Main panel of the visualization window, used to display the simulation results. This includes the visualization of the observation area along with obstacles and pedestrians etc. The panel holds several lists for thread-safe simulation data exchange between main and draw thread. The access to these lists is controlled by a synchronization object (drawDataSynchronizer) to avoid threading issues. While the simulation (main thread) pushes data at the end of the lists, the draw list pops the first element and displays the data. Currently the lists store only one -the last generated data- element which is replaced by the main thread when new data is available. As the exchanged data must not be shared between main and draw thread, the data exchanged is just a (incomplete) copy of the original simulation data.