Simple bullet rigidbody simulation

bullet_test.cpp

// compile as:
// $ g++ bullet_test.cpp -o bullet_test -I/usr/include/bullet/ -lBulletSoftBody -lBulletDynamics -lBulletCollision -lLinearMath
#include <iostream>
#include <memory>

#include <bullet/btBulletDynamicsCommon.h>

int main() {
    auto broadphase = std::make_shared<btDbvtBroadphase>();
    auto collision = std::make_shared<btDefaultCollisionConfiguration>();
    auto dispatcher = std::make_shared<btCollisionDispatcher>(collision.get());
    auto solver = std::make_shared<btSequentialImpulseConstraintSolver>();

    auto world = std::make_shared<btDiscreteDynamicsWorld>(
        dispatcher.get(), broadphase.get(), solver.get(), collision.get());

    world->setGravity(btVector3(0, 0, 0));

    btCollisionShape *shape = new btSphereShape(1);

    btDefaultMotionState *motionState = new btDefaultMotionState(
        btTransform(btQuaternion(0, 0, 0, 1), btVector3(-1.0, 0, 0)));

    btVector3 inertia;
    shape->calculateLocalInertia(1.0, inertia);

    btRigidBody::btRigidBodyConstructionInfo info(
        1.0, motionState, shape, inertia);
    auto body = new btRigidBody(info);

    body->setLinearVelocity(btVector3(1 / 3.0, 0, 0));
    body->setDamping(0, 0);

    world->addRigidBody(body);

    for(int i = 0; i < 100; i++) {
        world->stepSimulation(1 / 30.0, 10);
        btTransform transform;
        body->getMotionState()->getWorldTransform(transform);
        std::cout << "position: " << transform.getOrigin().x() << ","
                  << transform.getOrigin().y() << ","
                  << transform.getOrigin().z() << std::endl;
        body->setLinearVelocity(btVector3(1 / 3.0, 0, 0));
    }

    return 0;
}

output.txt

position: -0.994444,0,0
position: -0.983333,0,0
position: -0.972222,0,0
position: -0.961111,0,0
position: -0.95,0,0
position: -0.938889,0,0
position: -0.927778,0,0
position: -0.916666,0,0
position: -0.905555,0,0
position: -0.894444,0,0
position: -0.883333,0,0
position: -0.872222,0,0
position: -0.861111,0,0
position: -0.85,0,0
position: -0.838888,0,0
position: -0.827777,0,0
position: -0.816666,0,0
position: -0.805555,0,0
position: -0.794444,0,0
position: -0.783333,0,0
position: -0.772222,0,0
position: -0.76111,0,0
position: -0.749999,0,0
position: -0.738888,0,0
position: -0.727777,0,0
position: -0.716666,0,0
position: -0.705555,0,0
position: -0.694444,0,0
position: -0.683333,0,0
position: -0.672221,0,0
position: -0.66111,0,0
position: -0.649999,0,0
position: -0.638888,0,0
position: -0.627777,0,0
position: -0.616666,0,0
position: -0.605555,0,0
position: -0.594443,0,0
position: -0.583332,0,0
position: -0.572221,0,0
position: -0.56111,0,0
position: -0.549999,0,0
position: -0.538888,0,0
position: -0.527777,0,0
position: -0.516665,0,0
position: -0.505554,0,0
position: -0.494443,0,0
position: -0.483332,0,0
position: -0.472221,0,0
position: -0.46111,0,0
position: -0.449999,0,0
position: -0.438887,0,0
position: -0.427776,0,0
position: -0.416665,0,0
position: -0.405554,0,0
position: -0.394443,0,0
position: -0.383332,0,0
position: -0.372221,0,0
position: -0.361109,0,0
position: -0.349998,0,0
position: -0.338887,0,0
position: -0.333332,0,0
position: -0.333332,0,0
position: -0.333332,0,0
position: -0.333332,0,0
position: -0.333332,0,0
position: -0.333332,0,0
position: -0.333332,0,0
position: -0.333332,0,0
position: -0.333332,0,0
position: -0.333332,0,0
position: -0.333332,0,0
position: -0.333332,0,0
position: -0.333332,0,0
position: -0.333332,0,0
position: -0.333332,0,0
position: -0.333332,0,0
position: -0.333332,0,0
position: -0.333332,0,0
position: -0.333332,0,0
position: -0.333332,0,0
position: -0.333332,0,0
position: -0.333332,0,0
position: -0.333332,0,0
position: -0.333332,0,0
position: -0.333332,0,0
position: -0.333332,0,0
position: -0.333332,0,0
position: -0.333332,0,0
position: -0.333332,0,0
position: -0.333332,0,0
position: -0.333332,0,0
position: -0.333332,0,0
position: -0.333332,0,0
position: -0.333332,0,0
position: -0.333332,0,0
position: -0.333332,0,0
position: -0.333332,0,0
position: -0.333332,0,0
position: -0.333332,0,0
position: -0.333332,0,0