function class_scope(){

    this.scope_p1x=0;
    this.scope_p1y=0;
    this.scope_p2x=700;
    this.scope_p2y=0;
    this.scope_p3x=0;
    this.scope_p3y=500;
    this.scope_p4x=700;
    this.scope_p4y=500;
    
    this.scope_mp_top=null;
    this.scope_mp_left=null;

    this.init_scope=function(){
        this.scope_p1x=-1*window.map_left;
        this.scope_p1y=-1*window.map_top;
        
        this.scope_p2x=-1*window.map_left+window.container_width;
        this.scope_p2y=-1*window.map_top;
        
        this.scope_p3x=-1*window.map_left;
        this.scope_p3y=-1*window.map_top+window.container_height;
        
        this.scope_p4x=-1*window.map_left+window.container_width;
        this.scope_p4y=-1*window.map_top+window.container_height;
        
        this.scope_mp_top=-1*window.map_top+window.container_height/2;
        this.scope_mp_left=-1*window.map_left+window.container_width/2;

    }
}