我正在尝试在C#中使用opengl.我有以下代码失败,错误2000 ERROR_INVALID_PIXEL_FORMAT
首先定义:
[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);
现在代码失败了:
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
托管C++中的相同代码正在运行
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);
我已经在带有ATI显卡的VIsta 64位和带有Nvidia的32位Windows XP上尝试过,两种情况都有相同的结果.
另外我想提一下,我不想使用任何已编写的框架.
任何人都可以告诉我导致异常的C#代码中的错误在哪里?
找到解决方案
问题非常奇怪丑陋而且很难找到.在互联网上的Somwhere我发现当你在编译c ++应用程序时链接opengl32.lib时,它必须放在gdi32.lib之前.原因是(假设)opengl32.dll覆盖了ChoosePixelFormat和SetPixelFormat函数(可能更多:-).正如我在c ++版本中发现的那样,意外情况就是如此.
嘿,但是如何在C#中做到这一点
经过几天的搜索,我发现在tao框架中他们使用kernel32.dll LoadLibrary()函数解决了它并在调用SetPixelFormat之前加载了opengl32.dll
public static bool SetPixelFormat(IntPtr deviceContext, int pixelFormat, ref PIXELFORMATDESCRIPTOR pixelFormatDescriptor) { Kernel.LoadLibrary("opengl32.dll"); return _SetPixelFormat(deviceContext, pixelFormat, ref pixelFormatDescriptor); }
所以我们知道必须在gdi32.dll之前加载opengl32.dll,还有其他方法可以做到这一点.之后我想我们可以从opengl32.dll调用一些NOP函数来加载它.例如:
[DllImport("opengl32.dll", EntryPoint = "glGetString", CharSet = CharSet.Auto, SetLastError = true, ExactSpelling = true)] static extern IntPtr _glGetString(StringName name); public static string glGetString(StringName name) { return Marshal.PtrToStringAnsi(_glGetString(name)); } public enum StringName : uint { GL_VENDOR = 0x1F00, GL_RENDERER = 0x1F01, GL_VERSION = 0x1F02, GL_EXTENSIONS = 0x1F03 }
在应用程序启动时,在调用gdi32.dll之前我使用这个:
GL.glGetString(0);
两种方式都解决了这个问题.