Ok,but I also had a problem : How can I display the rendered image from different RC in a same window?Because the RC is created from different window,and the windows is created in different thread,so how to do it?The way I think out is readout the image from RC,and use “glDrawPixel()” to draw it in display window,but I think it is not a good idea.
There is no well supported way to transfer pixels between different pieces of hardware. You have to go through system memory. I would recommend rendering to a pbuffer or pixel buffer object, reading the data, uploading it as a texture on the second card, and rendering a quad with that texture.
It is not right all,I know if I use the same DC to render,that mean s first I call wglMakeCurrent(rc1,dc),second I call wglMakeCurrent(rc2,dc),and next I call wglMakeCurrent(rc1,dc),the rendered image from rc1 or rc2 can be displayed in dc;But I’m afraid this method will affect the parallel working of 2 RCs(the parallel working of 2 cards).