garjan

garjan (Sanskrit: गर्जन — roar / thunder) — Environmental and nature sound synthesis for Rust.

Procedural synthesis of weather, impacts, surfaces, fluids, fire, creatures, and aerodynamics. All sounds generated from physical models — modal resonance, stochastic particle impacts, stick-slip friction, turbulent noise shaping. No samples, no assets, pure math.

Features

Weather & Water

• Thunder: distance-based crack + rumble with atmospheric filtering
• Rain: 4 intensities with Poisson-distributed stochastic drops
• Wind: pink noise through state variable filter with gust modulation
• Precipitation: hail, snow, surface rain with terrain-dependent character
• Surf: 3-phase breaking wave cycle (approach, crash, wash)
• Underwater: submerged ambience at 3 depths
• Water: stream, drip, splash, waves

Impact & Contact

• Impact: 10 materials with modal synthesis (4-12 resonant modes), velocity-sensitive, shatter with debris cascade
• Footstep: 8 terrains, 4 movement types, auto-timed or game-driven
• Friction: stick-slip scraping, sliding, grinding
• Creak: doors, hinges, rope, wood stress
• Rolling: ball, wheel, boulder, barrel on surfaces
• Foliage: leaf rustle, grass swish, branch snap

Aerodynamic

• Whoosh: sword swing, projectile, vehicle pass-by
• Whistle: wind through gaps, pipes, bottles, wires
• Cloth: flag, cape, sail, tarp flapping

Creature & Fluid

• Insect: wing buzz, cricket chirp, cicada drone with swarm mode
• WingFlap: bird wings at 3 sizes
• Bubble: underwater, boiling, viscous, pouring

Ambient

• AmbientTexture: forest, city, ocean, cave, desert, night
• Fire: crackle + roar, intensity-scaled

Infrastructure

• Modal synthesis engine with SIMD-friendly SoA layout
• Voice management with priority-based polyphony
• LOD for CPU scaling of distant sources
• Science bridge mapping physical simulation outputs to synthesis parameters
• Builder pattern for complex constructors

Quick Start

use garjan::prelude::*;

// Thunder 2km away
let mut thunder = Thunder::new(2000.0, 44100.0).unwrap();
let samples = thunder.synthesize(3.0).unwrap();

// Streaming: fill your own buffer
let mut wind = Wind::new(15.0, 0.5, 44100.0).unwrap();
let mut buf = [0.0f32; 512];
wind.process_block(&mut buf);

// Modal impact with velocity
let mut impact = Impact::new(Material::Metal, 44100.0).unwrap();
let samples = impact.synthesize_velocity(ImpactType::Strike, 0.8).unwrap();

Performance

All synthesizers run well above real-time. Typical measurements at 44.1 kHz:

Feature Flags

Design

• No samples: every sound is synthesized from math
• No hot-path allocations: process_block never allocates
• Deterministic: seeded RNG, bit-identical replay guaranteed
• no_std compatible: libm fallback when std unavailable
• Composable: synthesizers are independent, caller mixes
• Physically grounded: modal resonance, Poisson processes, stick-slip models

AGNOS Ecosystem

garjan is one component of the AGNOS audio pipeline:

License

GPL-3.0-only