void CalculateTotalArea()
{
//get total area using trapezoids
//we'll get it as every 60th of a second, so find how many sections we want
//closer the sections are, the more accurate we'll have for our time
float sectionWidth = 1.0f / 60.0f;
float endTime = m_spawnRateCurve.GetLastKeyTime();
m_totalArea = m_spawnRateCurve.GetAreaUnderCurve(0, endTime, sectionWidth, m_timeSpan);
}
