOR)
- * Gitea Tracking Issue: #198
+ * Gitea Tracking Issue: #431
+ *
+ * 7-Dimensional Verification Coverage:
+ * D1: 1.13c Data Table Parsing & Canonical Missile Definition (Skills.txt row 44, Missiles.txt 'frostnova')
+ * D2: Visual Assets & Metadata Integrity (frostnova.png/json, ice_cast_2.png/json, Additive Blending)
+ * D3: Kinematics & 64-Bolt Circular Ring Dispersion (24 vel, 14 range, 2:1 isometric ground foreshortening)
+ * D4: NextDelay = 4 Single-Hit Lockout Protection (Prevents point-blank 64x multi-hit stack)
+ * D5: Obstacle & Terrain Collision Clipping (Wall collisions expire missiles, open space continues)
+ * D6: 1.13c 5-Band Damage Scaling, Chill Duration & Synergy Verification (2-4 at lvl 1, 22-28 at lvl 10, 56-67 at lvl 20; +10%/lvl Blizzard & Frozen Orb)
+ * D7: WorldArena & Runtime Cast Integration (Cast action frame, mana cost, 0 cooldown, overlay attachment, chill state application)
  */
 import { describe, expect, it } from 'vitest'
+import fs from 'node:fs'
+import path from 'node:path'
 import { getSharedDataRegistry } from '../../../src/game/engine/data-registry.ts'
 import { UnitStatList } from '../../../src/game/engine/stat-list.ts'
+import { StateBus } from '../../../src/game/engine/state-bus.ts'
 import { WorldArena } from '../../../src/game/engine/world-arena.ts'
 import { skillModule } from '../../../src/game/skills/impl/sor/skill-044-frost-nova.ts'
+import {
+  parseMissilesTxt,
+  getMissileTxtData,
+  CANONICAL_113C_MISSILES,
+  getSkillManaCost,
+  getSkillCooldownTicks,
+  getSkillCastOverlay,
+  SORCERESS_SKILL_CAST_OVERLAYS,
+  calculateFrostNovaDamage,
+  calculateFrostNovaChillLength,
+  calculateFrostNovaSynergyMultiplier,
+  calculateSkillDamage,
+  tickProjectiles,
+  ISO_GROUND_ASPECT_RATIO,
+  type Projectile,
+} from '../../../src/game/skills.ts'
+import {
+  MissileEngine,
+  spawnFrostNovaRing,
+  spawnNovaRing,
+} from '../../../src/game/engine/missile-engine.ts'
+import {
+  FROSTNOVA_META,
+  MISSILE_METAS,
+} from '../../../src/render/missiles-meta.ts'
+import {
+  ICE_CAST_2_META,
+  OVERLAY_METAS,
+} from '../../../src/render/overlays-meta.ts'
 
-describe('[Skill #044] Frost Nova (SOR) — 1.13c Parity (Issue #198)', () => {
+describe('[Skill #044] Frost Nova (SOR) — 1.13c 7-Dimensional Verification Suite (Issue #431)', () => {
-  it('evaluates exact 1.13c Skills.txt / Missiles.txt formulas at slvl 1, 10, and 20', async () => {
+  const missilesTxtPath = path.resolve(__dirname, '../../../samples/fixtures/data/global/excel/Missiles.txt')
-    const registry = await getSharedDataRegistry()
+  const missilesTxtContent = fs.readFileSync(missilesTxtPath, 'latin1')
-    const skillRec = registry.getSkillById(44)!
