__init__.py 文件源码

def on_draw():
            """The window contents must be redrawn.

            The `EventLoop` will dispatch this event when the window
            should be redrawn.  This will happen during idle time after
            any window events and after any scheduled functions were called.

            The window will already have the GL context, so there is no
            need to call `switch_to`.  The window's `flip` method will
            be called after this event, so your event handler should not.

            You should make no assumptions about the window contents when
            this event is triggered; a resize or expose event may have
            invalidated the framebuffer since the last time it was drawn.

            :since: pyglet 1.1

            :event:
            """