the position of the emitter in the previous frame and the new position in the new
frame, the number of particles added also scales up to compensate for this movement.
"The first is with
Particle.cpp. I made a change so that when the lifetime is 0 (lasts
forever) the sizeRange, colorRange, and alphaRange are used to create
a random size, color, and alpha."
"The second change is with range and SectorPlacer. The distribution of
particles across the sector was not uniform. I added get_random_sqrtf()
function where it is used in SectorPlacer::Place(). This seems to make
the distribution uniform (at least when minimum radius is 0)."
