Previously, compton fails to stop draw_idle in some cases when sw_opti
is enabled.
sw_opti is a feature that limits the draw frequence to vblank frequence.
It adds a delay to drawing when the screen is updated more frequently
than the vblank frequence. However when the delay is not used (i.e. the
screen is updated infrequent enough), compton will start drawing the
frame directly without using the delay. And specically in this case,
compton will fail to stop the draw_idle, causing a callback to be called
once per loop of the mainloop, resulting in high CPU usage.
Fixes#92
Signed-off-by: Yuxuan Shui <yshuiv7@gmail.com>
5e49ab0861