WGL_ARB_buffer_region
http://oss.sgi.com/projects/ogl-sample/registry/ARB/wgl_buffer_region.txt
	WGL_FRONT_COLOR_BUFFER_BIT_ARB 0x00000001
	WGL_BACK_COLOR_BUFFER_BIT_ARB 0x00000002
	WGL_DEPTH_BUFFER_BIT_ARB 0x00000004
	WGL_STENCIL_BUFFER_BIT_ARB 0x00000008
	HANDLE wglCreateBufferRegionARB (HDC hDC, int iLayerPlane, UINT uType)
	VOID wglDeleteBufferRegionARB (HANDLE hRegion)
	BOOL wglRestoreBufferRegionARB (HANDLE hRegion, int x, int y, int width, int height, int xSrc, int ySrc)
	BOOL wglSaveBufferRegionARB (HANDLE hRegion, int x, int y, int width, int height)