[转]flex+BlazeDS关于军标的实现思路和算法
前几天说要传军标的算法思想呢，结果有事耽误了，现在我把我军标思想给说一下。
首先利用的技术：前端as语言绘制军标（其实就是个多边形），把多边形的点组成 XML字符串《这里也可以传对象，但是在后台java段也要有相同的对应对象》通过BlazeDS的 RemoteObject方式传到后台。
后台可以通过java保存到数据库中，这个最好是保存为Clob字段。
下面我把关键代码给大家分享一下。。
//处理鼠标单击事件
public function map_mouseClickHandler(event:MouseEvent):void
{
map.mapNavigationEnabled=false;
//确定点击的地图点的坐标，然后放到数组中
var m_point:MapPoint=map.toMapFromStage(event.stageX, event.stageY);
if (m_firstpoints == null)
{
m_firstpoints=new Array();
}
m_firstpoints.push(m_point);
}
//处理鼠标双击事件
public function map_mouseDoubleClickHandler(event:MouseEvent):void
{
m_gbjGeometry=new Polyline();
//定义军标的多边形
if (m_firstpoints.length <= 2)
{
m_firstpoints.splice(0);
Alert.show("请最少点击三个点才能完成对军标的画法", "Error INFO");
return;
}
//根据贝塞尔曲线算法来画线和面
drawBezierCurve();
//形成graphic
full_polygon_graphic=new Graphic(full_gbjpolygon, gbjSymbol);
full_polygon_graphic.toolTip="gbj";
full_gbjpolygon.spatialReference=map.spatialReference;
graphicsLayer.add(full_polygon_graphic);
map.removeEventListener(MouseEvent.CLICK, map_mouseClickHandler);
map.removeEventListener(MouseEvent.DOUBLE_CLICK, map_mouseDoubleClickHandler);
m_firstpoints.splice(0);
this.dispatchEvent(new DrawEvent("drawEnd", full_polygon_graphic));
}
/**
*这个是贝塞尔曲线算法函数用于画军标
*
*/
private function drawBezierCurve():void
{
//主要算法思想是：由中轴线的两点确定一条直线，做直线的垂线，并取垂线上一定距离的点，作成上边曲线和下边曲线
if ((m_gbjGeometry.paths != null) && (m_gbjGeometry.paths.length > 0))
{
m_gbjGeometry.removePath(0);
}
//判断点击点的季偶性,得到军标的多边形
var jishu:Boolean=true;
if (m_firstpoints.length % 2 == 0)
{
jishu=false;
}
clogger.logger.info("你点击的个数是不是奇数:"+jishu);
var curvepoints:Array=getzz_geometry(m_firstpoints, jishu);
var dgbj_geometry:Array=getdbx_geometry(curvepoints);
full_gbjpolygon=new Polygon(dgbj_geometry);
}
/**
* 这个函数就是用来求中轴线的，中轴线上的所有点
* @param clickarray
* @param jishu
* @return
*
*/
private function getzz_geometry(clickarray:Array, jishu:Boolean):Array
{
//首先定义中轴曲线的点坐标
var curvepoints:Array=new Array();
//数组长度
var array_length:Number=clickarray.length;
if (jishu)
{
clogger.logger.info("你点击的次数是奇数个：并且他大于等于三，是：" + clickarray.length + "个");
for (var i:int=0; i < clickarray.length - 2; i=i + 2)
{
for (var j:Number=0; j <= 1; j=j + 0.1)
{
if (i != 0 && j == 0)
continue;
var pos_x:Number=Math.pow((1 - j), 2) * clickarray.x + 2 * j * (1 - j) * clickarray[i + 1].x + Math.pow(j, 2) * clickarray[i + 2].x;
var pos_y:Number=Math.pow((1 - j), 2) * clickarray.y + 2 * j * (1 - j) * clickarray[i + 1].y + Math.pow(j, 2) * clickarray[i + 2].y;
var m_point:MapPoint=new MapPoint(pos_x, pos_y);
curvepoints.push(m_point);
}
}
}
//下面的是偶数时后,前面那些点还是用三个点来确定，后面四个点用三次贝塞尔曲线来搞定。
if (!jishu)
{
//判断点击的点是不是大于6个，如果是六个的话，首先是先用二次贝塞尔曲线算出前三个来。
if (clickarray.length >= 6)
{
clogger.logger.info("你点击的次数是偶数个：并且他大于等于6，是：" + clickarray.length + "个");
for (var i:int=0; i < clickarray.length - 5; i=i + 2)
{
for (var j:Number=0; j <= 1; j=j + 0.1)
{
if (i != 0 && j == 0)
continue;
var pos_x:Number=Math.pow((1 - j), 2) * clickarray.x + 2 * j * (1 - j) * clickarray[i + 1].x + Math.pow(j, 2) * clickarray[i + 2].x;
