Bouncing Balls in OSG

#include "StdAfx.h"
#include "BounceWall.h"
#include "Ball.h"
#include "Situation.h"

//#include <iostream>
//	std::cout << "Next event predicted at " << Time() << std::endl;

CBounceWall::CBounceWall(CBall *ball, int d)
{
	this->ball = ball;
	this->d = d;
}

CBounceWall::~CBounceWall(void)
{
}

CSimulator *CBounceWall::Simulator()
{
	return ball->Simulator();
}

void CBounceWall::PredictCollisionBetweenBallAndWall( double t0 )
{
	CSituation *sit = &ball->situation;
	const double epsilon = 0.0;
	double v = sit->GetVelocity()[d];
    double x;
    if (v > epsilon)
		x = 10 - ball->radius;
	else if( v < epsilon )
		x = ball->radius - 10;
	else
	{
		Enable( false );
		return;
	}
	double t1 = sit->GetBaseTime() +
		(x - sit->GetBasePosition()[d]) / sit->GetVelocity()[d];
    ChangeTime(t1);
	Enable( true );
}

void CBounceWall::Expire()
{
	CSituation *sit = &ball->situation;
	sit->SetBaseTime( Time() );

	osg::Vec3d v = sit->GetVelocity();
	v[d] = -v[d];
	sit->SetVelocity( v );
	
#ifdef WITH_QUAT
	// Note: Axis of rotation is not accurate
	// Balls that rotate on collision should lose energy too
	v[d] = 0;
	sit->SetAngularVelocity( v );
#endif
	ball->PredictChanges();
}