README.md

boxjs

Boxjs is a javascript 2D physics engine based off of Box2D.

Boxjs can be used both in node as well as in browser.

For a demo (WIP), check out the testbed.

testbed info/controls

• There are 9 tests, accessible with the number keys 1-9.
• Click and drag anywhere to spawn a box with velocity.
• Shift + click to grab a body and drag it around.
• Press 0 to toggle debug view, which draws the broadphase AABBs.

test 1 - basic test

This test displays basic features of the physics engine. There are examples of various shapes and joints, including a rope with a heavy load.

test 2 - car test

This test sets up a short course for a car with a motorized joint, and various obstacles.

• use wasd controls to drive the car

test 3 - raycast test

This test demonstrates the raycast feature.

test 4 - fork test

This test demonstrates the fork feature, which is the ability of the engine to quickly clone itself, and later "restore" the forked state.

• press f to fork the solver state at the current position
• press r to restore the forked state, "rewinding" time.

test 5 - perf test

This test creates a 10x10 stack of boxes, and times how long it takes to run 5000 steps. It logs the result to the console.

test 6 - particle test

This test demonstrates "particle" support. Particles are bodies in the engine which can bounce off other bodies, but don't themselves take up any space or impart any forces.

test 7 - self-righting test

This test is a simulation of a one-wheeled vehicle. It uses a PID controller to translate player input to motor impulses that steer the vehicle without tipping.

• use wasd controls to drive the vehicle

test 8 - sensor test

This test demonstrates sensor shapes. The outlined shapes are the sensors, and will change color when detecting an overlap.

• use wasd controls to move the shape with the sensors around.

test 9 - continuous collision detection test

This test demonstrates continuous collision detection. It defaults to TOI off,

• press t to toggle time of impact.