// ========================================== 合并 ============================================= //
/// <summary>
/// 合并两个交叉的多边形(多边形必须先转换为顺时针方向，调用CW()函数!)
/// </summary>
/// <param name="other"></param>
/// <param name="polyRes"></param>
/// <returns></returns>
public PolyResCode Union(Polygon other, ref List <Polygon> polyRes)
{
if (this.m_lstPoints.Count == 0 || other.m_lstPoints.Count == 0)
{
return(PolyResCode.ErrEmpty);
}
else if (!NMath.CheckCross(GetCoverRect(), other.GetCoverRect()))
{
return(PolyResCode.ErrNotCross);
}
// 转换为顺时针方向
//this.CW();
//other.CW();
List <NavNode> mainNode = new List <NavNode>(); //主多边形顶点
List <NavNode> subNode = new List <NavNode>(); //需要合并的多边形顶点
// init main nodes
for (int i = 0; i < this.m_lstPoints.Count; i++)
{
NavNode currNode = new NavNode(this.m_lstPoints[i], false, true);
if (i > 0)
{
NavNode preNode = mainNode[i - 1];
preNode.next = currNode;
}
mainNode.Add(currNode);
}
// init sub nodes
for (int j = 0; j < other.m_lstPoints.Count; j++)
{
NavNode currNode = new NavNode(other.m_lstPoints[j], false, false);
if (j > 0)
{
NavNode preNode = subNode[j - 1];
preNode.next = currNode;
}
subNode.Add(currNode);
}
int insCnt = 0;
PolyResCode result = NavUtil.NavNodeIntersectPoint(mainNode, subNode, out insCnt);
if (result == PolyResCode.Success && insCnt > 0)
{
if (insCnt % 2 != 0)
{
return(PolyResCode.ErrCrossNum);
}
else
{
PolyResCode linkRes = NavUtil.LinkToPolygon(mainNode, subNode, ref polyRes);
return(linkRes);
}
}
return(PolyResCode.ErrCrossNum);
}
/// <summary>
/// Checks the line cross.
/// </summary>
/// <returns><c>true</c>, if line cross was checked, <c>false</c> otherwise.</returns>
public bool CheckLineCross()
{
Vector2 p1s, p1e, p2s, p2e;
int iPointCount = this.m_lstPoints.Count;
// 如果点的列表中只有两个点, 可以添加新点.
if (iPointCount <= 2)
{
return(true);
}
for (int i = 0; i < iPointCount - 2; i++)
{
p1s.x = this.m_lstPoints[i].transform.position.x;
p1s.y = this.m_lstPoints[i].transform.position.z;
p1e.x = this.m_lstPoints[i + 1].transform.position.x;
p1e.y = this.m_lstPoints[i + 1].transform.position.z;
for (int j = i + 2; j < iPointCount; j++)
{
if (j != iPointCount - 1)
{
p2s.x = this.m_lstPoints[j].transform.position.x;
p2s.y = this.m_lstPoints[j].transform.position.z;
p2e.x = this.m_lstPoints[j + 1].transform.position.x;
p2e.y = this.m_lstPoints[j + 1].transform.position.z;
}
else
{
p2s.x = this.m_lstPoints[j].transform.position.x;
p2s.y = this.m_lstPoints[j].transform.position.z;
p2e.x = this.m_lstPoints[0].transform.position.x;
p2e.y = this.m_lstPoints[0].transform.position.z;
if (0 == i)
{
continue;
}
}
if (NMath.CheckCross(p1s, p1e, p2s, p2e))
{
return(false);
}
}
}
return(true);
}
/// <summary>
/// 计算两条二维线段的交点
/// </summary>
/// <param name="other">Other line</param>
/// <param name="intersectPoint">输出的线段交点</param>
/// <returns>返回值说明了两条线段的位置关系(COLINE,PARALLEL,CROSS,NOT_CROSS) </returns>
public LineCrossState Intersection(Line2D other, out Vector2 intersectPoint)
{
intersectPoint.x = intersectPoint.y = float.NaN;
if (!NMath.CheckCross(this.m_cStartPoint, this.m_cEndPoint, other.m_cStartPoint, other.m_cEndPoint))
