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plotter/docs/building-and-testing.md
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Martino Ferrari 38ef459897
CI / debug (tests + all adapters) (push) Canceled after 0s
CI / coverage (floor + measured table) (push) Canceled after 0s
CI / asan (AddressSanitizer) (push) Canceled after 0s
feat(plot)!: harden pipeline, XY series, dash/markers, touch, packaging
Breaking: Series::gather emits x relative to x0() and takes a GatherMode;
consumers reconstruct absolute x in f64 before mapping (series.hpp documents
the contract).

Bugs, each pinned by a fail-before regression test:
- render: f32 staging quantised epoch-time x into 128 px columns; every
  data-space draw now stages to_space(x) - to_space(origin) with the origin
  folded into the offset uniform in f64 (epoch/zero-origin twins rasterise
  identically)
- ticks: major test was ULP-fragile and blanked epoch axes; majors are an
  integer-index test and are never truncated by the minor cap
- gather: LOD envelope emitted buckets straddling [begin,end); ceil/floor
  bucket edges + raw lead/trail spans
- live follow: log x axes held a linear span and zoomed every frame; span and
  offset now live in axis space (plot + both figure link-group paths)
- input: a zero-notch wheel disarmed auto_scale on every axis; dy==0 pans x,
  factor == 1 / inf refused in wheel and drag zoom
- render: the single text flush painted legend names over the crosshair
  readout panel; two batches, under flushed before the panel
- data: NaN dropped from min/max unless it seeded the fold; non-finite
  samples are now excluded from every aggregate and from cached bounds

Robustness: viewport normalisation (no clamp UB), non-finite range refusal,
pyramid level cap at 57 (no shift/div UB through public gather), rounded ring
capacity documented + pre-sized, GL blend func and UNPACK_ALIGNMENT
save/restore, Renderer::release_gl() teardown, u64 buffer epochs, annotation
captions clamped, button-aware GLFW row capture, cached figure row rects (no
per-event layout), ruler-pair measurement refused, span-nonfinite guards in
axis_ends.

Features: XY series (sorted x, binary-search neighbours/snap, LOD over sample
index); StreamSeries::freeze(); ArraySeries::push(); per-trace dash and
markers (scatter at width 0) with auto or literal stride; GatherMode
Envelope/Nearest/Mean via bucket_sum/sumsq; Style::line_aa_px; per-glyph text
colour (readout values in trace colour); wheel-dx x pan; arrow-key pan;
Escape cancels a drag and restores captured ranges; modifier-masked box zoom
(Shift both, Ctrl x, Alt y); double-click reset via PointerEvent::time_s;
ImGui key repeat unified; pinch gestures on Qt and GTK; pixelDelta wheel path
and DevicePixelRatioChange handling; GNUInstallDirs, SOVERSION,
SameMinorVersion, generated plot/version.hpp, relocatable plot.pc, licence
install, FILES_MATCHING, GitHub Actions CI (debug/coverage/asan).

Suite 283 -> 350 cases, 0 failed; coverage 93.9% (3730/3971) over 24 files,
floor 80/90 held; ASAN preset suite green; all four demos run headless (the
GTK scripted-resize check needs a window manager and fails identically on the
parent commit); readme_main.cpp committed and compiles with the README
command; pkg-config and find_package consumption verified from a relocated
install prefix.
2026-09-30 17:32:06 +02:00