var pos_y:Number=Math.pow((1 - j), 2) * clickarray.y + 2 * j * (1 - j) * clickarray[i + 1].y + Math.pow(j, 2) * clickarray[i + 2].y;
var m_point:MapPoint=new MapPoint(pos_x, pos_y);
//中轴线的点数
curvepoints.push(m_point);
}
}
//这最后四个点用三次贝塞尔曲线来确定
var p_1:MapPoint=clickarray[array_length - 4];
var p_2:MapPoint=clickarray[array_length - 3];
var p_3:MapPoint=clickarray[array_length - 2];
var p_4:MapPoint=clickarray[array_length - 1];
for (var k:Number=0; k < 1; k=k + 0.1)
{
if (k == 0)
continue;
var pos_x:Number=p_1.x * Math.pow((1 - k), 3) + 3 * p_2.x * k * Math.pow((1 - k), 2) + 3 * p_3.x * Math.pow(k, 2) * (1 - k) + p_4.x * Math.pow(k, 3);
var pos_y:Number=p_1.y * Math.pow((1 - k), 3) + 3 * p_2.y * k * Math.pow((1 - k), 2) + 3 * p_3.y * Math.pow(k, 2) * (1 - k) + p_4.y * Math.pow(k, 3);
var m_point:MapPoint=new MapPoint(pos_x, pos_y);
//中心轴的添加
curvepoints.push(m_point);
}
}
//如果仅仅就四个点的话，下面是求只有四个点的公式
else
{
clogger.logger.info("你点击的次数是4个，他是：" + clickarray.length + "个");
var p_1:MapPoint=clickarray[0];
var p_2:MapPoint=clickarray[1];
var p_3:MapPoint=clickarray[2];
var p_4:MapPoint=clickarray[3];
for (var k:Number=0; k < 1; k=k + 0.1)
{
var pos_x:Number=p_1.x * Math.pow((1 - k), 3) + 3 * p_2.x * k * Math.pow((1 - k), 2) + 3 * p_3.x * Math.pow(k, 2) * (1 - k) + p_4.x * Math.pow(k, 3);
var pos_y:Number=p_1.y * Math.pow((1 - k), 3) + 3 * p_2.y * k * Math.pow((1 - k), 2) + 3 * p_3.y * Math.pow(k, 2) * (1 - k) + p_4.y * Math.pow(k, 3);
var m_point:MapPoint=new MapPoint(pos_x, pos_y);
//中心轴的添加
curvepoints.push(m_point);
}
}
}
clogger.logger.info("这个中轴线上的所有的点的个数是：" + curvepoints.length);
return curvepoints;
}
/**
* 这个函数是用来求多边行的各个点的
* 他利用的原理就是求垂线的距离
* @return
*
*/
private function getdbx_geometry(curvepoints:Array):Array
{
//定义上边曲线的点坐标数组(当确定军标多边形的时候我是从这个数组开始的)
var topcurepoints:Array=new Array();
//定义下边曲线的点坐标数组
var bottomcurepoints:Array=new Array();
//定义左上测的直线
var left_top_points:Array=new Array();
//定义左下侧的直线
var left_bottom_points:Array=new Array();
//定义右上角边的数组
var right_top_points:Array=new Array();
//定义中轴线离上下两边的距离
var dis:Number=(8 - map.level) * (8 - map.level) * 40;
//大的框架肯定是从0--1
var c_length:Number=curvepoints.length;
for (var u:Number=0; u < curvepoints.length; u++)
{
if (u == 0)
{
continue;
}
else
{
var m_point:MapPoint=curvepoints;
var pos_x:Number=m_point.x;
var pos_y:Number=m_point.y;
//先求上一点的坐标
var pre_point:MapPoint=curvepoints[u - 1];
//进行计算取的上下边的点
var pre_pos_x:Number=pre_point.x;
var pre_pos_y:Number=pre_point.y;
var slope:Number=(pos_y - pre_pos_y) / (pos_x - pre_pos_x);
//上边点确定
var bb:Number=dis * (1 - u / c_length * 0.9);
var cos_number:Number=Math.cos(Math.atan(slope) - Math.PI / 2);
var sin_number:Number=Math.sin(Math.atan(slope) - Math.PI / 2);
var top_pos_x:Number=0.0;
var top_pos_y:Number=0.0;
//下面分四种情况画线。
if (pre_pos_x <= pos_x && pre_pos_y <= pos_y)
{
top_pos_x=pre_pos_x - ((bb * cos_number) < 0 ? (-bb * cos_number) : (bb * cos_number));
top_pos_y=pre_pos_y + ((bb * sin_number) < 0 ? (-bb * sin_number) : (bb * sin_number));
}
else if (pre_pos_x <= pos_x && pre_pos_y > pos_y)
{
