SetPixelFormat 出错，请帮忙？

[feng007lhf]

各位大侠，我使用Tao opengl 开一个项目，其中要使用opengl的 off-screen（渲染到一张位图）渲染，但是我在搭建opengl context的时候遇到如题的错误， 即我不能设置像素格式，具体代码如下： 其中SetPixelFormat返回FALSE, 使用GetLastError返回1： 表示无效功能或者函数，但是我应该如何做哪？

System.Drawing.Image img = new System.Drawing.Bitmap(width, height);
System.Drawing.Graphics g = System.Drawing.Graphics.FromImage(img);

CreateGLContext(width, height, 16);

//define CreateGLContext
private bool CreateGLContext (int width, int height, int bits)
{
int pixelFormat;
Gdi.PIXELFORMATDESCRIPTOR pfd = new Gdi.PIXELFORMATDESCRIPTOR ();
pfd.nSize = (short) Marshal.SizeOf ( pfd );
pfd.nVersion = 1;
pfd.dwFlags = Gdi.PFD_DRAW_TO_BITMAP |
Gdi.PFD_SUPPORT_OPENGL |
Gdi.PFD_SUPPORT_GDI;
pfd.iPixelType = (byte) Gdi.PFD_TYPE_RGBA;
pfd.cColorBits = (byte) bits;
pfd.cRedBits = 0;
pfd.cRedShift = 0;
pfd.cGreenBits = 0;
pfd.cGreenShift = 0;
pfd.cBlueBits = 0;
pfd.cBlueShift = 0;
pfd.cAlphaBits = 0;
pfd.cAlphaShift = 0;
pfd.cAccumBits = 0;
pfd.cAccumRedBits = 0;
pfd.cAccumGreenBits = 0;
pfd.cAccumBlueBits = 0;
pfd.cAccumAlphaBits = 0;
pfd.cDepthBits = 16;
pfd.cStencilBits = 0;
pfd.cAuxBuffers = 0;
pfd.iLayerType = (byte) Gdi.PFD_MAIN_PLANE;
pfd.bReserved = 0;
pfd.dwLayerMask = 0;
pfd.dwVisibleMask = 0;
pfd.dwDamageMask = 0;

if ( hDC == IntPtr.Zero )
{
KillGLContext ();
MessageBox.Show ( "Can't Create A GL Device Context.", "ERROR 1",
MessageBoxButtons.OK, MessageBoxIcon.Error );
return false;
}

pixelFormat = Gdi.ChoosePixelFormat ( hDC, ref pfd );
if ( pixelFormat == 0 )
{
KillGLContext ();
MessageBox.Show ( "Can't Find A Suitable PixelFormat.", "ERROR 2",
MessageBoxButtons.OK, MessageBoxIcon.Error );
return false;
}

try
{

if ( !Gdi.SetPixelFormat ( hDC, pixelFormat, ref pfd ) )
{

MessageBox.Show ( Gl.glGetError ().ToString () );
MessageBox.Show ( Marshal.GetLastWin32Error ().ToString () );
KillGLContext ();
MessageBox.Show ( "Can't Set The PixelFormat.", "ERROR 3",
MessageBoxButtons.OK, MessageBoxIcon.Error );
//return false;
}

}
catch ( Exception e )
{
MessageBox.Show ( e.Message );
}

hRC = Wgl.wglCreateContext ( hDC );
if ( hRC == IntPtr.Zero )
{
KillGLContext ();
MessageBox.Show ( "Can't Create A GL Rendering Context.", "ERROR 4",
MessageBoxButtons.OK, MessageBoxIcon.Error );
return false;
}

if ( !Wgl.wglMakeCurrent ( hDC, hRC ) )
{
KillGLContext ();
MessageBox.Show ( "Can't Activate The GL Rendering Context.", "ERROR 5",
MessageBoxButtons.OK, MessageBoxIcon.Error );
return false;
}