+  const skillsTxtPath = path.resolve(__dirname, '../../../samples/fixtures/data/global/excel/Skills.txt')
-    expect(skillRec).toBeDefined()
+  const skillsTxtContent = fs.readFileSync(skillsTxtPath, 'latin1')
-    expect(skillModule.skillId).toBe(44)
-    expect(skillModule.name).toBe("Frost Nova")
-    expect(skillModule.charClass).toBe("sor")
 
-    const stats1 = new UnitStatList()
+  // =========================================================================
-    stats1.setBaseSkillLevel(44, 1)
+  // Dimension 1: 1.13c Data Table Parsing & Canonical Missile Definition
-    const r1 = skillModule.evaluate!({ registry, skill: skillRec, slvl: 1, blvl: 1, statList: stats1 })
+  // =========================================================================
-    expect(r1.manaCost).toBe(9)
+  describe('Dimension 1: 1.13c Data Table Parsing & Canonical Missile Definition', () => {
-    expect(r1.manaCost256).toBe(2304)
+    it('parses authentic Skills.txt row 44 (Frost Nova)', () => {
-    expect(r1.minPhysDmg).toBe(0)
+      const lines = skillsTxtContent.split('\n')
-    expect(r1.maxPhysDmg).toBe(0)
+      const headers = lines[0]!.split('\t')
-    expect(r1.minElemDmg256).toBe(512)
+      const idIdx = headers.indexOf('Id')
-    expect(r1.maxElemDmg256).toBe(1024)
+      const skillIdx = headers.indexOf('skill')
+      const charClassIdx = headers.indexOf('charclass')
+      const manaIdx = headers.indexOf('mana')
+      const lvlManaIdx = headers.indexOf('lvlmana')
+      const srvDoFuncIdx = headers.indexOf('srvdofunc')
+      const castOverlayIdx = headers.indexOf('castoverlay')
+      const srvMissileAIdx = headers.indexOf('srvmissilea')
+      const delayIdx = headers.indexOf('delay')
 
-    const stats10 = new UnitStatList()
+      const fnRow = lines.slice(1).map(l => l.split('\t')).find(r => r[idIdx] === '44')
-    stats10.setBaseSkillLevel(44, 10)
+      expect(fnRow).toBeDefined()
-    const r10 = skillModule.evaluate!({ registry, skill: skillRec, slvl: 10, blvl: 10, statList: stats10 })
+      expect(fnRow![skillIdx]).toBe('Frost Nova')
-    expect(r10.manaCost).toBe(18)
+      expect(fnRow![charClassIdx]).toBe('sor')
-    expect(r10.manaCost256).toBe(4608)
+      expect(Number(fnRow![manaIdx])).toBe(9)
-    expect(r10.minPhysDmg).toBe(0)
+      expect(Number(fnRow![lvlManaIdx])).toBe(1)
-    expect(r10.maxPhysDmg).toBe(0)
+      expect(Number(fnRow![srvDoFuncIdx])).toBe(22) // Identical to Nova (#48)
-    expect(r10.minElemDmg256).toBe(5632)
+      expect(fnRow![castOverlayIdx]).toBe('ice_cast_2')
-    expect(r10.maxElemDmg256).toBe(7296)
+      expect(fnRow![srvMissileAIdx]).toBe('frostnova')
+      expect(fnRow![delayIdx] || '').toBe('') // 0 cooldown
+    })
 
-    const stats20 = new UnitStatList()
+    it('parses authentic Missiles.txt row for frostnova (ID 119)', () => {
-    stats20.setBaseSkillLevel(44, 20)
+      const map = parseMissilesTxt(missilesTxtContent)
-    const r20 = skillModule.evaluate!({ registry, skill: skillRec, slvl: 20, blvl: 20, statList: stats20 })
+      const fn = map.get('frostnova')
-    expect(r20.manaCost).toBe(28)
+      expect(fn).toBeDefined()
-    expect(r20.manaCost256).toBe(7168)
+      expect(fn!.id).toBe(119)
-    expect(r20.minPhysDmg).toBe(0)
+      expect(fn!.vel).toBe(24)
-    expect(r20.maxPhysDmg).toBe(0)
+      expect(fn!.range).toBe(14)
-    expect(r20.minElemDmg256).toBe(14336)
+      expect(fn!.speedPxPerSec).toBe(600) // 24 * 25
-    expect(r20.maxElemDmg256).toBe(17280)
+      expect(fn!.distancePx).toBe(336) // 24 * 14
-    expect(r20.durationFrames).toBe(675)
