Step Size

A SampleStream iterates through your query time.

Every time you call NextSample, your stream moves a certain number of seconds forwards (with a positive step size) or backwards (with a negative step size) in time.

A positive step size results in a sample stream that begins at the start time and continues until you hit the end time, or stop calling NextSample.

A negative step size results in a sample stream that begins at the end time and continues until you hit the start, or stop calling NextSample.