GD::Simple->fontMetrics doesn't seem to do what documentation says about perl-gd

[bcrowell]

The definition of ascent used by this API is also different from the standard definition. The standard definition is from the baseline to the top of the tallest character, whereas the code and pod here define it as the height above the xheight (my $ascent = $mbounds[7]-$jbounds[7];). This should be noted in the docs.

[lstein]

Thanks for identifying this problem. Would it be better in your opinion to fix the documentation so that it says what the code actually does, to fix the code so that it does what the documentation says, or fix both to follow the standard definition? I fear that changing the code will break people's applications, so probably it would be best to add a new method called fontMetricsCorrect() ? Lincoln

…

On Tue, May 25, 2021 at 6:03 PM Ben crowell ***@***.***> wrote: The definition of ascent used by this API is also different from the standard definition. The standard definition is from the baseline to the top of the tallest character, whereas the code and pod here define it as the height above the xheight (my $ascent = $mbounds[7]-$jbounds[7];). This should be noted in the docs. — You are receiving this because you are subscribed to this thread. Reply to this email directly, view it on GitHub <#37 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AAA3EVI6GXP2U27RAGGQKPTTPQNCRANCNFSM45LD2O3A> .

-- *Lincoln Stein* Head, Adaptive Oncology, OICR Senior Principal Investigator, OICR Professor, Department of Molecular Genetics, University of Toronto Tel: [phone] Cell: 416-817-8240 ***@***.*** *Executive Assistant* Tiia Kihlanki Tel: [phone] ***@***.*** *Ontario Institute for Cancer Research* MaRS Centre, 661 University Avenue, Suite 510, Toronto, Ontario, Canada M5G 0A3 @OICR_news <https://twitter.com/oicr_news> | www.oicr.on.ca *Collaborate. Translate. Change lives.* This message and any attachments may contain confidential and/or privileged information for the sole use of the intended recipient. Any review or distribution by anyone other than the person for whom it was originally intended is strictly prohibited. If you have received this message in error, please contact the sender and delete all copies. Opinions, conclusions or other information contained in this message may not be that of the organization.

[bcrowell]

Hi -- BTW, thanks for your work on maintaining this useful module!

The 'lineheight' output is wrong enough that I don't think anyone could have been using it without noticing that it was wrong. For that reason, my advice would just be to apply the patch in my original report, which corrects all the outputs to match the docs.

The nonstandard definition of the ascent seems like a smaller issue to me. I would just note in the docs that it's nonstandard, and applying the patch will make the code do what that says. I think what was previously being returned for 'ascent' was off compared to what the docs were defining, but maybe close enough in many cases that people could actually have working code that's using it under that definition.

[rurban]

Merged. I agree with bcrowell, even if some code needs to be adjusted.