fix(skill): implement Hydra summon cap and authentic entity visuals (Fixes #436)

src/scene/act-scene.ts

@@ -1509,6 +1509,8 @@ export function getSkillMana(skillId: number, hudManager?: HudManager | null): n
   }
 }
 
+let hydraGroupSeqCounter = 0
+
 export function castSkill(
   skillId: number,
   targetX: number,
@@ -1612,7 +1614,7 @@ export function castSkill(
       player.mana = Math.max(0, player.mana - manaCost)
       if (hudManager !== null) {
         hudManager.mana = Math.max(0, hudManager.mana - manaCost)
-        hudManager.syncPublishedState()
+        hudManager.syncPublishedState?.()
       }
     }
   }
@@ -2219,10 +2221,28 @@ export function castSkill(
       { dx: 0, dy: -7 },
       { dx: 4, dy: -15 },
     ]
-    const slvl = 1
+    const slvl = Math.max(1, (hudManager as any)?.getSkillLevel?.(62) ?? 1)
     const dmgRange = calculateSkillDamage(62, slvl)
     const hydraDamage = Math.round((dmgRange.min + dmgRange.max) / 2)
 
+    // Enforce 1.13c Hydra summon cap (MAX_ACTIVE_HYDRA_GROUPS = 6 groups, 18 heads max) with FIFO eviction
+    const MAX_ACTIVE_HYDRA_GROUPS = 6
+    const activeTurrets = engine.projectiles.filter(
+      p => (p.isTurret || p.missileType === 'hydra_turret') && p.ttl > 0
+    )
+    const existingGroupIds = Array.from(new Set(
+      activeTurrets.map(p => (p as any).groupId ?? 0)
+    )).sort((a, b) => a - b)
+
+    if (existingGroupIds.length >= MAX_ACTIVE_HYDRA_GROUPS) {
+      const groupsToEvictCount = (existingGroupIds.length - MAX_ACTIVE_HYDRA_GROUPS) + 1
+      const evictGids = new Set(existingGroupIds.slice(0, groupsToEvictCount))
+      engine.projectiles = engine.projectiles.filter(
+        p => !((p.isTurret || p.missileType === 'hydra_turret') && evictGids.has((p as any).groupId ?? 0))
+      )
+    }
+
+    const currentGroupId = ++hydraGroupSeqCounter
     for (let i = 0; i < offsets.length; i++) {
       const off = offsets[i]!
       engine.projectiles.push({
@@ -2238,9 +2258,10 @@ export function castSkill(
         isTurret: true,
         fireCadenceTicks: 25,
         headIndex: i,
+        groupId: currentGroupId,
         spawnMissileType: 'hydra',
         pierce: false,
-      })
+      } as any)
     }
 
     player.cooldown = 40
@@ -5359,16 +5380,54 @@ export function drawMissileProjectile(
   }
 
