International Text

Mapnik supports unicode text through ICU and has only very rudimentary support for Right-to-left (RTL) languages.

This page is to document and discuss improvements needed to unicode text handling.

Current Tickets

• #364 / #404 - RTL mirroring
• #1154 - Arabic font spacing
• #519 - RTL spacing wrong with numbers (UBIDI_MIXED)
• #112 - Indic RTL font shaping
• #189 / #409 - RTL wrapping (line breaks)
• from osm trac: http://trac.openstreetmap.org/ticket/2182 and http://trac.openstreetmap.org/ticket/1515
• #550 - line-follow: perhaps made worse by unicode chars, perhaps not, needs closer look
• #558 - Character spacing not correct for nepali text
• #582 - TextSymbolizer bug with Armenian letters

Resources

• "State of Text Rendering": http://behdad.org/text/
• HarfBuzz
• pango library
• liblinebreak
  • If used Pango would need to be an optional dependency because we don't want to have to depend on whole GLib/GTK stack.
• http://shapecatcher.com/
• Mozilla bug that has good testcases that could be harvested: https://bugzilla.mozilla.org/show_bug.cgi?id=721821