+      expect(fn!.celFile.toLowerCase()).toBe('frostnova')
-    expect(r20.radiusSubtiles).toBe(66)
+      expect(fn!.animLen).toBe(14)
-    expect(r20.petMax).toBe(0)
+      expect(fn!.nextHit).toBe(1)
-    expect(r20.cooldownFrames).toBe(0)
+      expect(fn!.nextDelay).toBe(4)
+      expect(fn!.trans).toBe(1)
+    })
+
+    it('CANONICAL_113C_MISSILES contains exact frostnova definition', () => {
+      const fn = getMissileTxtData('frostnova')
+      expect(fn.id).toBe(119)
+      expect(fn.vel).toBe(24)
+      expect(fn.range).toBe(14)
+      expect(fn.speedPxPerSec).toBe(600)
+      expect(fn.distancePx).toBe(336)
+      expect(fn.nextDelay).toBe(4)
+      expect(fn.celFile.toLowerCase()).toBe('frostnova')
+      expect(fn.trans).toBe(1)
+    })
   })
 
-  it('enforces 1.13c blvl synergy rule (hard points boost synergy; +skills and item charges do NOT)', async () => {
+  // =========================================================================
-    const registry = await getSharedDataRegistry()
+  // Dimension 2: Visual Assets & Metadata Integrity
-    const skillRec = registry.getSkillById(44)!
+  // =========================================================================
-    const synId = 59
+  describe('Dimension 2: Visual Assets & Metadata Integrity', () => {
+    it('verifies baked DCC atlas sprite sheet files exist with non-zero size', () => {
+      const missilePng = path.resolve(__dirname, '../../../public/missiles/frostnova.png')
+      const missileJson = path.resolve(__dirname, '../../../public/missiles/frostnova.json')
+      const overlayPng = path.resolve(__dirname, '../../../public/overlays/ice_cast_2.png')
+      const overlayJson = path.resolve(__dirname, '../../../public/overlays/ice_cast_2.json')
 
-    const statsBase = new UnitStatList()
+      expect(fs.existsSync(missilePng)).toBe(true)
-    statsBase.setBaseSkillLevel(44, 20)
+      expect(fs.statSync(missilePng).size).toBeGreaterThan(10000)
-    if (synId !== null) {
+      expect(fs.existsSync(missileJson)).toBe(true)
-      statsBase.setBaseSkillLevel(synId, 20)
+      expect(fs.existsSync(overlayPng)).toBe(true)
-    }
+      expect(fs.statSync(overlayPng).size).toBeGreaterThan(10000)
-    const withHardPoints = skillModule.evaluate!({
+      expect(fs.existsSync(overlayJson)).toBe(true)
-      registry,
-      skill: skillRec,
-      slvl: 20,
-      blvl: 20,
-      statList: statsBase,
     })
-    expect(withHardPoints.synergyBonusPct).toBe(200)
 
-    // +20 allskills and +33 Marrowwalk charges without hard points must yield 0 synergy
+    it('verifies FROSTNOVA_META metadata and registry registration', () => {
-    const statsSoftOnly = new UnitStatList()
+      expect(FROSTNOVA_META.name).toBe('frostnova')
-    statsSoftOnly.setBaseSkillLevel(44, 20)
+      expect(FROSTNOVA_META.celFile).toBe('FrostNova')
-    statsSoftOnly.addStat('item_allskills', 20)
+      expect(FROSTNOVA_META.directions).toBe(16)
-    if (synId !== null) {
+      expect(FROSTNOVA_META.framesPerDirection).toBe(14)
-      statsSoftOnly.setChargedSkillLevel(synId, 33)
+      expect(MISSILE_METAS['frostnova']).toBe(FROSTNOVA_META)
-    }
+      expect(MISSILE_METAS['FrostNova']).toBe(FROSTNOVA_META)
-    const withSoftOnly = skillModule.evaluate!({
+    })
-      registry,
+
-      skill: skillRec,
+    it('verifies cast overlay mapping and metadata', () => {
-      slvl: 20,
+      expect(SORCERESS_SKILL_CAST_OVERLAYS[44]).toBe('ice_cast_2')
-      blvl: 20,
+      expect(getSkillCastOverlay(44)).toBe('ice_cast_2')
-      statList: statsSoftOnly,
+      expect(ICE_CAST_2_META.name).toBe('ice_cast_2')
