I don't know what kind of patterns to choose.

I have idea. I want to create a physics of soft matter and a usual physics in 3d space.
But I don’t know what use…
I want to use such a scheme:
WinAPI(as GUI and I/O) + OpenGL(as graphics) + OpenCL(as heterogeneous computing).
But in many forums criticized WinAPI. They write, that need use a framework(for example Qt, SDL…etc). People, please answer, Qt/SDL/GTK or anything else is as fast as the WinAPI?
Please What will advice?

For a start I would recommend GLUT - good for simple demos. Should Your application/library get bigger, switch to SDL. Like GLUT it is platform independent but a bit more difficult (with greater capabilities). They both are at least less complex then WinAPI.