fontmake: help needed: I am unable to make progress on testing variable fonts

This is a follow up to https://github.com/googlei18n/fontmake/issues/167

From sources at https://github.com/googlei18n/noto-source/tree/master/src I managed to build the following variable files that have only weight axis:

The following newly built VF fonts have only single weight axis (axis=“wght”); see https://github.com/googlei18n/noto-fonts/tree/master/alpha/from-pipeline/unhinted/variable-ttf/sans for the sans fonts and in …/serif you can find serif fonts: NotoSansCherokee-VF.ttf NotoSansLao-VF.ttf NotoSansLaoUI-VF.ttf NotoSansSymbols-VF.ttf NotoSerifLao-VF.ttf NotoSerifSinhala-VF.ttf

… sample ttx output for Cherokee <fvar>

<!-- Weight -->
<Axis>
  <AxisTag>wght</AxisTag>
  <MinValue>100.0</MinValue>
  <DefaultValue>400.0</DefaultValue>
  <MaxValue>900.0</MaxValue>
  <NameID>256</NameID>
</Axis>

<!-- Thin -->
<NamedInstance nameID="257">
  <coord axis="wght" value="100.0"/>
</NamedInstance>

<!-- ExtraLight -->
<NamedInstance nameID="258">
  <coord axis="wght" value="200.0"/>
</NamedInstance>

When I run fontdiff tests (see https://github.com/googlei18n/noto-source/tree/master/test for the tests) I get the correct behavior. For example for Cherokee for test

<html lang="Cher">
  <p>
  <span style="font-weight:100">&#xAB93;&#x0300;</span>
  <span style="font-weight:200">&#xAB93;&#x0300;</span>
  <span style="font-weight:300">&#xAB93;&#x0300;</span>
  <span style="font-weight:400">&#xAB93;&#x0300;</span>
  <span style="font-weight:500">&#xAB93;&#x0300;</span>
  <span style="font-weight:600">&#xAB93;&#x0300;</span>
  <span style="font-weight:700">&#xAB93;&#x0300;</span>
  <span style="font-weight:800">&#xAB93;&#x0300;</span>
  <span style="font-weight:900">&#xAB93;&#x0300;</span>
  </p>

I get the following result in the PDF file created by fontdiff cherokee-lower-case

The following newly built VF fonts have only both weight axis (axis=“wght”) and width axis (axis=“wdth”); see https://github.com/googlei18n/noto-fonts/tree/master/alpha/from-pipeline/unhinted/variable-ttf/sans for the sans fonts and in …/serif you can find serif fonts: NotoSans-Italic-VF.ttf NotoSans-VF.ttf NotoSansArabic-VF.ttf NotoSansArabicUI-VF.ttf NotoSansArmenian-VF.ttf NotoSansDevanagari-VF.ttf NotoSansDisplay-Italic-VF.ttf NotoSansDisplay-VF.ttf NotoSansGeorgian-VF.ttf NotoSansHebrew-VF.ttf NotoSansKhmer-VF.ttf NotoSansKhmerUI-VF.ttf NotoSansMyanmar-VF.ttf NotoSansMyanmarUI-VF.ttf NotoSansSinhala-VF.ttf NotoSansSymbols2-Regular-VF.ttf NotoSansTamil-VF.ttf NotoSansThai-VF.ttf NotoSansThaiUI-VF.ttf NotoSerifArmenian-VF.ttf NotoSerifEthiopic-VF.ttf NotoSerifGeorgian-VF.ttf NotoSerifHebrew-VF.ttf NotoSerifKhmer-VF.ttf NotoSerifTamil-VF.ttf NotoSerifThai-VF.ttf

sample ttx output (Hebrew)

<fvar>
    <!-- Weight -->
    <Axis>
      <AxisTag>wght</AxisTag>
      <MinValue>100.0</MinValue>
      <DefaultValue>400.0</DefaultValue>
      <MaxValue>900.0</MaxValue>
      <AxisNameID>256</AxisNameID>
    </Axis>

    <!-- Width -->
    <Axis>
      <AxisTag>wdth</AxisTag>
      <MinValue>70.0</MinValue>
      <DefaultValue>100.0</DefaultValue>
      <MaxValue>100.0</MaxValue>
      <AxisNameID>257</AxisNameID>
    </Axis>

    <!-- Thin -->
    <NamedInstance subfamilyNameID="258">
      <coord axis="wght" value="100.0"/>
      <coord axis="wdth" value="100.0"/>
    </NamedInstance>

    <!-- ExtraLight -->
    <NamedInstance subfamilyNameID="259">
      <coord axis="wght" value="200.0"/>
      <coord axis="wdth" value="100.0"/>
    </NamedInstance>

However, when I ran my fontdiff tests with these dual axis fonts I do not get the expected results. For example for Hebrew Sans using https://github.com/googlei18n/noto-source/blob/master/test/Hebrew/specimen-he-weights-widths.html as a test. For the first line

<html lang="he">
  <p>
  <span style="font-weight:100">וַיִּפֶן </span>
  <span style="font-weight:200">וַיִּפֶן </span>
  <span style="font-weight:300">וַיִּפֶן </span>
  <span style="font-weight:400">וַיִּפֶן </span>
  <span style="font-weight:500">וַיִּפֶן </span>
  <span style="font-weight:600">וַיִּפֶן </span>
  <span style="font-weight:700">וַיִּפֶן </span>
  <span style="font-weight:800">וַיִּפֶן </span>
  <span style="font-weight:900">וַיִּפֶן </span>
  </p>

I get the following PDF output (note they all appear to be thin whereas I expected them to change weights) he-sans-width-test

Most likely it is not a fontmake problem: it might be a problem with my test HTML, might be a fontdiff problem, harfbuzz problem, pdf problem, etc… but I’m stumped and need help debugging this and fixing this (if this is an issue).

About this issue

Original URL
State: open
Created 7 years ago
Comments: 27 (25 by maintainers)

Most upvoted comments

If I drag n drop both the Hebrew VF into Axis Praxis and only change the width axis, it works fine.

hebrew-22

As soon as I change the weight, the width axis fails to work. I had the same behaviour with the Latin vf font.

I’m running webkit r214471. I’ll update this tomorrow and try build the fonts myself.

m4rc1e on Apr 21, 2017