Four review findings on the Task 7 renderer:
- InstanceStore::epoch() is derived from gl::Buffer::generation() -- advanced by
every allocation, deletion and move -- plus the slot the instances were written
to, so the orphan fallback of grow_persistent() can no longer leave the vertex
array's attribute pointers bound to a deleted buffer: the epoch reports the new
identity and upload() re-points them before the draw.
- PlotLayout reserves y_title_area/x_title_area outside axes (sized from the text
metrics) and draw_titles() draws in them, so a title can no longer land on the
data, whatever the envelope does.
- draw() computes plot.layout() once and hands it to the helpers, instead of six
times per frame, each of which rebuilt the ticks and the grid.
- A refused fence is no longer dropped: mark_drawn() falls back to the orphan path
and reports the failure rather than rotating through an unsynchronised slot.
New smoke cases force both refusals through the GL entry points (glMapBufferRange,
glFenceSync) and assert the pixels plus the live transfer mode; the title case
asserts the title colour is absent from the bands inside axes and present in both
strips. All three fail against the pre-fix sources.
Every pixel-to-data conversion in the controller now maps through the
same rectangle Plot::x_transform/y_transform are built from:
- pan() derives the scale from layout().axes.w/.h, so a drag moves the
grabbed data point by exactly the drag distance (the viewport model
stranded it behind the pointer by the label-strip fraction).
- apply_box_zoom() clamps the selection to layout().axes and sets each
range from the transforms (x_transform().to_data_x(l/r), y_transform()
.to_data_y(bottom/top)); the selection's bottom edge is the y minimum.
- end_drag() takes the release event and refreshes the selection from its
coordinates before applying, so a host that reports only press and
release still frames the box instead of degrading it to a click.
- axis_zoom() uses a per-pixel sensitivity (200 px == one decade) rather
than reusing the wheel's per-notch constant, so a pixel drag is no
longer treated as a wheel notch.
Tests now assert the grab-and-drag invariant through the transform (the
old pixel-fraction assertions certified the viewport defect), add a
press+release-only box zoom, and pin the axis-zoom magnitude.
The completion check was scheduling-dependent and the test could lose its TSan
overlap window. The producer now signals done with a release store, the consumer
reads in a do/while keyed on that flag so at least one read is guaranteed by
construction, and a started/reading handshake makes the producer's remaining
pushes provably overlap the reader's loop. Bounded to 4096 pushes on the 256-slot
ring, and the assertions moved after join() so a failure reports instead of
terminating. With the pre-fix ring restored, four TSan runs still flag push vs
copy_from, so the case keeps its teeth.
The pyramid's public query surface is the bucket-grained trio
(reduce_buckets/sum_buckets/sumsq_buckets); reduce() was the one
non-*_buckets query and silently over-covered non-aligned ranges, which
is exactly the misuse the exactness split exists to prevent. Exact range
queries stay on Series.
- delete the declaration, its doc paragraph and the definition; no
helper became dead (fold_range/cover_buckets/ceil_to_bucket are all
still used by the *_buckets queries)
- pyramid_clear_and_rebuild: complete bucket 0 and assert its extrema via
reduce_buckets(0, kBucket) -- a pyramid has no exact sub-bucket query
- stream_series_acquire_publishes_snapshot: s.pyramid().reduce(0, 100)
-> s.reduce(0, 100), keeping the == 99.0 assertion
cover_buckets chose one level per pass, so an odd first whole bucket (half of all
measurement ranges) never reached a level above 0 and folded every remaining
bucket at level 0 -- 15624 entries for a 1e6-sample pyramid. Pick the largest
aligned, in-range, materialised level at each cursor instead; the new cost test
counts folded entries through a PLOT_PYRAMID_COUNT_COVERS-only hook (absent from
normal builds) and fails on the old body.
Ring slots are now relaxed std::atomic: overwrite-on-full means the producer
reuses the slot of a snapshot's oldest sample while the consumer reads it, which
was a data race, not just a stale value. copy_from loads explicitly instead of
std::copy; push stays lock-free. A new producer/consumer case is the one TSan
flags without this.
Also extends the wrapped-window test with x0/bounds/pyramid/sum/sumsq/gather
checks, and corrects the StreamSeries threading note to the sample-count bound.
- loader: add available(), true only after load() has resolved every
required entry point (false at the start of load()). Program::from_source
and the other fallible constructors return ErrorCode::Unsupported while it
is false, so a failed load() with a partially populated table can no longer
fault on an unresolved entry point.
- caps: GL_CONTEXT_PROFILE_MASK only exists from 3.2, so query it only on
3.2+ contexts. A 3.0/3.1 query latches GL_INVALID_ENUM in the context, which
the next unrelated glGetError() (e.g. read_pixel) then reports as failure.
- tests: gate the dlsym/libGL.so.1 fallback assertions on libGL being
resolvable, so the GL suite also passes on a GLES-only host.
A zero pixel span previously produced sx/sy == 0, so to_data_* returned
NaN or +/-inf. axis_scale now substitutes a unit pixel span (1.0) when
|p1 - p0| <= 1e-12, keeping the mapping finite and invertible while
leaving non-collapsed spans byte-identical.
Add committed coverage for from_range (linear, flipped pixel axis, log x,
degenerate data range, collapsed pixel span) and log10_positive clamping.
Martino Ferrari