判断点是否在曲线上

gzxl

直线、多段线（1d 2d 3d）、圆弧、圆、椭圆弧、样条曲线


AutoCAD 2013 版本以上直接用
es = acdbConvertAcDbCurveToGelibCurve(pCurve, pGeCurve);
// 或者用 getAcGeCurve
// es = pCurve->getAcGeCurve(pGeCurve);
AcGeCurve3d::isOn

AutoCAD 2013 版本以下需要构造 AcGe 类，然后用
static_cast<AcGeCurve3d*>(pGeLine->copy())

至于曲线转换类高大侠分享过。

1. Acad::ErrorStatus es;
   
2. ads_name name;
   
3. AcGePoint3d pt;
   
4. if (acedEntSel(_T("\n请选择一条曲线:"), name, asDblArray(pt)) != RTNORM)
   
5.     return;
   
6. 
   
7. AcDbObjectId objId;
   
8. es = acdbGetObjectId(objId, name);
   
9. if (es != Acad::eOk) return;
   
10. AcDbEntity *pEnt = NULL;
    
11. es = acdbOpenObject(pEnt, objId, AcDb::kForRead);
    
12. if (es != Acad::eOk) return;
    
13. 
    
14. AcGeCurve3d* pGeCurve = NULL;
    
15. 
    
16. #if _MSC_VER > 1500
    
17. if (pEnt->isKindOf(AcDbCurve::desc()))
    
18. {
    
19.     AcDbCurve *pCurve = AcDbCurve::cast(pEnt);
    
20.     // 转换为几何类
    
21.     es = acdbConvertAcDbCurveToGelibCurve(pCurve, pGeCurve);
    
22.     // 或者用 getAcGeCurve
    
23.     // es = pCurve->getAcGeCurve(pGeCurve);
    
24.     pCurve->close();
    
25. }
    
26. #else   // 低于 AutoCAD 2013 版本
    
27. if (pEnt->isKindOf(AcDbLine::desc()))
    
28. {
    
29.     AcDbLine *pLine = AcDbLine::cast(pEnt);
    
30.     AcGeLineSeg3d* pGeLine = CCurveConversion::AcDbCurveToAcGeCurve(pLine);
    
31.     pGeCurve = static_cast<AcGeCurve3d*>(pGeLine->copy());
    
32.     pLine->close();
    
33. }
    
34. else if (pEnt->isKindOf(AcDbPolyline::desc()))
    
35. {
    
36.     AcDbPolyline *pPoly = AcDbPolyline::cast(pEnt);
    
37.     AcGeCompositeCurve3d* pGePoly = CCurveConversion::AcDbCurveToAcGeCurve(pPoly);
    
38.     pGeCurve = static_cast<AcGeCurve3d*>(pGePoly->copy());
    
39.     pPoly->close();
    
40. }
    
41. else if (pEnt->isKindOf(AcDb2dPolyline::desc()))
    
42. {
    
43.     AcDb2dPolyline *pPoly = AcDb2dPolyline::cast(pEnt);
    
44.     AcGeCompositeCurve3d* pGePoly = CCurveConversion::AcDbCurveToAcGeCurve(pPoly);
    
45.     pGeCurve = static_cast<AcGeCurve3d*>(pGePoly->copy());
    
46.     pPoly->close();
    
47. }
    
48. else if (pEnt->isKindOf(AcDb3dPolyline::desc()))
    
49. {
    
50.     AcDb3dPolyline *pPoly = AcDb3dPolyline::cast(pEnt);
    
51.     AcGeCompositeCurve3d* pGePoly = CCurveConversion::AcDbCurveToAcGeCurve(pPoly);
    
52.     pGeCurve = static_cast<AcGeCurve3d*>(pGePoly->copy());
    
53.     pPoly->close();
    
54. }
    
55. else if (pEnt->isKindOf(AcDbArc::desc()))
    