+      expect(OVERLAY_METAS['ice_cast_2']).toBe(ICE_CAST_2_META)
     })
-    expect(withSoftOnly.synergyBonusPct).toBe(0)
   })
 
-  it('executes runtime skill effect in WorldArena (castCount, action frame, and combat/state/missile/summon outcome)', async () => {
+  // =========================================================================
-    const registry = await getSharedDataRegistry()
+  // Dimension 3: Kinematics & 64-Bolt Circular Ring Dispersion
-    const arena = new WorldArena({
+  // =========================================================================
-      registry,
+  describe('Dimension 3: Kinematics & 64-Bolt Circular Ring Dispersion', () => {
-      classCode: "sor",
+    it('spawnFrostNovaRing emits exactly 64 bolts with uniform angular distribution and chill effect', () => {
-      skillId: 44,
+      const bolts = spawnFrostNovaRing(200, 300, 25, { slvl: 5 })
-      slvl: 20,
+      expect(bolts.length).toBe(64)
-    })
-    const outcome = arena.triggerCast()
-    arena.stepTicks(15)
-    const dbg = arena.getDebugState()
 
-    expect(dbg.ready).toBe(true)
+      for (let i = 0; i < 64; i++) {
-    expect(dbg.skillId).toBe(44)
+        const b = bolts[i]!
-    expect(dbg.castCount).toBeGreaterThanOrEqual(1)
+        expect(b.x).toBe(200)
-    expect(dbg.actionFrameTriggered).toBe(true)
+        expect(b.y).toBe(300)
-    expect(outcome?.executed).toBe(true)
+        expect(b.damage).toBe(25)
+        expect(b.ttl).toBe(14) // Range = 14
+        expect(b.missileType).toBe('frostnova')
+        expect(b.fromPlayer).toBe(true)
+        expect(b.nextDelay).toBe(4)
+        expect(b.statusEffect).toBe('chill')
+        expect(b.statusDuration).toBe(200 + (5 - 1) * 25) // 300 frames
+
+        const expectedAngle = (i / 64) * Math.PI * 2
+        const expectedVx = Math.cos(expectedAngle) * 24
+        const expectedVy = Math.sin(expectedAngle) * 24 * ISO_GROUND_ASPECT_RATIO
+
+        expect(b.vx).toBeCloseTo(expectedVx, 4)
+        expect(b.vy).toBeCloseTo(expectedVy, 4)
+      }
+    })
+
+    it('enforces 2:1 isometric ground foreshortening (ISO_GROUND_ASPECT_RATIO = 0.5)', () => {
+      const bolts = spawnFrostNovaRing(0, 0, 50)
+      const eastBolt = bolts[0]! // angle = 0, cos = 1, sin = 0
+      const southBolt = bolts[16]! // angle = pi/2, cos = 0, sin = 1
+      const westBolt = bolts[32]! // angle = pi, cos = -1, sin = 0
+      const northBolt = bolts[48]! // angle = 3pi/2, cos = 0, sin = -1
+
+      expect(eastBolt.vx).toBeCloseTo(24, 4)
+      expect(eastBolt.vy).toBeCloseTo(0, 4)
+
+      expect(southBolt.vx).toBeCloseTo(0, 4)
+      expect(southBolt.vy).toBeCloseTo(12, 4) // 24 * 0.5 = 12
+
+      expect(westBolt.vx).toBeCloseTo(-24, 4)
+      expect(westBolt.vy).toBeCloseTo(0, 4)
+
+      expect(northBolt.vx).toBeCloseTo(0, 4)
+      expect(northBolt.vy).toBeCloseTo(-12, 4) // -24 * 0.5 = -12
+    })
+
+    it('expanding ring maintains true elliptical shape over 5 ticks in open space', () => {
+      let bolts: readonly Projectile[] = spawnFrostNovaRing(0, 0, 50)
+      const openTerrain = { overlap: () => 0 }
+
+      for (let tick = 1; tick <= 5; tick++) {
+        const outcome = tickProjectiles(bolts, [], openTerrain)
+        bolts = outcome.alive
+      }
+
+      expect(bolts.length).toBe(64)
+      // At tick 5: horizontal displacement = 5 * 24 = 120 px, vertical = 5 * 12 = 60 px
+      for (const b of bolts) {
+        const normalizedX = b.x / 120
+        const normalizedY = b.y / 60
+        const radiusSq = normalizedX * normalizedX + normalizedY * normalizedY
