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https://issues.apache.org/jira/browse/PDFBOX-4106?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16362686#comment-16362686
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Tilman Hausherr commented on PDFBOX-4106:
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That looks interesting and is very welcome, of course. Some thoughts:
I looked at the first patch; are you aware that UnicodeScript is a JDK7 class?
This would mean your improvement can't be used in PDFBox 2.*, only in 3. That
one has no planned release date, it could be several months or several years.
I see you made an effort in patch 5 to make it non-breaking, but I suspect that
in patch 4 the use of the new CmapLookup interface would be a breaking change,
isn't it? That would be another reason it couldn't be used in 2.*.
The sample code
{code:java}
ttf.disableGsubFeature("vrt2");
ttf.disableGsubFeature("vert");
{code}
is too difficult for an average user. I'd prefer to have something on a high
level, e.g. an option in an additional vertical loader, or a method. The
"natural" setting should be the default. (What would a newbie "vertical font
user" expect? (2) or (3) in your sample PDF ?)
[~lehmi] do we need an ICLA for this?
> Vertical text creation
> ----------------------
>
> Key: PDFBOX-4106
> URL: https://issues.apache.org/jira/browse/PDFBOX-4106
> Project: PDFBox
> Issue Type: New Feature
> Components: FontBox, Parsing, Writing
> Reporter: Aaron Madlon-Kay
> Priority: Major
> Labels: embed, gsub, parsing, vertical
> Attachments: 0001-Parse-GSUB-table.patch,
> 0002-Abstract-cmap-lookup-into-an-interface.patch,
> 0003-Implement-GSUB-substitution-on-TrueTypeFont.patch,
> 0004-Use-vhea-vmtx-to-fix-vertical-displacements-in-PCIDF.patch,
> 0005-Add-factory-methods-for-loading-TTF-as-vertical-font.patch,
> 0006-Implement-vertical-metrics-support-when-embedding-su.patch,
> sample_code.txt, vertical.pdf
>
>
> I needed to output vertical Japanese text, but was stymied by several
> limitations:
> * No API to load a TTF as Identity-V encoding
> * No support for 'vert' glyph substitution
> * No support for vertical metrics ('vhea' and 'vmtx' tables are parsed but
> not used at all)
> I have attached a series of patches that implement the above features.
> Highlights:
> * The GSUB glyph substitution table is parsed (limitation: type 1 lookups
> only; this is sufficient for many features including 'vert'/'vrt2' vertical
> glyph substitution)
> * Cmap lookup makes use of GSUB when features are enabled on a TTF
> * 'vhea' and 'vmtx' metrics are applied to PDCIDFont when appropriate, and
> are embedded/subsetted correctly through the DW2/W2 CIDFont dictionary
> * An API has been added for loading a TTF as a vertical font, setting
> Identity-V encoding and enabling 'vert'/'vrt2' substitution
> Each patch could approximately be split out into a separate ticket, if
> desired.
> Also attached is some sample code that exercises these patches and
> illustrates the effect of vertical glyph positioning. The sample output PDF
> is also attached.
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