Question

我有一个SDI mfc应用程序，其中加载了位图图像，我想旋转该位图90Deg，180Deg＆amp; 270Deg。能够旋转180度。但我被困在90和270度。这是代码。

void CBmpView::OnRotate180() 
{
BYTE ptempBit ;
CBmpViewerDoc* pDoc = GetDocument();
ASSERT_VALID(pDoc);

int nLenght = (pDoc->dwBitsSize);
if(pBitsView != NULL){
    DeleteObject(pBitsView);    
}
if(pDoc->m_bRotationFlag == FALSE){
pDoc->m_bmpHandle = CreateDIBSection(NULL, pDoc->m_bitmapinfo,DIB_RGB_COLORS,
    (void **)&pBitsView, NULL, 0);
CopyMemory(pBitsView,pDoc->m_pBits,pDoc->dwBitsSize);

for(int i=0; i < ((nLenght-1)) ; i++ ){
    ptempBit = pBitsView[i];
    pBitsView[i] = pBitsView[nLenght - 1];
    pBitsView[nLenght - 1] = ptempBit;
    nLenght --;
}
pDoc->m_bRotationFlag = TRUE;
Invalidate();
}else if(pDoc->m_bRotationFlag == TRUE){
    pDoc->m_bmpHandle = CreateDIBSection(NULL, pDoc->m_bitmapinfo,DIB_RGB_COLORS,
        (void **)&pBitsView, NULL, 0);
    CopyMemory(pBitsView,pDoc->m_pBits,pDoc->dwBitsSize);
    pDoc->m_bRotationFlag = FALSE;
    Invalidate();
}
}

请告诉我是否可以使用任何其他方法。提前致谢

Answer 1

只是一些伪代码。让我们假设一个带有行和列的iMaxRows和iMaxCols的网格。应该是：

// Sourcegrid is always 
Pixels oldGrid[iMaxRows][iMaxCols]

+

// 90°
Pixels newGrid[iMaxCols][iMaxRows];
for (int iRow=0; iRow<iMaxRows; ++iRow)
{
  for (int iCol=0; iCol<iMaxCols; ++iCol)
    newGrid[iCol][iMaxRow-iRow-1] = oldGrid[iRow][iCol];
}

+

// 180°
Pixels newGrid[iMaxRows][iMaxCols];
for (int iRow=0; iRow<iMaxRows; ++iRow)
{
  for (int iCol=0; iCol<iMaxCols; ++iCol)
     newGrid[iMaxRow-iRow-1][iMaxCols-iCol-1] = oldGrid[iRow][iCol];
}

+

// 270°
Pixels newGrid[iMaxCols][iMaxRows];
for (int iRow=0; iRow<iMaxRows; ++iRow)
{
  for (int iCol=0; iCol<iMaxCols; ++iCol)
     newGrid[iMaxCols-iCol-1][iRow] = oldGrid[iRow][iCol];
}

在MFC中旋转位图90deg，270deg

1 个答案: