Box.js

class Box{
  constructor(x,y,bounds){
    this.x = x;
    this.y = y;
    this.isMarked = false; //  boolean
    this.isMerged = false; // boolean
    this.isExpanded = false;
    this.bounds = bounds; // bounds 
    this.isDraw = false;
    this.rectangle = null;
  }

  static MARKEDCOLOR(){
    return '#008c3a';
  }
  static  EMARKEDCOLOR(){
    return '#fcba03';
  }
  static UNMARKEDCOLOR(){
    return '#8f0096';
  }
  static MERGECOLOR(){
    return '#4284f5';
  }
  IsMarked(){
    return this.isMarked;
  }
  GetBounds(){
    return this.bounds;
  }
  Mark(point1, point2, method){
    if(this.IsCrossOrContainALine(point1,point2, method)){
      this.isMarked = true;
      if(this.rectangle !== null){
        this.rectangle.setOptions({
          strokeColor: Box.MARKEDCOLOR(),
          fillColor: Box.MARKEDCOLOR(),
        });
        return true;
      }}
    return false;
  }
  MarkExpanded(){
    if(!this.isMarked){
      this.rectangle.setOptions({
        strokeColor: Box.EMARKEDCOLOR(),
        fillColor: Box.EMARKEDCOLOR(),
      });
      this.isExpanded = true;
      this.isMarked = true;
    }
  }
  DrawBox(gmap, color = '#8f0096'){
    this.isDraw = true;
    this.rectangle = new google.maps.Rectangle({
      strokeColor: color,
      strokeOpacity: 0.9,
      strokeWeight: 2,
      fillColor: color,
      fillOpacity: 0.2,
      map: gmap,
      bounds: this.bounds,
    });
  }
  ClearBoxOnMap(){
    this.isDraw = false;
    this.rectangle.setMap(null);
  }
  // This function will return a boolean variable.
  // I'm using Cohen Sutherland line clipping algorithm to check it.
  // This is algorithm to check if a line is on the screen or outside the screen using in Computer Graphic.
  IsCrossOrContainALine(point1, point2, method){
    if(method == 'cohen-sutherland')
      return this.CohenSutherlandAlgorithm(point1, point2);
    else if (method == 'liang-barsky'){
      return this.LiangBarskyAlgorithm(point1,point2);
    }
    else if(method == 'cyrus-beck'){
      return this.CyrusBeckAlgorithm(point1,point2);
    }
  }
  CohenSutherlandAlgorithm(point1, point2){
    var x1 = point1.lng;
    var y1 = point1.lat * 2;
    var x2 = point2.lng;
    var y2 = point2.lat * 2;
    var xmax = this.bounds.east;
    var xmin = this.bounds.west;
    var ymax = this.bounds.north * 2;
    var ymin = this.bounds.south * 2;
    // Regions:
    // 1001 1000 1010
    // 0001 0000 0010
    // 0101 0100 0110
    var p1 = 0;
    if(x1 < xmin) p1 = p1 + 1;
    if(x1 > xmax) p1 = p1 + 2;
    if(y1 < ymin) p1 = p1 + 4
    if(y1 > ymax) p1 = p1 + 8;
    var p2 = 0;
    if(x2 < xmin) p2 = p2 + 1;
    if(x2 > xmax) p2 = p2 + 2;
    if(y2 < ymin) p2 = p2 + 4
    if(y2 > ymax) p2 = p2 + 8;
    if((p1 == 0) || (p2 == 0)){
      return true;
    } else if ((p1 & p2) != 0){
      return false;
    } else if ((p1 & p2) == 0){
      var x;
      var y;
      var p = 0;
      var cx = false;
      var cy = false;
      if((p1 & 8) == 8){
        x = x1 + (x2 - x1)*((ymax - y1)/(y2 - y1));
        cx = true;
      }else if((p1 & 4) == 4){
        x = x1 + (x2 - x1)*((ymin - y1)/(y2 - y1));
        cx = true;
      }else if((p1 & 2) == 2 ){
        y = y1 + (y2 - y1)*((xmax - x1)/(x2 - x1));
        cy = true;
      }else if((p1 & 1) == 1){
        y = y1 + (y2 - y1)*((xmin - x1)/(x2 - x1));
        cy= true;
      }
      if(cx){
        if(x < xmin) p = p + 1;
        if(x > xmax) p = p + 2;
      }
      if(cy){
        if(y < ymin) p = p + 4;
        if(y > ymax) p = p + 8;
      }  
      if((p2 & p) != 0) return false;
      return true;
    }
  }
  LiangBarskyAlgorithm(point1, point2){
    var x1 = point1.lng;
    var y1 = point1.lat;
    var x2 = point2.lng;
    var y2 = point2.lat;
    var xmax = this.bounds.east;
    var xmin = this.bounds.west;
    var ymax = this.bounds.north;
    var ymin = this.bounds.south;
    var p = new Array();
    p.push(x1 - x2);
    p.push(x2 - x1);
    p.push(y1 - y2);
    p.push(y2 - y1);
    var q = new Array();
    q.push(x1 - xmin);
    q.push(xmax - x1);
    q.push(y1 - ymin);
    q.push(ymax - y1);
    for(var i = 0; i < 4; ++i){
      if(p[i] == 0){
        if(q[i] < 0) return false;
      }
    }
    var pos = new Array();
    var neg = new Array();
    pos.push(1);
    neg.push(0);
    for(var i = 0; i < 4; ++i){
      var r = q[i]/p[i];
      if(p[i] > 0) pos.push(r);
      else neg.push(r);
    }
    var t1 = Math.max.apply(null,neg);
    var t2 = Math.min.apply(null,pos);
    if(t1 > t2) {
      return false;
    }
    return true;    
  }
  CyrusBeckAlgorithm(point1, point2){
    var xmax = this.bounds.east;
    var xmin = this.bounds.west;
    var ymax = this.bounds.north;
    var ymin = this.bounds.south;
    var pE = new Array();
    var x1 = point1.lng;
    var y1 = point1.lat;
    var x2 = point2.lng;
    var y2 = point2.lat;
    pE.push({x: xmin, y: ymax});
    pE.push({x: xmax, y: ymin});
    pE.push({x: xmax, y: ymax});
    pE.push({x: xmax, y: ymin});
    var N = new Array();
    var left_norm = {x: ymax - ymin, y: 0};
    var right_norm = {x: ymin - ymax, y: 0};
    var top_norm = {x: 0, y: xmin - xmax};
    var bottom_norm = {x: 0, y: xmax - xmin};
    N.push(left_norm);
    N.push(right_norm);
    N.push(top_norm);
    N.push(bottom_norm);
    var tL = new Array();
    var tE = new Array(); 
    for(var i = 0; i < 4; ++i){
      var numerator = N[i].x * (pE[i].x - x1) + N[i].y * (pE[i].y -y1);
      var denominator = (N[i].x*(x2 - x1) + N[i].y*(y2 - y1));
      var m = numerator / denominator; 
      if(denominator > 0){  
        tE.push(m);
      } else
      if(denominator < 0){
        tL.push(m);
      }
      else return false;
    }
    tE.push(0);
    tL.push(1);
    if(Math.min.apply(null,tL) < Math.max.apply(null,tE)) return false;
    return true;
  }
  Merge(box){
    var resultBox = null;
    if(this.bounds.north == box.GetBounds().north
      && this.bounds.south == box.GetBounds().south
      && ((this.bounds.west == box.GetBounds().east) || (this.bounds.east == box.GetBounds().west))
    ){
      resultBox = {
        north: this.bounds.north,
        south: this.bounds.south,
        east: (this.bounds.east > box.GetBounds().east)?this.bounds.east:box.GetBounds().east,
        west: (this.bounds.west < box.GetBounds().west)?this.bounds.west:box.GetBounds().west ,
      }
    }
    else if(this.bounds.east == box.GetBounds().east
      && this.bounds.west == box.GetBounds().west
      && ((this.bounds.north == box.GetBounds().south) || (this.bounds.south == box.GetBounds().north))
    ){
      resultBox = {
        north: (this.bounds.north > box.GetBounds().north)?this.bounds.north:box.GetBounds().north,
        south: (this.bounds.south < box.GetBounds().south)?this.bounds.south:box.GetBounds().south,
        east: this.bounds.east,
        west: this.bounds.west,
      }
    }
    else return false;
    this.bounds = resultBox;
    return true;
  }
}