   if (shot.isTurret || shot.missileType === 'hydra_turret') {
-    // Authentic stationary hydra head turret plume
+    const age = shot.ageTicks ?? 0
-    const wobble = Math.sin((shot.ageTicks ?? 0) * 0.3 + (shot.headIndex ?? 0) * 1.5) * 2.5
+    const wobble = Math.sin(age * 0.25 + (shot.headIndex ?? 0) * 2.1) * 3
-    // Soft outer fire aura
+    const swayX = Math.cos(age * 0.18 + (shot.headIndex ?? 0) * 1.7) * 2.5
-    renderer.drawSolid(x - 12, y - 12 + wobble * 0.5, 24, 24, [1.0, 0.32, 0.05, 0.35])
+
-    // Mid fire core
+    // 1. Ground magma / lava fire pit (2:1 isometric ground ellipse base)
-    renderer.drawSolid(x - 8, y - 8 + wobble, 16, 16, [1.0, 0.65, 0.12, 0.65])
+    renderer.drawSolid(x - 14, y - 5, 28, 10, [0.8, 0.2, 0.02, 0.5])
-    // Inner hot core
+    renderer.drawSolid(x - 9, y - 3, 18, 6, [1.0, 0.5, 0.08, 0.75])
-    renderer.drawSolid(x - 4, y - 4 + wobble, 8, 8, [1.0, 0.92, 0.3, 0.9])
+    renderer.drawSolid(x - 4, y - 2, 8, 4, [1.0, 0.9, 0.3, 0.9])
-    // White flame peak
+
-    renderer.drawSolid(x - 2, y - 6 + wobble, 4, 6, [1.0, 1.0, 0.85, 0.95])
+    // 2. Serpentine segmented neck rising from the lava pit
+    const seg1Y = y - 7 + wobble * 0.3
+    const seg1X = x + swayX * 0.3
+    renderer.drawSolid(seg1X - 5, seg1Y - 3, 10, 6, [0.85, 0.28, 0.05, 0.85])
+    renderer.drawSolid(seg1X - 3, seg1Y - 2, 6, 4, [1.0, 0.6, 0.15, 0.9])
+
+    const seg2Y = y - 14 + wobble * 0.6
+    const seg2X = x + swayX * 0.7
+    renderer.drawSolid(seg2X - 4, seg2Y - 3, 8, 6, [0.9, 0.35, 0.05, 0.85])
+    renderer.drawSolid(seg2X - 2, seg2Y - 2, 4, 4, [1.0, 0.7, 0.2, 0.9])
+
+    // 3. Serpent head crown with flaming mane & glowing eyes
+    const headY = y - 22 + wobble
+    const headX = x + swayX
+    // Flaming crest / mane
+    renderer.drawSolid(headX - 6, headY - 8, 12, 12, [1.0, 0.35, 0.05, 0.6])
+    renderer.drawSolid(headX - 4, headY - 6, 8, 9, [1.0, 0.65, 0.15, 0.85])
+    renderer.drawSolid(headX - 2, headY - 4, 4, 6, [1.0, 0.95, 0.4, 0.95])
+    // Dragon/serpent snout & jaw
+    renderer.drawSolid(headX - 3, headY, 6, 4, [0.8, 0.2, 0.05, 0.9])
+    // Glowing incandescent eye
+    renderer.drawSolid(headX - 1, headY - 2, 2, 2, [1.0, 1.0, 0.9, 1.0])
+
+    // 4. If missile sprite art is available (firebolt/hydra), render the fiery head sprite over the crest
+    const art = missileArtMap?.get('hydra') ?? missileArtMap?.get('firebolt')
+    if (art !== undefined) {
+      const group = art.frames[0]
+      const frameCount = Math.max(1, art.meta.framesPerDirection)
+      const frameIndex = Math.floor((age * art.meta.animSpeed) / 16) % frameCount
+      const frame = group?.[frameIndex] ?? group?.[0]
+      if (frame !== undefined) {
+        const drawX = frame.anchorX !== undefined ? headX + frame.anchorX : headX - frame.width / 2
+        const drawY = frame.anchorY !== undefined ? headY + frame.anchorY : headY - frame.height / 2
+        renderer.draw(frame, drawX, drawY, {
+          atlas: art.handle,
+          blendMode: 'additive',
+        })
+      }
+    }
     return
   }
 

tests/skills/sor/issue-435-charged-bolt-kinematics.test.ts

@@ -19,14 +19,14 @@ describe('Issue #435: Charged Bolt (#38) Kinematics & Random Walk', () => {
     // Launch a charged bolt moving strictly East (vx = 12, vy = 0)
     let p: Projectile = {
       missileType: 'chargedbolt',
-      sourceSkillId: 38,
+      skillId: '38',
       x: 500,
       y: 500,
       vx: 12,
       vy: 0,
       ttl: 50,
       damage: 10,
-      radius: 8,
+      fromPlayer: true,
       jitter: true,
       jitterIndex: 0,
       seed: 7,
@@ -54,14 +54,14 @@ describe('Issue #435: Charged Bolt (#38) Kinematics & Random Walk', () => {
   it('ensures distinct random seeds yield divergent trajectories', () => {
     let p1: Projectile = {
       missileType: 'chargedbolt',
-      sourceSkillId: 38,
+      skillId: '38',
       x: 0,
       y: 0,
       vx: 10,
       vy: 5,
       ttl: 30,
       damage: 10,
-      radius: 8,
+      fromPlayer: true,
       jitter: true,
       jitterIndex: 0,
       seed: 1,
@@ -69,14 +69,14 @@ describe('Issue #435: Charged Bolt (#38) Kinematics & Random Walk', () => {
 
     let p2: Projectile = {
       missileType: 'chargedbolt',
-      sourceSkillId: 38,
+      skillId: '38',
       x: 0,
       y: 0,
       vx: 10,
       vy: 5,
       ttl: 30,
       damage: 10,
-      radius: 8,
+      fromPlayer: true,
       jitter: true,
       jitterIndex: 5,
       seed: 29,

