ParticleCurve.custom constructor
Bakes an arbitrary function of the life progress t, where t goes
from 0 at spawn to 1 at death.
Implementation
ParticleCurve.custom(double Function(double t) f)
: _samples = Float32List(_resolution + 1) {
for (var i = 0; i <= _resolution; i++) {
_samples[i] = f(i / _resolution);
}
}