/*
*--------------------------------------------------------------------------------
* 成员函数名 : OnPaint()
* 功能描述 : 绘制窗体或窗体尺寸发生改变时重画窗体
* 算法 : 透明显示位图，透明色为 g_stuPaintSet.tranCol
* 附加说明 : 窗口缩放时图像并不改变，而是在显示时改变复制位图，然后缩放显示
*--------------------------------------------------------------------------------
*/
void CFloatDibWnd::OnPaint()
{
ASSERT(m_pDib);
CRect rect;
GetClientRect(&rect);
// 用当前图像创建一个临时位图，对它进行缩放显示，以防失真
CDib *pTmpDib = m_pDib->Clone();
pTmpDib->ChangeImageSize(rect.Width(), rect.Height());
pTmpDib->DisplayTransparent(GetDC(), 0, 0, g_stuPaintSet.tranCol);
delete pTmpDib;
CWnd::OnPaint();
}
/*
*--------------------------------------------------------------------------------
* 函数名 : RotateAngle
* 功能 : 旋转浮动窗口
* 参数 : double angle - 旋转的角度
*--------------------------------------------------------------------------------
*/
BOOL CFloatDibWnd::RotateAngle(double angle)
{
// 因为是对源图像进行旋转操作，所以要把上一次旋转角度与此次旋转角度叠加
m_dblPreRotateAngle += angle;
if (m_dblPreRotateAngle > 360)
m_dblPreRotateAngle -= 360;
angle = m_dblPreRotateAngle;
//对pDib操作实际上就是对m_pDib操作
HBITMAP *m_hBitmap ;
CDib * pDib;
pDib = m_pSrcDib->Clone();
CPoint cirpoint;
CRect rect;
GetClientRect(&rect);
//使源DIB缩放成当前画布区大小
pDib->ChangeImageSize(rect.Width(), rect.Height());
m_pDib->ChangeImageSize(rect.Width(), rect.Height());
//得到图形矩形区的中心点坐标值
cirpoint.x = rect.Width()/2;
cirpoint.y = rect.Height()/2;
CClientDC dc(this);
ASSERT_VALID(&dc);
//以下生成一相要操作的源内存设备上下文，它同目的内存上下文数据一致
BITMAP srcbm;
HBITMAP * hBitmap;
CDC srcDC;
CBitmap pBitmap;
// 产生源内存设备情境对象（为避免失真总是选用最初的源DIB）
srcDC.CreateCompatibleDC(NULL);
hBitmap=(HBITMAP *)pDib->GetBitmap()->GetSafeHandle();
srcDC.SetBkMode(TRANSPARENT);
// 将位图选入源内存设备情境对象
srcDC.SelectObject(hBitmap);
GetObject(hBitmap, sizeof(srcbm),&srcbm);
//为使旋转的源和目的设备上下文一致，必须使目的DIB使用m_pDib
CDC * MemDC = m_pDib->BeginPaint(&dc);
MemDC->SetBkMode(TRANSPARENT);
int i,j;
BITMAP m_Bm ;
m_hBitmap = (HBITMAP *)m_pDib->GetBitmap()->GetSafeHandle();
// 将目的位图选入内存设备情境对象(此时源及目的位图数据内容一致)
MemDC->SelectObject(m_hBitmap);
GetObject(m_hBitmap, sizeof(m_Bm),&m_Bm);
//将目的内存设备上下文件全部填充为粉红色
MemDC->FillSolidRect(CRect(0, 0, m_pDib->GetWidth(), m_pDib->GetHeight()),g_stuPaintSet.tranCol);
CPoint point1, point2;
point1.x = m_pDib->GetWidth()/ 2;
point1.y = m_pDib->GetHeight()/ 2;
//开始对内存DC进行旋转操作
for (i = (int) -0.4 * m_Bm.bmWidth; i < (int) 1.4 * m_Bm.bmWidth; i++)
for(j = (int) -0.4 * m_Bm.bmHeight; j < (int) 1.4 * m_Bm.bmHeight; j++)
{
point2.x = i;
point2.y = j;
point2 = CountPoint(point1, point2, angle);
if(srcDC.GetPixel(point2) != g_stuPaintSet.tranCol)
MemDC->StretchBlt(
cirpoint.x + i-point1.x, cirpoint.y + j-point1.y,
1, 1,
&srcDC,
point2.x, point2.y,
1,1,
SRCCOPY
);
}
m_pDib->EndPaint();
if (pDib)
delete pDib;
// 缩放窗口，以与旋转过后的图像大小相匹配
/* int nWidth, nHeight, left, top;
nWidth = m_pDib->GetWidth();
nHeight = m_pDib->GetHeight();
CPoint ptCenter = RectToParentClient().CenterPoint();
left = ptCenter.x - nWidth / 2;
top = ptCenter.y - nHeight / 2;
::MoveWindow(GetSafeHwnd(), left, top, nWidth, nHeight, TRUE);
*/
return TRUE;
}