forked from: delaunay triangulation
@author nicolas barradeau
http://en.nicoptere.net/
/**
* Copyright postite ( http://wonderfl.net/user/postite )
* MIT License ( http://www.opensource.org/licenses/mit-license.php )
* Downloaded from: http://wonderfl.net/c/8D3T
*/
// forked from nicoptere's delaunay triangulation
package
{
import flash.display.Sprite;
import flash.events.Event;
import flash.events.MouseEvent;
import flash.geom.Point;
import flash.text.TextField;
import flash.utils.getTimer;
/**
* @author nicolas barradeau
* http://en.nicoptere.net/
*/
public class Main extends Sprite
{
private var tf:TextField = new TextField();
private var delaunay:Delaunay;
private var indices:Vector.<int>;
private var points:Vector.<Point>;
public function Main():void
{
delaunay = new Delaunay();
points = new Vector.<Point>();
addChild( tf );
stage.addEventListener( MouseEvent.MOUSE_DOWN, onMouseDownHandler );
reset();
}
private function onMouseDownHandler(e:MouseEvent):void
{
reset();
}
private function reset():void
{
graphics.clear();
graphics.beginFill( 0xCC0000 );
points.length = 0;
for (var i:int = 0; i < 10; i++)
{
var p:Point = new Point( Math.random() * stage.stageWidth, Math.random() * stage.stageHeight );
points.push( p );
graphics.drawCircle( p.x, p.y, 2 );
}
graphics.endFill();
var t:uint = getTimer();
indices = delaunay.compute( points );
tf.text = 'time: ' + ( getTimer() - t ) + ' ms';
graphics.lineStyle( 0, 0xDDDDDD );
delaunay.render( graphics, points, indices );
/*
//alternate rendering
var vertices:Vector.<Number> = new Vector.<Number>();
for (var i:int = 0; i < points.length; i++) vertices.push( points[ i ].x, points[ i ].y );
graphics.drawTriangles( vertices, indices );
**/
}
}
}
import flash.display.Graphics;
import flash.geom.Point;
class Delaunay
{
static public var EPSILON:Number = Number.MIN_VALUE;
static public var SUPER_TRIANGLE_RADIUS:Number = 1000000000;
private var indices:Vector.<int>;
private var circles:Vector.<Number>;
public function compute( points:Vector.<Point> ):Vector.<int>
{
var nv:int = points.length;
if (nv < 3) return null;
var d:Number = SUPER_TRIANGLE_RADIUS;
points.push( new Point( 0, -d ), new Point( d, d ), new Point( -d, d ) );
indices = Vector.<int>( [ points.length-3, points.length-2, points.length-1 ] );
circles = Vector.<Number>( [ 0, 0, d ] );
var edgeIds:Vector.<int> = new Vector.<int>();
var i:int, j:int, k:int, id0:int, id1:int, id2:int;
for ( i = 0; i < nv; i++)
{
for ( j = 0; j < indices.length; j+=3 )
{
if ( circles[ j + 2 ] > EPSILON && circleContains( j, points[ i ] ) )
{
id0 = indices[ j ];
id1 = indices[ j + 1 ];
id2 = indices[ j + 2 ];
edgeIds.push( id0, id1, id1, id2, id2, id0 );
indices.splice( j, 3 );
circles.splice( j, 3 );
j -= 3;
}
}
for ( j = 0; j < edgeIds.length; j+=2 )
{
for ( k = j + 2; k < edgeIds.length; k+=2 )
{
if( ( edgeIds[ j ] == edgeIds[ k ] && edgeIds[ j + 1 ] == edgeIds[ k + 1 ] )
|| ( edgeIds[ j + 1 ] == edgeIds[ k ] && edgeIds[ j ] == edgeIds[ k + 1 ] ) )
{
edgeIds.splice( k, 2 );
edgeIds.splice( j, 2 );
j -= 2;
k -= 2;
if ( j < 0 ) break;
if ( k < 0 ) break;
}
}
}
for ( j = 0; j < edgeIds.length; j+=2 )
{
indices.push( edgeIds[ j ], edgeIds[ j + 1 ], i );
computeCircle( points, edgeIds[ j ], edgeIds[ j + 1 ], i );
}
edgeIds.length = 0;
}
id0 = points.length - 3;
id1 = points.length - 2;
id2 = points.length - 1;
for ( i = 0; i < indices.length; i+= 3 )
{
if ( indices[ i ] == id0 || indices[ i ] == id1 || indices[ i ] == id2
|| indices[ i + 1 ] == id0 || indices[ i + 1 ] == id1 || indices[ i + 1 ] == id2
|| indices[ i + 2 ] == id0 || indices[ i + 2 ] == id1 || indices[ i + 2 ] == id2 )
{
indices.splice( i, 3 );
i-=3;
continue;
}
}
points.pop();
points.pop();
points.pop();
return indices;
}
private function circleContains( circleId:int, p:Point ):Boolean
{
var dx:Number = circles[ circleId ] - p.x;
var dy:Number = circles[ circleId + 1 ] - p.y;
return circles[ circleId + 2 ] > dx * dx + dy * dy;
}
private function computeCircle( points:Vector.<Point>, id0:int, id1:int, id2:int ):void
{
var p0:Point = points[ id0 ];
var p1:Point = points[ id1 ];
var p2:Point = points[ id2 ];
var A:Number = p1.x - p0.x;
var B:Number = p1.y - p0.y;
var C:Number = p2.x - p0.x;
var D:Number = p2.y - p0.y;
var E:Number = A * (p0.x + p1.x) + B * (p0.y + p1.y);
var F:Number = C * (p0.x + p2.x) + D * (p0.y + p2.y);
var G:Number = 2.0 * (A * (p2.y - p1.y) - B * (p2.x - p1.x));
var x:Number = (D * E - B * F) / G;
circles.push( x );
var y:Number = (A * F - C * E) / G;
circles.push( y );
x -= p0.x;
y -= p0.y;
circles.push( x * x + y * y );
}
public function render( graphics:Graphics, points:Vector.<Point>, indices:Vector.<int> ):void
{
var id0:uint, id1:uint, id2:uint;
for ( var i:int = 0; i < indices.length; i+=3 )
{
id0 = indices[ i ];
id1 = indices[ i + 1 ];
id2 = indices[ i + 2 ];
graphics.lineStyle(0,0,0);
graphics.beginFill(Math.random()*0xFFFFFF);
graphics.moveTo( points[ id0 ].x, points[ id0 ].y );
graphics.lineTo( points[ id1 ].x, points[ id1 ].y );
graphics.lineTo( points[ id2 ].x, points[ id2 ].y );
graphics.lineTo( points[ id0 ].x, points[ id0 ].y );
}
}
}