top_pos_x=pre_pos_x + ((bb * cos_number) < 0 ? (-bb * cos_number) : (bb * cos_number));
top_pos_y=pre_pos_y + ((bb * sin_number) < 0 ? (-bb * sin_number) : (bb * sin_number));
}
else if (pre_pos_x >= pos_x && pre_pos_y >= pos_y)
{
top_pos_x=pre_pos_x + ((bb * cos_number) < 0 ? (-bb * cos_number) : (bb * cos_number));
top_pos_y=pre_pos_y - ((bb * sin_number) < 0 ? (-bb * sin_number) : (bb * sin_number));
}
else if (pre_pos_x >= pos_x && pre_pos_y <= pos_y)
{
top_pos_x=pre_pos_x - ((bb * cos_number) < 0 ? (-bb * cos_number) : (bb * cos_number));
top_pos_y=pre_pos_y - ((bb * sin_number) < 0 ? (-bb * sin_number) : (bb * sin_number));
}
var top_point:MapPoint=new MapPoint(top_pos_x, top_pos_y);
clogger.logger.info("上半部分是：" + top_pos_x + "yy:" + top_pos_y);
topcurepoints.push(top_point);
//下面来确定下边的曲线
var bottom_pos_x:Number;
var bottom_pos_y:Number;
if (pre_pos_x <= pos_x && pre_pos_y <= pos_y)
{
bottom_pos_x=pre_pos_x + ((bb * cos_number) < 0 ? (-bb * cos_number) : (bb * cos_number));
bottom_pos_y=pre_pos_y - ((bb * sin_number) < 0 ? (-bb * sin_number) : (bb * sin_number));
}
else if (pre_pos_x <= pos_x && pre_pos_y > pos_y)
{
bottom_pos_x=pre_pos_x - ((bb * cos_number) < 0 ? (-bb * cos_number) : (bb * cos_number));
bottom_pos_y=pre_pos_y - ((bb * sin_number) < 0 ? (-bb * sin_number) : (bb * sin_number));
}
else if (pre_pos_x >= pos_x && pre_pos_y >= pos_y)
{
bottom_pos_x=pre_pos_x - ((bb * cos_number) < 0 ? (-bb * cos_number) : (bb * cos_number));
bottom_pos_y=pre_pos_y + ((bb * sin_number) < 0 ? (-bb * sin_number) : (bb * sin_number));
}
else if (pre_pos_x >= pos_x && pre_pos_y <= pos_y)
{
bottom_pos_x=pre_pos_x + ((bb * cos_number) < 0 ? (-bb * cos_number) : (bb * cos_number));
bottom_pos_y=pre_pos_y + ((bb * sin_number) < 0 ? (-bb * sin_number) : (bb * sin_number));
}
var bottom_point:MapPoint=new MapPoint(bottom_pos_x, bottom_pos_y);
bottomcurepoints.push(bottom_point);
}
}
/*
**下面是添加军标箭头的程序,因为现在已经得到上下边界的曲线了。
**
*/
var end_curvepoint:MapPoint=curvepoints[curvepoints.length - 1];
var end_top_point:MapPoint=topcurepoints[topcurepoints.length - 1];
var end_top_point2:MapPoint=topcurepoints[topcurepoints.length - 2];
//求箭头上方的点
var x2:Number=end_curvepoint.x;
var y2:Number=end_curvepoint.y;
var pos_x:Number=end_top_point.x;
var pos_y:Number=end_top_point.y;
var pre_pos_x:Number=end_top_point2.x;
var pre_pos_y:Number=end_top_point2.y;
var end_slope:Number=(pre_pos_y - pos_y) / (pre_pos_x - pos_x);
var b:Number=dis;
var end_point_x:Number;
var end_point_y:Number;
var cos_number:Number=Math.cos(Math.atan(end_slope) - Math.PI / 2);
var sin_number:Number=Math.sin(Math.atan(end_slope) - Math.PI / 2);
//下面分四种情况画线。
if (pre_pos_x <= pos_x && pre_pos_y <= pos_y)
{
end_point_x=pre_pos_x - ((b * cos_number) < 0 ? (-b * cos_number) : (b * cos_number));
end_point_y=pre_pos_y + ((b * sin_number) < 0 ? (-b * sin_number) : (b * sin_number));
}
else if (pre_pos_x <= pos_x && pre_pos_y > pos_y)
{
end_point_x=pre_pos_x + ((b * cos_number) < 0 ? (-b * cos_number) : (b * cos_number));
end_point_y=pre_pos_y + ((b * sin_number) < 0 ? (-b * sin_number) : (b * sin_number));
