... 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?
... for functions in final classes.
override is like const -- it's not necessary, but it helps the compiler to
catch mistakes.
There may be some overriding functions not explicitly declared virtual and I did
not identify such cases, in which I might also add override.
... Should have no effect on generated code, except perhaps some slight faster
virtual function calls. Mostly useful as documentation of design intent.
Tried to mark every one of our classes that inherits from another, or is a
base for others, or has abstract virtual functions, and a few others besides.
... 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.
