-static size_t wxGetNumOfBitmapColors(size_t bitsPerPixel)
-{
- switch ( bitsPerPixel )
- {
- case 1:
- // monochrome bitmap, 2 entries
- return 2;
-
- case 4:
- return 16;
-
- case 8:
- return 256;
-
- case 24:
- // may be used with 24bit bitmaps, but we don't use it here - fall
- // through
-
- case 16:
- case 32:
- // bmiColors not used at all with these bitmaps
- return 0;
-
- default:
- wxFAIL_MSG( wxT("unknown bitmap format") );
- return 0;
- }
-}
-
-size_t wxConvertBitmapToDIB(LPBITMAPINFO pbi, const wxBitmap& bitmap)
-{
- wxASSERT_MSG( bitmap.Ok(), wxT("invalid bmp can't be converted to DIB") );
-
- // shouldn't be selected into a DC or GetDIBits() would fail
- wxASSERT_MSG( !bitmap.GetSelectedInto(),
- wxT("can't copy bitmap selected into wxMemoryDC") );
-
- // prepare all the info we need
- BITMAP bm;
- HBITMAP hbmp = (HBITMAP)bitmap.GetHBITMAP();
- if ( !GetObject(hbmp, sizeof(bm), &bm) )
- {
- wxLogLastError(wxT("GetObject(bitmap)"));
-
- return 0;
- }
-
- // calculate the number of bits per pixel and the number of items in
- // bmiColors array (whose meaning depends on the bitmap format)
- WORD biBits = bm.bmPlanes * bm.bmBitsPixel;
- WORD biColors = (WORD)wxGetNumOfBitmapColors(biBits);
-
- BITMAPINFO bi2;
-
- bool wantSizeOnly = pbi == NULL;
- if ( wantSizeOnly )
- pbi = &bi2;
-
- // just for convenience
- BITMAPINFOHEADER& bi = pbi->bmiHeader;
-
- bi.biSize = sizeof(BITMAPINFOHEADER);
- bi.biWidth = bm.bmWidth;
- bi.biHeight = bm.bmHeight;
- bi.biPlanes = 1;
- bi.biBitCount = biBits;
- bi.biCompression = BI_RGB;
- bi.biSizeImage = 0;
- bi.biXPelsPerMeter = 0;
- bi.biYPelsPerMeter = 0;
- bi.biClrUsed = 0;
- bi.biClrImportant = 0;
-
- // memory we need for BITMAPINFO only
- DWORD dwLen = bi.biSize + biColors * sizeof(RGBQUAD);
-
- // first get the image size
- ScreenHDC hdc;
- if ( !GetDIBits(hdc, hbmp, 0, bi.biHeight, NULL, pbi, DIB_RGB_COLORS) )
- {
- wxLogLastError(wxT("GetDIBits(NULL)"));
-
- return 0;
- }
-
- if ( wantSizeOnly )
- {
- // size of the header + size of the image
- return dwLen + bi.biSizeImage;
- }
-
- // and now copy the bits
- void *image = (char *)pbi + dwLen;
- if ( !GetDIBits(hdc, hbmp, 0, bi.biHeight, image, pbi, DIB_RGB_COLORS) )
- {
- wxLogLastError(wxT("GetDIBits"));
-
- return 0;
- }
-
- return dwLen + bi.biSizeImage;
-}
-
-wxBitmap wxConvertDIBToBitmap(const LPBITMAPINFO pbmi)
-{
- // here we get BITMAPINFO struct followed by the actual bitmap bits and
- // BITMAPINFO starts with BITMAPINFOHEADER followed by colour info
- const BITMAPINFOHEADER *pbmih = &pbmi->bmiHeader;
-
- // biClrUsed has the number of colors, unless it's 0
- int numColors = pbmih->biClrUsed;
- if (numColors==0)
- {
- numColors = wxGetNumOfBitmapColors(pbmih->biBitCount);
- }
-
- // offset of image from the beginning of the header
- DWORD ofs = numColors * sizeof(RGBQUAD);
- void *image = (char *)pbmih + sizeof(BITMAPINFOHEADER) + ofs;
-
- ScreenHDC hdc;
- HBITMAP hbmp = CreateDIBitmap(hdc, pbmih, CBM_INIT,
- image, pbmi, DIB_RGB_COLORS);
- if ( !hbmp )
- {
- wxLogLastError(wxT("CreateDIBitmap"));
- }
-
- wxBitmap bitmap(pbmih->biWidth, pbmih->biHeight, pbmih->biBitCount);
- bitmap.SetHBITMAP((WXHBITMAP)hbmp);
-
- return bitmap;
-}
-
projects / wxWidgets.git / blobdiff