ReSizeGLScene ( width, height );

if ( !InitGL () )
{
KillGLContext ();
MessageBox.Show ( "Initialization Failed.", "ERROR 6",
MessageBoxButtons.OK, MessageBoxIcon.Error );
return false;
}
return true;
}

private bool InitGL ()
private void KillGLContext ()

但是我在CSGL中 使用如下代码是可以创建off-screen的渲染环境的，

System.Drawing.Image img = new System.Drawing.Bitmap((int)(pj.ScreenSize.Width), (int)(pj.ScreenSize.Height));
System.Drawing.Graphics g = System.Drawing.Graphics.FromImage(img);
GDIGLContext gdictxt = new GDIGLContext(g);//将opengl和Graphics绑定

gdictxt.Create(new DisplayType(DisplayFlags.DRAW_TO_BITMAP, true), null);//创建GDIGLContext容器
gdictxt.Grab();//使该context为当前激活的context.

但是由于我要是用VBO,而 CSGL不支持，或者不知能如何自己产生这些扩展，所以转向了Tao OpenGL, 不过现在我连他的render context都搭建不起来， 有知道的，帮帮我啊，谢谢啦。

[feng007lhf]

自己顶一下

[feng007lhf]

没有人知道吗，

[happyboyxq1985]

帮你顶一下

[feng007lhf]

SetPixelForma() 返回false, 使用GetLastError()返回1， 表示函数不正确，应该如何解决啊

[gisyellow]

渲染到图片，也是在窗口中绘制啊。。

[ncjcz]

能弄出来就好了

[feng007lhf]

问题找到了，原来是我参数设置的不对，具体设置如下：

PIXELFORMATDESCRIPTOR pix;
memset(&pix, 0, sizeof(PIXELFORMATDESCRIPTOR));
pix.nSize = sizeof(PIXELFORMATDESCRIPTOR);
pix.nVersion = 1;

pix.dwFlags |= PFD_DRAW_TO_BITMAP;
pix.dwFlags |= PFD_DRAW_TO_WINDOW;
pix.dwFlags |= PFD_SUPPORT_GDI;
pix.iPixelType = PFD_TYPE_RGBA;
pix.cColorBits = 32;
pix.cRedBits = 8;
pix.cGreenBits = 8;
pix.cBlueBits = 8;
pix.cAlphaBits = 0;
pix.cAccumBits = 64;
pix.cAccumRedBits = 16;
pix.cAccumGreenBits = 16;
pix.cAccumBlueBits = 16;
pix.cAccumAlphaBits = 0;
pix.cDepthBits = 16;
pix.cStencilBits = 8;
pix.cAuxBuffers = 0;
//pix.iLayerType = 0;//(byte)PFD_MAIN_PLANE;
pix.bReserved = 0; // Reserved
pix.dwLayerMask = 0; // Layer Masks Ignored
pix.dwVisibleMask = 0;
pix.dwDamageMask = 0;


不过我还有一个疑问，既然是渲染到bitmap, 为什么还有设置PFD_DRAW_TO_WINDOW ？

[xxxxxzelda]

PIXELFORMATDESCRIPTOR pfd = {
sizeof(PIXELFORMATDESCRIPTOR), // size of this pfd
1, // version number
PFD_DRAW_TO_WINDOW | // support window
PFD_SUPPORT_OPENGL | // support OpenGL
PFD_DOUBLEBUFFER, // double buffered
PFD_TYPE_RGBA, // RGBA type
16, // 24-bit color depth
0, 0, 0, 0, 0, 0, // color bits ignored
0, // no alpha buffer
0, // shift bit ignored
0, // no accumulation buffer
0, 0, 0, 0, // accum bits ignored
16, // 32-bit z-buffer
0, // no stencil buffer
0, // no auxiliary buffer
PFD_MAIN_PLANE, // main layer
0, // reserved
0, 0, 0 // layer masks ignored
};

[hxl6983]

还是楼主靠的是自己呀