/// <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);
}
/// <summary>
/// Retrieves an hBitmap for a FreeImage bitmap.
/// Call FreeHbitmap(IntPtr) to free the handle.
/// </summary>
/// <param name="dib">Handle to a FreeImage bitmap.</param>
/// <param name="hdc">A reference device context.
/// Use IntPtr.Zero if no reference is available.</param>
/// <param name="unload">When true dib will be unloaded if the function succeeded.</param>
/// <returns>The hBitmap for the FreeImage bitmap.</returns>
/// <exception cref="ArgumentNullException">
/// <paramref name="dib"/> is null.</exception>
public static unsafe IntPtr GetHbitmap(FIBITMAP dib, IntPtr hdc, bool unload)
{
if (dib.IsNull)
{
throw new ArgumentNullException("dib");
}
IntPtr hBitmap = IntPtr.Zero;
bool release = false;
IntPtr ppvBits = IntPtr.Zero;
// Check if we have destination
if (release = (hdc == IntPtr.Zero))
{
// We don't so request dc
hdc = Gdi.GetDC(IntPtr.Zero);
}
if (hdc != IntPtr.Zero)
{
// Get pointer to the infoheader of the bitmap
IntPtr info = GetInfo(dib);
// Create a bitmap in the dc
hBitmap = Gdi.CreateDIBSection(hdc, info, DIB_RGB_COLORS, out ppvBits, IntPtr.Zero, 0);
if (hBitmap != IntPtr.Zero && ppvBits != IntPtr.Zero)
{
// Copy the data into the dc
CopyMemory(ppvBits, GetBits(dib), (GetHeight(dib) * GetPitch(dib)));
// Success: we unload the bitmap
if (unload)
{
Unload(dib);
}
}
// We have to release the dc
if (release)
{
Gdi.ReleaseDC(IntPtr.Zero, hdc);
}
}
return(hBitmap);
}
/// <summary>
/// Returns an HBITMAP created by the <c>CreateDIBitmap()</c> function which in turn
/// has always the same color depth as the reference DC, which may be provided
/// through <paramref name="hdc"/>. The desktop DC will be used,
/// if <c>IntPtr.Zero</c> DC is specified.
/// Call <see cref="FreeImage.FreeHbitmap(IntPtr)"/> to free the handle.
/// </summary>
/// <param name="dib">Handle to a FreeImage bitmap.</param>
/// <param name="hdc">Handle to a device context.</param>
/// <param name="unload">When true the structure will be unloaded on success.
/// If the function failed and returned false, the bitmap was not unloaded.</param>
/// <returns>If the function succeeds, the return value is a handle to the
/// compatible bitmap. If the function fails, the return value is <see cref="IntPtr.Zero"/>.</returns>
/// <exception cref="ArgumentNullException">
/// <paramref name="dib"/> is null.</exception>
public static IntPtr GetBitmapForDevice(FIBITMAP dib, IntPtr hdc, bool unload)
{
if (dib.IsNull)
{
throw new ArgumentNullException("dib");
}
IntPtr hbitmap = IntPtr.Zero;
bool release = false;
if (release = (hdc == IntPtr.Zero))
{
hdc = Gdi.GetDC(IntPtr.Zero);
}
if (hdc != IntPtr.Zero)
{
hbitmap = Gdi.CreateDIBitmap(
hdc,
GetInfoHeader(dib),
CBM_INIT,
GetBits(dib),
GetInfo(dib),
DIB_RGB_COLORS);
if (unload)
{
Unload(dib);
}
if (release)
{
Gdi.ReleaseDC(IntPtr.Zero, hdc);
}
}
return(hbitmap);
}
/// <summary>
/// Frees a bitmap handle.
/// </summary>
/// <param name="hbitmap">Handle to a bitmap.</param>
/// <returns>True on success, false on failure.</returns>
public static bool FreeHbitmap(IntPtr hbitmap)
{
return(Gdi.DeleteObject(hbitmap));
}
