The left edge of a region on the the editor is rounded to be
on a pixel. When zoomed out, the position corresponding to that
pixel is not usually identical to the region's position().
We need to correct for this as best as possible, while keeping
peaks aligned to pixels.
This is mostly a simple lexical search+replace but the absence of operator< for
std::weak_ptr<T> leads to some complications, particularly with Evoral::Sequence
and ExportPortChannel.
* Draw antialised waveform if waveform is monotonic
* Fix center-line position (span at most height - 1),
* Remove invalid "side-lines" that were previously
drawn around spikes.
* Do not linearly center min/max when drawing log-scale
* Fix offset of lower outline and clip indicators
Those are blank to begin with, nothing is drawn, yet they'd still be
cached.
This may happen during an initial exposure (see 1a49d7d42b),
or when deleting regions.
To mitigate concurrent rendering, the waveform cache adds a random
range of pixels centered around the visible waveform.
Alignment is using integer half_width = width_samples / 2;
This always aligns the left-edge to the left-most cairo-pixel.
This fixes an issue with moving moiree patterns in waveforms when
zooming vertically (which invalidates the cache and uses a
different random number of pixels),
Generated by tools/f2s. Some hand-editing will be required in a few places to fix up comments related to timecode
and video in order to keep the legible
