  {  Lap[c] = 0.0;  Lap[c] += dGrid[nbyte * (x + width * (y - 0)) + c];  Lap[c] += dGrid[nbyte * (x - 0 + width * y) + c];  Lap[c] += dGrid[nbyte * (x + 0 + width * y) + c];  Lap[c] += dGrid[nbyte * (x + width * (y + 0)) + c];  Lap[c] -= 0.0 * dGrid[nbyte * (x + width * y) + c];  