inline void __stdcall SetAlphaPixel(COLORREF* pBits,
int rect_Width,
int rect_Height,
int x,
int y,
int percent,
int iShadowSize,
COLORREF clrBase,
BOOL bIsRight)
{
// Our direct bitmap access swapped the y coordinate...
y = (rect_Height + iShadowSize) - y;
COLORREF* pColor = (COLORREF*)(bIsRight ? (pBits + (rect_Width + iShadowSize) * (y + 1) - x) : (pBits + (rect_Width + iShadowSize) * y + x));
*pColor = PixelAlpha(*pColor, percent);
if (clrBase == (COLORREF) - 1)
{
return;
}
*pColor = RGB(min(255, (3 * GetRValue(*pColor) + GetBValue(clrBase)) / 4), min(255, (3 * GetGValue(*pColor) + GetGValue(clrBase)) / 4), min(255, (3 * GetBValue(*pColor) + GetRValue(clrBase)) / 4));
}
BOOL WINAPI AlphaBitBlt(HDC hDC, int nDestX, int nDestY, int dwWidth, int dwHeight, HDC hSrcDC,
int nSrcX, int nSrcY, int wSrc, int hSrc, BLENDFUNCTION ftn)
{
HDC hTempDC = ::CreateCompatibleDC(hDC);
if (NULL == hTempDC)
return FALSE;
//Creates Source DIB
LPBITMAPINFO lpbiSrc = NULL;
// Fill in the BITMAPINFOHEADER
lpbiSrc = (LPBITMAPINFO) new BYTE[sizeof(BITMAPINFOHEADER)];
if (lpbiSrc == NULL)
{
::DeleteDC(hTempDC);
return FALSE;
}
lpbiSrc->bmiHeader.biSize = sizeof(BITMAPINFOHEADER);
lpbiSrc->bmiHeader.biWidth = dwWidth;
lpbiSrc->bmiHeader.biHeight = dwHeight;
lpbiSrc->bmiHeader.biPlanes = 1;
lpbiSrc->bmiHeader.biBitCount = 32;
lpbiSrc->bmiHeader.biCompression = BI_RGB;
lpbiSrc->bmiHeader.biSizeImage = dwWidth * dwHeight;
lpbiSrc->bmiHeader.biXPelsPerMeter = 0;
lpbiSrc->bmiHeader.biYPelsPerMeter = 0;
lpbiSrc->bmiHeader.biClrUsed = 0;
lpbiSrc->bmiHeader.biClrImportant = 0;
COLORREF* pSrcBits = NULL;
HBITMAP hSrcDib = CreateDIBSection(
hSrcDC, lpbiSrc, DIB_RGB_COLORS, (void **)&pSrcBits,
NULL, NULL);
if ((NULL == hSrcDib) || (NULL == pSrcBits))
{
delete[] lpbiSrc;
::DeleteDC(hTempDC);
return FALSE;
}
HBITMAP hOldTempBmp = (HBITMAP)::SelectObject(hTempDC, hSrcDib);
::StretchBlt(hTempDC, 0, 0, dwWidth, dwHeight, hSrcDC, nSrcX, nSrcY, wSrc, hSrc, SRCCOPY);
::SelectObject(hTempDC, hOldTempBmp);
//Creates Destination DIB
LPBITMAPINFO lpbiDest = NULL;
// Fill in the BITMAPINFOHEADER
lpbiDest = (LPBITMAPINFO) new BYTE[sizeof(BITMAPINFOHEADER)];
if (lpbiDest == NULL)
{
delete[] lpbiSrc;
::DeleteObject(hSrcDib);
::DeleteDC(hTempDC);
return FALSE;
}
lpbiDest->bmiHeader.biSize = sizeof(BITMAPINFOHEADER);
lpbiDest->bmiHeader.biWidth = dwWidth;
lpbiDest->bmiHeader.biHeight = dwHeight;
lpbiDest->bmiHeader.biPlanes = 1;
lpbiDest->bmiHeader.biBitCount = 32;
lpbiDest->bmiHeader.biCompression = BI_RGB;
lpbiDest->bmiHeader.biSizeImage = dwWidth * dwHeight;
lpbiDest->bmiHeader.biXPelsPerMeter = 0;
lpbiDest->bmiHeader.biYPelsPerMeter = 0;
lpbiDest->bmiHeader.biClrUsed = 0;
lpbiDest->bmiHeader.biClrImportant = 0;
COLORREF* pDestBits = NULL;
HBITMAP hDestDib = CreateDIBSection(
hDC, lpbiDest, DIB_RGB_COLORS, (void **)&pDestBits,
NULL, NULL);
if ((NULL == hDestDib) || (NULL == pDestBits))
{
delete[] lpbiSrc;
::DeleteObject(hSrcDib);
::DeleteDC(hTempDC);
return FALSE;
}
//这段用来绘制透明背景？
::SelectObject(hTempDC, hDestDib);
::BitBlt(hTempDC, 0, 0, dwWidth, dwHeight, hDC, nDestX, nDestY, SRCCOPY);
::SelectObject(hTempDC, hOldTempBmp);
double src_darken;
BYTE nAlpha;
for (int pixel = 0; pixel < dwWidth * dwHeight; pixel++, pSrcBits++, pDestBits++)
{
nAlpha = LOBYTE(*pSrcBits >> 24);
if (nAlpha > 0)
nAlpha++;
src_darken = (double)(nAlpha * ftn.SourceConstantAlpha) / 255.0 / 255.0;
if (src_darken < 0.0) src_darken = 0.0;
*pDestBits = PixelAlpha(*pSrcBits, src_darken, *pDestBits, 1.0 - src_darken);
} //for
::SelectObject(hTempDC, hDestDib);
::BitBlt(hDC, nDestX, nDestY, dwWidth, dwHeight, hTempDC, 0, 0, SRCCOPY);
::SelectObject(hTempDC, hOldTempBmp);
delete[] lpbiDest;
::DeleteObject(hDestDib);
delete[] lpbiSrc;
::DeleteObject(hSrcDib);
::DeleteDC(hTempDC);
return TRUE;
}
void CPPDrawManager::AlphaBitBlt(HDC hDestDC, int nDestX, int nDestY, DWORD dwWidth, DWORD dwHeight, HDC hSrcDC, int nSrcX, int nSrcY, int percent /* = 100 */)
{
_ASSERT ((NULL != hDestDC) || (NULL != hSrcDC));
if (percent >= 100)
{
::BitBlt(hDestDC, nDestX, nDestY, dwWidth, dwHeight, hSrcDC, nSrcX, nSrcY, SRCCOPY);
return;
} //if
HDC hTempDC = ::CreateCompatibleDC(hDestDC);
if (NULL == hTempDC)
return;
//Creates Source DIB
LPBITMAPINFO lpbiSrc;
// Fill in the BITMAPINFOHEADER
lpbiSrc = (LPBITMAPINFO) new BYTE[sizeof(BITMAPINFOHEADER)];
lpbiSrc->bmiHeader.biSize = sizeof(BITMAPINFOHEADER);
lpbiSrc->bmiHeader.biWidth = dwWidth;
lpbiSrc->bmiHeader.biHeight = dwHeight;
lpbiSrc->bmiHeader.biPlanes = 1;
lpbiSrc->bmiHeader.biBitCount = 32;
lpbiSrc->bmiHeader.biCompression = BI_RGB;
lpbiSrc->bmiHeader.biSizeImage = dwWidth * dwHeight;
lpbiSrc->bmiHeader.biXPelsPerMeter = 0;
lpbiSrc->bmiHeader.biYPelsPerMeter = 0;
lpbiSrc->bmiHeader.biClrUsed = 0;
lpbiSrc->bmiHeader.biClrImportant = 0;
COLORREF* pSrcBits = NULL;
HBITMAP hSrcDib = CreateDIBSection (
hSrcDC, lpbiSrc, DIB_RGB_COLORS, (void **)&pSrcBits,
NULL, NULL);
if ((NULL != hSrcDib) && (NULL != pSrcBits))
{
HBITMAP hOldTempBmp = (HBITMAP)::SelectObject (hTempDC, hSrcDib);
::BitBlt (hTempDC, 0, 0, dwWidth, dwHeight, hSrcDC, nSrcX, nSrcY, SRCCOPY);
::SelectObject (hTempDC, hOldTempBmp);
//Creates Destination DIB
LPBITMAPINFO lpbiDest;
// Fill in the BITMAPINFOHEADER
lpbiDest = (LPBITMAPINFO) new BYTE[sizeof(BITMAPINFOHEADER)];
lpbiDest->bmiHeader.biSize = sizeof(BITMAPINFOHEADER);
lpbiDest->bmiHeader.biWidth = dwWidth;
lpbiDest->bmiHeader.biHeight = dwHeight;
lpbiDest->bmiHeader.biPlanes = 1;
lpbiDest->bmiHeader.biBitCount = 32;
lpbiDest->bmiHeader.biCompression = BI_RGB;
lpbiDest->bmiHeader.biSizeImage = dwWidth * dwHeight;
lpbiDest->bmiHeader.biXPelsPerMeter = 0;
lpbiDest->bmiHeader.biYPelsPerMeter = 0;
lpbiDest->bmiHeader.biClrUsed = 0;
lpbiDest->bmiHeader.biClrImportant = 0;
COLORREF* pDestBits = NULL;
HBITMAP hDestDib = CreateDIBSection (
hDestDC, lpbiDest, DIB_RGB_COLORS, (void **)&pDestBits,
NULL, NULL);
if ((NULL != hDestDib) && (NULL != pDestBits))
{
::SelectObject (hTempDC, hDestDib);
::BitBlt (hTempDC, 0, 0, dwWidth, dwHeight, hDestDC, nDestX, nDestY, SRCCOPY);
::SelectObject (hTempDC, hOldTempBmp);
double src_darken = (double)percent / 100.0;
double dest_darken = 1.0 - src_darken;
for (DWORD pixel = 0; pixel < dwWidth * dwHeight; pixel++, pSrcBits++, pDestBits++)
{
*pDestBits = PixelAlpha(*pSrcBits, src_darken, *pDestBits, dest_darken);
} //for
::SelectObject (hTempDC, hDestDib);
::BitBlt (hDestDC, nDestX, nDestY, dwWidth, dwHeight, hTempDC, 0, 0, SRCCOPY);
::SelectObject (hTempDC, hOldTempBmp);
delete lpbiDest;
::DeleteObject(hDestDib);
} //if
delete lpbiSrc;
::DeleteObject(hSrcDib);
} //if
::DeleteDC(hTempDC);
} //End AlphaBitBlt