56. {
    
57.     AcDbArc *pArc = AcDbArc::cast(pEnt);
    
58.     AcGeCircArc3d* pGeArc = CCurveConversion::AcDbCurveToAcGeCurve(pArc);
    
59.     pGeCurve = static_cast<AcGeCurve3d*>(pGeArc->copy());
    
60.     pArc->close();
    
61. }
    
62. else if (pEnt->isKindOf(AcDbCircle::desc()))
    
63. {
    
64.     AcDbCircle *pCircle = AcDbCircle::cast(pEnt);
    
65.     AcGeCircArc3d* pGeCircle = CCurveConversion::AcDbCurveToAcGeCurve(pCircle);
    
66.     pGeCurve = static_cast<AcGeCurve3d*>(pGeCircle->copy());
    
67.     pCircle->close();
    
68. }
    
69. else if (pEnt->isKindOf(AcDbEllipse::desc()))
    
70. {
    
71.     AcDbEllipse *pEllipse = AcDbEllipse::cast(pEnt);
    
72.     AcGeCircArc3d* pGeEllipse = CCurveConversion::AcDbCurveToAcGeCurve(pEllipse);
    
73.     pGeCurve = static_cast<AcGeCurve3d*>(pGeEllipse->copy());
    
74.     pEllipse->close();
    
75. }
    
76. else if (pEnt->isKindOf(AcDbSpline::desc()))
    
77. {
    
78.     AcDbSpline *pSpline = AcDbSpline::cast(pEnt);
    
79.     AcGeCircArc3d* pGeSpline = CCurveConversion::AcDbCurveToAcGeCurve(pSpline);
    
80.     pGeCurve = static_cast<AcGeCurve3d*>(pGeSpline->copy());
    
81.     pSpline->close();
    
82. }
    
83. #endif
    
84. if (pGeCurve)
    
85. {
    
86.     // 设置捕捉
    
87.     resbuf rb;
    
88.     rb.rbnext = NULL;
    
89.     rb.restype = RTSHORT;
    
90.     rb.resval.rint = 555;
    
91.     acedSetVar(_T("osmode"), &rb);
    
92. 
    
93.     AcGePoint3d ptTest;
    
94.     while (acedGetPoint(NULL, _T("\n请拾取点测试是否在曲线上:"), asDblArray(ptTest)) == RTNORM)
    
95.     {
    
96.         // 拾取点是否位于曲线上
    
97.         if (pGeCurve->isOn(ptTest))
    
98.             acutPrintf(_T("\n点在曲线上"));
    
99.         else
    
100.             acutPrintf(_T("\n点不在曲线上"));
     
101.     }
     
102. 
     
103.     rb.resval.rint = 0;
     
104.     acedSetVar(_T("osmode"), &rb);
     
105. 
     
106.     delete pGeCurve;
     
107. }
     
108. 
     
109. pEnt->close();

