blackroad-physics-engine

2D rigid body physics engine with AABB collision, restitution, friction, and projectile simulation.

Part of BlackRoad-Interactive — production game and graphics infrastructure.

Features

Module	Contents
Vector2D	+/-/*/dot/cross/magnitude/normalize/reflect/rotate/lerp
AABB	intersects/overlap/contains_point/expanded/moved
RigidBody	pos/vel/mass/restitution/friction/integrate/impulse
PhysicsWorld	add_body/step/check_collisions/resolve_collision/bounds
Trajectories	projectile_path, range_equation, time_of_flight, max_height

Quick Start

from src.physics import PhysicsWorld, RigidBody, Vector2D, projectile_path

world = PhysicsWorld(gravity=9.81, bounds=(0, 0, 20, 20))
ball = world.add_body(RigidBody(
    pos=Vector2D(2, 2), vel=Vector2D(5, -3),
    mass=1.0, restitution=0.8
))

for _ in range(120):
    world.step(1/60)

print(f"Ball position: {ball.pos}")
print(f"Total KE: {world.total_kinetic_energy():.2f} J")

# Projectile
path = projectile_path(v0=20, angle_deg=45, steps=100)

Run Demo

python src/physics.py

Tests

pip install pytest
pytest tests/ -v

CI

GitHub Actions · Python 3.11 + 3.12 · pytest + flake8 + coverage