Re: [PATCH v3 2/2] docs/conf.py: Respect env variable SPHINX_IMGMATH

Akira Yokosawa
2022-08-28T03:47:29Z

Hi Randy, thank you for looking into this!

On Sat, 27 Aug 2022 17:38:41 -0700, Randy Dunlap wrote:
> Hi Akira,
>
> On 8/26/22 21:38, Akira Yokosawa wrote:
>> On some distros with coarse-grained packaging policy, dvipng is
>> installed along with latex. In such cases, math rendering will
>> use imgmath by default. It is possible to override the choice by
>> specifying the option string of "-D html_math_renderer='mathjax'"
>> to sphinx-build (Sphinx >= 1.8).
>>
>> To provide developers an easier-to-use knob, add code for an env
>> variable "SPHINX_IMGMATH" which overrides the automatic choice
>> of math renderer for html docs.
>>
>> SPHINX_IMGMATH=yes : Load imgmath even if dvipng is not found
>> SPHINX_IMGMATH=no : Don't load imgmath (fall back to mathjax)
>
> Please add SPHINX_IMGMATH to Documentation/doc-guide/sphinx.rst
> (I guess), where other Sphinx environment variables are listed.

Right.
As I mentioned in the coverletter, (quoted below):

> I mentioned in the thread of [3] that imgmath can generate scalable
> math images in SVG.
>
> My plan was to implement that option as well. But during tests under
> Fedora/CentOS/openSUSE, I encountered a couple of warnings from dvisvgm.
> That would be regressions on existing systems which happen to have
> not-working dvisvgm along with working dvipng. I'm thinking of adding
> the SVG option later if I can figure out the minimal requirement for
> dvisvgm under imgmath.

, I'm working on follow-up changes related to SPHINX_IMGMATH.

My plan is to update related docs and help text in Makefile when I manage
the SVG option. At that time, SPHINX_IMGMATH will have additional options
like 'svg' and 'png'.

Hopefully, such follow-up changes can make the v6.1 merge window.

Does this plan work for you?

Thanks, Akira
>
>> Signed-off-by: Akira Yokosawa <akiyks@gmail.com>
>> Acked-by: Mauro Carvalho Chehab <mchehab@kernel.org>
>> ---
>> Changes since v2:
>> - Emit warning on unknown setting of SPHINX_IMGMATH.
>>
>> Changes since v1:
>> - No logical changes.
>> - Renames:
>> LOAD_IMGMATH -> SPHINX_IMGMATH (Mauro),
>> opt_load_imgmath -> env_sphinx_imgmath.
>> - Acked-by from Mauro.
>> --
>> Documentation/conf.py | 16 ++++++++++++++--
>> 1 file changed, 14 insertions(+), 2 deletions(-)
>>
>> diff --git a/Documentation/conf.py b/Documentation/conf.py
>> index c4aaedd96220..9678a8215457 100644
>> --- a/Documentation/conf.py
>> +++ b/Documentation/conf.py
>> @@ -124,8 +124,20 @@ autosectionlabel_maxdepth = 2
>> # mathjax is the default math renderer since Sphinx 1.8.
>> have_latex = have_command('latex')
>> have_dvipng = have_command('dvipng')
>> -load_imgmath = ((have_latex and have_dvipng)
>> - or (major == 1 and minor < 8)
>> +load_imgmath = have_latex and have_dvipng
>> +
>> +# Respect SPHINX_IMGMATH (for html docs only)
>> +if 'SPHINX_IMGMATH' in os.environ:
>> + env_sphinx_imgmath = os.environ['SPHINX_IMGMATH']
>> + if 'yes' in env_sphinx_imgmath:
>> + load_imgmath = True
>> + elif 'no' in env_sphinx_imgmath:
>> + load_imgmath = False
>> + else:
>> + sys.stderr.write("Unknown env SPHINX_IMGMATH=%s ignored.\n" % env_sphinx_imgmath)
>> +
>> +# Always load imgmath for Sphinx <1.8 or for epub docs
>> +load_imgmath = (load_imgmath or (major == 1 and minor < 8)
>> or 'epub' in sys.argv)
>>
>> if load_imgmath:
>
> thanks.