Two changes in the trigger pane, landed together.
**Persistence.** Trigger mode keeps the last N published acquisitions and draws them fading toward
the background, N being a panel control (1..8, default 1) with N=1 meaning today's behaviour
exactly, so the knob is the switch. The layers are the accumulate path's own -- one layer per
(signal, age) in the row's free trace slots, named with the accumulate vocabulary so
`layer_base_name()` strips the suffix and `signal_color()` resolves the base signal -- so a layer is
not a signal: the signal list, the colours and the measurements see one row per signal.
`ScopeModel` retains the outgoing snapshot in seven atomic `shared_ptr` slots (no lock, no copy; the
snapshot already exists) and a layer's channel is resolved **by name inside the snapshot**, because
the channel list is renumbered by any structural change since that acquisition was cut.
`RowSet::sync_layers()` re-plans from the rows and the depth alone, so a latch costs no rebuild, and
`event_data_window()` skips layer slots so an older acquisition can never re-pin the axis. The
schedule is 0.5^age -- the acquisition on screen at full brightness and each older one half the
previous, independent of N, so raising the depth adds dimmer acquisitions rather than rescaling the
ones already on screen. Memory is bounded by the ring's own `--buffer-mb` rather than by the depth,
which is the bound that cannot be driven into an OOM, and the panel says when either bound bites.
This also wired up `set_trace_alpha()`, which the accumulate path was setting and nothing was
reading -- so the documented 0.35 translucency of an accumulation was opaque in fact.
**Force.** In the trigger pane beside Arm/Disarm, shown only while trigger mode is on: one
acquisition now, with the configured window. It is a synthetic edge rather than a second publisher
-- the engine opens one capture at the present moment and everything else is the ordinary latch, so
a forced acquisition is cut, pinned, framed, recorded and cached exactly like a latched one, and
the button owns no window and no publish. The pre-trigger gate is deliberately skipped (capture now
is a request for the history that exists, and the snapshot reports its own shorter pre_s), a
capture already filling is refused rather than restarted, and the state afterwards is the mode's:
Normal stays armed, Single disarms. The request is one atomic flag written under the model mutex
with `armed` -- the producer reads `armed` at the top of a packet and the request at the bottom, so
a request written between the two would be dropped -- and consumed at the end of a packet, after
the channel loop and before the pending publish.
**A defect fixed in passing, in the function Force was modelled on:** `on_arm_clicked()` passed
`TriggerConfig::channel` (an index into `channels()`) to `set_signal_enabled()` (an index into
`signals()`). With one signal acquired, arming switched on the stream's clock signal and left the
watched signal untouched -- and since a signal the panel was not showing is a change, it rebuilt
the buffer under the click, dropping the very pre-trigger window the arming, and now the Force, was
about to capture. Measured before: `0.0100 s of history behind it`; after: `2.5299 s`.
`trigger_signal_index()` is now the one resolution, used by both buttons.
A measurement is a statistic of the window the pane is *about*, and on a
pinned view -- a held event, a paused stream, an opened file -- that is the
frame, not the part of it on screen. The pane followed the viewport
instead, so a wheel on a latched event moved `average` and `top`: the
reported "when measuring a still frame, moving the zoom makes measurements
such as average or top change". Nothing about the data had changed; the
user was only looking closer.
The window is `RowSet::pinned_range()` while the pin frames the view and
the viewport otherwise, and the choice is made in `update_measures()` --
the call site -- rather than inside `MeasureWindowReader`, because it is
*booked* as well as read: that window is what the "it moved" test compares
against `App::measure_window`, so a gesture inside the pin spends no
recompute either, and a reader that chose its own would leave a pinned
view recomputing every gesture frame for a number that cannot change.
`pinned_range()` is now the one expression of the pin's extent, shared
with the framing (`hold_pinned_window()`, `fit_x()`), and the reader is
handed the window instead of reading the plot. Live is unchanged: there
the window really moves and the statistic follows it, and the
accumulator's rule about what resets the history is about neither.
