import box2d
# Create world definition
var worldDef = b2DefaultWorldDef()
worldDef.gravity = b2Vec2(x: 0.0f, y: -10.0f)
# Create world from definition
let worldId = b2CreateWorld(worldDef.addr)
# worldDef no longer needed
# Create body definition
var bodyDef = b2DefaultBodyDef()
bodyDef.bodyType = b2_dynamicBody
bodyDef.position = b2Vec2(x: 0.0f, y: 4.0f)
# Create body from definition
let bodyId = b2CreateBody(worldId, bodyDef.addr)
# bodyDef no longer needed
# Create polygon (indirectly through b2MakeSquare)
let dynamicBox = b2MakeSquare(1.0f)
# Create shape definition
var shapeDef = b2DefaultShapeDef()
shapeDef.density = 1.0f
shapeDef.material.friction = 0.3f
# Add polygon to simulation using body, shape definition, and box
discard b2CreatePolygonShape(bodyId, shapeDef.addr, dynamicBox.addr)
# shapeDef and dynamicBox no longer needed
# C wrappers need C types, such as cfloats and cints
let timeStep: cfloat = 1/60
let subStepCount: cint = 4
# Step simulation 60 times
for _ in 0..<60:
    b2World_Step(worldId, timeStep, subStepCount)
# Check that the box fell
echo "Dynamic box y-position: ", b2Body_GetPosition(bodyId).y
# Cleanup
b2DestroyBody(bodyId)
b2DestroyWorld(worldId)