What is the formula used to calculate Faith pressure?

/// Is there a religion that at least half of the population follows?
ReligionTypes CvCityReligions::GetReligiousMajority()
{
	int iTotalFollowers = 0;
	int iMostFollowerPressure = 0;
	int iMostFollowers = -1;
	ReligionTypes eMostFollowers = NO_RELIGION;
	ReligionInCityList::iterator religionIt;

	for(religionIt = m_ReligionStatus.begin(); religionIt != m_ReligionStatus.end(); ++religionIt)
	{
		iTotalFollowers += religionIt->m_iFollowers;

		if(religionIt->m_iFollowers > iMostFollowers || religionIt->m_iFollowers == iMostFollowers && religionIt->m_iPressure > iMostFollowerPressure)
		{
			iMostFollowers = religionIt->m_iFollowers;
			iMostFollowerPressure = religionIt->m_iPressure;
			eMostFollowers = religionIt->m_eReligion;
		}
	}

	if ((iMostFollowers * 2) >= iTotalFollowers)
	{
		return eMostFollowers;
	}
	else
	{
		return NO_RELIGION;
	}
}

/// Just asked to simulate a conversion - who would be the majority religion?
ReligionTypes CvCityReligions::GetSimulatedReligiousMajority()
{
	int iTotalFollowers = 0;
	int iMostFollowerPressure = 0;
	int iMostFollowers = -1;
	ReligionTypes eMostFollowers = NO_RELIGION;
	ReligionInCityList::iterator religionIt;

	for(religionIt = m_SimulatedStatus.begin(); religionIt != m_SimulatedStatus.end(); ++religionIt)
	{
		iTotalFollowers += religionIt->m_iFollowers;

		if(religionIt->m_iFollowers > iMostFollowers || religionIt->m_iFollowers == iMostFollowers && religionIt->m_iPressure > iMostFollowerPressure)
		{
			iMostFollowers = religionIt->m_iFollowers;
			iMostFollowerPressure = religionIt->m_iPressure;
			eMostFollowers = religionIt->m_eReligion;
		}
	}

	if ((iMostFollowers * 2) >= iTotalFollowers)
	{
		return eMostFollowers;
	}
	else
	{
		return NO_RELIGION;
	}
}

/// What is the most popular religion in this city?
ReligionTypes CvCityReligions::GetFavoredReligion()
{
	int iTotalFollowers = 0;
	int iMostFollowers = -1;
	ReligionTypes eMostFollowers = NO_RELIGION;
	ReligionInCityList::iterator religionIt;

	for(religionIt = m_ReligionStatus.begin(); religionIt != m_ReligionStatus.end(); ++religionIt)
	{
		iTotalFollowers += religionIt->m_iFollowers;

		if(religionIt->m_iFollowers >= iMostFollowers && religionIt->m_eReligion != NO_RELIGION)
		{
			iMostFollowers = religionIt->m_iFollowers;
			eMostFollowers = religionIt->m_eReligion;
		}
	}

	CvAssertMsg(eMostFollowers != NO_RELIGION, "Improper call usage: called GetFavoredReligion() with no religion present in city");

	return eMostFollowers;
}

/// How many followers are there of religions OTHER than this one?
int CvCityReligions::GetFollowersOtherReligions(ReligionTypes eReligion)
{
	int iOtherFollowers = 0;
	ReligionInCityList::iterator religionIt;

	for(religionIt = m_ReligionStatus.begin(); religionIt != m_ReligionStatus.end(); ++religionIt)
	{
		if (religionIt->m_eReligion > RELIGION_PANTHEON && religionIt->m_eReligion != eReligion)
		{
			iOtherFollowers += religionIt->m_iFollowers;
		}
	}

	return iOtherFollowers;
}

/// Total pressure exerted by all religions
int CvCityReligions::GetTotalPressure()
{
	int iTotalPressure = 0;

	ReligionInCityList::iterator it;
	for(it = m_ReligionStatus.begin(); it != m_ReligionStatus.end(); it++)
	{
		iTotalPressure += it->m_iPressure;
	}

	return iTotalPressure;
}

/// Pressure exerted by one religion
int CvCityReligions::GetPressure(ReligionTypes eReligion)
{
	ReligionInCityList::iterator it;
	for(it = m_ReligionStatus.begin(); it != m_ReligionStatus.end(); it++)
	{
		if(it->m_eReligion == eReligion)
		{
			return it->m_iPressure;
		}
	}

	return 0;
}

/// Pressure exerted by one religion per turn
int CvCityReligions::GetPressurePerTurn(ReligionTypes eReligion)
{
	int iPressure = 0;

	// Loop through all the players
	for(int iI = 0; iI < MAX_PLAYERS; iI++)
	{
		CvPlayer& kPlayer = GET_PLAYER((PlayerTypes)iI);
		if(kPlayer.isAlive())
		{
			// Loop through each of their cities
			int iLoop;
			CvCity* pLoopCity;
			for(pLoopCity = kPlayer.firstCity(&iLoop); pLoopCity != NULL; pLoopCity = kPlayer.nextCity(&iLoop))
			{
				// Ignore the same city
				if (m_pCity == pLoopCity)
				{
					continue;
				}

				// Does this city have the matching majority religion?
				ReligionTypes eMajorityReligion = pLoopCity->GetCityReligions()->GetReligiousMajority();
				if(eMajorityReligion == eReligion)
				{
					iPressure += GC.getGame().GetGameReligions()->GetAdjacentCityReligiousPressure (eMajorityReligion, pLoopCity, m_pCity);
				}
			}
		}
	}

	// Holy city for this religion?
	if (IsHolyCityForReligion(eReligion))
	{
		int iHolyCityPressure = GC.getGame().getGameSpeedInfo().getReligiousPressureAdjacentCity();
		iHolyCityPressure *=  GC.getRELIGION_PER_TURN_FOUNDING_CITY_PRESSURE();
		iPressure += iHolyCityPressure;
	}

	return iPressure;
}