`UDPSCOPE_PROBE_MEASUREPIN_MS` is the guard, three legs of before/after a
gesture on the row's own axis. On a latched event zoomed to a quarter
(`view=[-1..1]` -> `[-0.25..0.25]`, `pin` unchanged): `same=4/4
for_same=1 pass_delta=0`, every value bit-identical -- `average=0.000000
top=0.957975 peak to peak=2.000000 amplitude=1.915950` both sides. The
same on a pause taken from it. Since the key `for=` follows `pin=` now,
`[measure-trace]` gained the field, so a held run reads `for==pin` with
`swin` free to sit inside it. On a live view a zoom to an eighth reads
`same=0/4 for_same=0 pass_delta=3 span_after=0.125000 follows=1` with the
values moving -- the case the rule must not swallow.
Before the fix the same probe reads `same=1/4 for_same=0 pass_delta=1
span_after=0.500000` on the held event (`top` `0.957975` -> `0.957966`)
and `same=0/4 span_after=0.125000` on the pause (`top` `0.957944` ->
`0.358614`). Live reads the same either way.
Also fixed, found by the pause leg: pausing while an event is *held*
froze an **empty** picture. `on_pause_toggled()` read `stream_at_x0()`
after setting the pause state, and that accessor follows the display --
`paused` with no pause view published yet answers `-display_epoch()`,
which on a held event is 0, so the cut searched the ring at edge-relative
x, found nothing, and the frame bound an empty snapshot: every
measurement `--`, every ruler gone (`ev=650001` on the probe's line now,
`ev=0` before). The offset and the window are read first, which is the
offset the axis is actually displaying. The live case is unaffected, which
is why the pause probe, which pauses a live view, never saw it.
Docs corrected where they asserted the old half-truth: the invariants now
separate the accumulator's rule (unchanged) from the window a value is
computed over (this change), the trigger/pinning file names the pin as
load-bearing for both the framing and the numbers and records the pause
ordering rule, `verification.md`/`probe-readings.md` describe the new
probe and `pin=`, and the README and the manual say what a still frame
measures.
Checked: `cmake --build build --clean-first -j4` 0 errors and the
documented three warnings; `make -C build test-ui` 13 ok; `make -C build
test-help` green; an exit-dump run 0 Gtk-WARNING/Gtk-CRITICAL and `gtk
warnings: 0`; `[measurepin-probe]`, `[pan-probe]` (`held=1`,
`allowed=1`, `limited=1`), `[pause-probe]` (`event_size` non-zero exactly
while paused, `axis` inside `frozen_x`, `skips` 0 live / 30 paused),
`[stats-probe]` (`dn=1` across the pause), `[zoom-probe]` (`gap_px=0.0`
at every step) and `[measure-probe]` + the dump's `measures
window:` (all-types run `marks_in_window=4/4`, `pin=off` live) on the fast
mock. `measure cost:` is unchanged in kind: `raw=37298 (0.0%)` of
`covered=121704537`, 1.04 ms a pass -- the runs that read higher are the
probe's own zoomed-to-a-slice windows, where the window is legitimately
shorter than a bucket.
GTK4 and libadwaita. It receives one UDP stream through the vendored
udpsclient, buffers it in a large ring, and draws it with the vendored
plotter: a trigger with a pre/post event window, a pause that freezes the
window, cursors, measurements, math channels in a node editor, an event cache,
named configurations, preferences, and an export of the visible window to
.npy/.csv. Waveform files can be opened and analysed in place.
The interface is two threads -- a producer that owns the socket and the GTK
main thread that owns every widget and the GL context -- sharing one model
under one mutex, with samples crossing through lock-free rings.
deps/plotter is a submodule pinned to the commit this tree builds against;
deps/udpsclient is vendored in place. docs/claude/ documents the rules that
cost a defect to learn, and SPECS.md is the requirement document.
Clicking the coloured chip in the signal list opens a GtkColorDialog and the
colour it returns overrides that signal's palette entry. Held by name, like
every other identity here, and persisted as a session `[[color]]` table.
RowSet::signal_color() becomes the one resolver: install() builds the trace
through it and all three chip sites read it, because a chip exists to say which
trace a row is about and an override is exactly the state in which two routes to
a colour would disagree. A grey chip names no trace and so is not clickable, and
the way back is `Default colour` in the signal's menu -- a setting with no undo
is a trap.
The gesture sits on the existing label rather than in a GtkButton: padding on
this row is what made the signal list twice as tall once. It claims its sequence
so a click on the chip cannot become the start of a row drag.
