sampling: Ensure tracking is done at the new-time mesh state

src/lagrangian/basic/Cloud/Cloud.C

@@ -2,7 +2,7 @@
   =========                 |
   \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
    \\    /   O peration     | Website:  https://openfoam.org
-    \\  /    A nd           | Copyright (C) 2011-2020 OpenFOAM Foundation
+    \\  /    A nd           | Copyright (C) 2011-2021 OpenFOAM Foundation
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
 License
@@ -169,7 +169,7 @@ void Foam::Cloud<ParticleType>::move
     // Initialise the stepFraction moved for the particles
     forAllIter(typename Cloud<ParticleType>, *this, pIter)
     {
-        pIter().reset();
+        pIter().reset(0);
     }
 
     // List of lists of particles to be transferred for all of the

src/lagrangian/basic/particle/particle.C

@@ -447,11 +447,11 @@ void Foam::particle::locate
         const class face& f = mesh_.faces()[c[cellTetFacei]];
         for (label tetPti = 1; tetPti < f.size() - 1; ++ tetPti)
         {
-            reset();
             coordinates_ = barycentric(1, 0, 0, 0);
             tetFacei_ = c[cellTetFacei];
             tetPti_ = tetPti;
             facei_ = -1;
+            reset(1);
 
             label tetTriI = -1;
             const scalar f = trackToTri(displacement, 0, tetTriI);
@@ -472,11 +472,11 @@ void Foam::particle::locate
 
     // The particle must be (hopefully only slightly) outside the cell. Track
     // into the tet which got the furthest.
-    reset();
     coordinates_ = barycentric(1, 0, 0, 0);
     tetFacei_ = minTetFacei;
     tetPti_ = minTetPti;
     facei_ = -1;
+    reset(1);
 
     track(displacement, 0);
     if (!onFace())

src/lagrangian/basic/particle/particle.H

@@ -528,9 +528,9 @@ public:
 
     // Track
 
-        //- Set step fraction and behind data to zero in preparation for a new
-        //  track
-        inline void reset();
+        //- Set the step fraction and clear the behind data in preparation for
+        //  a new track
+        inline void reset(const scalar stepFraction);
 
         //- Track along the displacement for a given fraction of the overall
         //  step. End when the track is complete, or when a boundary is hit.

src/lagrangian/basic/particle/particleI.H

@@ -281,9 +281,9 @@ inline Foam::vector Foam::particle::position() const
 }
 
 
-inline void Foam::particle::reset()
+inline void Foam::particle::reset(const scalar stepFraction)
 {
-    stepFraction_ = 0;
+    stepFraction_ = stepFraction;
     stepFractionBehind_ = 0;
     nTracksBehind_ = 0;
 }

src/sampling/sampledSet/lineFace/lineFace.C

@@ -146,7 +146,7 @@ void Foam::sampledSets::lineFace::calcSamples
             const vector s =
                 sign*(end - start)*(1 - dist/mag(end - start));
 
-            sampleParticle.reset();
+            sampleParticle.reset(1);
 
             if
             (

src/sampling/sampledSet/lineUniform/lineUniform.C

@@ -89,7 +89,7 @@ void Foam::sampledSets::lineUniform::calcSamples
                 if (++ sampleI < nPoints_)
                 {
                     sampleT = scalar(sampleI)/(nPoints_ - 1);
-                    sampleParticle.reset();
+                    sampleParticle.reset(1);
                     sampleParticle.track((end_ - start_)/(nPoints_ - 1), 0);
                 }
             }

src/sampling/sampledSet/points/points.C

@@ -118,7 +118,7 @@ void Foam::sampledSets::points::calcSamplesOrdered
                 {
                     const vector s = points_[sampleI] - points_[sampleI - 1];
                     sampleDist += mag(s);
-                    sampleParticle.reset();
+                    sampleParticle.reset(1);
                     sampleParticle.track(s, 0);
                 }
             }