Does replacing the same context for different windows as follows is faster than replacing different contexts (each context for window)?
hglrc = handle for context.
// make context active for window 1
wglMakeCurrent(hdc1, hglrc);
// draw here for window 1
// make context active for window 2
wglMakeCurrent(hdc2, hglrc);
// draw here for window 2
:
:
// make context active for window N
wglMakeCurrent(hdcN, hglrc);
// draw here for window N