/* static */
HBITMAP wxDIB::ConvertToBitmap(const BITMAPINFO *pbmi, HDC hdc, void *bits)
{
wxCHECK_MSG( pbmi, 0, wxT("invalid DIB in ConvertToBitmap") );
// 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;
// get the pointer to the start of the real image data if we have a plain
// DIB and not a DIB section (in the latter case the pointer must be passed
// to us by the caller)
if ( !bits )
{
// we must skip over the colour table to get to the image data
//
// colour table either has the real colour data in which case its
// number of entries is given by biClrUsed or is used for masks to be
// used for extracting colour information from true colour bitmaps in
// which case it always have exactly 3 DWORDs
int numColors;
switch ( pbmih->biCompression )
{
case BI_BITFIELDS:
numColors = 3;
break;
case BI_RGB:
// biClrUsed has the number of colors but it may be not initialized at
// all
numColors = pbmih->biClrUsed;
if ( !numColors )
{
numColors = GetNumberOfColours(pbmih->biBitCount);
}
break;
default:
// no idea how it should be calculated for the other cases
numColors = 0;
}
bits = (char *)pbmih + sizeof(*pbmih) + numColors*sizeof(RGBQUAD);
}
HBITMAP hbmp = ::CreateDIBitmap
(
hdc ? hdc // create bitmap compatible
: (HDC) ScreenHDC(), // with this DC
pbmih, // used to get size &c
CBM_INIT, // initialize bitmap bits too
bits, // ... using this data
pbmi, // this is used for palette only
DIB_RGB_COLORS // direct or indexed palette?
);
if ( !hbmp )
{
wxLogLastError(wxT("CreateDIBitmap"));
}
return hbmp;
}
/* static */
bool wxGLCanvasBase::IsDisplaySupported(const int *attribList)
{
// We need a device context to test the pixel format, so get one
// for the root window.
return wxGLCanvas::ChooseMatchingPixelFormat(ScreenHDC(), attribList) > 0;
}
