GLUT多个Windows和OpenGL上下文

I would like to use GLUT 3.7 Window Toolkit in a program written in php because i saw that there was a binding in php. I am interesting in having multiple windows ! In order to have a clean code, i was wondering to separate on the one hand the window toolkit and on the other hand the OpenGL implementation. I hope that i can program event with the glut callbacks in php then the application get the events and can interacts ! But i don't know how to draw in each window from php with opengl ? They say in the man page that each glut window has an opengl context. How to get each context ? Can i render offscreen with each context ?

I found it all by myself. There's a primitive glutSetWindow( windowHandle ) that can switch between context in the same process. Thus we have one opengl context per window.

I hope it will help