VIP 1.0    

This demo applet calculates the visibility polygon in linear time.

Quick Help

• input a polygon
• press left mouse button to set polygon point.
• when finished press right mouse button to connect the first and the last point.
• the polygon should be simple. if it's not simple, you get a message and you have to draw the polygon again.
• set the visibility point
• simply click where you want to set the visibility point. you can also drag the point and see how the visibility polygon changes.
• the visibility point should be inside the polygon. if the point is outside, it changes to blue.
• editing the polygon
• you can drag and drop polygon points. if you drag a point, such that the polygon wont be simple anymore, the mouse releases the point before that happens.
• zooming
• if you click on the zoom-button, you switch to zoom mode. if you want to leave the zoom mode, simply click again on that button.
• in zoom mode you can draw rectangles to specify the area you want to zoom in. the aspect ratio will be maintained. click the right mouse button to see the previous adjustment.
• replay control
• for every scene you can replay the calculation of the visibility polygon in detail. (step by step.)

This is applet is a technology preview to demonstrate the capabilities of Gishur and IVY.