Add method to reorder send and recvIndices

Find all send and recv indices which also are interface cells fine to coarse, coarse (iCellFCC).
Move them to the front of the vector of send and recv indices. Return their number as well.

src/gpu/GridGenerator/grid/GridBuilder/GridBuilder.h

@@ -86,6 +86,10 @@ public:
     virtual uint getNumberOfReceiveIndices( int direction, uint level ) = 0;
     virtual void getSendIndices( int* sendIndices, int direction, int level ) = 0;
     virtual void getReceiveIndices( int* sendIndices, int direction, int level ) = 0;
+    virtual void reorderSendRecvIndexForCommAfterFtoC(int *sendIndices, int *recvIndices,
+                                                      int &numberOfSendNeighborsAfterFtoC,
+                                                      int &numberOfRecvNeighborsAfterFtoC, uint *iCellFCCBorder,
+                                                      uint sizeOfICellFCCBorder, int direction, int level) = 0;
 
     virtual uint getNumberOfFluidNodes(unsigned int level) const = 0;
     virtual void getFluidNodeIndices(uint *fluidNodeIndices, const int level) const = 0;

src/gpu/GridGenerator/grid/GridBuilder/LevelGridBuilder.cpp

@@ -266,6 +266,57 @@ GRIDGENERATOR_EXPORT void LevelGridBuilder::getReceiveIndices(int * receiveIndic
     }
 }
 
+GRIDGENERATOR_EXPORT void LevelGridBuilder::reorderSendRecvIndexForCommAfterFtoC(int *sendIndices, int *recvIndices,
+                                                                                 int &numberOfSendNeighborsAfterFtoC,
+                                                                                 int &numberOfRecvNeighborsAfterFtoC,
+                                                                                 uint* iCellFCCBorder, 
+                                                                                 uint sizeOfICellFCCBorder,
+                                                                                 int direction, int level)
+{
+    uint numberOfIndices = getNumberOfSendIndices(direction, level);
+    int sparseIndexSend;
+    bool isInICellFCCBorder;
+    std::vector<int> sendIndicesAfterFtoC;
+    std::vector<int> sendIndicesOther;
+    std::vector<int> recvIndicesAfterFtoC;
+    std::vector<int> recvIndicesOther;
+
+    for (uint i = 0; i < numberOfIndices; i++) {
+        sparseIndexSend = sendIndices[i];
+
+        // check if sparse index is in ICellFCC border
+        isInICellFCCBorder = false;
+        for (uint j = 0; j < sizeOfICellFCCBorder; j++) {
+            if (iCellFCCBorder[j] == sparseIndexSend) {
+                isInICellFCCBorder = true;
+                break;
+            }
+        }
+
+        // add index to corresponding vector
+        if (isInICellFCCBorder) {
+            sendIndicesAfterFtoC.push_back(sparseIndexSend);
+            recvIndicesAfterFtoC.push_back(sparseIndexSend);
+        } else {
+            sendIndicesOther.push_back(recvIndices[i]);
+            recvIndicesOther.push_back(recvIndices[i]);
+        }
+    }
+
+    numberOfSendNeighborsAfterFtoC = sendIndicesAfterFtoC.size();
+    numberOfRecvNeighborsAfterFtoC = recvIndicesAfterFtoC.size();
+
+    // copy new vectors back to sendIndices and receive indices arrays
+    for (uint i = 0; i < numberOfSendNeighborsAfterFtoC; i++) {
+        sendIndices[i] = sendIndicesAfterFtoC[i];
+        recvIndices[i] = recvIndicesAfterFtoC[i];
+    }
+    for (uint i = 0; i < sendIndicesOther.size(); i++) {
+        sendIndices[i + numberOfSendNeighborsAfterFtoC] = sendIndicesOther[i];
+        recvIndices[i + numberOfRecvNeighborsAfterFtoC] = recvIndicesOther[i];
+    }
+}
+
 uint LevelGridBuilder::getNumberOfNodes(unsigned int level) const
 {
     return grids[level]->getSparseSize();

src/gpu/GridGenerator/grid/GridBuilder/LevelGridBuilder.h

@@ -149,6 +149,11 @@ public:
     GRIDGENERATOR_EXPORT uint getNumberOfReceiveIndices( int direction, uint level ) override;
     GRIDGENERATOR_EXPORT void getSendIndices( int* sendIndices, int direction, int level ) override;
     GRIDGENERATOR_EXPORT void getReceiveIndices( int* sendIndices, int direction, int level ) override;
+    GRIDGENERATOR_EXPORT void reorderSendRecvIndexForCommAfterFtoC(int *sendIndices, int *recvIndices,
+                                                                   int &numberOfSendNeighborsAfterFtoC,
+                                                                   int &numberOfRecvNeighborsAfterFtoC,
+                                                                   uint *iCellFCCBorder, uint sizeOfICellFCCBorder,
+                                                                   int direction, int level) override;
 
 };
 

src/gpu/VirtualFluids_GPU/Parameter/Parameter.h

@@ -293,6 +293,13 @@ struct LBMSimulationParameter
     std::vector<ProcessNeighbor27> recvProcessNeighborX;
     std::vector<ProcessNeighbor27> recvProcessNeighborY;
     std::vector<ProcessNeighbor27> recvProcessNeighborZ;
+
+    std::vector<int> numberOfSendProcessNeighborsAfterFtoCX;
+    std::vector<int> numberOfSendProcessNeighborsAfterFtoCY;
+    std::vector<int> numberOfSendProcessNeighborsAfterFtoCZ;
+    std::vector<int> numberOfRecvProcessNeighborsAfterFtoCX;
+    std::vector<int> numberOfRecvProcessNeighborsAfterFtoCY;
+    std::vector<int> numberOfRecvProcessNeighborsAfterFtoCZ;
     ///////////////////////////////////////////////////////
     // 3D domain decomposition convection diffusion
     std::vector<ProcessNeighbor27> sendProcessNeighborADX;