rust_physics_engine 0.1.0

A comprehensive, zero-dependency Rust library for physics, mathematics, and engineering computation. Every public function validates its inputs, every formula is tested against known values, and the entire codebase sits at 99.98% line coverage across 1,659 tests.

What's in it

Classical & Continuum Mechanics

• classical — Newtonian mechanics: projectile motion, collisions, SHM, damping, resonance
• solid_mechanics — Stress, strain, elastic moduli, beam deflection, Mohr's circle
• continuum_mechanics — 3D Hooke's law, compliance matrices, plane stress/strain
• fluid_instabilities — Rayleigh-Taylor, Kelvin-Helmholtz, Jeans instability, Plateau-Rayleigh

Thermodynamics & Statistical Mechanics

• thermodynamics — Ideal gas, Carnot, entropy, heat conduction, radiation, Nusselt/Biot/Grashof
• statistical_mechanics — Maxwell-Boltzmann, Boltzmann/Einstein/Debye models, diffusion, partition functions

Electromagnetism & Electronics

• electromagnetism — Coulomb, Lorentz, Faraday, Maxwell, RLC circuits, transformers
• electronics — Semiconductors, diodes, MOSFETs, solar cells, PN junctions
• rf — Friis, skin depth, antenna gain, impedance, VSWR, Smith chart quantities
• photonics — Gaussian beams, fiber optics, ray transfer matrices, coherence, Fabry-Perot

Waves, Optics & Acoustics

• waves — Doppler, standing waves, diffraction, Snell, seismic waves, dispersion
• optics — Lenses, mirrors, thin films, diffraction gratings, Rayleigh resolution
• acoustics — Sabine/Eyring reverberation, psychoacoustic scales (mel, bark, ERB), room modes, STC
• signal_processing — Waveform generation, FIR/IIR filters, convolution, windowing, resampling

Relativity & Quantum

• relativity — Lorentz transformations, relativistic energy-momentum, time dilation, Doppler
• general_relativity — Schwarzschild metric, geodesics, frame dragging, cosmological distances
• quantum — De Broglie, uncertainty principle, particle-in-a-box, tunneling, Planck radiation
• particle_physics — Invariant mass, Rutherford scattering, Breit-Wigner, rapidity, Lorentz boosts

Nuclear & Radiation

• nuclear — Decay chains, binding energy, Q-values, dosimetry
• neutronics — Criticality, diffusion, moderation, burnup, shielding
• radiation — Blackbody, Wien, Planck, radiative transfer, view factors
• plasma — Debye length, cyclotron/plasma frequencies, Alfven speed, beta, Larmor radius

Astrophysics

• astrophysics::nbody — N-body gravitational simulation (leapfrog integrator)
• astrophysics::octree — Barnes-Hut tree for O(N log N) force computation
• astrophysics::orbital_elements — Keplerian elements from state vectors, orbit propagation
• astrophysics::gravitational_waves — Strain, luminosity, frequency, chirp mass
• astrophysics::tidal — Tidal forces, Roche limits, tidal tensors
• astrophysics::lagrange — L1–L5 Lagrange point computation
• astrophysics::habitable_zone — Habitable zone boundaries, tidal locking
• astrophysics::magnetosphere — Dipole fields, magnetopause radius, field line tracing
• astrophysics::collisions — Impact cratering, orbital debris, collision probabilities

Fluids & Propulsion

• fluids — Bernoulli, Poiseuille, Reynolds, drag, capillarity, compressible flow
• propulsion — Tsiolkovsky rocket equation, Hohmann transfers, nozzle design, staging
• magnetohydrodynamics — Alfven waves, Hartmann flow, magnetic reconnection, pinch equilibria

Chemistry & Biophysics

• chemistry — Arrhenius, Nernst, pH, electrochemistry, reaction kinetics
• biophysics — Nernst/Goldman potentials, Michaelis-Menten, Hill equation, hemodynamics

