1.0.0-rc.174 (#84)

* Rugnux: Performance improvements on GPU and CPU (more of the pre-scan and of scaling on the GPU, faster CPU spot finding and crystal refinement), with unchanged results.
* Rugnux: More robust processing - patches of persistently hot pixels are masked, an inconsistent merge triggers a retry at the measured beam centre, and builds targeting different CPU levels give the same results.
* Rugnux: Improved scaling and merging - reflections with an overloaded pixel are dropped, as in XDS, sparse rotation sweeps are scaled more reliably, and French-Wilson amplitudes use an anisotropic Wilson prior.
* Rugnux: Improved space-group determination - glide planes in groups without a centre of symmetry, screw axes from short or weak axial rows kept when a higher group is adopted, and more reliable decisions on twinned and pseudo-symmetric crystals.
* Rugnux: Improved small-molecule processing - spots that grow wider than the integration disk and split spots are integrated over their measured footprint, sparse lattices are integrated on every frame, and the `.hkl` file holds unmerged scaled reflections (SHELX HKLF 4).
* Rugnux: Reads Rigaku d*TREK SMV images (Saturn CCD), including detector 2theta and encoded pixel overflows; home-source (rotating-anode) datasets were added to the validation battery.
* jfjoch_viewer: Fixed processing failing at the end with "Wrong JPEG library version" on Linux; the merge window shows the space group with proper subscripts and a checklist of crystal pathologies.

Reviewed-on: #84
Co-authored-by: Filip Leonarski <filip.leonarski@psi.ch>

tests/BeamCenterFromBackgroundTest.cpp

@@ -307,3 +307,29 @@ TEST_CASE("FindBeamCenter_BlanksTheBeamStopOutOfTheCapture", "[BeamCenter]") {
     CHECK(masked_error < 12.0f);
     CHECK(masked_error <= unmasked_error);
 }
+
+#ifdef JFJOCH_USE_CUDA
+#include "../common/CUDAWrapper.h"
+
+// With a GPU the passes over the pixels run on it. The cell a pixel lands in is computed from IEEE
+// operations alone and without contraction on both sides, and each cell is summed in the host's order,
+// so the walk ends on the same bits - a tilted detector and an offset centre included.
+TEST_CASE("BeamCenterFromBackground_DeviceMatchesHost", "[BeamCenter]") {
+    if (get_gpu_count() == 0)
+        SKIP("no GPU");
+    DiffractionExperiment x = TestExperiment();
+    x.PoniRot1_rad(0.005f).PoniRot2_rad(-0.003f);
+    PixelMask pixel_mask(x);
+
+    const DiffractionGeometry geom_true = OffsetBy(x.GetDiffractionGeometry(), 7.0f, -4.5f);
+    const auto projection = SynthesiseProjection(x, pixel_mask, geom_true, 60.0f, 0.5f);
+    const auto host = FindBeamCenterFromBackground(x, pixel_mask, projection, 0, {}, /*allow_device=*/false);
+    const auto device = FindBeamCenterFromBackground(x, pixel_mask, projection, 0, {}, /*allow_device=*/true);
+
+    REQUIRE(host.has_value());
+    REQUIRE(device.has_value());
+    CHECK(device->beam_x_pxl == host->beam_x_pxl);
+    CHECK(device->beam_y_pxl == host->beam_y_pxl);
+    CHECK(device->sigma_pxl == host->sigma_pxl);
+}
+#endif