wglCreateContext in C# failing but not in managed C++
- by SeeR
I'm trying to use opengl in C#. I have following code which fails with error 2000 ERROR_INVALID_PIXEL_FORMAT
First definitions:
[DllImport("user32.dll", CharSet = CharSet.Auto, SetLastError = true, ExactSpelling = true)]
public static extern IntPtr GetDC(IntPtr hWnd);
[StructLayout(LayoutKind.Sequential)]
public struct PIXELFORMATDESCRIPTOR
{
public void Init()
{
nSize = (ushort) Marshal.SizeOf(typeof (PIXELFORMATDESCRIPTOR));
nVersion = 1;
dwFlags = PFD_FLAGS.PFD_DRAW_TO_WINDOW | PFD_FLAGS.PFD_SUPPORT_OPENGL | PFD_FLAGS.PFD_DOUBLEBUFFER | PFD_FLAGS.PFD_SUPPORT_COMPOSITION;
iPixelType = PFD_PIXEL_TYPE.PFD_TYPE_RGBA;
cColorBits = 24;
cRedBits = cRedShift = cGreenBits = cGreenShift = cBlueBits = cBlueShift = 0;
cAlphaBits = cAlphaShift = 0;
cAccumBits = cAccumRedBits = cAccumGreenBits = cAccumBlueBits = cAccumAlphaBits = 0;
cDepthBits = 32;
cStencilBits = cAuxBuffers = 0;
iLayerType = PFD_LAYER_TYPES.PFD_MAIN_PLANE;
bReserved = 0;
dwLayerMask = dwVisibleMask = dwDamageMask = 0;
}
ushort nSize;
ushort nVersion;
PFD_FLAGS dwFlags;
PFD_PIXEL_TYPE iPixelType;
byte cColorBits;
byte cRedBits;
byte cRedShift;
byte cGreenBits;
byte cGreenShift;
byte cBlueBits;
byte cBlueShift;
byte cAlphaBits;
byte cAlphaShift;
byte cAccumBits;
byte cAccumRedBits;
byte cAccumGreenBits;
byte cAccumBlueBits;
byte cAccumAlphaBits;
byte cDepthBits;
byte cStencilBits;
byte cAuxBuffers;
PFD_LAYER_TYPES iLayerType;
byte bReserved;
uint dwLayerMask;
uint dwVisibleMask;
uint dwDamageMask;
}
[Flags]
public enum PFD_FLAGS : uint
{
PFD_DOUBLEBUFFER = 0x00000001,
PFD_STEREO = 0x00000002,
PFD_DRAW_TO_WINDOW = 0x00000004,
PFD_DRAW_TO_BITMAP = 0x00000008,
PFD_SUPPORT_GDI = 0x00000010,
PFD_SUPPORT_OPENGL = 0x00000020,
PFD_GENERIC_FORMAT = 0x00000040,
PFD_NEED_PALETTE = 0x00000080,
PFD_NEED_SYSTEM_PALETTE = 0x00000100,
PFD_SWAP_EXCHANGE = 0x00000200,
PFD_SWAP_COPY = 0x00000400,
PFD_SWAP_LAYER_BUFFERS = 0x00000800,
PFD_GENERIC_ACCELERATED = 0x00001000,
PFD_SUPPORT_DIRECTDRAW = 0x00002000,
PFD_DIRECT3D_ACCELERATED = 0x00004000,
PFD_SUPPORT_COMPOSITION = 0x00008000,
PFD_DEPTH_DONTCARE = 0x20000000,
PFD_DOUBLEBUFFER_DONTCARE = 0x40000000,
PFD_STEREO_DONTCARE = 0x80000000
}
public enum PFD_LAYER_TYPES : byte
{
PFD_MAIN_PLANE = 0,
PFD_OVERLAY_PLANE = 1,
PFD_UNDERLAY_PLANE = 255
}
public enum PFD_PIXEL_TYPE : byte
{
PFD_TYPE_RGBA = 0,
PFD_TYPE_COLORINDEX = 1
}
[DllImport("gdi32.dll", CharSet = CharSet.Auto, SetLastError = true, ExactSpelling = true)]
public static extern int ChoosePixelFormat(IntPtr hdc, [In] ref PIXELFORMATDESCRIPTOR ppfd);
[DllImport("gdi32.dll", CharSet = CharSet.Auto, SetLastError = true, ExactSpelling = true)]
public static extern bool SetPixelFormat(IntPtr hdc, int iPixelFormat, ref PIXELFORMATDESCRIPTOR ppfd);
[DllImport("opengl32.dll", CharSet = CharSet.Auto, SetLastError = true, ExactSpelling = true)]
public static extern IntPtr wglCreateContext(IntPtr hDC);
And now the code that fails:
IntPtr dc = Win.GetDC(hwnd);
var pixelformatdescriptor = new GL.PIXELFORMATDESCRIPTOR();
pixelformatdescriptor.Init();
var pixelFormat = GL.ChoosePixelFormat(dc, ref pixelformatdescriptor);
if(!GL.SetPixelFormat(dc, pixelFormat, ref pixelformatdescriptor))
throw new Win32Exception(Marshal.GetLastWin32Error());
IntPtr hglrc;
if((hglrc = GL.wglCreateContext(dc)) == IntPtr.Zero)
throw new Win32Exception(Marshal.GetLastWin32Error()); //<----- here I have exception
the same code in managed C++ is working
HDC dc = GetDC(hWnd);
PIXELFORMATDESCRIPTOR pf;
pf.nSize = sizeof(PIXELFORMATDESCRIPTOR);
pf.nVersion = 1;
pf.dwFlags = PFD_DRAW_TO_WINDOW | PFD_SUPPORT_OPENGL | PFD_DOUBLEBUFFER | PFD_SUPPORT_COMPOSITION;
pf.cColorBits = 24;
pf.cRedBits = pf.cRedShift = pf.cGreenBits = pf.cGreenShift = pf.cBlueBits = pf.cBlueShift = 0;
pf.cAlphaBits = pf.cAlphaShift = 0;
pf.cAccumBits = pf.cAccumRedBits = pf.cAccumGreenBits = pf.cAccumBlueBits = pf.cAccumAlphaBits = 0;
pf.cDepthBits = 32;
pf.cStencilBits = pf.cAuxBuffers = 0;
pf.iLayerType = PFD_MAIN_PLANE;
pf.bReserved = 0;
pf.dwLayerMask = pf.dwVisibleMask = pf.dwDamageMask = 0;
int ipf = ChoosePixelFormat(dc, &pf);
SetPixelFormat(dc, ipf, &pf);
HGLRC hglrc = wglCreateContext(dc);
I've tried it on VIsta 64-bit with ATI graphic card and on Windows XP 32-bit with Nvidia with the same result in both cases.
Also I want to mention that I don't want to use any already written framework for it.
Can anyone show me where is the bug in C# code that is causing the exception?
