【C++】GDI+图像编程入门（三、图像的膨胀弹出显示编程）

C++本人也是初学者，很多地方也不是很懂，写博客的原因主要有以下三个原因：

1.对于学习的得思路和资料进行整理

2.为比我还菜的朋友提供一定得参考

3.请优快云高手对我写的代码进行批评和指正。

图像的膨胀主要是利用光栅效果中的StretchBlt 的SRCCOPY光栅效果来制作，简单易懂。

图像水平膨胀式显示效果：

//图像水平膨胀式显示效果
void CGPShowView::OnHpopup()
{
if(m_ImageShow==NULL)
{
  MessageBox("没有图像文件是不能执行此项操作的!","信息提示",MB_OK);
  return;
}
CWaitCursor WaitCursor;
Invalidate();
CImage *pImage=&m_ImageShow;
int Width=pImage->GetWidth();
int Height=pImage->GetHeight();
CRect crect;
this->GetClientRect(&crect);
Width=Width<crect.Width()?Width:crect.Width();
Height=Height<crect.Height()?Height:crect.Height();
CMainFrame *pWnd=(CMainFrame*)AfxGetMainWnd();
pWnd->m_wndStatusBar.SetPaneText(0,"正在演示的是图像水平膨胀式显示效果",TRUE);
CClientDC *pDC=new CClientDC(this);
for(int i=0;i<Width;i+=Width/30)
{
  pImage->StretchBlt(pDC->m_hDC,CRect(CPoint(i,0),CPoint(0,Height)),CRect(CPoint(0,0),CPoint(Width,Height)),SRCCOPY);
  Sleep(10);
}
delete pDC;
}

图像垂直膨胀式显示效果：

//图像垂直膨胀式显示效果
void CGPShowView::OnVpopup()
{
if(m_ImageShow==NULL)
{
  MessageBox("没有图像文件是不能执行此项操作的!","信息提示",MB_OK);
  return;
}
CWaitCursor WaitCursor;
Invalidate();
CImage *pImage=&m_ImageShow;
int Width=pImage->GetWidth();
int Height=pImage->GetHeight();
CRect crect;
this->GetClientRect(&crect);
Width=Width<crect.Width()?Width:crect.Width();
Height=Height<crect.Height()?Height:crect.Height();
CMainFrame *pWnd=(CMainFrame*)AfxGetMainWnd();
pWnd->m_wndStatusBar.SetPaneText(0,"正在演示的是图像垂直膨胀式显示效果",TRUE);
CClientDC *pDC=new CClientDC(this);
for(int i=0;i<Height;i+=Height/30)
{
  pImage->StretchBlt(pDC->m_hDC,CRect(CPoint(Width,Height-i),CPoint(0,Height)),CRect(CPoint(0,0),CPoint(Width,Height)),SRCCOPY);
  Sleep(30);
}
delete pDC;
}

图像中心膨胀式显示效果：

//图像中心膨胀式显示效果
void CGPShowView::OnCpopup()
{
if(m_ImageShow==NULL)
{
  MessageBox("没有图像文件是不能执行此项操作的!","信息提示",MB_OK);
  return;
}
CWaitCursor WaitCursor;
Invalidate();
CImage *pImage=&m_ImageShow;
int Width=pImage->GetWidth();
int Height=pImage->GetHeight();
CRect crect;
this->GetClientRect(&crect);
Width=Width<crect.Width()?Width:crect.Width();
Height=Height<crect.Height()?Height:crect.Height();
CMainFrame *pWnd=(CMainFrame*)AfxGetMainWnd();
pWnd->m_wndStatusBar.SetPaneText(0,"正在演示的是图像中心膨胀式显示效果",TRUE);
CClientDC *pDC=new CClientDC(this);
for(int i=Height/4;i<Height;i+=Height/30)
{
  pImage->StretchBlt(pDC->m_hDC, CRect(CPoint(Width/2-i*Width/Height,Height/2-i),CPoint(Width/2+i*Width/Height,Height/2+i)),CRect(CPoint(0,0),CPoint(Width,Height)),SRCCOPY);
  Sleep(30);
}
delete pDC;
}

图像部分膨胀式显示效果：

//图像部分膨胀式显示效果
void CGPShowView::OnPpopup()
{
if(m_ImageShow==NULL)
{
  MessageBox("没有图像文件是不能执行此项操作的!","信息提示",MB_OK);
  return;
}
CWaitCursor WaitCursor;
Invalidate();
CImage *pImage=&m_ImageShow;
int Width=pImage->GetWidth();
int Height=pImage->GetHeight();
CRect crect;
this->GetClientRect(&crect);
Width=Width<crect.Width()?Width:crect.Width();
Height=Height<crect.Height()?Height:crect.Height();
CMainFrame *pWnd=(CMainFrame*)AfxGetMainWnd();
pWnd->m_wndStatusBar.SetPaneText(0,"正在演示的是图像部分膨胀式显示效果",TRUE);
CClientDC *pDC=new CClientDC(this);
pImage->Draw(pDC->m_hDC,CPoint(0,0));
for(int i=Width/3;i<Width;i++)
{
  pImage->StretchBlt(pDC->m_hDC,CRect(0,0,i,(double)Height/Width*i),CRect(0,0,Width/3,Height/3));
  Sleep(10);
}
pImage->Draw(pDC->m_hDC,CPoint(0,0));
for(int i=Width/3;i>0;i--)
{
  pImage->StretchBlt(pDC->m_hDC,CRect(i,0,Width-i,(double)Height/Width*(Width-i)),CRect(Width/3,0,Width*2/3,Height/3));
  Sleep(20);
}
pImage->Draw(pDC->m_hDC,CPoint(0,0));
for(int i=Width*2/3;i>0;i--)
{
  pImage->StretchBlt(pDC->m_hDC,CRect(i,0,Width,(double)Height/Width*(Width-i)),CRect(Width*2/3,0,Width,Height/3));
  Sleep(10);
}
delete pDC;
}

代码很简单，但是图像的效果还是不错，建议新手动手写写。

StretchBlt最后一个参数（dwRop）

Specifies the raster operation to be performed. Raster operation codes define how GDI combines colors in output operations that involve a current brush, a possible source bitmap, and a destination bitmap. This parameter may be one of the following values:

执行指定的光栅操作，光栅操作定义了用最近的画刷将源图用颜色集合输出目标图。参数可以为下面的值。

BLACKNESS Turns all output black.
DSTINVERT Inverts the destination bitmap.
MERGECOPY Combines the pattern and the source bitmap using the Boolean AND operator.
MERGEPAINT Combines the inverted source bitmap with the destination bitmap using the Boolean OR operator.
NOTSRCCOPY Copies the inverted source bitmap to the destination.
NOTSRCERASE Inverts the result of combining the destination and source bitmaps using the Boolean OR operator.
PATCOPY Copies the pattern to the destination bitmap.
PATINVERT Combines the destination bitmap with the pattern using the Boolean XOR operator.
PATPAINT Combines the inverted source bitmap with the pattern using the Boolean OR operator. Combines the result of this operation with the destination bitmap using the Boolean OR operator.
SRCAND Combines pixels of the destination and source bitmaps using the Boolean AND operator.
SRCCOPY Copies the source bitmap to the destination bitmap.
SRCERASE Inverts the destination bitmap and combines the result with the source bitmap using the Boolean AND operator.
SRCINVERT Combines pixels of the destination and source bitmaps using the Boolean XOR operator.
SRCPAINT Combines pixels of the destination and source bitmaps using the Boolean OR operator.
WHITENESS Turns all output white.