ARX 点在区域内

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点在区域内


功能：判断点 pt 是否在区域 ptArr 内
实现：根据射线法求交点个数，偶数－区域外，奇数－区域内
变量：pt 指定点 ptArr 判断区域
返回：在区域 TRUE 不在 FALSE


code: BOOL BaseHandle::PointIsInPolygon(AcGePoint3d pt, AcGePoint3dArray ptArr)
{
int ptNum,i,interNum;
AcGePoint3d ptA,ptB;
ads_point pt0,pt1,pt2,ptIns,ptX;

interNum = 0;
pt0[X] = 0.0;
pt0[Y] = 0.0;
pt0[Z] = 0.0;
ptX[X] = pt.x;
ptX[Y] = pt.y;
ptX[Z] = pt.z;
ptNum = ptArr.length();
for (i = 0;i < ptNum - 1;i++){
   ptA = ptArr.at(i);
   ptB = ptArr.at(i + 1);
   pt1[X] = ptA.x;
   pt1[Y] = ptA.y;
   pt1[Z] = 0.0;
   pt2[X] = ptB.x;
   pt2[Y] = ptB.y;
   pt2[Z] = 0.0;
   if (acdbInters(ptX,pt0,pt1,pt2,1,ptIns) == RTNORM){
    interNum++;
   }
}
if (interNum % 2 == 0){
   return false;
}else{
   return true;
}