Several metrics issues in Roboto Mono worth fixing together

[thundernixon]

In a pull request for a quick fix to the isFixedPitch flag of Roboto Mono, I came across a few other bugs. I'm not the first person to notice these, but I wanted to track my notes in an issue, and combine the other issues into this one, as I believe the fixing work should be done together.

Related issues:

• #142, Roboto mono italics different width. This has 10 👍 reactions so far, indicated this as a problem that is affecting a substantial number of users.
• #249, Roboto Mono regular and italic do not display as the same width
• #251, Roboto Mono is considered variable-pitch by PuTTY in Windows if it isn't completely solved by PR Hotfix: update roboto mono isFixedPitch flag to true #1824
• #1408, Roboto Mono unusable for ASCII art / plain text diagrams shows that 1) Roboto Mono has arrows which are the wrong character width and 2) line heights are very different from other Monospace fonts

When there is time for a designer to dedicate to fixing Roboto Mono, they should:

• ensure that all glyphs – across all styles – have the exact same advance width
• ensure that vertical metrics are consistent across platforms and relatively similar to other monospace fonts
• potentially, we could also add box-drawing glyphs to close issue Problem with the box-drawing characters in the Roboto Mono font on Windows 10 #360, though this would get into glyph extension rather than bug-fixing
• test that these updates allow Roboto Mono to be used in the Windows Console (see thread for more context)

Roboto Mono Regular - Fontbakery fails

🔥 FAIL: Checking OS/2 usWinAscent & usWinDescent.

• com.google.fonts/check/040
• 🔥 FAIL OS/2.usWinAscent value should be equal or greater than 2163, but got 1946 instead [code: ascent]
• 🔥 FAIL OS/2.usWinDescent value should be equal or greater than 555, but got 512 instead [code: descent]

🔥 FAIL: Checking OS/2 Metrics match hhea Metrics.

• com.google.fonts/check/042
• 🔥 FAIL OS/2 sTypoAscender and hhea ascent must be equal. [code: ascender]

🔥 FAIL: Checking correctness of monospaced metadata.

• com.google.fonts/check/033
• 🔥 FAIL On monospaced fonts, the value of OS/2.panose.bProportion must be set to 9 (proportion: monospaced), but got 0 instead. [code: mono-bad-panose-proportion]
• ⚠️ WARN Font is monospaced but 34 glyphs (3.266090297790586%) have a different width. You should check the widths of: ['hyphen', 'f', 'gravecomb', 'acutecomb', 'tildecomb', 'hook', 'uni030F', 'dotbelow', 'uni0483', 'uni0484', 'uni0485', 'uni0486', 'uni0488', 'uni0489', 'at.alt', 'uni00AD', 'Dcroat', 'Eth', 'hbar', 'dcaron', 'lcaron', 'ldot', 'tcaron', 'Epsilontonos', 'Etatonos', 'Iotatonos', 'Omicrontonos', 'Upsilontonos', 'Omegatonos', 'exclamdbl', 'dcroat', 'uni20AB', 'uni049E', 'uni049F'] [code: mono-outliers]

🔥 FAIL: Does the font have a DSIG table?

• com.google.fonts/check/045
• 🔥 FAIL This font lacks a digital signature (DSIG table). Some applications may require one (even if only a dummy placeholder) in order to work properly.

The most obvious problem for a monospace is that some glyphs are not the standard width – a few are around 8% wider than they should be:

Roboto Mono Italic

🔥 FAIL: Checking post.italicAngle value.

• com.google.fonts/check/130
• 🔥 FAIL Font is italic, so post.italicAngle should be non-zero. [code: zero-italic]

🔥 FAIL: Checking OS/2 usWinAscent & usWinDescent.

• com.google.fonts/check/040
• 🔥 FAIL OS/2.usWinAscent value should be equal or greater than 2163, but got 1946 instead [code: ascent]
• 🔥 FAIL OS/2.usWinDescent value should be equal or greater than 555, but got 512 instead [code: descent]

🔥 FAIL: Checking OS/2 Metrics match hhea Metrics.

• com.google.fonts/check/042
• 🔥 FAIL OS/2 sTypoAscender and hhea ascent must be equal. [code: ascender]

🔥 FAIL: Checking correctness of monospaced metadata.

