v1.0.0-rc.166 (#76)

* `rugnux --mode calibration` writes `<prefix>.json` beside the `.poni`, whose `dataset_settings` member is a `jfjoch_broker` `dataset_settings` body as it stands.
* `rugnux` and `jfjoch_viewer` read PILATUS miniCBF sweeps natively, without conversion.
* Masters written by other facilities open, including Eiger 1.x and third-party NXmx variants.
* `rugnux` measures the beam centre on every run, and indexes with it when the file's value indexes nothing.
* A detector swung out on a 2theta arm is placed where the file says it stands, and the calibration can hold the tilt fixed.
* `rugnux` writes the unmerged MTZ by default, and a P1 merge beside it, so a wrong space group can be re-merged without reprocessing.
* Significant improvements to symmetry handling in `rugnux`: the lattice, the point group, the setting and the systematic absences.
* The `rugnux` report gives the resolution the CC1/2 fit reached, beside the range the reflections were written to.
* The `rugnux` report gives the twinning statistics measured before the space group was decided, beside the ones measured after.
* The `rugnux` report gives the strong-direction diffraction limit, and warns when CC1/2 is not monotone with resolution.
* `rugnux` ranks screw axes on the evidence their absences carry, rather than on how many control reflections a candidate happens to have.
* Twinning is no longer reported when the L-test contradicts it.
* The `rugnux` report gives the detector tilt, the measured tilt and the direct beam beside the beam centre, and a post-refined beam centre is judged against the run's own measurement rather than the file's.
* `--no-refine-tilt` holds the detector tilt at the value in the file, instead of zeroing it, when the calibration starts from the spots.
* The `jfjoch_viewer` grid scan view draws the cells in the proportion of the scan steps, so the map has the shape of the scanned area.

Reviewed-on: #76
Co-authored-by: Filip Leonarski <filip.leonarski@psi.ch>

tests/BeamCenterFromBackgroundTest.cpp

@@ -124,3 +124,24 @@ TEST_CASE("BeamCenterFromBackground_AnAzimuthalShadowIsNotACentreError", "[BeamC
     CHECK(estimate->beam_x_pxl == Catch::Approx(geom_true.GetBeamX_pxl()).margin(1.0));
     CHECK(estimate->beam_y_pxl == Catch::Approx(geom_true.GetBeamY_pxl()).margin(1.0));
 }
+
+// The same, with the detector tilted. Every pixel's 2-theta and azimuth, and the derivative of
+// 2-theta with respect to the centre that the fit is built on, go through the detector rotation
+// matrix, so the tilt is not a detail of the geometry here - it is in the Jacobian.
+TEST_CASE("BeamCenterFromBackground_SurvivesADetectorTilt", "[BeamCenter]") {
+    DiffractionExperiment x = TestExperiment();
+    x.PoniRot1_rad(0.005f).PoniRot2_rad(-0.003f);
+    PixelMask pixel_mask(x);
+
+    const DiffractionGeometry geom_true = OffsetBy(x.GetDiffractionGeometry(), 3.0f, -2.5f);
+    const auto [direct_x, direct_y] = geom_true.GetDirectBeam_pxl();
+    REQUIRE(std::hypot(direct_x - geom_true.GetBeamX_pxl(), direct_y - geom_true.GetBeamY_pxl()) > 5.0f);
+
+    const auto projection = SynthesiseProjection(x, pixel_mask, geom_true, 60.0f, 1.0f);
+    const auto estimate = FindBeamCenterFromBackground(x, pixel_mask, projection);
+
+    REQUIRE(estimate.has_value());
+    CHECK(estimate->beam_x_pxl == Catch::Approx(geom_true.GetBeamX_pxl()).margin(0.5));
+    CHECK(estimate->beam_y_pxl == Catch::Approx(geom_true.GetBeamY_pxl()).margin(0.5));
+    CHECK(estimate->sigma_pxl < 1.0f);
+}