}
else if (pre_pos_x >= pos_x && pre_pos_y >= pos_y)
{
end_point_x=pre_pos_x + ((b * cos_number) < 0 ? (-b * cos_number) : (b * cos_number));
end_point_y=pre_pos_y - ((b * sin_number) < 0 ? (-b * sin_number) : (b * sin_number));
}
else if (pre_pos_x >= pos_x && pre_pos_y <= pos_y)
{
end_point_x=pre_pos_x - ((b * cos_number) < 0 ? (-b * cos_number) : (b * cos_number));
end_point_y=pre_pos_y - ((b * sin_number) < 0 ? (-b * sin_number) : (b * sin_number));
}
//创建第三个点，然后创建三角形
clogger.logger.info("右上面的点的横坐标点x:" + end_point_x + "----------右上方点的纵坐标的y:" + end_point_y);
//得到右上方的点
var end_right_point:MapPoint=new MapPoint(end_point_x, end_point_y);
topcurepoints.push(end_right_point);
//最右边，箭头顶点的坐标是
clogger.logger.info("顶点的横坐标是x:" + end_curvepoint.x + "---------顶点的纵坐标y:" + end_curvepoint.y);
topcurepoints.push(end_curvepoint);
//下边线
var end_bottom_point:MapPoint=bottomcurepoints[bottomcurepoints.length - 1];
var end_bottom_point2:MapPoint=bottomcurepoints[bottomcurepoints.length - 2];
//求箭头下方向的点
var bx1:Number=end_bottom_point.x;
var by1:Number=end_bottom_point.y;
var bx0:Number=end_bottom_point2.x;
var by0:Number=end_bottom_point2.y;
var bend_slope:Number=(by1 - by0) / (bx1 - bx0);
var bend_point_x:Number;
var bend_point_y:Number;
var bend_cos_number:Number=Math.cos(Math.atan(bend_slope) - Math.PI / 2);
var bend_sin_number:Number=Math.sin(Math.atan(bend_slope) - Math.PI / 2);
if (bx0 <= bx1 && by0 <= by1)
{
bend_point_x=bx0 + ((b * bend_cos_number) < 0 ? (-b * bend_cos_number) : (b * bend_cos_number));
bend_point_y=by0 - ((b * bend_sin_number) < 0 ? (-b * bend_sin_number) : (b * bend_sin_number));
}
else if (bx0 <= bx1 && by0 > by1)
{
bend_point_x=bx0 - ((b * bend_cos_number) < 0 ? (-b * bend_cos_number) : (b * bend_cos_number));
bend_point_y=by0 - ((b * bend_sin_number) < 0 ? (-b * bend_sin_number) : (b * bend_sin_number));
}
else if (bx0 >= bx1 && by0 >= by1)
{
bend_point_x=bx0 - ((b * bend_cos_number) < 0 ? (-b * bend_cos_number) : (b * bend_cos_number));
bend_point_y=by0 + ((b * bend_sin_number) < 0 ? (-b * bend_sin_number) : (b * bend_sin_number));
}
else if (bx0 >= bx1 && by0 <= by1)
{
bend_point_x=bx0 + ((b * bend_cos_number) < 0 ? (-b * bend_cos_number) : (b * bend_cos_number));
bend_point_y=by0 + ((b * bend_sin_number) < 0 ? (-b * bend_sin_number) : (b * bend_sin_number));
}
clogger.logger.info("下方的点的横坐标x为:" + bend_point_x + "-------下方的点的纵坐标y为:" + bend_point_y);
//得到右下方的点
var bend_right_point:MapPoint=new MapPoint(bend_point_x, bend_point_y);
topcurepoints.push(bend_right_point);
for (var k:Number=bottomcurepoints.length - 1; k >= 0; k--)
{
// 这个是下半部分
clogger.logger.info("由此开始下半部分:" + bottomcurepoints[k].x + "yyyyy:" + bottomcurepoints[k].y);
topcurepoints.push(bottomcurepoints[k]);
}
//添加尾部的部分,至此完成对军标多边行的算法，
topcurepoints.push(curvepoints[1]);
topcurepoints.push(topcurepoints[0]);
clogger.logger.info("军标上的点的个数是" + topcurepoints.length);
var rings:Array=new Array();
rings.push(topcurepoints);
return rings;
}
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