• com.google.fonts/check/033
• 🔥 FAIL On monospaced fonts, the value of OS/2.panose.bProportion must be set to 9 (proportion: monospaced), but got 0 instead. [code: mono-bad-panose-proportion]
• ⚠️ WARN Font is monospaced but 35 glyphs (3.3621517771373677%) have a different width. You should check the widths of: ['hyphen', 'f', 'gravecomb', 'acutecomb', 'tildecomb', 'hook', 'uni030F', 'dotbelow', 'uni0483', 'uni0484', 'uni0485', 'uni0486', 'uni0488', 'uni0489', 'uniFFFD', 'at.alt', 'uni00AD', 'Dcroat', 'Eth', 'hbar', 'dcaron', 'lcaron', 'ldot', 'tcaron', 'Epsilontonos', 'Etatonos', 'Iotatonos', 'Omicrontonos', 'Upsilontonos', 'Omegatonos', 'exclamdbl', 'dcroat', 'uni20AB', 'uni049E', 'uni049F'] [code: mono-outliers]

🔥 FAIL: Does the font have a DSIG table?

• com.google.fonts/check/045
• 🔥 FAIL This font lacks a digital signature (DSIG table). Some applications may require one (even if only a dummy placeholder) in order to work properly.

In the Italic, quite a few of the glyphs mentioned (e.g. /hyphen are off by just 1 unit (1203 vs the standard 1202). However, quite a few are off by significantly more, which probably isn't killing anyone, but isn't ideal:

Of course, the most significant problem here is that the standard width in the regular is 1229, but the standard width in the italic is 1202. This is about 2.25% different. Here's a codepen test showing the effect this has over a line of text:

There are also issues around vertical metrics which probably make display inconsistent between platforms.

[mailinglists35]

repasting my issue from comments in 1408

There is extra vertical spacing for ALL characters

To better understand, open midnight commander inside a latest version putty in a latest version rhel 7 clone. screenshots below at 12pt

normal look (Liberation Mono)

roboto mono wrong look

this does not seem to happen on native linux terminals (terminator, xfce terminal)

On Notepad is also visible. Observe another issue that some ascii extended chars are not standard width (ascii extended 186 for example, could more more but I did not verify them all)

[mailinglists35]

Also the patch to make it appear in putty works (PR #1824), but it does not appear in windows console:

[mailinglists35]

screenshots from windows 10.0.17134.556

[mailinglists35]

To appear in windows console, it must meet these conditions

[thundernixon]

Thanks for adding detail and for correcting my assumption on the windows console, @mailinglists35!

Thanks also for including images related to vertical metrics. I did include that in the top comment:

ensure that vertical metrics are consistent across platforms and relatively similar to other monospace fonts

... but it's definitely helpful to have the screenshots showing exactly why it's a problem.

One follow-up question:

I am having difficulties adding any monospace fonts to my windows console. I've tried to follow this guide to add them, but no luck. Have you had success in adding any other fonts, e.g. Fira Mono?

[mailinglists35]

I installed/see these non-default fonts on mine:

DejaVu Sans Mono
Inconsolata
Liberation Mono
Menlo

also Lucida Console but can't remember if I installed it or it came with OS

[thundernixon]

Okay, thanks for confirming! It may be that the windows console checks all glyph width metrics before allowing a font, then. I've added a test in the Windows console in the top comment of the issue, to make sure it's addressed when someone has capacity for this.

[twse]

This issue is also related to #360.

[gbmarc1]

I think #1394 pull request also relates to the problem.

[mailinglists35]

Hi
I understand this is not Urgent priority, but... what is an expected timeline?

Will Google eventually simply drop roboto altogether and make a new one that is working properly this time?

[thundernixon]

@mailinglists35 this is only speculation, but I’m guess this can’t really be fixed, without the risk of breaking websites/documents that may be designed using the current width of Roboto Mono Italic. So yes, basically the only two options, as I see it, are:

• people use a font other than Roboto Mono, if this issue is a blocker for them
• a new version of Roboto Mono is made, with a slightly different name so it doesn’t break existing things. No idea when/if this would happen, but it is open source, so in some sense, anyone could do it and suggest that it be added to the GF directory

[mangelozzi]

Robotomono doesnt work with block chars for making borders:
In Neovim, Font: RobotoMono:

In Neovim, Font: Consolas:

[Secret-chest]

PLEASE FIX!

[mailinglists35]

I eventually gave up on roboto mono and gave up hope Google fixing it.

Fantasque Sans Mono no loop k is now my first choice, seconded by Microsoft's new default Cascadia Mono and macOS' SF Mono ripped from my macOS root filesystem. Recently I stumbled upon Intellij's JetBrains Mono which also looks good. RIP Google Roboto Mono...🤔😥

[Secret-chest]

Is it any coincidence all 4 fonts you mentioned suck? I don't want a robotic font but neither a fun handwritten one.

[mailinglists35]

then good luck finding the font of your taste, what can I say. google does not seem to care how Robot looks on Windows, they just wanted something for Android and it seems to satisfy their original requirements

[Secret-chest]

For italics, uninstall the italic variants. You will get faux italics, but at least in code editors they're going to be the same width.