Module vehicle 

Cars and trucks: weight, speed, engine, gears, steering, brakes, fuel and sounds.

A vehicle is an optional part of a physics Body. Add one with Body::car, Body::truck or Body::with_vehicle; every other body is not affected. The physics world drives it at the fixed physics rate: the pedals and the steering wheel are plain fields you set every frame (or let Context::drive set them from the arrow keys).

let car = ctx.physics.add(Body::car(vec3(0.0, 0.0, 0.0)).with_vehicle(
    Vehicle::car().with_engine_sound("engine").with_horn_sound("horn"),
));
ctx.follow(car);
// every frame:
ctx.drive(car);   // Up = gas, Down = brake / reverse, Left / Right = steer, Space = handbrake
if let Some(v) = ctx.physics.vehicle(car) {
    let kmh = v.speed_kmh();
}

The model

• The weight is the body’s mass plus the vehicle’s load, in kilograms. The engine force and the brake force are fixed, so a heavier vehicle speeds up more slowly and needs a longer way to stop.
• The speed is a signed number along the facing of the body (negative when reversing), limited by top_speed and reverse_speed. Engine force fades out towards the top speed.
• Steering turns the body’s facing. The turn rate grows with speed (a parked car cannot turn) up to max_turn_rate; the tightest circle has the radius turn_radius.
• The vehicle moves with World::move_by, so it stops at walls, slides along them, pushes loose objects and triggers sensors (checkpoints). Running into something loses the speed going into it and reports PhysicsEvent::Crashed.
• Vehicles drive level (they keep their height) and are not pulled by gravity.
• An automatic gearbox picks gears from the speed; the engine speed (rpm) follows. Vehicle::engine_pitch turns it into a pitch for a looping engine sound.

Structs

Vehicle

The vehicle part of a body: settings, pedals and the driving state.