context.cpp

_hWnd = CreateOffscreenWindow();
_hDC  = GetDC(_hWnd);

PIXELFORMATDESCRIPTOR descriptor;
memset(&descriptor, 0, sizeof(PIXELFORMATDESCRIPTOR));

descriptor.nSize = sizeof(PIXELFORMATDESCRIPTOR);
descriptor.nVersion = 1;
descriptor.dwFlags = PFD_DRAW_TO_WINDOW | PFD_SUPPORT_OPENGL | PFD_DOUBLEBUFFER;
descriptor.iPixelType = PFD_TYPE_RGBA;
descriptor.cColorBits = 24;
descriptor.cAlphaBits = 8;
descriptor.iLayerType = PFD_MAIN_PLANE;

_pixelFormat = ChoosePixelFormat(_hDC, &descriptor);
SetPixelFormat(_hDC, _pixelFormat, &descriptor);

if(!wglCreateContextAttribsARB)
{
	HGLRC _temp = wglCreateContext(_hDC);
	wglMakeCurrent(_hDC, _temp);

	wglGetExtensionsStringARB = (PFNWGLGETEXTENSIONSSTRINGARBPROC)wglGetProcAddress("wglGetExtensionsStringARB");
	std::string extensions = std::string((const char *)wglGetExtensionsStringARB(_hDC));
	
	auto createContext = extensions.find("WGL_ARB_create_context");
	auto coreProfile = extensions.find("WGL_ARB_create_context_profile");

	wglCreateContextAttribsARB = (PFNWGLCREATECONTEXTATTRIBSARBPROC)wglGetProcAddress("wglCreateContextAttribsARB");
	wglChoosePixelFormatARB = (PFNWGLCHOOSEPIXELFORMATARBPROC)wglGetProcAddress("wglChoosePixelFormatARB");

	wglMakeCurrent(_hDC, 0);
	wglDeleteContext(_temp);
}

	
int attributes[] =
{
	WGL_CONTEXT_MAJOR_VERSION_ARB, 3,
	WGL_CONTEXT_MINOR_VERSION_ARB, 2,
	WGL_CONTEXT_PROFILE_MASK_ARB, WGL_CONTEXT_CORE_PROFILE_BIT_ARB,
	0
};

_context = wglCreateContextAttribsARB(_hDC, _shared ? _shared->_context : 0, attributes);