Mapping for U+2B05, U+2B06 & U+2B07 in vertical writing

[doraTeX]

In Adobe-Japan1-6, there are many series of arrows which have adjoining CID codes, for example:

• simple arrows: 736→, 737←, 738↑, 739↓
• white arrows: 8011⇩, 8012⇧, 8013⇦, 8014⇨
• finger arrows: 8219☞, 8220☜, 8221☝, 8222☟
• black arrows: 8206➡, 8207⬅, 8208⬆, 8209⬇

I attached a zipped PostScript file which includes Japanese vertical writing using UniJIS-UTF16-V.

ja-vertical-arrows.ps.zip

Processed by Acrobat Distiller, this produces the following PDF:

By UniJIS-UTF16-V, most of these arrows are rotated 90 degrees clockwise, but U+2B05(⬅), U+2B06(⬆) and U+2B07(⬇) are not rotated. As a result, there is no way of outputting CID+8206(➡) in vertical writing. I suppose this results from the fact that U+27A1(➡) belongs to a different Unicode block from other black arrows.

I suggest the following mappings be added into UniJIS-UTF16-V and other related CMaps.

<2b05> 8208
<2b06> 8206
<2b07> 8207

[kenlunde]

The last time that the vertical CMap resources were touched, in terms of the actual mappings, was at the end of 2005, which was years before we open-sourced them. That change involved removing the mapping for U+303B 〻 VERTICAL IDEOGRAPHIC ITERATION MARK. In other words, the vertical CMap resources are effectively deprecated in favor of the 'vert' GSUB feature, which defines substitutions at the GID level.

For more details, please read this CJK Type Blog article.

Unless there is a valid reason and existing use case for adding these mappings to the vertical CMap resources, I'd prefer to leave them alone. BTW, CID+8206 is mapped from U+27A1 and U+2B95 (Unicode Version 7.0). This suggests the following additional vertical mapping (U+27A1 already maps to CID+8209 in the vertical CMap resources):

<00002b95> 8209

[doraTeX]

Unless there is a valid reason and existing use case for adding these mappings to the vertical CMap resources, I'd prefer to leave them alone.

I understand. I'll cope with this problem by preparing my own customized CMaps for the time being.