/// <summary>
/// 以半径为基准作为获取过渡圆弧
/// </summary>
/// <param name="lineStart">线起点</param>
/// <param name="intersection">线与原始圆弧交点</param>
/// <param name="oriArcCenter">原始圆弧圆心</param>
/// <param name="transitionR">过渡圆弧半径</param>
/// <param name="oriArcClockwise">原始圆弧方向</param>
/// <returns>过渡圆弧的起点、圆心、终点</returns>
public static List <PointD> GetLineToArcTransitionArcByR(PointD lineStart, PointD intersection, PointD oriArcCenter, double transitionR, double oriArcClockwise)
{
List <PointD> points = new List <PointD>();
PointD transitionArcCenter, newLineEnd, newArcStart;
double angle = GetAngleOfTwoLine(lineStart, intersection, oriArcCenter);
VectorD vArcS = intersection - oriArcCenter;
double oriR = vArcS.Length;
VectorD vArcSRotate1;
if (oriArcClockwise == 1)
{
vArcSRotate1 = vArcS.Rotate(-90);
}
else
{
vArcSRotate1 = vArcS.Rotate(90);
}
if (angle != Math.PI)
{
//求原始圆弧半径
double len1;
if (GetAngleOfTwoLine(lineStart, intersection, (intersection + vArcSRotate1)) > (Math.PI / 2))
{
len1 = oriR * Math.Sin(Math.PI - angle) + transitionR;
}
else
{
len1 = oriR * Math.Sin(Math.PI - angle) - transitionR;
}
double len2 = Math.Sqrt((oriR + transitionR) * (oriR + transitionR) - len1 * len1);
PointD footPoint = MathUtils.GetFootPoint(oriArcCenter, lineStart, intersection);
VectorD vLenTemp = (footPoint - oriArcCenter);
VectorD vLen1 = vLenTemp.ScaleBy(len1 / vLenTemp.Length);
VectorD vLine = lineStart - intersection;
VectorD vLen2 = vLine.ScaleBy(len2 / vLine.Length);
transitionArcCenter = oriArcCenter + vLen1 + vLen2;
newLineEnd = MathUtils.GetFootPoint(transitionArcCenter, lineStart, intersection);
newArcStart = transitionArcCenter + (oriArcCenter - transitionArcCenter).ScaleBy(transitionR / (oriR + transitionR));
}
else
{
double len1 = transitionR;
double len2 = Math.Sqrt((oriR + transitionR) * (oriR + transitionR) - len1 * len1);
VectorD vLen2 = vArcS.ScaleBy(len2 / oriR);
newLineEnd = oriArcCenter + vLen2;
VectorD vLen1 = vArcSRotate1.ScaleBy(transitionR / vArcSRotate1.Length);
transitionArcCenter = newLineEnd + vLen1;
newArcStart = transitionArcCenter + (oriArcCenter - transitionArcCenter).ScaleBy(transitionR / (transitionR + oriR));
}
points.Add(newLineEnd);
points.Add(transitionArcCenter);
points.Add(newArcStart);
return(points);
}
/// <summary>
/// 获取直线到圆弧的过渡圆弧
/// </summary>
/// <param name="lineStart">线起点</param>
/// <param name="intersection">线与圆弧交点</param>
/// <param name="oriArcCenter">圆弧圆心</param>
/// <param name="transitionAngle">过渡舍去的圆弧角度，单位度</param>
/// <returns>过渡圆弧的起点、圆心、终点</returns>
public static List <PointD> GetLineToArcTransitionArc(PointD lineStart, PointD intersection, PointD oriArcCenter, double transitionAngle, double oriArcClockwise)
{
List <PointD> points = new List <PointD>();
// 获取圆弧上过渡的切点(即过渡圆弧的终点)
VectorD vOriArcStart = intersection - oriArcCenter;
if (oriArcClockwise == 0)
{
transitionAngle = -transitionAngle;
}
VectorD temp = vOriArcStart.Rotate(transitionAngle);
PointD newArcStart = oriArcCenter + temp;
// 做圆弧切点切线，与原直线相交得到新的拐角交点
VectorD tempV1 = temp.Rotate(90);
PointD inflexionLinePoint1 = newArcStart + tempV1 * 10;
PointD inflexionLinePoint2 = newArcStart - tempV1 * 10;
PointD newIntersection = GetIntersection(lineStart, intersection, inflexionLinePoint1, inflexionLinePoint2);
// 得到新的拐角角度
double newAngle = GetAngleOfTwoLine(lineStart, newIntersection, newArcStart);
// 求得新的拐角圆弧半径
VectorD tempV2 = newArcStart - newIntersection;
double r = Math.Tan(newAngle / 2) * tempV2.Length;
points = GetLineTransitionArc(lineStart, newIntersection, newArcStart, r);
return(points);
}
