WPF绘制光滑连续贝塞尔曲线 WPF怎样绘制光滑连续贝塞尔曲线代码实例

/// <summary>
 /// 获得贝塞尔曲线
 /// </summary>
 /// <param name="currentPt">当前点</param>
 /// <param name="lastPt">上一个点</param>
 /// <param name="nextPt1">下一个点1</param>
 /// <param name="nextPt2">下一个点2</param>
 /// <returns></returns>
 private BezierSegment GetBezierSegment(Point currentPt, Point lastPt, Point nextPt1, Point nextPt2)
 {
  //计算中点
  var lastC = GetCenterPoint(lastPt, currentPt);
  var nextC1 = GetCenterPoint(currentPt, nextPt1); //贝塞尔控制点
  var nextC2 = GetCenterPoint(nextPt1, nextPt2);
  //计算相邻中点连线跟目的点的垂足
  //效果并不算太好，因为可能点在两个线上或者线的延长线上，计算会有误差
  //所以就直接使用中点平移方法。
  //var C1 = GetFootPoint(lastC, nextC1, currentPt);
  //var C2 = GetFootPoint(nextC1, nextC2, nextPt1);
  //计算“相邻中点”的中点
  var c1 = GetCenterPoint(lastC, nextC1);
  var c2 = GetCenterPoint(nextC1, nextC2);
  //计算【"中点"的中点】需要的点位移
  var controlPtOffset1 = currentPt - c1;
  var controlPtOffset2 = nextPt1 - c2;
  //移动控制点
  var controlPt1 = nextC1 + controlPtOffset1;
  var controlPt2 = nextC1 + controlPtOffset2;
  //如果觉得曲线幅度太大，可以将控制点向当前点靠近一定的系数。
  controlPt1 = controlPt1 + 0 * (currentPt - controlPt1);
  controlPt2 = controlPt2 + 0 * (nextPt1 - controlPt2);
  var bzs = new BezierSegment(controlPt1, controlPt2, nextPt1, true);
  return bzs;
 }