Java Applets Centre

Fill-Area Algorithm

Description
This applet demonstrates how the interior of a polygon is filled using a recursive four-connected fill algorithm.

Click on an interior point of the polygon. The process of filling is initiated at that point. Once filling is complete, click the 'Clear' button.

Click on a boundary point to create a hole in the boundary polyline. Now click on an interior point. Notice that both interior and exterior points get filled. Click the 'Clear' button when complete.

Code (Recursive Fill Algorithm)

void boundaryFill(int x, int y){
if(getPixel(x,y)==0){
   setPixel(x,y);
   boundaryFill(x+1,y);
   boundaryFill(x-1,y);
   boundaryFill(x,y+1);
   boundaryFill(x,y-1);
}
}

Computer Graphics
Java Applets Centre

R. Mukundan
Department of Computer Science
University of Canterbury
Private Bag 4800, Christchurch
New Zealand.