gather() staged x as f32 relative to the series' own x0() -- the start of
the whole retained window -- so the quantisation was a fraction of the
ring rather than of the view: 1.9 us at 20 s of retained data, which at a
10 us view across a 716 px axis is over 100 px between where a sample is
drawn and the x a readout quotes for it (crosshair_point() reads x_at()
in exact f64). It halved on every zoom out, which is what made it read as
"zooming in makes the crosshair select a point beside the data".
The origin is now the caller's (plotter c2c8c59): the renderer passes the
visible range's minimum, so the error is a fixed 2^-24 of what is on
screen -- about 4e-5 px over a 700 px axis -- at any zoom. The parameter
sits before out_xy so every call site is a compile error rather than a
silent change of behaviour.
The renderer no longer reads series.x0() at paint time at all, which
removes two of the three symptoms of the torn window_x0_ read by
construction; the ink probe's now-vacuous kept_fixed_x0 walk goes with
them, replaced by a drawn-vs-quoted pixel figure. neighbours() still
tests the visible range against x_at(0), so the cache stays load-bearing.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
The caption that names the relative x labels' anchor was an `Annotation`, whose anchor
is a data coordinate -- so it crawled across the plot under a pan and drifted under a
zoom, which is how it was reported. It is now `Plot::set_x_note()`: the bottom row's
caption, drawn by the renderer in the axes' bottom-left corner in pixels, on the
legend's own backplate.
The text stays the host's, because only the host knows that label + caption has to be
the exact absolute time (`%.6g`, where `format_time()` would round to three figures).
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
The time scale is more than the axis: it is also the trigger's event span, the
buffer partition and the control's readout. A zoom or a pan was already clean --
the controller writes the member axis and `clamp_to_data()` caps the span -- but
both fits moved `window_s_` alone and only restated the control. The event span
then stayed on the previous window until the next decade step or unit change
applied the fitted value for real, so one action changed the time scale twice.
`apply_window_scale()` is split out of `apply_time_window()` for the fits to use:
it moves the partition, the event span, the control and the session, and leaves
the view alone, because `set_time_window()` re-arms the live follow and would
throw a held event or a paused view back onto the stream. The fits report the
span they framed, `fit_all()` delegates its x half to `fit_x()` so the two cannot
drift, and the probe drives the menu handlers rather than `RowSet` so it sees the
half that lives there. `[fit-probe]` gained `event_span=`, which must equal
`window=` on every line.
Also moves the plotter pin to 03c41ad (three build warnings, no behaviour).
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
The value was already the nearest stored sample's, but every mark drawn for it was
placed at the *marker's* x with that sample's y -- so the dot the eye follows and the
number in the pane were a different datum whenever the marker fell between two samples.
Half a sample period is nothing across a whole window and the width of the panel once a
few samples span the axes, which is the only zoom at which anyone is asking which point
a number came from.
`place_crossings()` now goes through the plotter's new `Plot::crosshair_point()`, which
returns the quoted sample's x alongside its y -- one lookup for the mark and the number,
so they cannot name different samples. The dot consequently sits a little off its own
vertical cursor line: the line is where the marker is, the dot is the datum being quoted,
and between two samples those are two places.
Pin moves to the upstream commit that does the same for the library's own hover crosshair
and draws its mark larger than a trace's sample dots, and that keeps the old blend
reachable as `CrosshairValue::Interpolated` -- which udpscope never states.
Verified: plotter suite 370 cases 0 failed; `[cursors-probe]` lines=3 marks=6 with
`first mark at x=3.292400 y=-0.525175` against the pane's `-525.17 mV`; `[help]`
pages=14 parsed=14 closed ok.
The crosshair and the cursors pane's mix values are one library call, and it
interpolated linearly between the two samples bracketing the pointer. That is
wrong twice over here. Ingest decimation is a boxcar average over `time_stride`
samples, so a number computed between two stored samples is a second, undeclared
estimate laid over the first that nothing on screen or in an export holds. And
past the sample spacing the polyline is a line the renderer drew, so quoting a
point on it reports the drawing rather than the data.
The fix is upstream and unconditional (plotter c028f48): `crosshair_span()`'s `t`
selects the nearer end instead of blending, with a tie reading the earlier
sample. `CrosshairRow::marker` is placed from the same y, so the dot follows the
quoted sample.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
The flicker ("no data" at no constant frequency, worse with the measurements
and cursors panes up) was a torn read of the window's first stamp: acquire()
pins the window to the ring's oldest slot, and reading it at paint time races
the producer lapping it, returning a stamp one ring span too new. x0() is the
origin every trace point is reconstructed from, so one torn read produced a
refused neighbours(), a filter that dropped three quarters of the points, and
a polyline shifted off its axis. It is cached by acquire() under the lock now.
EventSeries::neighbours() answered from the (x - x0)/dx grid, whose drift from
the real arrival stamps arrives as a constant offset in seconds -- a doubling
share of the screen per zoom step, which is the "zooming into a held event
clips it more from the left" report. Both series binary-search the stamps now.
The measurements pane went through the LOD pyramid rather than reading its
window raw (19.7 ms per recompute to 1.2 ms, 0.1% of a 2 M-sample window) and
recomputes on a cadence; the math engine lost a per-slot heap allocation, a
per-sample source lookup by name and a fetch_add that cost more than the
arithmetic it counted.
The cursors pane's mix mode drew a line per *named* slot, so a slot holding a
signal that can never produce a channel -- the stream's timestamp -- got a row
that could only read "--", and such names were re-saved every session. It
counts bound traces now and apply_layout() refuses them.
Four toolbar icons are drawn for this app and compiled in as a GResource: the
stock ones were a record dot for the trigger and three magnifiers for cursors,
measurements and math.
New probes and dump lines for all of it (trace ink, measure cost, math cost,
event zoom, toolbar icons); README and CLAUDE.md record what they cure.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
