关于圆弧、扇形对象的点选和框选

已知圆弧、扇形的中心点ptCT、起始点ptDrawStart、终点ptDrawEnd、选择框的LT/RB点、起始角度StartAngle、圆弧或扇形对应的角度SweepAngle、半径Radius等

一、点选

在while循环中，根据SweepAngle角度的自增或自减，然后来根据中心点、偏移角度、起点算得偏移后的pt点，然后拿pt点与传进来的点ptReserve（如果对线被旋转缩放过，会进代码中的反旋转缩放回来）点计算距离。如果两点距离小于等于线宽，则判定是在圆弧或扇形上的弧线点。

扇形还需通过点是否在两边直线上，可以判定点是否在两点线段上来判定是否在两边直线上。

如果扇形是填充的，点在扇形里面怎么判断呢？也可以通过上面的while(SweepAngle)循环中判断该点是否在中心点与弧线上点的两点线段直线上。

 1     //点旋转
 2     //CPoint ptReserve;
 3     //ReservePoint(pt, ptReserve);
 4     CPoint ptReserve = pt;
 5     if (m_dbAngle != 0 || m_dbXZoomScale != 1 || m_dbYZoomScale != 1)
 6     {//根据旋转缩放后的点求旋转缩放前的点,如果没有旋转缩放不会进
 7         double y = (m_xform.eDy - pt.y + pt.x* m_xform.eM12/m_xform.eM11 - m_xform.eDx*m_xform.eM12/m_xform.eM11)/(m_xform.eM21*m_xform.eM12/m_xform.eM11-m_xform.eM22);
 8         double x = (pt.x - y*m_xform.eM21 - m_xform.eDx)/m_xform.eM11;
 9         ptReserve = CPoint((int) x, (int) y);
10     }
11 
12     if (m_bSelectFrameIsShow)
13     {
14         if (m_pWBImageButton != NULL)
15         {
16             if (m_pWBImageButton->IsInButtonArea(pt))    //判断点是否在选择框的按钮上
17             {
18                 return WB_PS_SELECTBUTTON;
19             }
20         }
21 
22         if (m_pRectSelect != NULL && m_pRectSelect->PointIn(pt)) //判断点是否在选择框内
23         {
24             return WB_PS_SELECTFRAME;
25         }
26 
27         return WB_PS_NONE;
28     }
29     XAutoLock lock(m_csSectorItemLock);
30     if (m_pWBSectorItem->bIsFillSolid || !m_bHaveFillRgn) //如果是填充的，或者没有填充区域
31     {
32         if (PointIn(ptReserve))
33         {
34             return WB_PS_OBJ;
35         }
36         return WB_PS_NONE;
37     }
38     else
39     { 
40 
41         int nWidth = m_pWBSectorItem->nWidth/2;
42         double dbZoomScale = GetXZoomScale() > GetYZoomScale() ? GetXZoomScale() : GetYZoomScale();
43         nWidth = (int)((nWidth * dbZoomScale) > WB_OBJECT_SELECT_SEGMENT ? (nWidth * dbZoomScale) : WB_OBJECT_SELECT_SEGMENT);
44 
45         double dSweepAngle = m_pWBSectorItem->dSectorSweepAngle;
46         CPoint ptTemp;
47         CPoint ptDrawStart = m_pWBSectorItem->ptDrawStart;
48         double dDistan = 0;
49         //根据选择角度的自增、自减，通过起点旋转得到旋转角度后的点，判断这些点到中心点的距离是否为半径大小
50         if (dSweepAngle > 0)
51         {
52             while(dSweepAngle > 0)
53             {
54                 PointRotationPoint(m_pWBSectorItem->ptSectorCT,dSweepAngle, ptDrawStart, ptTemp);
55                 if (CalDistancePointToPoint(ptTemp, ptReserve) < nWidth)
56                 {
57                     return WB_PS_OBJ;
58                 }
59                 dSweepAngle -= 1;
60             }
61         }
62         else
63         {
64             while(dSweepAngle < 0)
65             {
66                 PointRotationPoint(m_pWBSectorItem->ptSectorCT, dSweepAngle, ptDrawStart, ptTemp);
67                 if (CalDistancePointToPoint(ptTemp, ptReserve) < nWidth)
68                 {
69                     return WB_PS_OBJ;
70                 }
71                 dSweepAngle += 1;
72             }
73         }
74         //判断是否在边线上
75         if (CWBObject::PointInLine(ptReserve, m_pWBSectorItem->ptDrawStart, m_pWBSectorItem->ptSectorCT, m_pWBSectorItem->nWidth)
76             || CWBObject::PointInLine(ptReserve, m_pWBSectorItem->ptDrawEnd, m_pWBSectorItem->ptSectorCT, m_pWBSectorItem->nWidth))
77         {
78             return WB_PS_OBJ;
79         }
80         else
81         {
82             return WB_PS_NONE;
83         }
84 
85     }

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