[求助]：什么函数可以用一长度等分一条曲线？

wang_tianyu

我想用一长度值来等分一条直线或曲线，然后将等分的点存在数组中，不知何汉书可以实现？请高手指点，谢谢！

LoveArx

最初由 wang_tianyu 发布
[B]我想用一长度值来等分一条直线或曲线，然后将等分的点存在数组中，不知何汉书可以实现？请高手指点，谢谢！ [/B]

AcDbCurve::getSplitCurves(...)

1. 
   
2. virtual Acad::ErrorStatus
   
3. 
   
4. getSplitCurves(
   
5. 
   
6. const AcGePoint3dArray& points,
   
7. 
   
8. AcDbVoidPtrArray& curveSegments) const;
   
9. 
   
10. points Input array of points (in WCS coordinates) on the curve
    
11. curveSegments Returns with pointers to newly created entities that are
    
12. subcurves of the original
    

复制代码

你要仅仅得到这些点，而不是实际上把曲线断开，那么先求出曲线上度，然后除以等分数，每段的长度，然后循环下，利用：

2. 
   
3. AcDbCurve::getPointAtDist Function virtual Acad::ErrorStatus
   
4. 
   
5. getPointAtDist(
   
6. 
   
7. double unnamed,
   
8. 
   
9. AcGePoint3d& unnamed) const;
   
10. 
    
11. unnamed Input distance along the curve from the beginning of the curve
    
12. to the location of the desired point
    
13. 
    
14. unnamed Returns the point located at the location specified by dist
    
15. 
    
16. 
    
17. This function determines the point on the curve that is a distance of dist
    
18. along the curve from the curve start, and returns the point in point. point is
    
19. in WCS coordinates.
    
20. 
    
21. 
    
22. Returns Acad::eOk if successful. If dist is not valid for the curve, then
    
23. 
    
24. Acad::eInvalidInput is returned. Other ErrorStatus return values are
    
25. 
    
26. implementation-dependent.
    
27. 
    
28. 
    
29. The default implementation returns Acad::eNotImplemented.
    
30. 
    

<br /> AcDbCurve::getPointAtDist Function virtual Acad::ErrorStatus<br /> <br /> getPointAtDist(<br /> <br /> double unnamed,<br /> <br /> AcGePoint3d& unnamed) const;<br /> <br /> unnamed Input distance along the curve from the beginning of the curve<br /> to the location of the desired point <br /> <br /> unnamed Returns the point located at the location specified by dist <br /> <br /> <br /> This function determines the point on the curve that is a distance of dist <br /> along the curve from the curve start, and returns the point in point. point is <br /> in WCS coordinates.<br /> <br /> <br /> Returns Acad::eOk if successful. If dist is not valid for the curve, then <br /> <br /> Acad::eInvalidInput is returned. Other ErrorStatus return values are <br /> <br /> implementation-dependent.<br /> <br /> <br /> The default implementation returns Acad::eNotImplemented.<br /> <br />

binbin

你可以用getStartParam 得到起点的"参数"dParamS,getEndParam 得到终点的"参数"dParamE,然后(dParamE-dParamS)/等分数,得每份的参数 n ,再用getPointAtDist(dParamS + n*i),得每等分点的坐标.
(对于cad的实体  参数 正比于 长度,自定义实体就难说了)