private void resetBuffer(boolean activeRepaint)
  {
    Graphics draw = buffer.getGraphics().create();
    for (int x = 0; x < dataSource.getMaxTargetNode(); x++)
    {
      for (int y = 0; y < dataSource.getMaxStartNode(); y++)
      {
        // y is start node, x is target node
        IntegerAggregate val = dataSource.getAggregate(y, x);
        draw.setColor(colorPicker.getColor(val));
        draw.drawLine(x, y, x, y);
      }
      if(activeRepaint)
        repaint();
    }
    draw.dispose();
    repaint();
  }