Acad::ErrorStatus es;<br /> ads_name name;<br /> AcGePoint3d pt;<br /> if (acedEntSel(_T("\n请选择一条曲线:"), name, asDblArray(pt)) != RTNORM)<br />     return;<br /> <br /> AcDbObjectId objId;<br /> es = acdbGetObjectId(objId, name);<br /> if (es != Acad::eOk) return;<br /> AcDbEntity *pEnt = NULL;<br /> es = acdbOpenObject(pEnt, objId, AcDb::kForRead);<br /> if (es != Acad::eOk) return;<br /> <br /> AcGeCurve3d* pGeCurve = NULL;<br /> <br /> #if _MSC_VER > 1500<br /> if (pEnt->isKindOf(AcDbCurve::desc()))<br /> {<br />     AcDbCurve *pCurve = AcDbCurve::cast(pEnt);<br />     // 转换为几何类<br />     es = acdbConvertAcDbCurveToGelibCurve(pCurve, pGeCurve);<br />     // 或者用 getAcGeCurve<br />     // es = pCurve->getAcGeCurve(pGeCurve);<br />     pCurve->close();<br /> }<br /> #else   // 低于 AutoCAD 2013 版本<br /> if (pEnt->isKindOf(AcDbLine::desc()))<br /> {<br />     AcDbLine *pLine = AcDbLine::cast(pEnt);<br />     AcGeLineSeg3d* pGeLine = CCurveConversion::AcDbCurveToAcGeCurve(pLine);<br />     pGeCurve = static_cast<AcGeCurve3d*>(pGeLine->copy());<br />     pLine->close();<br /> }<br /> else if (pEnt->isKindOf(AcDbPolyline::desc()))<br /> {<br />     AcDbPolyline *pPoly = AcDbPolyline::cast(pEnt);<br />     AcGeCompositeCurve3d* pGePoly = CCurveConversion::AcDbCurveToAcGeCurve(pPoly);<br />     pGeCurve = static_cast<AcGeCurve3d*>(pGePoly->copy());<br />     pPoly->close();<br /> }<br /> else if (pEnt->isKindOf(AcDb2dPolyline::desc()))<br /> {<br />     AcDb2dPolyline *pPoly = AcDb2dPolyline::cast(pEnt);<br />     AcGeCompositeCurve3d* pGePoly = CCurveConversion::AcDbCurveToAcGeCurve(pPoly);<br />     pGeCurve = static_cast<AcGeCurve3d*>(pGePoly->copy());<br />     pPoly->close();<br /> }<br /> else if (pEnt->isKindOf(AcDb3dPolyline::desc()))<br /> {<br />     AcDb3dPolyline *pPoly = AcDb3dPolyline::cast(pEnt);<br />     AcGeCompositeCurve3d* pGePoly = CCurveConversion::AcDbCurveToAcGeCurve(pPoly);<br />     pGeCurve = static_cast<AcGeCurve3d*>(pGePoly->copy());<br />     pPoly->close();<br /> }<br /> else if (pEnt->isKindOf(AcDbArc::desc()))<br /> {<br />     AcDbArc *pArc = AcDbArc::cast(pEnt);<br />     AcGeCircArc3d* pGeArc = CCurveConversion::AcDbCurveToAcGeCurve(pArc);<br />     pGeCurve = static_cast<AcGeCurve3d*>(pGeArc->copy());<br />     pArc->close();<br /> }<br /> else if (pEnt->isKindOf(AcDbCircle::desc()))<br /> {<br />     AcDbCircle *pCircle = AcDbCircle::cast(pEnt);<br />     AcGeCircArc3d* pGeCircle = CCurveConversion::AcDbCurveToAcGeCurve(pCircle);<br />     pGeCurve = static_cast<AcGeCurve3d*>(pGeCircle->copy());<br />     pCircle->close();<br /> }<br /> else if (pEnt->isKindOf(AcDbEllipse::desc()))<br /> {<br />     AcDbEllipse *pEllipse = AcDbEllipse::cast(pEnt);<br />     AcGeCircArc3d* pGeEllipse = CCurveConversion::AcDbCurveToAcGeCurve(pEllipse);<br />     pGeCurve = static_cast<AcGeCurve3d*>(pGeEllipse->copy());<br />     pEllipse->close();<br /> }<br /> else if (pEnt->isKindOf(AcDbSpline::desc()))<br /> {<br />     AcDbSpline *pSpline = AcDbSpline::cast(pEnt);<br />     AcGeCircArc3d* pGeSpline = CCurveConversion::AcDbCurveToAcGeCurve(pSpline);<br />     pGeCurve = static_cast<AcGeCurve3d*>(pGeSpline->copy());<br />     pSpline->close();<br /> }<br /> #endif<br /> if (pGeCurve)<br /> {<br />     // 设置捕捉<br />     resbuf rb;<br />     rb.rbnext = NULL;<br />     rb.restype = RTSHORT;<br />     rb.resval.rint = 555;<br />     acedSetVar(_T("osmode"), &rb);<br /> <br />     AcGePoint3d ptTest;<br />     while (acedGetPoint(NULL, _T("\n请拾取点测试是否在曲线上:"), asDblArray(ptTest)) == RTNORM)<br />     {<br />         // 拾取点是否位于曲线上<br />         if (pGeCurve->isOn(ptTest))<br />             acutPrintf(_T("\n点在曲线上"));<br />         else<br />             acutPrintf(_T("\n点不在曲线上"));<br />     }<br /> <br />     rb.resval.rint = 0;<br />     acedSetVar(_T("osmode"), &rb);<br /> <br />     delete pGeCurve;<br /> }<br /> <br /> pEnt->close();

