Method rotationBounds

src/openlayers/overlay/Label.js:733–759

* @function Label.prototype.rotationBounds * @description 旋转 bounds。 * @param {Bounds} bounds - 要旋转的 bounds。 * @param {Object} rotationCenterPoi - 旋转中心点对象，此对象含有属性 x（横坐标），属性 y（纵坐标）。 * @param {number} angle - 旋转角度（顺时针）。 * @returns {Array. } bounds 旋转后形成的多边形节点数组。是一个四边形，形

(bounds, rotationCenterPoi, angle)

     * @returns {Array.<Object>} bounds 旋转后形成的多边形节点数组。是一个四边形，形如：[{"x":1,"y":1},{"x":3,"y":1},{"x":6,"y":4},{"x":2,"y":10},{"x":1,"y":1}]。
     */
    rotationBounds(bounds, rotationCenterPoi, angle) {
        var ltPoi = new Point([bounds.left, bounds.top]);
        var rtPoi = new Point([bounds.right, bounds.top]);
        var rbPoi = new Point([bounds.right, bounds.bottom]);
        var lbPoi = new Point([bounds.left, bounds.bottom]);

        var ver = [];
        ver.push(this.getRotatedLocation(ltPoi.getCoordinates()[0], ltPoi.getCoordinates()[1], rotationCenterPoi.x, rotationCenterPoi.y, angle));
        ver.push(this.getRotatedLocation(rtPoi.getCoordinates()[0], rtPoi.getCoordinates()[1], rotationCenterPoi.x, rotationCenterPoi.y, angle));
        ver.push(this.getRotatedLocation(rbPoi.getCoordinates()[0], rbPoi.getCoordinates()[1], rotationCenterPoi.x, rotationCenterPoi.y, angle));
        ver.push(this.getRotatedLocation(lbPoi.getCoordinates()[0], lbPoi.getCoordinates()[1], rotationCenterPoi.x, rotationCenterPoi.y, angle));

        //bounds旋转后形成的多边形节点数组
        var quad = [];

        for (var i = 0; i < ver.length; i++) {
            quad.push({
                "x": ver[i].x,
                "y": ver[i].y
            });
        }
        quad.push({
            "x": ver[0].x,
            "y": ver[0].y
        });
        return quad;
    }

    /**
     * @function Label.prototype.getRotatedLocation