//-----------------------------------------------------------------------------
// Box2D Wrapper implementation.
// This will server as a wrapper for the Box2D library:
// http://box2d.org/ 
//-----------------------------------------------------------------------------

#include "NetWars.h"

//-----------------------------------------------------------------------------
// The B2DWrapper class constructor.
//-----------------------------------------------------------------------------
B2DWrapper::B2DWrapper()
{
	m_worldAABB.lowerBound.Set(-200.0f, -200.0f);
	m_worldAABB.upperBound.Set(200.0f, 200.0f);
	b2Vec2 gravity;
	gravity.Set(0.0f, 0.0f);
	bool doSleep = true;
	m_world = new b2World( m_worldAABB, gravity, doSleep );

	
	// Creating the Box2D GameBorder:
	b2BodyDef groundBodyDef;
	groundBodyDef.massData.mass = 0.0f;

	// Lower Border
	groundBodyDef.position.Set(  0.0f, -GAMEBORDER_HEIGHT - 10.0f );
	b2Body* groundBody = m_world->CreateBody(&groundBodyDef);
	b2PolygonDef groundShapeDef;
	groundShapeDef.SetAsBox(GAMEBORDER_WIDTH, 10.0f);
	groundBody->CreateShape(&groundShapeDef);

	// Upper Border
	groundBodyDef.position.Set(  0.0f, GAMEBORDER_HEIGHT + 10.0f );
	groundBody = m_world->CreateBody(&groundBodyDef);
	groundShapeDef.SetAsBox(GAMEBORDER_WIDTH, 10.0f);
	groundBody->CreateShape(&groundShapeDef);

	// Right Border
	groundBodyDef.position.Set( GAMEBORDER_WIDTH + 10.0f, 0.0f );
	groundBody = m_world->CreateBody(&groundBodyDef);
	groundShapeDef.SetAsBox( 10.0f, GAMEBORDER_HEIGHT);
	groundBody->CreateShape(&groundShapeDef);

	// Left Border
	groundBodyDef.position.Set( -GAMEBORDER_WIDTH - 10.0f, 0.0f );
	groundBody = m_world->CreateBody(&groundBodyDef);
	groundShapeDef.SetAsBox( 10.0f, GAMEBORDER_HEIGHT );
	groundBody->CreateShape(&groundShapeDef);
	 
}

//-----------------------------------------------------------------------------
// The B2DWrapper class destructor.
//-----------------------------------------------------------------------------
B2DWrapper::~B2DWrapper()
{
	SAFE_DELETE( m_world );
}


/// Updates the Box2D System with the elapsed time.
/// @param elapsedTime since the previous frame
void B2DWrapper::Update( float elapsedTime )
{
	m_world->Step( elapsedTime, 10 );
}


/// Adds a new body to the Box2D physics system
/// @param   b2BodyDef bodyDef of new body
/// @param   b2ShapeDef shapeDef of new body
/// returns a pointer to the body 
void B2DWrapper::AddBody( b2Body ** body, b2BodyDef * bodyDef, b2ShapeDef * shapeDef )
{
	(*body) = m_world->CreateBody( bodyDef );
	(*body)->CreateShape( shapeDef );
	(*body)->SetMassFromShapes();
}


/// Removes a body from the Box2D physics system
/// @param   b2BodyDef the bodyDef to remove
void B2DWrapper::RemoveBody( b2Body * body )
{
	m_world->DestroyBody( body );
}