+ HBITMAP hbmpMask = 0;
+
+#if wxUSE_PALETTE
+ HPALETTE oldPal = 0;
+#endif // wxUSE_PALETTE
+
+ // do we have AlphaBlend() and company in the headers?
+#ifdef AC_SRC_OVER
+ if ( bmp.HasAlpha() )
+ {
+ // yes, now try to see if we have it during run-time
+
+ typedef BOOL (WINAPI *AlphaBlend_t)(HDC,int,int,int,int,
+ HDC,int,int,int,int,
+ BLENDFUNCTION);
+
+ // bitmaps can be drawn only from GUI thread so there is no need to
+ // protect this static variable from multiple threads
+ static bool s_triedToLoad = FALSE;
+ static AlphaBlend_t pfnAlphaBlend = NULL;
+ if ( !s_triedToLoad )
+ {
+ s_triedToLoad = TRUE;
+
+ // don't give errors about the DLL being unavailable, we're
+ // prepared to handle this
+ wxLogNull nolog;
+
+ wxDynamicLibrary dll(_T("msimg32.dll"));
+ if ( dll.IsLoaded() )
+ {
+ pfnAlphaBlend = (AlphaBlend_t)dll.GetSymbol(_T("AlphaBlend"));
+ if ( pfnAlphaBlend )
+ {
+ // we must keep the DLL loaded if we want to be able to
+ // call AlphaBlend() so just never unload it at all, not a
+ // big deal
+ dll.Detach();
+ }
+ }
+ }
+
+ if ( pfnAlphaBlend )
+ {
+ MemoryHDC hdcMem;
+ SelectInHDC select(hdcMem, GetHbitmapOf(bmp));
+
+#ifndef AC_SRC_ALPHA
+ #define AC_SRC_ALPHA 1
+#endif
+
+ BLENDFUNCTION bf;
+ bf.BlendOp = AC_SRC_OVER;
+ bf.BlendFlags = 0;
+ bf.SourceConstantAlpha = 0xff;
+ bf.AlphaFormat = AC_SRC_ALPHA;
+
+ if ( !pfnAlphaBlend(GetHdc(), x, y, width, height,
+ hdcMem, 0, 0, width, height,
+ bf) )
+ {
+ wxLogLastError(_T("AlphaBlend"));
+ }
+
+ return;
+ }
+ //else: AlphaBlend() not available
+ }
+#endif // defined(AC_SRC_OVER)
+
+ if ( useMask )
+ {
+ wxMask *mask = bmp.GetMask();
+ if ( mask )
+ hbmpMask = (HBITMAP)mask->GetMaskBitmap();
+
+ if ( !hbmpMask )
+ {
+ // don't give assert here because this would break existing
+ // programs - just silently ignore useMask parameter
+ useMask = FALSE;
+ }
+ }
+ if ( useMask )
+ {
+#ifdef __WIN32__
+ // use MaskBlt() with ROP which doesn't do anything to dst in the mask
+ // points
+ // On some systems, MaskBlt succeeds yet is much much slower
+ // than the wxWindows fall-back implementation. So we need
+ // to be able to switch this on and off at runtime.
+ bool ok = FALSE;
+#if wxUSE_SYSTEM_OPTIONS
+ if (wxSystemOptions::GetOptionInt(wxT("no-maskblt")) == 0)
+#endif
+ {
+ HDC cdc = GetHdc();
+ HDC hdcMem = ::CreateCompatibleDC(GetHdc());
+ HGDIOBJ hOldBitmap = ::SelectObject(hdcMem, GetHbitmapOf(bmp));
+#if wxUSE_PALETTE
+ wxPalette *pal = bmp.GetPalette();
+ if ( pal && ::GetDeviceCaps(cdc,BITSPIXEL) <= 8 )
+ {
+ oldPal = ::SelectPalette(hdcMem, GetHpaletteOf(*pal), FALSE);
+ ::RealizePalette(hdcMem);
+ }
+#endif // wxUSE_PALETTE
+
+ ok = ::MaskBlt(cdc, x, y, width, height,
+ hdcMem, 0, 0,
+ hbmpMask, 0, 0,
+ MAKEROP4(SRCCOPY, DSTCOPY)) != 0;
+
+#if wxUSE_PALETTE
+ if (oldPal)
+ ::SelectPalette(hdcMem, oldPal, FALSE);
+#endif // wxUSE_PALETTE
+
+ ::SelectObject(hdcMem, hOldBitmap);
+ ::DeleteDC(hdcMem);
+ }
+
+ if ( !ok )
+#endif // Win32
+ {
+ // Rather than reproduce wxDC::Blit, let's do it at the wxWin API
+ // level
+ wxMemoryDC memDC;
+ memDC.SelectObject(bmp);
+
+ Blit(x, y, width, height, &memDC, 0, 0, wxCOPY, useMask);
+
+ memDC.SelectObject(wxNullBitmap);
+ }
+ }
+ else // no mask, just use BitBlt()
projects / wxWidgets.git / blobdiff