+        expect(radiusSq).toBeCloseTo(1.0, 2)
+      }
+    })
+  })
+
+  // =========================================================================
+  // Dimension 4: NextDelay = 4 Single-Hit Lockout Protection
+  // =========================================================================
+  describe('Dimension 4: NextDelay = 4 Single-Hit Lockout Protection', () => {
+    it('prevents point-blank overlapping multi-hit stack (target takes damage from only 1 bolt)', () => {
+      // Spawn 64 radial bolts from (0, 0)
+      const bolts = spawnFrostNovaRing(0, 0, 50)
+      // Target at point-blank (x: 10, y: 0) with radius 15
+      const target = { index: 1, x: 10, y: 0, radius: 15, alive: true }
+      const nextDelayMap = new Map<number, number>()
+
+      const outcome = tickProjectiles(bolts, [target], {
+        overlap: () => 0,
+        nextDelayByTarget: nextDelayMap,
+        currentTick: 1,
+      })
+
+      // Multiple bolts passed through the target, but NextDelay = 4 locks out further hits
+      expect(outcome.hits.length).toBe(1)
+      expect(outcome.hits[0]!.targetIndex).toBe(1)
+      expect(outcome.hits[0]!.damage).toBe(50)
+
+      // Target must have lockout until tick 1 + 4 = 5
+      expect(nextDelayMap.get(1)).toBe(5)
+
+      // Next tick (tick 2), target is still in lockout
+      const outcome2 = tickProjectiles(outcome.alive, [target], {
+        overlap: () => 0,
+        nextDelayByTarget: nextDelayMap,
+        currentTick: 2,
+      })
+      expect(outcome2.hits.length).toBe(0)
+      expect(nextDelayMap.get(1)).toBe(5)
+    })
+  })
+
+  // =========================================================================
+  // Dimension 5: Obstacle & Terrain Collision Clipping
+  // =========================================================================
+  describe('Dimension 5: Obstacle & Terrain Collision Clipping', () => {
+    it('expires bolts moving into solid walls while open-air bolts continue', () => {
+      const bolts = spawnFrostNovaRing(0, 0, 50)
+      // Solid wall at x >= 40
+      const wallTerrain = { overlap: (x: number) => (x >= 40 ? 1 : 0) }
+
+      // Step 3 ticks: x speed is 24 px/tick. By tick 3, all eastern bolts reach x >= 40
+      const step1 = tickProjectiles(bolts, [], wallTerrain)
+      const step2 = tickProjectiles(step1.alive, [], wallTerrain)
+      const step3 = tickProjectiles(step2.alive, [], wallTerrain)
+
+      expect(step3.wallHits).toBeGreaterThan(0)
+      // Eastern bolts (vx > 15) must have hit the wall and died
+      const survivingEastBolts = step3.alive.filter(b => b.vx > 15)
+      expect(survivingEastBolts.length).toBe(0)
+
+      // Western bolts (vx < 0) are in negative x (open space) and survive
+      const survivingWestBolts = step3.alive.filter(b => b.vx < 0)
+      expect(survivingWestBolts.length).toBeGreaterThan(0)
+    })
+
+    it('MissileEngine.tick detects obstacle collision and sets expired = true', async () => {
+      const registry = await getSharedDataRegistry()
+      const engine = new MissileEngine(registry)
+      const statList = new UnitStatList()
+      const stateBus = new StateBus(statList, registry)
+      const dummyOwner = {
+        id: 'player',
+        x: 0,
+        y: 0,
+        statList,
+        stateBus,
+      } as any
+      engine.spawnMissile({
+        missileNameOrId: 'frostnova',
+        sourceSkillId: 44,
+        slvl: 1,
+        owner: dummyOwner,
+        startX: 0,
+        startY: 0,
+        targetX: 100,
+        targetY: 0,
+        dmgPacket: { minDamage: 10, maxDamage: 10, damageType: 'cold' } as any,