{
return(LineCrossState.NOT_CROSS);
}
double A1, B1, C1, A2, B2, C2;
A1 = this.m_cEndPoint.y - this.m_cStartPoint.y;
B1 = this.m_cStartPoint.x - this.m_cEndPoint.x;
C1 = this.m_cEndPoint.x * this.m_cStartPoint.y - this.m_cStartPoint.x * this.m_cEndPoint.y;
A2 = other.m_cEndPoint.y - other.m_cStartPoint.y;
B2 = other.m_cStartPoint.x - other.m_cEndPoint.x;
C2 = other.m_cEndPoint.x * other.m_cStartPoint.y - other.m_cStartPoint.x * other.m_cEndPoint.y;
if (NMath.IsEqualZero(A1 * B2 - B1 * A2))
{
if (NMath.IsEqualZero((A1 + B1) * C2 - (A2 + B2) * C1))
{
return(LineCrossState.COLINE);
}
else
{
return(LineCrossState.PARALLEL);
}
}
else
{
intersectPoint.x = (float)((B2 * C1 - B1 * C2) / (A2 * B1 - A1 * B2));
intersectPoint.y = (float)((A1 * C2 - A2 * C1) / (A2 * B1 - A1 * B2));
return(LineCrossState.CROSS);
}
}
/// <summary>
/// 根据原始点计算出正确的落在导航区内的位置,修复无效点和三角形
/// </summary>
/// <param name="orgTarTri">起源三角形</param>
/// <param name="orgTarPos">起源点</param>
/// <param name="otherTri">参考方向三角形</param>
/// <param name="otherPos">参考方向点</param>
/// <returns>结果</returns>
private PathResCode FixPos(ref NavTriangle orgTarTri, ref Vector2 orgTarPos, NavTriangle otherTri, Vector2 otherPos, int extendLength)
{
Vector2 tarPos = orgTarPos;
//////////////////////////////////////////////////////////////////////////
//为了精确判断,需要逆向延长线段一定长度
if (extendLength > 0)
{
Vector2 newTarPos = NMath.ExtendPos(otherPos, tarPos, extendLength);
tarPos = newTarPos;
}
//////////////////////////////////////////////////////////////////////////
Line2D linePath = new Line2D(tarPos, otherPos); //参考线段
Rect lineRect = NMath.LineRect(linePath); //获取线段矩形包围盒
//1)找到所有与参考线段矩形相交的三角形,并判断是否groupID相等
List <NavTriangle> crossNavTris = new List <NavTriangle>();
foreach (NavTriangle tri in this.m_lstTriangle)
{
if (NMath.CheckCross(lineRect, tri.GetBoxCollider()))
{
if (otherTri != null && otherTri.GetGroupID() != tri.GetGroupID())
{
continue;
}
crossNavTris.Add(tri);
}
}
//2)找出所有与参考线段相交的三角形,并记录相交点
List <Vector2> crossPoints = new List <Vector2>(); //相交点列表
List <int> triIndex = new List <int>(); //相交三角形索引列表
for (int index = 0; index < crossNavTris.Count; index++)
{
NavTriangle crossTri = crossNavTris[index];
Line2D triLine;
for (int i = 0; i < 3; i++)
{
Vector2 insPoint;
triLine = new Line2D(crossTri.GetPoint(i), crossTri.GetPoint((i + 1) % 3));
if (linePath.Intersection(triLine, out insPoint) == LineCrossState.CROSS)
{
crossPoints.Add(insPoint);
triIndex.Add(index);
}
}
}
if (crossPoints.Count == 0)
{
return(PathResCode.NoCrossPoint);
}
//3)找到最接近起源点的点
Vector2 lastPos = crossPoints[0];
int lastTriIndex = triIndex[0];
double lastLength = Math.Pow(lastPos.x - orgTarPos.x, 2.0) + Math.Pow(lastPos.y - orgTarPos.y, 2.0);
for (int i = 1; i < crossPoints.Count; i++)
{
double newLength = Math.Pow(crossPoints[i].x - orgTarPos.x, 2.0) + Math.Pow(crossPoints[i].y - orgTarPos.y, 2.0);
if (newLength < lastLength)
{
lastPos = crossPoints[i];
lastTriIndex = triIndex[i];
lastLength = newLength;
}
}
//4)保存目标
orgTarPos = lastPos;
orgTarTri = crossNavTris[lastTriIndex];
return(PathResCode.Success);
}
