This adds api to be able to request that the window system allows a
given onscreen framebuffer to be resizable, and api to add and remove
resize handlers to be called whenever the framebuffer does actually
change size.
The new functions are:
cogl_onscreen_{get,set}_resizable()
cogl_onscreen_{add,remove}_resize_handler()
The examples cogl-hello and cogl-x11-foreign have been updated to use
the new api. To smoke test how Cogl updates the viewport automatically
in response to window resizes the cogl-hello test doesn't explicitly
respond to resize events by setting the viewport and cogl-x11-foreign
responds by setting a viewport that is offset by a quarter of the
window's width/height and half the width and height of the window.
Reviewed-by: Neil Roberts <neil@linux.intel.com>
(cherry picked from commit a1a8cc00bfa2cecaf1007aec5f3dd95dc07b1786)
df51574116