Rendering issue under windows: pyglet must be updated

[aiAdrian]

Description
Flatland 4.0.0 doesn't work under Windows with python 3.8< due of a pyglet 1.3.2 issue
mmatl/pyrender#95

To Reproduce
List the steps needed to reproduce the behavior:

Windows:

1. conda create python=3.8 --name flatland_4_0_0
2. conda activate flatland_4_0_0
3. python custom_railmap_example.py

Tracer
Traceback (most recent call last):
File "custom_railmap_example.py", line 129, in
main(sys.argv[1:])
File "custom_railmap_example.py", line 122, in main
custom_railmap_example(sleep_for_animation, do_rendering)
File "custom_railmap_example.py", line 95, in custom_railmap_example
env_renderer.render_env(show=True, show_observations=False)
File "C:\Users\u216993\AppData\Local\miniconda3\envs\flatland_4_0_0\lib\site-packages\flatland\utils\rendertools.py", line 62, in render_env
return self.renderer.render_env(show, show_agents, show_inactive_agents, show_observations,
File "C:\Users\u216993\AppData\Local\miniconda3\envs\flatland_4_0_0\lib\site-packages\flatland\utils\rendertools.py", line 526, in render_env
return self.render_env_svg(show=show,
File "C:\Users\u216993\AppData\Local\miniconda3\envs\flatland_4_0_0\lib\site-packages\flatland\utils\rendertools.py", line 761, in render_env_svg
self.gl.show()
File "C:\Users\u216993\AppData\Local\miniconda3\envs\flatland_4_0_0\lib\site-packages\flatland\utils\graphics_pgl.py", line 56, in show
self.open_window()
File "C:\Users\u216993\AppData\Local\miniconda3\envs\flatland_4_0_0\lib\site-packages\flatland\utils\graphics_pgl.py", line 24, in open_window
self.window = pgl.window.Window(resizable=True, vsync=False, width=1200, height=800)
File "C:\Users\u216993\AppData\Local\miniconda3\envs\flatland_4_0_0\lib\site-packages\pyglet_init_.py", line 384, in getattr
import(import_name)
File "C:\Users\u216993\AppData\Local\miniconda3\envs\flatland_4_0_0\lib\site-packages\pyglet\window_init_.py", line 1896, in
gl.create_shadow_window()
File "C:\Users\u216993\AppData\Local\miniconda3\envs\flatland_4_0_0\lib\site-packages\pyglet\gl_init.py", line 208, in create_shadow_window
shadow_window = Window(width=1, height=1, visible=False)
File "C:\Users\u216993\AppData\Local\miniconda3\envs\flatland_4_0_0\lib\site-packages\pyglet\window\win32_init.py", line 134, in init
super(Win32Window, self).init(*args, **kwargs)
File "C:\Users\u216993\AppData\Local\miniconda3\envs\flatland_4_0_0\lib\site-packages\pyglet\window_init.py", line 501, in init
display = get_platform().get_default_display()
File "C:\Users\u216993\AppData\Local\miniconda3\envs\flatland_4_0_0\lib\site-packages\pyglet\window_init_.py", line 1845, in get_default_display
return pyglet.canvas.get_display()
File "C:\Users\u216993\AppData\Local\miniconda3\envs\flatland_4_0_0\lib\site-packages\pyglet\canvas_init_.py", line 77, in get_display
from pyglet.app import displays
File "C:\Users\u216993\AppData\Local\miniconda3\envs\flatland_4_0_0\lib\site-packages\pyglet\app_init_.py", line 175, in
event_loop = EventLoop()
File "C:\Users\u216993\AppData\Local\miniconda3\envs\flatland_4_0_0\lib\site-packages\pyglet\app\base.py", line 119, in init
self.clock = clock.get_default()
File "C:\Users\u216993\AppData\Local\miniconda3\envs\flatland_4_0_0\lib\site-packages\pyglet_init_.py", line 384, in getattr
import(import_name)
File "C:\Users\u216993\AppData\Local\miniconda3\envs\flatland_4_0_0\lib\site-packages\pyglet\clock.py", line 166, in
_default_time_function = time.clock
A

[aiAdrian]

(flatland_4_0_0) C:\devsbb\workspace\flatland\flatland-rl\examples>pip install pyglet -U
Requirement already satisfied: pyglet in c:\users\u216993\appdata\local\miniconda3\envs\flatland_4_0_0\lib\site-packages (1.3.2)
Collecting pyglet
Using cached pyglet-2.0.9-py3-none-any.whl.metadata (8.4 kB)
Downloading pyglet-2.0.9-py3-none-any.whl (854 kB)
---------------------------------------- 854.7/854.7 kB 2.0 MB/s eta 0:00:00
Installing collected packages: pyglet
Attempting uninstall: pyglet
Found existing installation: pyglet 1.3.2
Uninstalling pyglet-1.3.2:
Successfully uninstalled pyglet-1.3.2
ERROR: pip's dependency resolver does not currently take into account all the packages that are installed. This behaviour is the source of the following dependency conflicts.
gym 0.14.0 requires pyglet<=1.3.2,>=1.2.0, but you have pyglet 2.0.9 which is incompatible.
Successfully installed pyglet-2.0.9

[fnberta]

Ok, so the culprit here is that we currently pin gym to version 0.14.0 which then depends on an old version of pyglet. I tried to update gym in #55, but only partly succeeded. Please see the PR for more info.

Also, tackling #26 would really simplify resolving this issue. Is this something that could be done rather quickly?

[fnberta]

Thanks to your work in #56, we can fix this in #57.