[mapserver-users] Indic Support in Mapserver?
Paul Ramsey
pramsey at cleverelephant.ca
Thu Apr 24 08:13:12 PDT 2008
Nevermind, I see that freetype dropped it, and it was picked up later
by the projects you mentioned...
http://www.freedesktop.org/wiki/Software/HarfBuzz
On Thu, Apr 24, 2008 at 8:10 AM, Paul Ramsey <pramsey at cleverelephant.ca> wrote:
> Intriguing problem... is it possible that we could achieve this
> through more sophisticated use of freetype?
>
> http://www.freetype.org/opentype/index.html
>
> P.
>
>
>
> On Wed, Apr 23, 2008 at 12:26 AM, Swapnil Hajare <dreamil at gmail.com> wrote:
> >
> >
> > Hello All,
> > I have been trying unsuccessfully to login to trac.osgeo.org/mapserver
> > using my OSGeo userid (dreamil). After trying for last 2 days, I am posting
> > here the bug report which I wanted to post there. Please go through this and
> > let me know your opinion on the same:
> >
> > ********************************************************************************************
> > Title: Indic Support (using OpenType fonts) in Mapserver
> >
> > The current version of Mapserver can render labels on map using LABEL
> > directive in a map file.For labels, you can use truetype fonts which is
> > achieved using freetype.Due to this map labels can be displayed in various
> > non-English languages such as europian and some Asian scripts.
> >
> > However, for rendering some CTL (Complex Text Layout) scripts, truetype
> > fonts are not sufficient.Indic Scripts, for example, require much more than
> > mere juxtaposition of glyphs from a font.Rendering Indic scripts such as
> > Devanagari, Gujarati, Tamil, Telugu, Bengali etc. is much more complex than
> > others.To handle this, "intelligent" fonts were designed which contain
> > embedded rules to help rendering.These were called OpenType fonts (see
> > http://www.microsoft.com/typography/otfntdev/indicot/default.htm). Though
> > initiated by M$, OpenType fonts are are now Industry standard for rendering
> > these complex scripts on Computer using script and language rules. All major
> > Linux desktops such as GNOME and KDE support OpenType font rendering.To
> > handle OpenType fonts, various rendering engines have been developed and
> > have become part of rendering libraries such as
> > Pango(http://www.pango.org/)/ICU(http://www.icu-project.org/), Qt etc.It
> > should be noted that, in absence of such a rendering engine, OpenType fonts
> > act as Truetype fonts i.e. the embedded rendering rules are not used while
> > doing the glyph formation.
> >
> > There are numerous OpenType fonts available free/proprietory for Indic
> > scripts. We have ourselves developed gargi, the first GPLed OpenType font
> > for Devanagari(http://savannah.nongnu.org/projects/gargi).
> >
> > Current Mapserver supports truetype fonts using freetype routines, but there
> > is no support for OpenType fonts. As a result, a text label in any of the
> > indic scripts is rendered using justaposition of glyphs from the font
> > provided, without using rendering rules.The result is incorrect rendering.
> > To show you the difference, here is the snapshot of a map with labels in
> > Devanagari script (which is a indic script), rendered in correct
> > fashion(http://indictrans.in/~swapnil/mapserver/required_result.png) and
> > here is the snapshot as rendered by
> > Mapserver(http://indictrans.in/~swapnil/mapserver/mapserv_no_render_support_for_ttf.png)
> > You may not be able to make out much if you are not familiar with the
> > script, but for someone who knows the script, its an incorrect or broken
> > representation of the text.
> >
> > To solve this, we should add support for OpenType font rendering in
> > Mapserver.This can be done by embedding some indic rendering routines from
> > Pango or ICU into the label rendering engine of mapserver. I don't know the
> > details of how labels are rendered in Mapserver, so somebody knowledgable
> > should guide. I am prepared to take up the task on behalf of my team
> > (www.indictrans.in) if I get some guidance about internal working of
> > Mapserver.As far as performance is concerned, this will hit the speed badly,
> > but then this can be encoded as a configure options (--with-pango similar to
> > Firefox implementation
> > http://developer.spikesource.com/wiki/index.php/Firefox_Indic_Build) so that
> > it becomes optional.
> >
> > You may have look at the temporary solution which we are using for the time
> > being to show indic text on maps using Mapserver here:
> > http://www.indictrans.in/old/doublebyte/English/doublebyte_l10n_25march_4PM.html
> > We have numerous localized GIS demo on our website using this approach.
> >
> > ********************************************************************************************
> >
> > regards,
> > --
> > Swapnil Hajare
> > dreamil.indictrans.in
> > _______________________________________________
> > mapserver-users mailing list
> > mapserver-users at lists.osgeo.org
> > http://lists.osgeo.org/mailman/listinfo/mapserver-users
> >
> >
>
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