+        vx: 24,
+        vy: 0,
+        maxRangeTicks: 14,
+      })
+
+      // Wall at x >= 20 passed as 4th argument (collision) to engine.tick
+      const collision = { isMissileBlocked: (x: number) => x >= 20 }
+      engine.tick(1, [], new Map(), collision)
+
+      // Missile moved to x=24 >= 20, must be marked expired and purged
+      const active = engine.getActiveMissiles()
+      expect(active.length).toBe(0)
+    })
+  })
+
+  // =========================================================================
+  // Dimension 6: 1.13c 5-Band Damage Scaling & Synergy Verification
+  // =========================================================================
+  describe('Dimension 6: 1.13c 5-Band Damage Scaling, Chill Duration & Synergy Verification', () => {
+    it('calculates exact 1.13c 5-band damage at slvl 1, 10, 20, and 30', () => {
+      // slvl 1: EMin 4, EMax 8, HitShift 7 -> 2-4
+      const d1 = calculateFrostNovaDamage(1)
+      expect(d1.min).toBe(2)
+      expect(d1.max).toBe(4)
+
+      // slvl 10: baseMin = 4 + 7*4 + 2*6 = 44 -> 22, baseMax = 8 + 7*5 + 2*7 = 57 -> 28
+      const d10 = calculateFrostNovaDamage(10)
+      expect(d10.min).toBe(22)
+      expect(d10.max).toBe(28)
+
+      // slvl 20: baseMin = 4 + 7*4 + 8*6 + 4*8 = 112 -> 56, baseMax = 8 + 7*5 + 8*7 + 4*9 = 135 -> 67
+      const d20 = calculateFrostNovaDamage(20)
+      expect(d20.min).toBe(56)
+      expect(d20.max).toBe(67)
+
+      // slvl 30: baseMin = 112 + 2*8 + 6*10 + 2*12 = 212 -> 106, baseMax = 135 + 2*9 + 6*11 + 2*13 = 245 -> 122
+      const d30 = calculateFrostNovaDamage(30)
+      expect(d30.min).toBe(106)
+      expect(d30.max).toBe(122)
+    })
+
+    it('calculates exact 1.13c chilling duration (200 + (slvl - 1) * 25 frames)', () => {
+      expect(calculateFrostNovaChillLength(1)).toBe(200) // 8.0s
+      expect(calculateFrostNovaChillLength(10)).toBe(425) // 17.0s
+      expect(calculateFrostNovaChillLength(20)).toBe(675) // 27.0s
+      expect(calculateFrostNovaChillLength(30)).toBe(925) // 37.0s
+    })
+
+    it('calculates synergy bonus from Blizzard (#59) and Frozen Orb (#64) (+10% per hard point)', () => {
+      // 0 synergy
+      expect(calculateFrostNovaSynergyMultiplier({})).toBe(1.0)
+      expect(calculateFrostNovaSynergyMultiplier({ blizzard: 0, frozenOrb: 0 })).toBe(1.0)
+
+      // 20 points in Blizzard: +200% -> multiplier 3.0
+      expect(calculateFrostNovaSynergyMultiplier({ blizzard: 20 })).toBe(3.0)
+      const dBlizzard20 = calculateFrostNovaDamage(20, { blizzard: 20 })
+      expect(dBlizzard20.min).toBe(56 * 3) // 168
+      expect(dBlizzard20.max).toBe(Math.floor(67.5 * 3)) // 202
+
+      // 20 points Blizzard + 20 points Frozen Orb: +400% -> multiplier 5.0
+      expect(calculateFrostNovaSynergyMultiplier({ blizzard: 20, frozenOrb: 20 })).toBe(5.0)
+      const dMaxSyn = calculateFrostNovaDamage(20, { blizzard: 20, frozenOrb: 20 })
+      expect(dMaxSyn.min).toBe(56 * 5) // 280
+      expect(dMaxSyn.max).toBe(Math.floor(67.5 * 5)) // 337
+    })
+
+    it('calculateSkillDamage routes skill 44 correctly', () => {
+      const d1 = calculateSkillDamage(44, 1)
+      expect(d1.min).toBe(2)
+      expect(d1.max).toBe(4)
+
+      const d20Syn = calculateSkillDamage('frostnova', 20, { blizzard: 20, frozenOrb: 20 })
+      expect(d20Syn.min).toBe(280)
+      expect(d20Syn.max).toBe(337)
+    })
+
+    it('evaluates exact 1.13c Skills.txt formulas in skillModule.evaluate', async () => {
+      const registry = await getSharedDataRegistry()
+      const skillRec = registry.getSkillById(44)!
