/// <summary>
/// Creates a FreeImage DIB from a Device Context/Compatible Bitmap.
/// </summary>
/// <param name="hbitmap">Handle to the bitmap.</param>
/// <param name="hdc">Handle to a device context.</param>
/// <returns>Handle to a FreeImage bitmap.</returns>
/// <exception cref="ArgumentNullException">
/// <paramref name="hbitmap"/> is null.</exception>
public unsafe static FIBITMAP CreateFromHbitmap(IntPtr hbitmap, IntPtr hdc)
{
if (hbitmap == IntPtr.Zero)
{
throw new ArgumentNullException("hbitmap");
}
FIBITMAP dib = new FIBITMAP();
BITMAP bm;
uint colors;
bool release;
if (Gdi.GetObject(hbitmap, sizeof(BITMAP), (IntPtr)(&bm)) != 0)
{
dib = Allocate(bm.bmWidth, bm.bmHeight, bm.bmBitsPixel, 0, 0, 0);
if (!dib.IsNull)
{
colors = GetColorsUsed(dib);
if (release = (hdc == IntPtr.Zero))
{
hdc = Gdi.GetDC(IntPtr.Zero);
}
if (Gdi.GetDIBits(
hdc,
hbitmap,
0,
(uint)bm.bmHeight,
GetBits(dib),
GetInfo(dib),
DIB_RGB_COLORS) != 0)
{
if (colors != 0)
{
BITMAPINFOHEADER *bmih = (BITMAPINFOHEADER *)GetInfo(dib);
bmih[0].biClrImportant = bmih[0].biClrUsed = colors;
}
}
else
{
UnloadEx(ref dib);
}
if (release)
{
Gdi.ReleaseDC(IntPtr.Zero, hdc);
}
}
}
return(dib);
}
