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  1. POwglCreateContext in C# failing but not in managed C++
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    copied!<p>I'm trying to use opengl in C#. I have following code which fails with error 2000 ERROR_INVALID_PIXEL_FORMAT<br> First definitions:</p> <pre><code>[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); </code></pre> <p>And now the code that fails:</p> <pre><code>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()); //&lt;----- here I have exception </code></pre> <p>the same code in managed C++ is working</p> <pre><code>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, &amp;pf); SetPixelFormat(dc, ipf, &amp;pf); HGLRC hglrc = wglCreateContext(dc); </code></pre> <p>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.<br> Also I want to mention that I don't want to use any already written framework for it.<br> <br> Can anyone show me where is the bug in C# code that is causing the exception?<br> <br></p>
 

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