AnimateCC H5怎么用event.offsetX/Y实现同步拖拽？

Question

想用AnimateCC H5来研究一下event.offsetX/Y，大致概念是两个点连成一条线，拖拽Cpoint1可控制两个点与线的整体拖动，拖拽Cpoint2可控制线的方向与长短。

this.stop();
var home = this;

var ShapeLine1 = new createjs.Shape(); 
var graphics1 = ShapeLine1.graphics;
graphics1.beginStroke("white");
graphics1.setStrokeStyle(3); 
graphics1.moveTo(home.Linepoint1.x, home.Linepoint1.y);
graphics1.lineTo(home.Linepoint2.x, home.Linepoint2.y);

home.addChild(ShapeLine1);
init();

home.Linepoint1.addEventListener("mousedown", StartLine1)
home.Linepoint1.addEventListener("pressup", StopLine1)

function StartLine1()
{
    canvas.addEventListener('mousemove', MoveLine1)
}

function StopLine1()
{
    canvas.removeEventListener('mousemove', MoveLine1)
}

function MoveLine1(event)
{
    var e = event

    home.Linepoint1.x = stage.mouseX / stage.scaleX
    home.Linepoint1.y = stage.mouseY / stage.scaleY

    home.Linepoint2.x = e.offsetX + (home.Linepoint2.x - home.Linepoint1.x)
    home.Linepoint2.y = e.offsetY + (home.Linepoint2.y - home.Linepoint1.y)

    init();
}
/**这段本意是想通过获取鼠标事件的坐标，加上两点坐标的差值来定位新的Linepoint2，现在就出现个问题，Linepoint1在拖动的时候，Linepoint2的坐标在事件中会不断放大**/


home.Linepoint2.addEventListener("mousedown", StartLine2)
home.Linepoint2.addEventListener("pressup", StopLine2)

function StartLine2()
{
    canvas.addEventListener('mousemove', MoveLine2)
}

function StopLine2()
{
    canvas.removeEventListener('mousemove', MoveLine2)
}

function MoveLine2()
{
    home.Linepoint2.x = stage.mouseX / stage.scaleX
    home.Linepoint2.y = stage.mouseY / stage.scaleY
    init();
}


function init(){
    graphics1.clear();
    graphics1.beginStroke("white");
    graphics1.setStrokeStyle(3);
    graphics1.moveTo(home.Linepoint1.x, home.Linepoint1.y);
    graphics1.lineTo(home.Linepoint2.x, home.Linepoint2.y);
    }

我是设计师所以只能明白AnimateCC H5中的编程逻辑，还请大神指点！

Answer 1

解决了，在命令function MoveLine1()中加入点位绑定，创建Cp1.x/y，再用home.Linepoint1.x-Cp1.x

function MoveLine1()
{
var Cp1 = {
x: (home.Cpoint2.x - home.Cpoint1.x),
y: (home.Cpoint2.y - home.Cpoint1.y)
}

home.Linepoint1.x = stage.mouseX / stage.scaleX
home.Linepoint1.y = stage.mouseY / stage.scaleY

home.Linepoint2.x = home.Linepoint1.x-Cp1.x
home.Linepoint2.y = home.Linepoint1.y-Cp1.y

init();

}