(13)一步一步开发一个简单CAD之像皮筋类

在画线画圆等实体中都可拖动一个像皮筋类来重用,此像皮筋可以在8个方向,每隔45度指示方向

 

 

class CEraseLine//像皮筋类，可以在八个方向上画出像皮筋
{
public:
 CEraseLine();
 virtual ~CEraseLine();
public:
 void SetBegin(CPosition begin);
 void SetEnd(CPosition end);
 void SetCancle(CPosition pos);
 BOOL GetPoints(CPosition cen);//取得第二个实际点的坐标

 void OnLButtonDown(UINT nFlags,  CPosition pos);
    void OnMouseMove(UINT nFlags,  CPosition pos);
    void OnRButtonDown(UINT nFlags,  CPosition pos);

public:
  CPosition m_begin;
  CPosition m_end;
  int m_nStep;

};

 

 

 

CEraseLine::CEraseLine()
{
          m_nStep = 1;
 
}

CEraseLine::~CEraseLine()
{
    
}

void CEraseLine::SetBegin(CPosition begin)
{
     
         OnLButtonDown(0,  begin);
 
  
}

void CEraseLine::SetEnd(CPosition end)
{
      
          OnMouseMove(0,  end);
    GetPoints(end);
}

BOOL CEraseLine::GetPoints(CPosition cen)//如果第二个点改变，则反回改变后的点
{

 

  
   CLine *line[8];
   CDC * pDC = g_pView->GetDC();
   for (int i = 0; i < 8; i++)
   {
   
  line[i] = new CLine(m_begin, m_begin + CPosition(cos( 45 * i  * PI / 180), sin( 45 * i * PI /180)) * 1000); 

   
 if ( line[i]->PickSolid(m_end, g_pView->m_scale* 5 ) &&m_nStep == 2)//只在过程中画
 {
 
 
  line[i]->DrawSolid(pDC,Select);

 }

 else
 {
  line[i]->DrawSolid(pDC,Back);
 
 }

 delete line[i];

   }      

    g_pView->ReleaseDC(pDC);
 
 return  TRUE;

 

      
}

void CEraseLine::OnLButtonDown(UINT nFlags,  CPosition pos)
{
   
 switch(m_nStep)
 {

 case 1://输出提示信息
 {
  
 

         m_end = m_begin = pos;
         m_nStep++;
         break;
  
 }

 case 2:
 {
     
      m_end = pos;

    CDC *pDC = g_pView->GetDC();
    CLine *line1 = new CLine(m_begin, m_end);//画像皮线,消除上一个
       line1->DrawSolid(pDC,Drag);
       delete line1;
    g_pView->ReleaseDC(pDC);
    m_nStep = 1;
 }
  
 
  default:
     break;
 }
 
  
}

void CEraseLine::OnMouseMove(UINT nFlags,  CPosition pos)
{
     
     switch(m_nStep)
  {
  case 2:
  
      
   CDC *pDC = g_pView->GetDC();

  

   
         CLine *line1 = new CLine(m_begin, m_end);//画像皮线,消除上一个
   line1->DrawSolid(pDC,Drag);
   delete line1;
 
         g_pView->m_suject->Notify();

  

    CLine *line = new CLine(m_begin, pos);//画像皮线,最后一个
    line->DrawSolid(pDC,Normal);
    delete line;

   m_end  = pos;
 
        
      g_pView->ReleaseDC(pDC);
 
   break;
  }
}

void CEraseLine::OnRButtonDown(UINT nFlags,  CPosition pos)
{
      CDC *pDC = g_pView->GetDC();
         CLine *line1 = new CLine(m_begin, pos);//画像皮线,消除上一个
   line1->DrawSolid(pDC,Back);
   delete line1;
   g_pView->ReleaseDC(pDC);

   m_nStep = 1;
}

void CEraseLine::SetCancle(CPosition pos)
{
     OnRButtonDown(0, pos);
 
}

 

int g_Refresh = 0;//记录屏幕刷新次数
int c_Refresh = 0;

CCreateLine::CCreateLine()
{
    m_nStep = 1;
 c_Refresh = g_Refresh;

}

CCreateLine::~CCreateLine()
{

}