Castle Siege

Original Prompt

Castle Siege Defense — 3D tower defense where player taps to launch projectiles at enemies marching toward a medieval castle.

Step 1: Scaffold

• Three.js 3D game with isometric camera
• Castle with keep, towers, walls, battlements, gate, banners
• Enemy soldiers march from far end toward castle
• Tap/click to fire parabolic projectiles with splash damage
• Wave system with increasing difficulty
• Health bar, wave banner, game over overlay
• EventBus + GameState + Constants architecture

Step 2: Design

Visual polish pass — particles, effects, screen shake, juice, and atmosphere.

Particle System (src/systems/ParticleSystem.js)

• Object-pooled particle system (300 particles, 5 impact flashes, 30 scorch marks, 60 trail segments)
• Explosion burst: 18 orange/red/yellow particles fly outward and fade on projectile impact
• Enemy death fragments: 10 body-colored fragments scatter on kill
• Dust clouds: 3 rising dust puffs per enemy at regular intervals while marching
• Castle damage sparks: 12 stone debris particles when castle takes damage
• Projectile fire trail: Glowing orange trail segments behind arcing projectiles that fade and shrink
• Impact flash: Bright expanding sphere at point of impact
• Ground scorch marks: Dark circles on terrain where projectiles land, slowly fade

Camera Shake (src/systems/CameraShake.js)

• Small brief shake (0.3 intensity, 0.15s) on projectile impact
• Larger longer shake (0.7 intensity, 0.3s) when castle is hit
• Damped oscillation with exponential decay

Atmosphere & Lighting

• Sunset sky dome: Vertex-colored gradient from deep night blue (zenith) through dark blue to warm orange/glow at horizon
• Fog: Purple-tinted exponential fog that gets denser each wave (increases tension)
• Lighting: Low-angle warm sunset directional light with 2048px shadow maps, rim backlight for enemy silhouettes
• ACES filmic tone mapping for cinematic color response
• Decorative rocks added around the battlefield edges

Castle Visual Enhancements

• Flickering torch lights on all 4 tower tops (PointLights with randomized phase offsets)
• Small flame meshes at torch positions
• Banner wave animation: PlaneGeometry vertices deformed with sine wave over time
• Gate glow: Pulsing red PointLight at gate entrance
• Progressive damage darkening: Castle materials darken as health decreases (up to 40% darker at 0 HP)
• Flash + darken combo on damage

Enemy Visual Enhancements

• Larger enemies: Body 1.0x2.0x0.8 (was 0.8x1.6x0.6), head radius 0.45 (was 0.35) for better visibility
• Wave-based colors: 6 color tiers that cycle (dark red, dark green, dark blue, indigo, saddle brown, dark slate)
• Sword + handle geometry: Right-hand sword with angled blade and brown handle
• Larger shield: 0.7x0.9 (was 0.6x0.8)
• Death animation: Flash white, then fade opacity over 0.5s while sinking and rotating
• Walking swing: Subtle body rotation during march for liveliness

Screen Effects (src/systems/ScreenEffects.js)

• Red vignette flash: Radial gradient overlay pulses on castle damage (0.3s fade)
• Health tint: Screen gets reddish tint as castle health drops below 50%
• Victory glow: Golden radial glow on wave completion (1.0s fade)
• Floating damage numbers: "-10" text rises and fades when castle is hit
• Kill combo text: "DOUBLE KILL!", "TRIPLE KILL!", "QUAD KILL!", "MEGA KILL!" with colored text and glow (1.5s combo window)

UI Juice

• Wave banner slides: Slides in from left, slides out to right (cubic-bezier easing)
• Health bar pulses: Scales and glows red when health drops below 25%
• Health bar container: Improved styling with transitions

Constants Updates

• All new visual values in Constants.js (PARTICLES, SKY, UI_JUICE, CAMERA shake params)
• New ENEMY values: WAVE_COLORS, SWORD_LENGTH, SWORD_COLOR, DEATH_FLASH_COLOR, DEATH_FADE_DURATION, DUST_INTERVAL
• New CASTLE values: TORCH_*, GATE_GLOW_*, DAMAGE_DARKEN_FACTOR, BANNER_WAVE_*
• Updated COLORS for dramatic sunset mood

EventBus Additions

• camera:shake — triggers CameraShake with type param
• particles:spawn — generic particle spawner
• enemy:dust — dust puffs at enemy feet
• ui:kill_combo — kill combo tracking

Architecture Compliance

• All visual systems communicate only through EventBus
• No gameplay mechanics altered (same scoring, speeds, projectile behavior)
• Particles properly disposed on restart (ParticleSystem recreated)
• All magic numbers in Constants.js

Step 3: Audio

Procedural audio using Strudel.cc for BGM and Web Audio API for SFX. Medieval siege theme.

BGM Patterns (src/audio/music.js — Strudel)

• Gameplay BGM (120 cpm): Epic medieval battle theme with war drums (low sine kicks), brass-like sawtooth lead, heavy triangle bass, tension arpeggio, and dark minor power chord pad. Driving but not overwhelming.
• Game Over BGM (60 cpm): Somber defeat theme with descending mournful triangle melody, dark minor sine pad, and funeral sine bass. Heavy reverb and slow tempo for finality.
• Wave Complete Fanfare: Brief ascending victory stinger (sawtooth lead + sine chord). Plays for ~2.5 seconds, then AudioBridge resumes gameplay BGM.

SFX Event Mappings (src/audio/sfx.js — Web Audio API)

Audio Architecture

• AudioManager (src/audio/AudioManager.js): Wraps Strudel initStrudel(), hush(), .play(). Checks gameState.isMuted before playing. Handles mute toggle with localStorage persistence.
• AudioBridge (src/audio/AudioBridge.js): Glue layer wiring EventBus events to audio functions. Manages wave-complete fanfare timing (play fanfare, then resume gameplay BGM after 2.5s).
• Two-engine split: Strudel for looping BGM (can be stopped/switched with hush()), Web Audio API for instant one-shot SFX (unaffected by hush()).

Mute Wiring

• AUDIO_TOGGLE_MUTE event added to EventBus
• M key shortcut toggles mute
• Mute button in bottom-right corner (circular, semi-transparent) — shows "SOUND"/"MUTED" text
• Mute preference persisted to localStorage (key: castle-siege-muted)
• AudioManager checks gameState.isMuted before playing BGM; each SFX function checks before playing
• Mute button click uses stopPropagation() to prevent projectile fire; InputSystem ignores clicks on #mute-btn

Constants (AUDIO section in Constants.js)

• BGM tempos: gameplay 120 cpm, game over 60 cpm
• BGM gains: lead 0.14, pad 0.10, bass 0.18, drums 0.22, arp 0.05
• SFX gains: launch 0.25, explosion 0.3, enemy death 0.2, castle hit 0.3, war horn 0.2, castle destroyed 0.35, score 0.2

Integration Points

• main.js: Imports and calls initAudioBridge() before Game constructor. Adds first-interaction audio unlock (click/touch/keydown). Wires M key and mute button click.
• Game.js: Emits MUSIC_GAMEPLAY on startGame(), MUSIC_STOP + MUSIC_GAMEOVER on onGameOver().
• index.html: Mute button element with CSS styling.
• InputSystem.js: Ignores clicks on #mute-btn to prevent accidental projectile fire.
• No gameplay mechanics altered.