From 1b76ff6001bf1bf7760ef5b32960522f619e21c0 Mon Sep 17 00:00:00 2001
From: Mark Olesen <Mark.Olesen@esi-group.com>
Date: Wed, 11 Jul 2018 07:53:51 +0200
Subject: [PATCH] BUG: vtkCloud suppresses output for empty clouds (closes
 #866)

- the original intention was to avoid vtp output when the clouds are
  empty anyhow. However, it is useful for post-processing to have
  clouds with zero parcels (eg, before the start of injection).

  Pruning of empty clouds is now an option in the vtkCloud dictionary
  controls, with the default being false (no pruning). This represents
  a non-breaking change in behaviour since it generates more output
  than previously.

  Example,
  {
      type    vtkCloud;
      //- Suppress writing of empty clouds (default: false)
      prune   true;
  }
---
 .../lagrangian/vtkCloud/vtkCloud.C            |  4 ++-
 .../lagrangian/vtkCloud/vtkCloud.H            |  4 +++
 .../reactingParcelFoam/filter/Allrun-parallel | 19 ++++++++++++
 .../filter/system/controlDict                 |  4 +++
 .../filter/system/decomposeParDict            |  5 +--
 .../reactingParcelFoam/filter/system/vtkCloud | 31 +++++++++++++++++++
 6 files changed, 62 insertions(+), 5 deletions(-)
 create mode 100755 tutorials/lagrangian/reactingParcelFoam/filter/Allrun-parallel
 create mode 100644 tutorials/lagrangian/reactingParcelFoam/filter/system/vtkCloud

diff --git a/src/functionObjects/lagrangian/vtkCloud/vtkCloud.C b/src/functionObjects/lagrangian/vtkCloud/vtkCloud.C
index 26981fceea..4575bed954 100644
--- a/src/functionObjects/lagrangian/vtkCloud/vtkCloud.C
+++ b/src/functionObjects/lagrangian/vtkCloud/vtkCloud.C
@@ -139,7 +139,7 @@ bool Foam::functionObjects::vtkCloud::writeCloud
     label nTotParcels = pointsPtr->size();
     reduce(nTotParcels, sumOp<label>());
 
-    if (!nTotParcels)
+    if (pruneEmpty_ && !nTotParcels)
     {
         return false;
     }
@@ -331,6 +331,7 @@ Foam::functionObjects::vtkCloud::vtkCloud
     writeOpts_(vtk::formatType::INLINE_BASE64),
     printf_(),
     useVerts_(false),
+    pruneEmpty_(false),
     selectClouds_(),
     selectFields_(),
     dirName_("VTK"),
@@ -396,6 +397,7 @@ bool Foam::functionObjects::vtkCloud::read(const dictionary& dict)
     // useTimeName_ = dict.lookupOrDefault<bool>("useTimeName", false);
 
     useVerts_ = dict.lookupOrDefault<bool>("cellData", false);
+    pruneEmpty_ = dict.lookupOrDefault<bool>("prune", false);
 
 
     //
diff --git a/src/functionObjects/lagrangian/vtkCloud/vtkCloud.H b/src/functionObjects/lagrangian/vtkCloud/vtkCloud.H
index 498df102e3..b73a985523 100644
--- a/src/functionObjects/lagrangian/vtkCloud/vtkCloud.H
+++ b/src/functionObjects/lagrangian/vtkCloud/vtkCloud.H
@@ -59,6 +59,7 @@ Usage
         directory    | The output directory name        | no          | VTK
         width        | Padding width for file name      | no          | 8
         format       | ascii or binary format           | no          | binary
+        prune        | suppress writing of empty clouds | no          | false
         writePrecision | write precision in ascii       | no | same as IOstream
     \endtable
 
@@ -125,6 +126,9 @@ class vtkCloud
         //- Write lagrangian as cell data (verts) instead of point data
         bool useVerts_;
 
+        //- Suppress writing of empty clouds
+        bool pruneEmpty_;
+
         //- Requested names of clouds to process
         wordRes selectClouds_;
 
diff --git a/tutorials/lagrangian/reactingParcelFoam/filter/Allrun-parallel b/tutorials/lagrangian/reactingParcelFoam/filter/Allrun-parallel
new file mode 100755
index 0000000000..268bd680fb
--- /dev/null
+++ b/tutorials/lagrangian/reactingParcelFoam/filter/Allrun-parallel
@@ -0,0 +1,19 @@
+#!/bin/sh
+cd ${0%/*} || exit 1                        # Run from this directory
+. $WM_PROJECT_DIR/bin/tools/RunFunctions    # Tutorial run functions
+
+restore0Dir
+
+runApplication blockMesh
+
+runApplication topoSet
+
+runApplication createBaffles -overwrite
+
+runApplication decomposePar
+
+runParallel $(getApplication)
+
+runApplication reconstructPar
+
+#------------------------------------------------------------------------------
diff --git a/tutorials/lagrangian/reactingParcelFoam/filter/system/controlDict b/tutorials/lagrangian/reactingParcelFoam/filter/system/controlDict
index 50c895427a..15290e5c12 100644
--- a/tutorials/lagrangian/reactingParcelFoam/filter/system/controlDict
+++ b/tutorials/lagrangian/reactingParcelFoam/filter/system/controlDict
@@ -51,5 +51,9 @@ maxCo           1.0;
 
 maxDeltaT       1;
 
+functions
+{
+    #include "vtkCloud"
+}
 
 // ************************************************************************* //
diff --git a/tutorials/lagrangian/reactingParcelFoam/filter/system/decomposeParDict b/tutorials/lagrangian/reactingParcelFoam/filter/system/decomposeParDict
index cd5aa39936..6ca27c3a10 100644
--- a/tutorials/lagrangian/reactingParcelFoam/filter/system/decomposeParDict
+++ b/tutorials/lagrangian/reactingParcelFoam/filter/system/decomposeParDict
@@ -26,10 +26,7 @@ preserveFaceZones
 
 coeffs
 {
-    n           (2 2 1);
-    //delta       0.001; // default=0.001
-    //order       xyz;   // default=xzy
-    dataFile    "";
+    n       (2 2 1);
 }
 
 // ************************************************************************* //
diff --git a/tutorials/lagrangian/reactingParcelFoam/filter/system/vtkCloud b/tutorials/lagrangian/reactingParcelFoam/filter/system/vtkCloud
new file mode 100644
index 0000000000..808f9d36d9
--- /dev/null
+++ b/tutorials/lagrangian/reactingParcelFoam/filter/system/vtkCloud
@@ -0,0 +1,31 @@
+// -*- C++ -*-
+
+cloudWrite
+{
+    type    vtkCloud;
+    libs    ("liblagrangianFunctionObjects.so");
+    log     true;
+
+    writeControl    writeTime;
+
+    // cloud   reactingCloud1;
+    clouds  ( ".*" );
+
+    // Fields to output (words or regex)
+    fields  ( U T d "Y.*" );
+
+    //- Output format (ascii | binary) - default = binary
+    // format  binary;
+
+    // format   ascii;
+    // writePrecision 12;
+
+    //- Suppress writing of empty clouds - default = false
+    // prune   true;
+
+    //- Output directory name - default = "VTK"
+    // directory       "VTK";
+}
+
+
+// ************************************************************************* //