Was playing around with your subplots example the other day to get a feel for the library (am very excited about reducing my matplotlib render times), and I ran into an unexpected issue. While the figure was active, and without any mouse or keyboard input, one of my cpu cores was fully loaded, and gpu use was around ~30%. Did a little digging, and over a ~25 second profiling run, it seems like fastplotlib/layouts/_plot_area.py:363(render) is calling the pygfx viewport render function almost 40,000 times. Is this expected/desired behavior? Based on my limited understanding of the current codebase, there is a render loop, which I assume is constantly redrawing the figure. This cpu/gpu use seems problematic to me, especially if the figure isn't being interacted with most of the time. I do not observe this behavior if I use snapshot().

My code, run in jupyterlab (using version 0.2.0):

names = [['subplot']*8]*16
figure_grid = fpl.Figure(shape=(16,8), size=(1000,2000), names=names)
for subplot in figure_grid:
    data = np.random.rand(512, 512)
    subplot.add_image(data, name="rand-img")

pr = cProfile.Profile()
pr.enable()
figure_grid.show()
## wait ~25 seconds before running the next block
pr.disable()
pr.create_stats()
pr.print_stats(sort='tottime')

Top 10 calls by tottime

Ordered by: internal time

   ncalls  tottime  percall  cumtime  percall filename:lineno(function)
  1029298    4.403    0.000    5.023    0.000 _helpers.py:304(proxy_func)
      409    2.081    0.005    2.081    0.005 {method 'poll' of 'select.epoll' objects}
 20191744    1.979    0.000    2.226    0.000 _weakrefset.py:63(__iter__)
   526029    1.260    0.000    2.323    0.000 _api.py:101(_new_struct_p)
    39168    1.100    0.000    3.220    0.000 environment.py:402(check_inactive)
    39168    0.745    0.000    1.567    0.000 matrix.py:452(mat_orthographic)
   203812    0.734    0.000    0.734    0.000 {built-in method builtins.dir}
   201508    0.634    0.000    1.054    0.000 structs.py:18(<listcomp>)
    78489    0.628    0.000    5.812    0.000 _api.py:2202(begin_render_pass)
    39168    0.521    0.000   23.825    0.001 renderer.py:392(render)