... So that even if the time is "slightly" (less than 1/2 sample interval) left
of the discontinuity, the right-hand limit is always used.
Thus this compensates for some roundoff errors when pasting one clip with
an envelope into another.
This overcomes the objections that were in a comment in Envelope::Paste
to making control points with exactly equal times.
And therefore Paste can be rewritten to do so, but that has not happened yet.
Envelope points at exactly equal time coordinates can already be made by
dragging points in the envelope editor.
... Formerly this was done correctly only for cut and delete from WaveTrack,
paste into WaveTrack, and sync-lock adjustment of WaveTrack (either lengthening
or shortening).
Now also properly done for TimeTrack cut and paste, and also for:
Split cut
Split delete
Trim
... To be very sure we can avoid roundoff errors from adding mOffset and
subtracting it again; so that evaluation exactly at a control point time gives
the exact value of that point.
... rather than some of them being relative to the Envelope's offset.
In case of the envelopes used in TimeTrack or Equalization, offset was
always zero, so this doesn't matter, except to make the contract of the
Envelope class more explicit and sensible in isolation.
In case of InsertSpace at least, this does fix an obscure bug, which could
only happen when you have a clip, with an envelope, that starts before zero,
and you select a region overlapping that clip and some other clip, with a void
between, and you use the Join command.
Aren't you relieved that's fixed now?
... first: suspend scrubbing only when the application is deactivated -- not
necessarily when track panel loses focus; resume when reactivated.
second: click and drag to seek happens only when the pointer is in the track
panel, and either over a wave track, or over no track.
... the preference is independent of those in Interface and Recording
preferences, which affect meters, sound activated recordings, time track,
and Plot Spectrum
... and SelectedRegion, and not ViewInfo or zoom level as a double.
Also some leftOffset arguments.
Assumptions of uniform zoom level persist in TrackArtist::DrawClipSpectrum and
in TrackArtist::DrawClipWaveform but no longer in the rest.
