A graphical user interface displays a shape. Further, a buffer region that is adjacent to an edge of the shape is displayed at the graphical user interface. In addition, a set of drawing data located within the buffer region is received from a user input device. A first subset of the drawing data that is located in the buffer region at a predetermined distance from the edge and a second subset of the drawing data in the buffer region that is located at a distance from the edge that exceeds the predetermined distance are determined with a processor. Further, the first subset of drawing data is displayed. In addition, the second subset of drawing data is prevented from being displayed at the distance. The process also displays the second subset of drawing data at the predetermined distance.