tests/skills/sor/issue-436-hydra-cap-and-animation.test.ts

@@ -0,0 +1,97 @@
+/**
+ * Issue #436: Hydra (#62) Summon Cap & Entity Visuals
+ *
+ * 1.13c Ground Truth Invariants Verification Suite:
+ * 1. Summon Cap: Maximum 6 active Hydra groups (18 heads total) concurrently active.
+ * 2. FIFO Eviction: When 7th group is cast, the oldest 1st group is automatically evicted (pruned to 0 ttl).
+ * 3. Exact 3-Head Offsets: Offsets [(-6, -11), (0, -7), (4, -15)] correctly assigned per group.
+ * 4. Slvl Scaling: Hydra damage properly respects caster skill level instead of hardcoded slvl 1.
+ */
+import { describe, expect, it } from 'vitest'
+import { GameEngine } from '../../../src/game/engine.ts'
+import { castSkill } from '../../../src/scene/act-scene.ts'
+
+describe('Issue #436: Hydra (#62) Summon Cap & Entity Visuals', () => {
+  it('enforces maximum 6 groups (18 heads) and FIFO eviction on successive casts', () => {
+    const engine = new GameEngine(
+      { widthPx: 1000, heightPx: 1000, overlap: () => 0 },
+      { spawn: { x: 200, y: 200 }, stats: [], questDefs: [], npcDefs: [] } as any,
+    )
+    engine.world.player.x = 200
+    engine.world.player.y = 200
+    engine.world.player.mana = 1000
+
+    const statusEl = { textContent: '' } as HTMLElement
+    const dummyRuntime = {
+      walkable: { isWalkable: () => true },
+      collision: { isWalkable: () => true },
+    } as any
+
+    // Cast Hydra 6 times (filling cap to 6 groups = 18 heads)
+    for (let c = 1; c <= 6; c++) {
+      engine.world.player.cooldown = 0
+      const ok = castSkill(62, 300 + c * 20, 300, {
+        engine,
+        runtime: dummyRuntime,
+        hudManager: null,
+        status: statusEl,
+      })
+      expect(ok).toBe(true)
+      expect(engine.projectiles.length).toBe(c * 3)
+    }
+
+    expect(engine.projectiles.length).toBe(18)
+    const firstGroupHeadX = engine.projectiles[0]!.x
+
+    // Cast 7th time -> triggers FIFO eviction of group 1
+    engine.world.player.cooldown = 0
+    const ok7 = castSkill(62, 500, 300, {
+      engine,
+      runtime: dummyRuntime,
+      hudManager: null,
+      status: statusEl,
+    })
+    expect(ok7).toBe(true)
+
+    // Total active heads must be capped at 18 (6 groups * 3 heads)
+    expect(engine.projectiles.length).toBe(18)
+
+    // First group must have been evicted and no longer present in engine.projectiles
+    const containsOldHead = engine.projectiles.some(p => p.x === firstGroupHeadX)
+    expect(containsOldHead).toBe(false)
+  })
+
+  it('correctly reads slvl from hudManager for damage calculation', () => {
+    const engine = new GameEngine(
+      { widthPx: 1000, heightPx: 1000, overlap: () => 0 },
+      { spawn: { x: 200, y: 200 }, stats: [], questDefs: [], npcDefs: [] } as any,
+    )
+    engine.world.player.x = 200
+    engine.world.player.y = 200
+    engine.world.player.mana = 1000
+    engine.world.player.cooldown = 0
+
+    const mockHudManager = {
+      getSkillLevel: (skillId: number) => (skillId === 62 ? 20 : 0),
+      syncPublishedState: () => {},
+    }
+
+    const statusEl = { textContent: '' } as HTMLElement
+    const dummyRuntime = {
+      walkable: { isWalkable: () => true },
+      collision: { isWalkable: () => true },
+    } as any
+
+    castSkill(62, 350, 250, {
+      engine,
+      runtime: dummyRuntime,
+      hudManager: mockHudManager as any,
+      status: statusEl,
+    })
+
+    expect(engine.projectiles.length).toBe(3)
+    // At slvl 20, damage is ~162 (150-175 range), much higher than slvl 1 (14-19)
+    const head = engine.projectiles[0]!
+    expect(head.damage).toBeGreaterThan(100)
+  })
+})