Space: generate neighboring cells

src/md/Space.cpp

@@ -94,8 +94,9 @@ void Space::buildCells() {
     int j = static_cast<int>(atom.y / this->m_cutoff);
     int k = static_cast<int>(atom.z / this->m_cutoff);
 
-    Cell &cell =
-        this->m_cells[i * this->m_cellsDim.y * this->m_cellsDim.z + j * this->m_cellsDim.z + k];
+    int idx = i * this->m_cellsDim.y * this->m_cellsDim.z + j * this->m_cellsDim.z + k;
+
+    Cell &cell = this->m_cells[idx];
 
     cell.x.push_back(atom.x);
     cell.y.push_back(atom.y);
@@ -109,6 +110,43 @@ void Space::printCells() const {
     cell.printCell();
 }
 
+Cell Space::getNeighboringCells(int idx) const {
+  Cell neighboringCells;
+
+  const Cell &cell = this->m_cells[idx];
+
+  // For each cell adjacent to the cell of the given index, add its atoms to neighboringCells
+  for (int i = -1; i <= 1; i++)
+    for (int j = -1; j <= 1; j++)
+      for (int k = -1; k <= 1; k++) {
+        int x = cell.m_x + i * this->m_cutoff;
+        int y = cell.m_y + j * this->m_cutoff;
+        int z = cell.m_z + k * this->m_cutoff;
+
+        if (x < 0 || x >= this->m_box.x || y < 0 || y >= this->m_box.y || z < 0 ||
+            z >= this->m_box.z)
+          continue;
+
+        std::cout << "Adding cell (" << x << ", " << y << ", " << z << ") to neighboringCells"
+                  << std::endl;
+
+        int idx = i * this->m_cellsDim.y * this->m_cellsDim.z + j * this->m_cellsDim.z + k;
+
+        const Cell &neighboringCell = this->m_cells[idx];
+
+        neighboringCells.x.insert(
+            neighboringCells.x.end(), neighboringCell.x.begin(), neighboringCell.x.end());
+        neighboringCells.y.insert(
+            neighboringCells.y.end(), neighboringCell.y.begin(), neighboringCell.y.end());
+        neighboringCells.z.insert(
+            neighboringCells.z.end(), neighboringCell.z.begin(), neighboringCell.z.end());
+        neighboringCells.idx.insert(
+            neighboringCells.idx.end(), neighboringCell.idx.begin(), neighboringCell.idx.end());
+      }
+
+  return neighboringCells;
+}
+
 void Cell::printCell() const {
   std::cout << "Cell " << this->m_idx << " (" << this->m_x << ", " << this->m_y << ", " << this->m_z
             << "):" << std::endl;