XtalOptimizer: add option to refine distance mm

image_analysis/geom_refinement/XtalOptimizer.cpp

@@ -458,7 +458,8 @@ bool XtalOptimizerInternal(XtalOptimizerData &data,
         if (problem.NumResidualBlocks() < data.min_spots)
             return false;
 
-        problem.SetParameterBlockConstant(&distance_mm);
+        if (!data.refine_distance_mm)
+            problem.SetParameterBlockConstant(&distance_mm);
 
         if (!data.refine_beam_center) {
             problem.SetParameterBlockConstant(&beam_x);
@@ -503,6 +504,9 @@ bool XtalOptimizerInternal(XtalOptimizerData &data,
             data.geom.BeamX_pxl(beam_x).BeamY_pxl(beam_y);
         }
 
+        if (data.refine_distance_mm)
+            data.geom.DetectorDistance_mm(distance_mm);
+
         if (data.crystal_system == gemmi::CrystalSystem::Orthorhombic)
             data.latt = AngleAxisAndLengthsToLattice(latt_vec0, latt_vec1, false);
         else if (data.crystal_system == gemmi::CrystalSystem::Tetragonal) {