Papervision Perspective Line material

// Perspective Line material for PV3D
// Author : Seb Lee-Delisle
// Blog : www.sebleedelisle.com
// Company : www.pluginmedia.net
// Date : 25th March 2008
//
// This work is licensed under a Creative Commons  2.0 License.
 
// Full details at 
// http://creativecommons.org/licenses/by/2.0/uk/
 
// You may re-use this code as you wish, but a credit would be 
// appreciated. And I'd love to see what you do with it! 
// mail me : sebleedelisle@gmail.com
 
 
// NB!!! THIS CODE WILL ONLY WORK WITH THE CURRENT BUILDS OF GW AND 
// EFFECTS BRANCHES IN PV3D AND WILL VERY LIKELY BREAK VERY SOON!
 
package net.pluginmedia.pv3d.materials.special
{
	import org.papervision3d.materials.special.LineMaterial;	
	import org.papervision3d.core.geom.renderables.Vertex3DInstance;	
	import org.papervision3d.core.math.Number3D;	
	import org.papervision3d.core.math.Number2D;	
 
	import flash.display.Graphics;
 
	import org.papervision3d.core.geom.renderables.Line3D;
	import org.papervision3d.core.proto.MaterialObject3D;
	import org.papervision3d.core.render.data.RenderSessionData;
	import org.papervision3d.core.render.draw.ILineDrawer;
 
	public class LineMaterial3D extends LineMaterial implements ILineDrawer
	{
		private var vertex1 : Number2D = new Number2D();
		private var vertex2 : Number2D = new Number2D();
		private var p1 : Number2D = new Number2D();
		private var p2 : Number2D = new Number2D();
		private var p3 : Number2D = new Number2D();
		private var p4 : Number2D = new Number2D();
		private var lineVector : Number2D = new Number2D();
		private var spur : Number2D = new Number2D();
 
		public function LineMaterial3D(color:Number = 0xFF0000, alpha:Number = 1)
		{
			super(color, alpha);
		}
 
		override public function drawLine(line:Line3D, graphics:Graphics, renderSessionData:RenderSessionData):void
		{	
			var fz:Number = (renderSessionData.camera.focus*renderSessionData.camera.zoom);
 
			var radius1:Number = fz / (renderSessionData.camera.focus + line.v0.vertex3DInstance.z) * line.size;
			var radius2:Number = fz / (renderSessionData.camera.focus + line.v1.vertex3DInstance.z) * line.size;
 
			graphics.lineStyle();
 
 
			drawLine3D(graphics, line.v0.vertex3DInstance, line.v1.vertex3DInstance, radius1, radius2);
			graphics.moveTo(0,0);
		}
 
		function drawLine3D(graphics : Graphics, v1:Vertex3DInstance, v2:Vertex3DInstance, radius1:Number, radius2:Number) : void
		{
 
 
			vertex1.reset(v1.x, v1.y); 
			vertex2.reset(v2.x, v2.y); 
 
			// the vector from vertex2 to vertex1
			lineVector.copyFrom(vertex1); 
			lineVector.minusEq(vertex2);
 
			// the distance between points
			var d : Number = lineVector.modulo; 	
 
			// the angle of the spur from v1
			var spurangle:Number = Math.acos( (radius2-radius1) / d) * Number3D.toDEGREES; 	
			if(isNaN(spurangle)) spurangle = 0; 
			spur.copyFrom(lineVector);
			spur.divideEq(d); 
			spur.rotate(spurangle); 
 
			// the first point in the polygon to draw
			p1.copyFrom(vertex1); 
			spur.multiplyEq(radius1); 
			p1.plusEq(spur); 
 
			// now change the spur's length to that of radius2 and add to vertex2 to get the second polygon point
			p2.copyFrom(vertex2); 
			spur.multiplyEq(radius2/radius1); 
			p2.plusEq(spur); 
 
			// now rotate the spur round to get the 3rd point
			spur.rotate(spurangle*-2); 
			p3.copyFrom(vertex2); 
			p3.plusEq(spur); 
 
			// and now change the length back to radius1
			spur.multiplyEq(radius1/radius2); 
			p4.copyFrom(vertex1); 
			p4.plusEq(spur); 
 
			graphics.lineStyle(); 
			graphics.beginFill(lineColor, lineAlpha); 
			graphics.moveTo(vertex1.x, vertex1.y); 
			graphics.lineTo(p1.x, p1.y); 
			graphics.lineTo(p2.x, p2.y); 
 
			graphics.lineTo(vertex2.x, vertex2.y); 
 
			graphics.lineTo(p3.x, p3.y); 
			graphics.lineTo(p4.x, p4.y); 
 
			graphics.lineTo(vertex1.x, vertex1.y); 
 
			graphics.endFill(); 
 
			graphics.beginFill(lineColor, lineAlpha); 
			graphics.drawCircle(vertex1.x, vertex1.y, radius1); 
			graphics.endFill(); 
 
 
			graphics.beginFill(lineColor, lineAlpha); 
			graphics.drawCircle(vertex2.x, vertex2.y, radius2); 
			graphics.endFill(); 
 
		}
 
 
	}
}