128 lines
7.5 KiB
Markdown

# Building and testing
## Presets and options
Four configure/build presets live in `CMakePresets.json`:
| preset | binaryDir | what it builds |
|---|---|---|
| `linux-debug` | `build/debug` | Debug; tests, examples and all four adapters |
| `linux-release` | `build/release` | Release; `PLOT_BUILD_TESTS=OFF` (so the installed `libplot_core.a` carries none of the test-only counter instrumentation); examples and all four adapters |
| `linux-asan` | `build/asan` | Debug with `PLOT_SANITIZE=address`; tests and all four adapters |
| `linux-coverage` | `build/cov` | the instrumented tree behind `tools/coverage.sh`: `--coverage -O0 -g`, `PLOT_COVERAGE=ON`, tests on, adapters and examples off |
The options (`cmake/plot_options.cmake`) and their defaults:
| option | default | meaning |
|---|---|---|
| `PLOT_BUILD_TESTS` | `ON` | build the test suite (needs EGL) |
| `PLOT_BUILD_EXAMPLES` | `OFF` | build the demos |
| `PLOT_BUILD_GLFW` | `OFF` | build the GLFW adapter and its demo |
| `PLOT_BUILD_IMGUI` | `OFF` | build the Dear ImGui adapter and its demo (ImGui is fetched at configure time) |
| `PLOT_BUILD_QT6` | `OFF` | build the Qt6 adapter and its demo |
| `PLOT_BUILD_GTK4` | `OFF` | build the GTK4 adapter and its demo |
| `PLOT_BUILD_TTF_FONT` | on iff `third_party/stb_truetype.h` exists | build the optional `plot::text::TrueTypeFont` backend |
| `PLOT_INSTALL` | `ON` | generate install/export rules for `find_package(plot)` |
| `PLOT_SANITIZE` | `""` | sanitizer list for `-fsanitize=` (e.g. `address`) |
| `PLOT_COVERAGE` | `OFF` | add the `coverage` target (requires an instrumented tree) |
Adapters and examples are off by default, so the core library and its tests build on a bare
toolchain. Each example is guarded by the adapter target it needs, so
`-DPLOT_BUILD_EXAMPLES=ON` without the matching adapter is a no-op rather than a configure
error.
## Running the suite
```sh
cmake --preset linux-debug
cmake --build build/debug
ctest --test-dir build/debug --output-on-failure
```
ctest registers four tests: `plot_tests` (the test binary), the two header/umbrella build
checks (`plot_headers_self_contained`, `plot_umbrella_covers_public_headers`) and
`plot_umbrella_check`. The `plot_tests` binary itself runs **350 cases** in the `linux-debug`
preset; its harness prints one line per case and a final `350 cases, 0 failed` summary line.
The case counts per file are the `PLOT_TEST(...)` declarations under `tests/` — recount them
(`grep -c '^PLOT_TEST(' tests/test_*.cpp`) after adding or removing cases.
## Install layout
`cmake --install` follows `GNUInstallDirs`, so every path honours the standard cache
variables (`CMAKE_INSTALL_LIBDIR`, `CMAKE_INSTALL_INCLUDEDIR`, …) and their distribution
defaults — plain `lib`, `include` and `share` unless a packager overrides them:
| prefix-relative path | what |
|---|---|
| `lib/` | the `plot_core` archive (and `libplot_core.so` with its version and SONAME symlinks when built with `BUILD_SHARED_LIBS=ON`) |
| `include/plot/` | every public header, including the generated `plot/version.hpp` (`plot::version::major/minor/patch/string` and the `PLOT_VERSION_*` macros) |
| `lib/cmake/plot/` | the CMake package: `plotConfig.cmake`, `plotConfigVersion.cmake` (Compatibility **SameMinorVersion**, so `find_package(plot 0.1 …)` accepts 0.1.x only), `plotTargets.cmake` |
| `lib/pkgconfig/plot.pc` | pkg-config metadata for consumers whose build is not CMake |
| `share/licenses/plot/` | `LICENSE` (MIT) and `licences/OFL-1.1.txt` (the embedded font) |
Adapters that were built and exported install themselves alongside the core (their headers
under `include/<adapter>/`, their targets in the same package).
## Headless demo modes
Each demo supports two environment variables, implemented once and reused:
- `PLOT_DEMO_EXIT_AFTER_MS=<n>` — stop the loop after `n` milliseconds and return. Unset,
unparsable or not positive means "run until the window is closed". A run with a deadline
creates its window hidden, so an automated run never flashes a window on a real display,
and its frame times are not throttled by a vblank.
- `PLOT_DEMO_SCREENSHOT=<path>` — on that final frame, write it as a binary PPM before the
swap. The GLFW host writes the framebuffer with `Renderer::dump_frame_ppm()`; the ImGui
demo writes the whole framebuffer, while Qt and GTK write their widget's/area's own
framebuffer (their toolkits' chrome lives outside it).
That pair is what lets CI run the GUI demos under `xvfb-run` with no display access and no
screen capture (the invocations are in [embedding.md](embedding.md)).
Three demos add env-gated **self-checking** modes. These are verification affordances for
the project's own testing, driven through the real host and its own controllers — they are
not a second implementation of anything, and they exit non-zero if a measured property fails:
| variable | demo | what it drives |
|---|---|---|
| `PLOT_DEMO_FOLLOW=1` | `plot_glfw_demo` | the live-follow sequence: three wheel notches and a pan on a `XFollow::Live` axis, printing the range width, the distance behind the newest sample and the follow state at each step |
| `PLOT_DEMO_REGIONS` (`=hot` to hover a bound) | `plot_glfw_demo` | the direct-manipulation sequence: freeze the view, place a region, pan 100 px with the press outside it, and check the region came along with its width untouched |
| `PLOT_DEMO_SYNC=1` | `plot_multiplot_demo` | the synced-follow check: the three rows hold one range and its right edge keeps tracking the newest sample through a zoom and a pan on different rows |
| `PLOT_DEMO_CROSSHAIR=<row>` | `plot_multiplot_demo` | parks the pointer in a row each frame so a headless screenshot shows the one horizontal line the hovered row draws |
(`plot_glfw_demo` also accepts `PLOT_DEMO_CROSSHAIR=1`, which parks the pointer at the centre
of the data area so the two-line crosshair has ink to measure.)
## Coverage
```sh
tools/coverage.sh # from the repository root
cmake --build build/cov --target coverage # the same thing, through CMake
```
The script configures `build/cov` from the `linux-coverage` preset, builds it, clears the
`.gcda` counters, runs the whole suite, captures `src/**` with `lcov`, renders an HTML report
to `build/cov/html/index.html`, prints the per-file table, and **exits non-zero when a floor
is violated**. It needs `cmake`, `ninja`, `ctest`, `lcov`, `genhtml` and `python3`, and exits
`2` with a message when one is missing.
The floors are enforced by `tools/coverage_floor.py`:
| scope | floor |
|---|---|
| every file under `src/` | **80%** of its instrumented lines |
| `src/` as a whole | **90%** of instrumented lines |
Branch coverage is deliberately off. This page carries no measured totals — a number written
here would be stale the moment `src/` moved, and the report is reproducible: the method, the
per-file table and the floor verdict live in [docs/coverage.md](coverage.md), which
`tools/coverage.sh` rewrites from the very run that measured them. Re-run the command for the
live numbers.
**One thing to know about the coverage preset:** it builds **333 of the 350 cases**. The 17
that are missing are the adapter cases that need an adapter target to exist — 11 in
`test_imgui_widget.cpp` and 6 in `test_glfw_host.cpp` — and the coverage preset turns the
adapters off. The toolkit-free adapter seams still run there: `test_qt_pointer.cpp` (5 cases)
and `test_gtk_input.cpp` (11 cases) compile without Qt or GTK. So the coverage number measures
the library plus its unit suite, not the adapter bodies (which the headless demo runs cover).