ChaiScript Extras Liquidfun

Provides ChaiScript bindings to Liquidfun.

This is currently just a proof of concept. Any assistance in getting this up and running would be much appreciated.

Usage

1. Include the module source...

   #include "ChaiScript_Extras_Liquidfun/include/chaiscript/extras/box2d.hpp"

2. Add the module to the ChaiScript instance...

   auto Box2Dlib = chaiscript::extras::box2d::bootstrap();
   chai.add(Box2Dlib);

   Note:

   As you cannot pass void* with Chaiscript, SetUserData / GetUserData have been removed from b2Body / b2Fixture

   You can create your own wrapper class (as you probably would anyway) and add missing chaiscript bindings like this:

       chai.add(chaiscript::fun([](const b2Body* body)
   	{
   		return static_cast<MyAwesomeDataWrapper*>(body->GetUserData());
   	}), "GetUserData");
   	chai.add(chaiscript::fun([](b2Body* body, MyAwesomeDataWrapper* data)
   	{
   		body->SetUserData(data);
   	}), "SetUserData");

3. Use Liquidfun in ChaiScript...

   // Define the gravity vector.
   var gravity = b2Vec2(0.0f, -10.0f)
   
   // Construct a world object, which will hold and simulate the rigid bodies.
   var world = b2World(gravity)
   
   // Define the ground body.
   var groundBodyDef = b2BodyDef()
   groundBodyDef.position.Set(0.0f, -10.0f)
   
   // Call the body factory which allocates memory for the ground body
   // from a pool and creates the ground box shape (also from a pool).
   // The body is also added to the world.
   var groundBody = world.CreateBody(groundBodyDef)
   
   // Define the ground box shape.
   var groundBox = b2PolygonShape()
   
   // The extents are the half-widths of the box.
   groundBox.SetAsBox(50.0f, 10.0f)
   
   // Add the ground fixture to the ground body.
   groundBody.CreateFixture(groundBox, 0.0f)
   
   // Define the dynamic body. We set its position and call the body factory.
   var bodyDef = b2BodyDef()
   bodyDef.type = b2_dynamicBody
   bodyDef.position.Set(0.0f, 4.0f)
   var body = world.CreateBody(bodyDef)
   
   // Define another box shape for our dynamic body.
   var dynamicBox = b2PolygonShape()
   dynamicBox.SetAsBox(1.0f, 1.0f)
   
   // Define the dynamic body fixture.
   var fixtureDef = b2FixtureDef()
   //fixtureDef.shape = dynamicBox
   SetShape(fixtureDef, dynamicBox)
   
   // Set the box density to be non-zero, so it will be dynamic.
   fixtureDef.density = 1.0f
   
   // Override the default friction.
   fixtureDef.friction = 0.3f
   
   // Add the shape to the body.
   body.CreateFixture(fixtureDef)
   
   // Prepare for simulation. Typically we use a time step of 1/60 of a
   // second (60Hz) and 10 iterations. This provides a high quality simulation
   // in most game scenarios.
   var timeStep = 1.0f / 60.0f
   var velocityIterations = 6
   var positionIterations = 2
   
   // This is our little game loop.
   for (var i = 0; i < 60; ++i) {
       // Instruct the world to perform a single step of simulation.
       // It is generally best to keep the time step and iterations fixed.
       world.Step(timeStep, velocityIterations, positionIterations)
   
       // Now print the position and angle of the body.
       var position = body.GetPosition()
       var angle = body.GetAngle()
   
       print("X: " + to_string(position.x))
       print("Y: " + to_string(position.y))
       print("A: " + to_string(angle))
   }

Development

git submodule update --init
mkdir build
cd build
cmake ..
make
make test

License

MIT