function SceneGraphRoot(w, h){
    sg_exec_tree = null

    //controller = create_controller()

    sg_draw_tree = new Array()
    sg_available_list = null

    screen_w = w
    screen_h = h

    position_xyz = new Array(0, 0, 0)
    aim_xyz = new Array(0 ,0, 1)
    eye_xyz = new Array(0, -1, 0)
    this.sg_src = new Array()
    this.camera = null

    angleRate_xyz = new Array(1, 0, 0)

    //cnt = 0
}


SceneGraphRoot.prototype.createFromXMLfile = function(gl, sgroot, url){
    if(gl.obj == undefined) gl.obj = new Object();
    var xmlChara = new Object();
    xmlChara = parsePanel(url);
    for (var name in xmlChara)
        {
            gl.obj[name] = makeXmlObj(gl, xmlChara[name])
            gl.obj[name].texture = loadImageTexture(gl, xmlChara[name].image)
	    sgroot.sg_src[name] = gl.obj[name] 
 	}
}


SceneGraphRoot.prototype.createSceneGraph1 = function(id){
    if(id < 0){
	alert("error: createSceneGraph(id): id not found")
	return null
    }

    var src = new SceneGraph(id)
    src.id = id

    if(sg_exec_tree != null){
	sg_exec_tree.addChild(src)
    }

    SceneGraphRoot.prototype.addNext(src)

    return src
}


SceneGraphRoot.prototype.createSceneGraph3 = function(){
   var p = new SceneGraph() 

   p.sgroot = this

   SceneGraphRoot.prototype.addNext(p)
   
   p.flag_drawable = 0

   return p
}


SceneGraphRoot.prototype.addNext = function(sg){
    sg_available_list = sg
}

/* 渡された引数をもとにイメージを検索する */
SceneGraphRoot.prototype.getSgid = function(obj_name){
    for(var name in sg_src){
        if(obj_name == sg_src[name].name){
	    return sg_src[name]
	}
    }
    return -1
}


SceneGraphRoot.prototype.setCamera = function(sgroot, node){
    this.camera = node
}



SceneGraphRoot.prototype.getCamera = function(ctx, node){
    if(node.mat != null){
        ctx.perspectiveMatrix = new J3DIMatrix4()
        node.mat.getAsArrayMatrix(ctx.perspectiveMatrix.$matrix)
    }else{
	ctx.perspectiveMatrix = new J3DIMatrix4()
    }

    ctx.perspectiveMatrix.perspective(45, width/height, 1, 10000);
    ctx.perspectiveMatrix.rotate(cameraAngle_xyz[0],0,1,0)
    ctx.perspectiveMatrix.rotate(cameraAngle_xyz[1], angleRate_xyz[0], 0, angleRate_xyz[2])
    

    ctx.perspectiveMatrix.lookat(position_xyz[0],position_xyz[1],position_xyz[2], aim_xyz[0], aim_xyz[1], aim_xyz[2], 0, -1, 0);
    //ctx.perspectiveMatrix.lookat( 0, 0, 0, 0, 0, 1, 0, -1, 0);
}






SceneGraphRoot.prototype.getController = function(){   
    var left_push     = currentlyPressedKeys[37]     /* ←  */
    var down_push     = currentlyPressedKeys[40]     /* ↓  */
    var right_push    = currentlyPressedKeys[39]     /* →  */
    var up_push       = currentlyPressedKeys[38]     /* ↑  */
    var cross_push    = currentlyPressedKeys[90]     /* Z */
    var circle_push   = currentlyPressedKeys[88]     /* X */
    var start_push    = currentlyPressedKeys[13]     /* Enter */ 
    var zoom_in_push  = currentlyPressedKeys[75]     /* K */
    var zoom_out_push = currentlyPressedKeys[76]     /* L */
    var left_move     = currentlyPressedKeys[65]     /* A */
    var right_move    = currentlyPressedKeys[68]     /* D */
    var front_move    = currentlyPressedKeys[87]     /* W */
    var back_move     = currentlyPressedKeys[83]     /* S */
    var space_push    = currentlyPressedKeys[32]     /* SPACE */


    this.right_isHold = function(){
	return right_push
    }

    this.right_isRelease = function(){
	return !right_push
    }

    this.left_isHold = function(){
	return left_push
    }

    this.left_isRelease = function(){
	return !left_push
    }

    this.up_isHold = function(){
	return up_push
    }

    this.up_isRelease = function(){
	return !up_push
    }

    this.down_isHold = function(){
	return down_push
    }

    this.down_isRelease = function(){
	return !down_push
    }

    this.cross_isHold = function(){
	return cross_push
    }

    this.cross_isRelease = function(){
	return !cross_push
    }

    this.circle_isHold = function(){
	return circle_push
    }

    this.circle_isRelease = function(){
	return !circle_push
    }

    this.start_isHold = function(){
	return start_push
    }

    this.start_isRelease = function(){
	return !start_push
    }

    this.zoom_in_isHold = function(){
	return zoom_in_push
    }

    this.zoom_out_isHold = function(){
	return zoom_out_push
    }

    this.left_move_isHold = function(){
	return left_move
    }

    this.right_move_isHold = function(){
        return right_move
    }

    this.front_move_isHold = function(){
	return front_move
    }

    this.back_move_isHold = function(){
        return back_move
    }

    this.space_isHold = function(){
	return space_push
    }
}



/* rootになるnodeを設定する */
SceneGraphRoot.prototype.setSceneData = function(sg){
    sg.parents = null
    sg_exec_tree = sg
}