package org.papervision3d.core.math.util
  {
          import org.papervision3d.core.geom.renderables.Vertex3D;
          import org.papervision3d.core.math.Number3D;
          import org.papervision3d.core.math.Plane3D;
          
          public class @ax-student-ar-org-papervision3d-core-math-util-Intersection
          {
                  public static const NONE:int = 0;
                  public static const INTERSECTION:int=1;
                  public static const PARALLEL:int = 2;
                  
                  public var point:Number3D;
                  public var vert:Vertex3D;
                  public var alpha:Number = 0;
                  public var status:int;
                  
                  public function @ax-student-ar-org-papervision3d-core-math-util-Intersection(point:Number3D = null, vert:Vertex3D = null)
                  {
                          if(point != null){
                                  this.point = point;
                          }else{
                                  this.point = new Number3D();
                          }
                          if(vert != null){
                                  this.vert = vert;
                          }else{
                                  this.vert = new Vertex3D();
                          }
                  }
  
                  public static function linePlane(pA:Vertex3D, pB:Vertex3D, plane:Plane3D, e:Number=0.01, dst:@ax-student-ar-org-papervision3d-core-math-util-Intersection = null):@ax-student-ar-org-papervision3d-core-math-util-Intersection
                  {
                          if(dst == null){
                                  dst = new @ax-student-ar-org-papervision3d-core-math-util-Intersection();
                          }
                          var a:Number = plane.normal.x;
                          var b:Number = plane.normal.y;
                          var c:Number = plane.normal.z;
                          var d:Number = plane.d;
                          var x1:Number = pA.x;
                          var y1:Number = pA.y;
                          var z1:Number = pA.z;
                          var x2:Number = pB.x;
                          var y2:Number = pB.y;
                          var z2:Number = pB.z;
                          
                          var r0:Number = (a * x1) + (b * y1) + (c * z1) + d;
                          var r1:Number = a*(x1-x2) + b*(y1-y2) + c*(z1-z2);
                          var u:Number = r0 / r1;
                          
                          if( Math.abs(u) < e ) {
                                  dst.status = @ax-student-ar-org-papervision3d-core-math-util-Intersection.PARALLEL;
                          } else if( (u > 0 && u < 1 ) ) {
                                  dst.status = @ax-student-ar-org-papervision3d-core-math-util-Intersection.INTERSECTION;
                                  var pt:Number3D = dst.point;
                                  pt.x = x2 - x1;
                                  pt.y = y2 - y1;
                                  pt.z = z2 - z1;
                                  pt.x *= u;
                                  pt.y *= u;
                                  pt.z *= u;
                                  pt.x += x1;
                                  pt.y += y1;
                                  pt.z += z1;
                                  
                                  dst.alpha = u;
                                  
                                  dst.vert.x = pt.x;
                                  dst.vert.y = pt.y;
                                  dst.vert.z = pt.z;
                          }else{
                                  dst.status = @ax-student-ar-org-papervision3d-core-math-util-Intersection.NONE;
                          }
                          
                          return dst;
                  }
  
          }
  }