/// <summary>
/// 获取近的相交点
/// </summary>
/// <param name="line"></param>
/// <param name="intersectStart"></param>
/// <returns></returns>
public override bool GetNearIntersectPoint(LineSegment2D line, ref Double2 intersectStart)
{
double radis2 = this.radius * this.radius;
Double2 projectoint = line.ProjectPoint(this.circleCenter);
Double2 diff = this.circleCenter - projectoint;
// 跟直线相交奥
double dis = diff.sqrMagnitude - radis2;
if (dis < 0)
{
double dis1 = (this.circleCenter - line.startPoint).sqrMagnitude;
double dis2 = (this.circleCenter - line.endPoint).sqrMagnitude;
if (dis1 >= radis2 && dis2 <= radis2)
{
dis = System.Math.Sqrt(dis);
intersectStart = projectoint - line.normalizedDir * dis;
return(true);
}
else if (dis1 <= radis2 && dis2 >= radis2)
{
dis = System.Math.Sqrt(dis);
intersectStart = projectoint + line.normalizedDir * dis;
return(true);
}
}
return(false);
}
/// <summary>
/// 计算超出线段范围
/// </summary>
/// <param name="lineStart"></param>
/// <param name="lineEnd"></param>
/// <param name="listMidPoint"></param>
/// <param name="nearestIndex"></param>
/// <param name="farestIndex"></param>
private static void CalcNearFarest(Double2 lineStart, Double2 lineEnd, List <Double2> listMidPoint, ref int nearestIndex, ref int farestIndex)
{
if (listMidPoint == null || listMidPoint.Count == 0)
{
return;
}
nearestIndex = -1;
farestIndex = -1;
double outStartdis = 0;
double outEnddis = 0;
LineSegment2D line = new LineSegment2D(lineStart, lineEnd);
for (int i = 0; i < listMidPoint.Count; i++)
{
ProjectPointInLine pp = line.CheckProjectInLine(listMidPoint[i]);
if (pp == ProjectPointInLine.In)
{
continue;
}
Double2 projectPoint = line.ProjectPoint(listMidPoint[i]);
if (pp == ProjectPointInLine.OutStart)
{
double dis = (projectPoint - lineStart).sqrMagnitude;
if (dis > outStartdis)
{
outStartdis = dis;
nearestIndex = i;
}
}
else if (pp == ProjectPointInLine.OutStart)
{
double dis = (projectPoint - lineEnd).sqrMagnitude;
if (dis > outEnddis)
{
outEnddis = dis;
farestIndex = i;
}
}
}
}
/// <summary>
/// 最短射线包围盒路径
/// </summary>
/// <param name="line">线段</param>
/// <param name="offset">偏移值</param>
/// <param name="rbi">包围盒信息</param>
/// <returns>true，表示线段与aabb有相交，并返回最短包围路径</returns>
public override RBIResultType RayboundingNearestPath(LineSegment2D line, double offset, ref RayboundingInfo rbi)
{
if (rbi == null)
{
rbi = new RayboundingInfo();
}
Double2 diff = this.circleCenter - line.startPoint;
if (diff == Double2.zero)
{
return(RBIResultType.Fail);
}
//
Double2 projectoint = line.ProjectPoint(this.circleCenter);
diff = this.circleCenter - projectoint;
// 跟直线相交奥
double dis = diff.sqrMagnitude - this.radius * this.radius;
if (dis >= 0)
{
return(RBIResultType.Fail);
}
dis = -dis;
// 在同侧不行。
Double2 diff1 = line.startPoint - projectoint;
Double2 diff2 = line.endPoint - projectoint;
if (Double2.Dot(diff1, diff2) >= 0)
{
return(RBIResultType.Fail);
}
//
if (diff1.sqrMagnitude < dis || diff2.sqrMagnitude < dis)
{
return(RBIResultType.Fail);
}
dis = System.Math.Sqrt(dis) + offset;
Double2 p1 = projectoint - line.normalizedDir * dis;
Double2 p2 = projectoint + line.normalizedDir * dis;
double bigRadius = this.radius + offset;
double angle = SignedAngleInCircle(p1 - this.circleCenter, p2 - this.circleCenter, bigRadius);
int count = (int)(System.Math.Abs(angle / 0.25f));
double diffangle = angle / count;
List <Double2> listpath = new List <Double2>();
Double2 startVector = (p1 - this.circleCenter).normalized * bigRadius;
for (int i = 1; i <= count - 1; i++)
{
Double2 rorateVector = Double2.Rotate(startVector, -diffangle * i);
listpath.Add(rorateVector + this.circleCenter);
}
rbi.listpath = listpath;
if (rbi.listpath != null && rbi.listpath.Count > 0)
{
rbi.CalcHelpData(line, offset, p1, p2);
return(RBIResultType.Succ);
}
return(RBIResultType.Fail);
}