Mathematics & Numerical Methods

• math — Vec3 type, physical constants (NIST CODATA), linear algebra primitives
• linalg — 3x3 matrices, rotations, eigenvalue decomposition, SVD-like operations
• quaternion — Quaternion algebra, slerp/nlerp, axis-angle, Euler angle conversions
• numerical — Root finding (bisection, Newton, secant), integration (Simpson, Gauss-Legendre), cubic splines
• optimization — Golden section, Brent, Nelder-Mead, simulated annealing, linear regression, polynomial fitting
• statistics — Mean, variance, median, distributions (Gaussian, Poisson, exponential), DFT, power spectrum
• monte_carlo — MC integration, Metropolis-Hastings, Ising model, Langevin dynamics, random walks
• vector_calculus — Gradient, divergence, curl, Laplacian, Poisson solver, line/surface/volume integrals
• nonlinear — Logistic map, Lorenz/Rossler attractors, Lyapunov exponents, bifurcation diagrams
• information_theory — Shannon entropy, mutual information, KL divergence, channel capacity

Geometry, Curves & Fractals

• geometry — Areas, volumes, perimeters for standard shapes, regular polygons
• curves — Conic sections, Bezier curves, arc length, curvature
• fractals — Mandelbrot, Julia, burning ship, Newton fractals, Barnsley fern, box counting
• trigonometry — Trig identities, hyperbolic functions, angle conversions, haversine

Simulation Engines

• sim::rigid_body — 3D rigid body dynamics with quaternion orientation, Euler equations, collision response
• sim::fluid_sim — Column fluid, 1D shallow water, 2D incompressible Euler (pressure projection)
• sim::heat_sim — 2D/3D heat conduction (explicit finite difference), convection-diffusion
• sim::wave_sim — 1D/2D wave equation solvers, absorbing boundary conditions (Mur ABC)
• sim::em_sim — 1D/2D FDTD electromagnetic simulation, PEC/Mur boundaries, dielectric media
• sim::cloth_sim — Verlet integration cloth/rope, spring-damper constraints, collision

Reference Data

• materials::elements — All 118 elements with atomic mass, density, melting/boiling points, thermal/electrical conductivity
• materials::common — Engineering materials (steel, aluminum, copper, etc.)
• materials::fluids — 16 common fluids with density, viscosity, surface tension, speed of sound
• materials::gases — Common gases with molar mass, specific heat ratio, thermal conductivity

Utilities

• units — SI unit conversions (temperature, pressure, energy, length, speed, angle, etc.)
• color_science — RGB/HSV/HSL/XYZ, wavelength-to-color, blackbody color, CIE color difference
• control_systems — Transfer functions, step/impulse response, PID tuning, stability margins
• atmosphere — ISA model, barometric formula, lapse rates, humidity, wind shear

Usage

Add to your Cargo.toml:

[dependencies]
rust_physics_engine = { path = "." }

use rust_physics_engine::classical::{projectile_range, kinetic_energy};
use rust_physics_engine::math::constants::{G, C, K_B};
use rust_physics_engine::thermodynamics::ideal_gas_pressure;
use rust_physics_engine::sim::rigid_body::RigidBody;

// Projectile on Earth
let range = projectile_range(50.0, 0.7854, 9.81); // v₀=50 m/s, θ=45°, g=9.81

// Ideal gas
let p = ideal_gas_pressure(2.0, 8.314, 300.0, 0.05); // n, R, T, V

// Rigid body simulation
let mut body = RigidBody::new_sphere(10.0, 0.5); // mass=10 kg, radius=0.5 m
body.apply_force(rust_physics_engine::math::Vec3::new(0.0, -98.1, 0.0));
body.step(0.01);

Design

• Zero dependencies — pure Rust, no external crates
• f64 throughout — double precision for all computation
• Input validation — every function asserts valid inputs (positive mass, non-zero denominators, physical bounds)
• NIST constants — physical constants from CODATA 2018/2019
• 99.98% line coverage — 1,659 tests across 67 source files

Building & Testing

cargo build              # Build
cargo test               # Run all 1,659 tests
cargo llvm-cov           # Coverage report (requires cargo-llvm-cov)

License

MIT