gravity
f = (gravity/rsquared) * frameRateModifier;
particle_list[i].gravity = -(((double)((rand_max>>1)+(random()%(rand_max>>1)))/rand_max))*0.599; // more magic
y = s->y = (int32)(cy + (int32)((s->gravity/2)*(s->timeval*s->timeval)*1.94) + ((s->init_velocity - (s->gravity*s->timeval)) * s->timeval));
float gravity;