Some Update and Save before making dangerous changes

src/draw/Draw.java

@@ -30,9 +30,7 @@ public class Draw extends JPanel {
         currentGrid = new boolean[xSize][ySize];
 
         for (int x = 0; x < xSize; x++) {
-            for (int y = 0; y < ySize; y++) {
-                currentGrid[x][y] = grid[x][y];
-            }
+            if (ySize >= 0) System.arraycopy(grid[x], 0, currentGrid[x], 0, ySize);
         }
     }
 

src/game/Control.java

@@ -167,7 +167,7 @@ public class Control {
 
     }
 
-//    public void checkN(Cell[][] arr, Cell[][] futureGen, int columns, int rows) {
+//    public void checkN(Boolean[][] arr, Boolean[][] futureGen, int columns, int rows) {
 //        ArrayList<Thread> threads = new ArrayList<>();
 //        final int NUM_OF_THREADS = 8; //Or can be passed as an argument
 //        for (int tid = 0; tid < NUM_OF_THREADS; tid++) {