tigcat

可能需要增加容差
支持容差判断（考虑浮点精度）

gzxl

GE_DLLEXPIMPORT Adesk::Boolean isOn(
    const AcGePoint3d& pnt,
    const AcGeTol& tol = AcGeContext::gTol
) const;

第二个参数

asen

求点到线的最近点, 在计算这两点距离

gzxl

asen 发表于 2025-9-3 08:10
求点到线的最近点, 在计算这两点距离

多种方法可以比较。

lhg

曲线转换类 能否在提供？谢谢！！

cable2004

1.         // 获取点到曲线最近点并判断是否在曲线上
   
2.         static void GetClosestPointOnCurve()
   
3.         {
   
4.                 ads_name ename; // 实体选择结果
   
5.                 AcGePoint3d ptPick; // 选择点坐标
   
6. 
   
7.                 // 选择曲线实体
   
8.                 if (acedEntSel(_T("\n请选择一条曲线:"), ename, asDblArray(ptPick)) != RTNORM)
   
9.                         return;
   
10. 
    
11.                 AcDbObjectId objId; // 实体对象ID
    
12.                 Acad::ErrorStatus es = acdbGetObjectId(objId, ename); // 获取对象ID
    
13.                 if (es != Acad::eOk) return;
    
14. 
    
15.                 AcDbEntity* pEnt = NULL; // 实体指针
    
16.                 es = acdbOpenObject(pEnt, objId, AcDb::kForRead); // 以只读方式打开实体
    
17.                 if (es != Acad::eOk) return;
    
18. 
    
19.                 // 检查是否为曲线类型
    
20.                 if (pEnt->isKindOf(AcDbCurve::desc()))
    
21.                 {
    
22.                         AcDbCurve* pCurve = AcDbCurve::cast(pEnt); // 转换为曲线对象
    
23.                         if (pCurve != NULL)
    
24.                         {
    
25.                                 AcGePoint3d ptTest; // 测试点坐标
    
26. 
    
27.                                 // 循环获取测试点
    
28.                                 while (acedGetPoint(NULL, _T("\n请拾取点测试是否在曲线上:"), asDblArray(ptTest)) == RTNORM)
    
29.                                 {
    
30.                                         AcGePoint3d ptNearest; // 最近点坐标
    
31. 
    
32.                                         // 获取曲线上最近点
    
33.                                         if (pCurve->getClosestPointTo(ptTest, ptNearest) == Acad::eOk)
    
34.                                         {
    
35.                                                 // 计算距离判断是否在曲线上
    
36.                                                 double dDist = ptTest.distanceTo(ptNearest);
    
37.                                                 if (dDist < 1e-7)
    
38.                                                         acutPrintf(_T("\n点在曲线上"));
    
39.                                                 else
    
40.                                                         acutPrintf(_T("\n点不在曲线上，最近距离: %f"), dDist);
    
41.                                         }
    
42.                                         else
    
43.                                         {
    
44.                                                 acutPrintf(_T("\n获取最近点失败"));
    
45.                                         }
    
46.                                 }
    
47. 
    
48.                                 pCurve->close(); // 关闭曲线对象
    
49.                         }
    
50.                 }
    
51. 
    
52.                 pEnt->close(); // 关闭实体对象
    
53.         }

复制代码

gzxl

在曲线某些方面 AcGe 比 AcDb 好用又快，比如这个求自相交点

http://www.mjtd.com/home.php?mod ... do=blog&id=16373329

gzxl

lhg 发表于 2025-9-3 21:19
曲线转换类 能否在提供？谢谢！！

https://www.cnblogs.com/mjgw/p/12459597.html

lhg

谢谢了谢谢了