+      expect(skillRec).toBeDefined()
+      expect(skillModule.skillId).toBe(44)
+      expect(skillModule.name).toBe("Frost Nova")
+      expect(skillModule.charClass).toBe("sor")
+
+      const stats1 = new UnitStatList()
+      stats1.setBaseSkillLevel(44, 1)
+      const r1 = skillModule.evaluate!({ registry, skill: skillRec, slvl: 1, blvl: 1, statList: stats1 })
+      expect(r1.manaCost).toBe(9)
+      expect(r1.manaCost256).toBe(2304)
+      expect(r1.minElemDmg256).toBe(512) // 2 * 256
+      expect(r1.maxElemDmg256).toBe(1024) // 4 * 256
+      expect(r1.durationFrames).toBe(200)
+
+      const stats10 = new UnitStatList()
+      stats10.setBaseSkillLevel(44, 10)
+      const r10 = skillModule.evaluate!({ registry, skill: skillRec, slvl: 10, blvl: 10, statList: stats10 })
+      expect(r10.manaCost).toBe(18)
+      expect(r10.manaCost256).toBe(4608)
+      expect(r10.minElemDmg256).toBe(5632) // 22 * 256
+      expect(r10.maxElemDmg256).toBe(7296) // 28.5 * 256
+      expect(r10.durationFrames).toBe(425)
+
+      const stats20 = new UnitStatList()
+      stats20.setBaseSkillLevel(44, 20)
+      const r20 = skillModule.evaluate!({ registry, skill: skillRec, slvl: 20, blvl: 20, statList: stats20 })
+      expect(r20.manaCost).toBe(28)
+      expect(r20.manaCost256).toBe(7168)
+      expect(r20.minElemDmg256).toBe(14336) // 56 * 256
+      expect(r20.maxElemDmg256).toBe(17280) // 67.5 * 256
+      expect(r20.durationFrames).toBe(675)
+      expect(r20.cooldownFrames).toBe(0)
+    })
+
+    it('enforces 1.13c blvl synergy rule (hard points boost synergy; +skills and item charges do NOT)', async () => {
+      const registry = await getSharedDataRegistry()
+      const skillRec = registry.getSkillById(44)!
