# Chipmunk++

Chipmunk Physics for C++

View the Project on GitHub jhasse/chipmunkpp

## Welcome

Chipmunk++ is a C++ wrapper for the Chipmunk Physics library. Learn more »

### Example

Chipmunk's Hello World example with Chipmunk++:

``````#include <iostream>
#include <iomanip>
#include <chipmunk.hpp>

using namespace cp;
using namespace std;

int main() {
// cp::Vect is a 2D vector.
Vect gravity(0, -100);

// Create an empty space.
Space space;
space.setGravity(gravity);

// Add a static line segment shape for ground.
// We'll make it slightly tilted so the ball will roll off.
// We attach it to space.staticBody to tell Chipmunk it shouldn't be movable.
auto ground = make_shared<SegmentShape>(space.staticBody,
Vect(-20, 5), Vect(20, -5), 0);
ground->setFriction(1);

// Now let's make a ball that falls onto the line and rolls off.
// First we need to make a Body to hold the physical properties of the object.
// These include the mass, position, velocity, angle, etc. of the object.
// Then we attach collision shapes to the cpBody to give it a size and shape.

const Float radius = 5;
const Float mass = 1;

// The moment of inertia is like mass for rotation
// Use the cp::momentFor*() functions to help you approximate it.
const Float moment = momentForCircle(mass, 0, radius);

auto ballBody = make_shared<Body>(mass, moment);
ballBody->setPos(Vect(0, 15));

// Now we create the collision shape for the ball.
// You can create multiple collision shapes that point to the same body.
// They will all be attached to the body and move arount to follow it.
auto ballShape = make_shared<CircleShape>(ballBody, radius);
ballShape->setFriction(0.7);

// Now that it's all set up, we simulate all the objects in the space by
// stepping forward through time in small increments called steps.
// It is *highly* recommended to use a fixed size time step.
Float timeStep = 1.0/60.0;
for (Float time = 0; time < 2; time += timeStep) {
Vect pos = ballBody->getPos();
Vect vel = ballBody->getVel();
cout << setprecision(2) << fixed
<< "Time is "          << setw(5) << time << ". "
<< "ballBody is at "   << setw(5) << pos  << ". "
<< "It's velocity is " << setw(5) << vel  << endl;
space.step(timeStep);
}
}
``````