[yt-dev] Issue #1250: annotate_cell_edges: Have to increase buff_size for highly refined grids (yt_analysis/yt)

[Dominik Derigs]

New issue 1250: annotate_cell_edges: Have to increase buff_size for highly refined grids
https://bitbucket.org/yt_analysis/yt/issues/1250/annotate_cell_edges-have-to-increase

Dominik Derigs:

This issue is related to issue #1249. It addresses a related but different problem that is potentially easier to be solved and should be solved for 3.3.

One always has to increase buff_size to get nice annotated cell edges for high resolution data. I think it is necessary to automate the increase of the buffer size when needed.
An alternative approach could be to increase it to some high value when the user calls the annotate_cell_edges function explicitly.

MWE:

```
#!python

import yt
ds = yt.load("WindTunnel/windtunnel_4lev_hdf5_plt_cnt_0040")
slc = yt.SlicePlot(ds, 'z', 'density', width=(1.0, 1.0))
slc.annotate_cell_edges()
slc.annotate_grids()
slc.hide_axes()
slc.hide_colorbar()
slc.save("800x800.png",mpl_kwargs={'dpi': 200})
slc.set_buff_size((3200, 3200))
slc.save("3200x3200.png",mpl_kwargs={'dpi': 200})

```

800x800:

![800x800.png](https://bitbucket.org/repo/BXbAb/images/2420740934-800x800.png)

3200x3200:
![3200x3200.png](https://bitbucket.org/repo/BXbAb/images/1803891906-3200x3200.png)