polyctl.cpp

VisualC++实践与提高-ActiveX篇源码

// PolyCtl.cpp : Implementation of CPolyCtl

#include "stdafx.h"
#include "AxAtlCtl.h"
#include "PolyCtl.h"

/////////////////////////////////////////////////////////////////////////////
// CPolyCtl


STDMETHODIMP CPolyCtl::get_Slides(short *pVal)
{
   *pVal = m_nSides;
   return S_OK;
}

STDMETHODIMP CPolyCtl::put_Slides(short newVal)
{
   if (newVal >=3 && newVal <= 100)
   {
      m_nSides = newVal;
      FireViewChange();
      return S_OK;
   }
   else
      return Error(_T("圆内接正多边形的边数必须在3~100之间！"));
}

void CPolyCtl::CalcPoints(const RECT& rc)
{
   const double pi = 3.14159265358979;
   POINT   ptCenter;
   double  dblRadiusx = (rc.right - rc.left) / 2;
   double  dblRadiusy = (rc.bottom - rc.top) / 2;
   double  dblAngle = 3 * pi / 2;          // Start at the top
   double  dblDiff  = 2 * pi / m_nSides;   // Angle each side will make
   ptCenter.x = (rc.left + rc.right) / 2;
   ptCenter.y = (rc.top + rc.bottom) / 2;

   // Calculate the points for each side
   for (int i = 0; i < m_nSides; i++)
   {
      m_arrPoint[i].x = (long)(dblRadiusx * cos(dblAngle) + ptCenter.x + 0.5);
      m_arrPoint[i].y = (long)(dblRadiusy * sin(dblAngle) + ptCenter.y + 0.5);
      dblAngle += dblDiff;
   }
}