Marching Squares

A marching squares implementation for Actionscript 3.

How to use

Create a class that implements IIsoData interface.

public interface IIsoData
{
	function get width():int;
	function get height():int;
	function getValueAt( inX:int, inY:int ):int;
}

IIsoData.getValueAt method must return zero for outer locations and a higher value for inner locations.

Example:

public class BitmapAlphaIsoData implements IIsoData

Use IIsoData implementation with MarchingSquare class.

var closeLines:Boolean = true;
var isoData:BitmapAlphaIsoData = new BitmapAlphaIsoData( image );
var marchingSquare:MarchingSquare = new MarchingSquare( );
marchingSquare.execute( isoData, _closeLines );

Iterate on results.

for( var i:int=0 ; i<marchingSquare.closedIsoLineCount; i++ )
{
    var pointList:Vector.<Point> = marchingSquare.createClosedIsoLinePoints( i );
    .
    .
    .
}

for( var i:int=0 ; i<marchingSquare.openIsoLineCount; i++ )
{
    var pointList:Vector.<Point> = marchingSquare.createOpenIsoLinePoints( i );
    .
    .
    .
}

Things to do

• Better an more complete readme file
• More comments
• Better usage examples
• Optimisations