A simple-as-possible 2D physics rigid-body physics engine for Elm. Supports only bubbles (circles) and boxes (axis-aligned rectangles).

Here's an example (source) of the engine in action. To run the example locally, start elm-reactor in the examples directory.

It does this:

• resolve collisions between bodies of different mass and bounciness.
• gravity (ignores mass) / global time-varying forces (mass-dependent)

It doesn't do:

• arbitrary polygons
• friction / drag
• rotation
• time-integrated movement
• graphics
• colliding unstoppable forces with immovable objects (infinite masses will be glitchy)