UDPSCOPE_PROBE_COLOR_MS reads the result out of plot::Plot::trace() and out of
the chip's own markup, with an override in no palette slot, so neither leg can
pass by asking the resolver what it already said.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
With the axis titles gone the left gutter was 200 px of an 870 px viewport and the right
side had no margin at all, so the newest tick's label was drawn half outside the plot and
the newest sample's ink landed on the frame.
Two causes on the left. The reservation covered `format_si()`'s `%.3g` fallback
(`-1.23e-45`), which no signal on an `Si` axis produces -- the widest real label for a
unitless axis is `-1.23m` -- and `note_y_gutter()` added 6 px of slack to a figure that is
already the maximum of the labels and last frame's floor, making the gutter a ratchet that
climbed to its 200 px cap in ~19 frames. It settles at 104 px now, with `axes.w changes: 1`
where it read 17.
The right side did not exist: a plot's `axes` rect reached the viewport's right edge by
construction. `deps/plotter` gains `Plot::set_right_gutter()` and `Figure::set_right_gutter()`
-- a want rather than a measurement, since nothing is drawn there, imposed figure-wide so
the rows end on one column as they already start on one. udpscope asks for half the widest
time label plus the label padding (59 px), x labels being centred on their tick.
Separately: the exit dump asked two destroyed widgets for their size, which is where the
"exactly two Gtk-CRITICALs" baseline came from. The pointer is freed memory by then, so a
run that had destroyed other windows first (UDPSCOPE_PROBE_HELP_MS opens three) segfaulted
in the middle of the dump instead. Both sizes are captured on the tick; a clean run now
carries no critical.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Three asked-for changes, one commit because they are one coordinate system.
The live axis is a fixed [-window, 0] with the newest sample at 0, so x reads
as an age and the labels stand still while the trace rolls under them. That
makes the display clock distinct from the stream clock for the first time, so
`ScopeModel::stream_at_x0()` becomes the single conversion between them
(`display_x = stream_t - stream_at_x0()` in all four modes) and a snapshot
carries its own origin in `EventSnapshot::x_offset`. The pause view is now
rebased like an event's, reversing an earlier deliberate choice: a frozen
absolute-stamped picture would sit a whole uptime right of a newest-relative
axis. That also fixed a latent bug, the export adding `trigger_time()` to a
*paused* view's stamps.
The status bar says how long you have been paused -- wall time, since the
producer never stops, through `format_elapsed()` so the field cannot widen.
The export writes two time columns: `time`, the axis as displayed, and
`abs_seconds`, the stream's own clock for the same sample. f64 seconds and
not the wire's integer, because `udps_frame_t::values` is a `const double*`
and the integer never exists in this process.
Cursors and measurement marks move in opposite directions under the rolling
axis, deliberately: a cursor is a position on screen and stays put, a mark
names a sample and travels with it. `App::measure_window` is stream-clocked
for a sharper reason -- a display-coordinate live window never moves, so the
"the window moved" recompute would never fire again.
Moves the deps/plotter pin to 58473db, which stops a time label's mantissa
reaching its own radix: a one-second tick differenced off a live axis read
`1e+3ms`.
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 previous commit took "fit x sets the window properly" to mean a fit should
frame the data and propagate that as the new time scale. It should not: a fit is
a plot interaction, and the window is also the trigger's event span and how the
samples are stored, so a fit that framed the data could re-plan the rings and
drop the history on a menu click. What a fit means here is the undo of a zoom --
a 2 s window zoomed into reads 2 s again.
`fit_x()` therefore reads `window_s_` and never writes it. Live it takes the
window-control path with the window already set, which re-arms the follow and
parks the newest span at the live edge. Pinned -- a held event, a filling capture
or a paused view -- it restores the pin's full range, which is the snapshot's own
span and may be narrower than the requested window, and it writes the per-row
member axes as well as the link group: `hold_pinned_window()` prefers a member
that differs from `pinned_stated_`, so writing the group alone is reverted to the
zoomed range one frame later. `apply_window_scale()` is folded back into
`apply_time_window()`, which the window control is again the only caller of.
The probe now zooms in before fitting, since otherwise there is nothing to undo,
and reports `pinned=`. `window` and `event_span` must be unchanged on every line.
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>
