private void _initializeWgl()
{
// wglGetProcAddress does not work without an active OpenGL context,
// but we need wglChoosePixelFormatARB's address before we can
// create our main window. Thank you very much, Microsoft!
//
// The solution is to create a dummy OpenGL window first, and then
// test for WGL_ARB_pixel_format support. If it is not supported,
// we make sure to never call the ARB pixel format functions.
//
// If is is supported, we call the pixel format functions at least once
// to initialize them (pointers are stored by glprocs.h). We can also
// take this opportunity to enumerate the valid FSAA modes.
SWF.Form frm = new SWF.Form();
IntPtr hwnd = frm.Handle;
// if a simple CreateWindow fails, then boy are we in trouble...
if (hwnd == IntPtr.Zero)
throw new Exception("Window creation failed");
// no chance of failure and no need to release thanks to CS_OWNDC
IntPtr hdc = User.GetDC(hwnd);
// assign a simple OpenGL pixel format that everyone supports
Gdi.PIXELFORMATDESCRIPTOR pfd = new Gdi.PIXELFORMATDESCRIPTOR();
;
pfd.nSize = (short)Marshal.SizeOf(pfd);
pfd.nVersion = 1;
pfd.cColorBits = 16;
pfd.cDepthBits = 15;
pfd.dwFlags = Gdi.PFD_DRAW_TO_WINDOW | Gdi.PFD_SUPPORT_OPENGL | Gdi.PFD_DOUBLEBUFFER;
pfd.iPixelType = Gdi.PFD_TYPE_RGBA;
// if these fail, wglCreateContext will also quietly fail
int format;
format = Gdi.ChoosePixelFormat(hdc, ref pfd);
if (format != 0)
Gdi.SetPixelFormat(hdc, format, ref pfd);
IntPtr hrc = Wgl.wglCreateContext(hdc);
if (hrc != IntPtr.Zero)
{
// if wglMakeCurrent fails, wglGetProcAddress will return null
Wgl.wglMakeCurrent(hdc, hrc);
Wgl.ReloadFunctions(); // Tao 2.0
// check for pixel format and multisampling support
//IntPtr wglGetExtensionsStringARB = Wgl.wglGetProcAddress( "wglGetExtensionsStringARB" );
//if ( wglGetExtensionsStringARB != IntPtr.Zero )
//{
// string exts = Wgl.wglGetExtensionsStringARB( wglGetExtensionsStringARB, hdc );
// _hasPixelFormatARB = exts.Contains( "WGL_ARB_pixel_format" );
// _hasMultisample = exts.Contains( "WGL_ARB_multisample" );
//}
_hasPixelFormatARB = Wgl.IsExtensionSupported("WGL_ARB_pixel_format");
_hasMultisample = Wgl.IsExtensionSupported("WGL_ARB_multisample");
if (_hasPixelFormatARB && _hasMultisample)
{
// enumerate all formats w/ multisampling
int[] iattr = {
Wgl.WGL_DRAW_TO_WINDOW_ARB, 1,
Wgl.WGL_SUPPORT_OPENGL_ARB, 1,
Wgl.WGL_DOUBLE_BUFFER_ARB, 1,
Wgl.WGL_SAMPLE_BUFFERS_ARB, 1,
Wgl.WGL_ACCELERATION_ARB, Wgl.WGL_FULL_ACCELERATION_ARB,
// We are no matter about the colour, depth and stencil buffers here
//WGL_COLOR_BITS_ARB, 24,
//WGL_ALPHA_BITS_ARB, 8,
//WGL_DEPTH_BITS_ARB, 24,
//WGL_STENCIL_BITS_ARB, 8,
//
Wgl.WGL_SAMPLES_ARB, 2,
0
};
int[] formats = new int[256];
int[] count = new int[256]; // Tao 2.0
//int count;
// cheating here. wglChoosePixelFormatARB proc address needed later on
// when a valid GL context does not exist and glew is not initialized yet.
_wglChoosePixelFormatARB = Wgl.wglGetProcAddress("wglChoosePixelFormatARB");
if (Wgl.wglChoosePixelFormatARB(hdc, iattr, null, 256, formats, count)) // Tao 2.0
//if ( Wgl.wglChoosePixelFormatARB( _wglChoosePixelFormatARB, hdc, iattr, null, 256, formats, out count ) != 0 )
{
// determine what multisampling levels are offered
int query = Wgl.WGL_SAMPLES_ARB, samples;
for (int i = 0; i < count[0]; ++i) // Tao 2.0
//for ( int i = 0; i < count[ 0 ]; ++i )
{
IntPtr wglGetPixelFormatAttribivARB = Wgl.wglGetProcAddress("wglGetPixelFormatAttribivARB");
if (Wgl.wglGetPixelFormatAttribivARB(hdc, formats[i], 0, 1, ref query, out samples)) // Tao 2.0
//if ( Wgl.wglGetPixelFormatAttribivARB( wglGetPixelFormatAttribivARB, hdc, formats[ i ], 0, 1, ref query, out samples ) != 0 )
{
if (!_fsaaLevels.Contains(samples))
_fsaaLevels.Add(samples);
}
}
}
}
Wgl.wglMakeCurrent(IntPtr.Zero, IntPtr.Zero);
Wgl.wglDeleteContext(hrc);
}
// clean up our dummy window and class
frm.Dispose();
frm = null;
}
