QWT

代码说明：

/*       QwtPlot3D license -- January 5th, 2005   Copyright (C) 2003-2005 Michael Bieber   This software is provided "as-is", without any express or implied   warranty.  In no event will the author be held liable for any damages   arising from the use of this software.   Permission is granted to anyone to use this software for any purpose,   including commercial applications, and to alter it and redistribute it   freely, subject to the following restrictions:   1. The origin of this software must not be misrepresented; you must not      claim that you wrote the original software. If you use this software      in a product, an acknowledgment in the product documentation would be      appreciated but is not required. &nb