private bool bFillBitmapInfo(IntPtr hdc, IntPtr hpal, ref System.Drawing.NativeMethods.BITMAPINFO_FLAT pbmi)
{
IntPtr zero = IntPtr.Zero;
bool flag = false;
try
{
zero = SafeNativeMethods.CreateCompatibleBitmap(new HandleRef(null, hdc), 1, 1);
if (zero == IntPtr.Zero)
{
throw new OutOfMemoryException(System.Drawing.SR.GetString("GraphicsBufferQueryFail"));
}
pbmi.bmiHeader_biSize = Marshal.SizeOf(typeof(System.Drawing.NativeMethods.BITMAPINFOHEADER));
pbmi.bmiColors = new byte[0x400];
SafeNativeMethods.GetDIBits(new HandleRef(null, hdc), new HandleRef(null, zero), 0, 0, IntPtr.Zero, ref pbmi, 0);
if (pbmi.bmiHeader_biBitCount <= 8)
{
return(this.bFillColorTable(hdc, hpal, ref pbmi));
}
if (pbmi.bmiHeader_biCompression == 3)
{
SafeNativeMethods.GetDIBits(new HandleRef(null, hdc), new HandleRef(null, zero), 0, pbmi.bmiHeader_biHeight, IntPtr.Zero, ref pbmi, 0);
}
flag = true;
}
finally
{
if (zero != IntPtr.Zero)
{
SafeNativeMethods.DeleteObject(new HandleRef(null, zero));
zero = IntPtr.Zero;
}
}
return(flag);
}
private void DisposeBitmap()
{
if (this.dib != IntPtr.Zero)
{
SafeNativeMethods.DeleteObject(new HandleRef(this, this.dib));
this.dib = IntPtr.Zero;
}
}
/// <summary>
/// Fills in the fields of a BITMAPINFO so that we can create a bitmap
/// that matches the format of the display.
///
/// This is done by creating a compatible bitmap and calling GetDIBits
/// to return the color masks. This is done with two calls. The first
/// call passes in biBitCount = 0 to GetDIBits which will fill in the
/// base BITMAPINFOHEADER data. The second call to GetDIBits (passing
/// in the BITMAPINFO filled in by the first call) will return the color
/// table or bitmasks, as appropriate.
/// </summary>
/// <returns>True if successful, false otherwise.</returns>
private bool FillBitmapInfo(IntPtr hdc, IntPtr hpal, ref NativeMethods.BITMAPINFO_FLAT pbmi)
{
IntPtr hbm = IntPtr.Zero;
bool bRet = false;
try
{
// Create a dummy bitmap from which we can query color format info
// about the device surface.
hbm = SafeNativeMethods.CreateCompatibleBitmap(new HandleRef(null, hdc), 1, 1);
if (hbm == IntPtr.Zero)
{
throw new OutOfMemoryException(SR.GraphicsBufferQueryFail);
}
pbmi.bmiHeader_biSize = Marshal.SizeOf(typeof(NativeMethods.BITMAPINFOHEADER));
pbmi.bmiColors = new byte[NativeMethods.BITMAPINFO_MAX_COLORSIZE * 4];
// Call first time to fill in BITMAPINFO header.
SafeNativeMethods.GetDIBits(new HandleRef(null, hdc),
new HandleRef(null, hbm),
0,
0,
IntPtr.Zero,
ref pbmi,
NativeMethods.DIB_RGB_COLORS);
if (pbmi.bmiHeader_biBitCount <= 8)
{
bRet = FillColorTable(hdc, hpal, ref pbmi);
}
else
{
if (pbmi.bmiHeader_biCompression == NativeMethods.BI_BITFIELDS)
{
// Call a second time to get the color masks.
SafeNativeMethods.GetDIBits(new HandleRef(null, hdc),
new HandleRef(null, hbm),
0,
pbmi.bmiHeader_biHeight,
IntPtr.Zero,
ref pbmi,
NativeMethods.DIB_RGB_COLORS);
}
bRet = true;
}
}
finally
{
if (hbm != IntPtr.Zero)
{
SafeNativeMethods.DeleteObject(new HandleRef(null, hbm));
hbm = IntPtr.Zero;
}
}
return(bRet);
}
/// <summary>
/// Disposes the bitmap, will ASSERT if bitmap is being used (checks oldbitmap). if ASSERTed, call DisposeDC() first.
/// </summary>
private void DisposeBitmap()
{
if (_dib != IntPtr.Zero)
{
Debug.Assert(_oldBitmap == IntPtr.Zero);
SafeNativeMethods.DeleteObject(new HandleRef(this, _dib));
_dib = IntPtr.Zero;
}
}
/// <devdoc>
/// Disposes the bitmap, will ASSERT if bitmap is being used (checks oldbitmap).
/// if ASSERTed, call DisposeDC() first.
/// </devdoc>
private void DisposeBitmap()
{
if (dib != IntPtr.Zero)
{
Debug.Assert(oldBitmap == IntPtr.Zero);
Debug.WriteLineIf(DoubleBuffering.TraceVerbose, "delete dib");
SafeNativeMethods.DeleteObject(new HandleRef(this, dib));
dib = IntPtr.Zero;
}
}