+
+      const statsBase = new UnitStatList()
+      statsBase.setBaseSkillLevel(44, 20)
+      statsBase.setBaseSkillLevel(59, 20) // Blizzard 20
+      statsBase.setBaseSkillLevel(64, 20) // Frozen Orb 20
+
+      const withHardPoints = skillModule.evaluate!({
+        registry,
+        skill: skillRec,
+        slvl: 20,
+        blvl: 20,
+        statList: statsBase,
+      })
+      expect(withHardPoints.synergyBonusPct).toBe(400)
+
+      const statsSoftOnly = new UnitStatList()
+      statsSoftOnly.setBaseSkillLevel(44, 20)
+      statsSoftOnly.addStat('item_allskills', 20)
+      statsSoftOnly.setChargedSkillLevel(59, 33)
+      statsSoftOnly.setChargedSkillLevel(64, 33)
+
+      const withSoftOnly = skillModule.evaluate!({
+        registry,
+        skill: skillRec,
+        slvl: 20,
+        blvl: 20,
+        statList: statsSoftOnly,
+      })
+      expect(withSoftOnly.synergyBonusPct).toBe(0)
+    })
+  })
+
+  // =========================================================================
+  // Dimension 7: WorldArena & Runtime Cast Integration
+  // =========================================================================
+  describe('Dimension 7: WorldArena & Runtime Cast Integration', () => {
+    it('executes runtime skill effect in WorldArena (castCount, action frame, and combat outcome)', async () => {
+      const registry = await getSharedDataRegistry()
+      const arena = new WorldArena({
+        registry,
+        classCode: "sor",
+        skillId: 44,
+        slvl: 20,
+      })
+      const outcome = arena.triggerCast()
+      arena.stepTicks(15)
+      const dbg = arena.getDebugState()
+
+      expect(dbg.ready).toBe(true)
+      expect(dbg.skillId).toBe(44)
+      expect(dbg.castCount).toBeGreaterThanOrEqual(1)
+      expect(dbg.actionFrameTriggered).toBe(true)
+      expect(outcome?.executed).toBe(true)
+    })
+
+    it('verifies getSkillManaCost and getSkillCooldownTicks (0 cooldown)', () => {
+      expect(getSkillManaCost(44, 1)).toBe(9)
+      expect(getSkillManaCost(44, 10)).toBe(18)
+      expect(getSkillManaCost(44, 20)).toBe(28)
+      expect(getSkillCooldownTicks(44)).toBe(0)
+    })
+
+    it('applies chill state to target stateBus upon frostnova missile collision in MissileEngine.tick', async () => {
+      const registry = await getSharedDataRegistry()
+      const engine = new MissileEngine(registry)
+
+      const playerStatList = new UnitStatList()
+      const playerStateBus = new StateBus(playerStatList, registry)
+      const playerUnit = {
+        id: 'player',
+        x: 0,
+        y: 0,
+        statList: playerStatList,
+        stateBus: playerStateBus,
+      } as any
+
+      const monsterStatList = new UnitStatList()
+      monsterStatList.setBaseStat('maxhp', 500)
+      monsterStatList.setHp256(500 * 256)
+      const monsterStateBus = new StateBus(monsterStatList, registry)
+      const monsterUnit = {
+        id: 'monster-1',
+        statList: monsterStatList,
+        stateBus: monsterStateBus,
+      } as any
+
+      // Spawn a frostnova missile directed straight at the monster at (24, 0)
+      engine.spawnMissile({
+        missileNameOrId: 'frostnova',
+        sourceSkillId: 44,
+        slvl: 10,
+        owner: playerUnit,
+        startX: 0,
+        startY: 0,
+        targetX: 100,
+        targetY: 0,
+        dmgPacket: {
+          skillId: 44,
+          attackKind: 'spell',
+          elemType: 'cold',
+          elemMin256: 22 * 256,
+          elemMax256: 28 * 256,
+          elemDurationFrames: 425,
+          autoHit: true,
+        },
+        vx: 24,
+        vy: 0,
+        maxRangeTicks: 14,
+      })
+
+      const targetPositions = new Map<string, { x: number; y: number }>([
+        ['monster-1', { x: 24, y: 0 }],
+      ])
+
+      const outcome = engine.tick(1, [monsterUnit], targetPositions)
+      expect(outcome.hits.length).toBe(1)
+      expect(outcome.hits[0]!.targetId).toBe('monster-1')
+      expect(outcome.hits[0]!.missileName).toBe('frostnova')
+
+      // Target must have received chill state with durationFrames = 425
+      expect(monsterStateBus.hasState('chill')).toBe(true)
+      const entry = monsterStateBus.getActiveEntries().find(s => s.stateName === 'chill')
+      expect(entry).toBeDefined()
+      expect(entry!.durationFrames).toBe(425)
+    })
   })
 })