cocos绘画（cc.DrawNode的使用）

if (this._underLine) {
    this._underLine.clear();
}
else
    this._underLine = cc.DrawNode.create().addToEx(this);

var lineColor = this._label.getColor();
lineColor = lineColor.a === undefined ? cc.c4b(lineColor.r, lineColor.g, lineColor.b, 255) : lineColor;
var labelSize = this._label.getContentSize();
var labelPos = this._label.getPosition();

var y = labelPos.y - labelSize.height / 2;
var start = cc.p(labelPos.x - labelSize.width / 2, y);
var end = cc.p(labelPos.x + labelSize.width / 2, y);

// 两个点确定一条线段
this._underLine.drawSegment(start, end, 1, lineColor);

绘制矩形：drawRect

        //创建draw对象
        var drawNode =new cc.DrawNode();
        //绘制矩形，参数：坐标，大小，填充颜色，边框大小，边框颜色
        drawNode.drawRect(cc.p(0,0),cc.p(300,300),cc.color(),5,cc.color(255,255,0,255));
        //加入Layer层 
        this.addChild(drawNode);

 

绘制圆形：drawCircle

        //创建draw对象
        var drawNode =new cc.DrawNode();
        //圆形，参数：原点，半径，弧度，分段(越大越接近圆)，原点到弧度的线是否显示，线条宽度，颜色
        drawNode.drawCircle(cc.p(200, 200), 50, 0, 50, false, 2, cc.color(0, 255, 0, 255));
        //加入Layer层 
        this.addChild(drawNode);

画圆点：drawDot

        //创建draw对象
        var drawNode =new cc.DrawNode();
        //画点，参数：坐标，半径， 颜色
        drawNode.drawDot(cc.p(100,100),10,cc.color(255,255,255));
        //加入Layer层 
        this.addChild(drawNode);

绘制直线：drawSegment

        //创建draw对象
        var drawNode =new cc.DrawNode();
        //线，参数：起点，终点，线条宽度，线条颜色
        drawNode.drawSegment(cc.p(0, 0), cc.p(200,300), 1, cc.color(255, 0, 255, 255));
        //加入Layer层 
        this.addChild(drawNode);

绘制曲线：drawCardinalSpline

        //创建draw对象
        var drawNode =new cc.DrawNode();
        var vertices = [cc.p(60, 80), cc.p(60, 300), cc.p(300, 60)];
        //曲线，参数：点数组，张力，段落，线条宽度，颜色
        drawNode.drawCardinalSpline(vertices, 0.5,4,2,cc.color(255, 255, 255, 255));
        //加入Layer层 
        this.addChild(drawNode);