Pango-1.17.0 released
Posted on: 05/15/2007 11:34 AM

Pango-1.17.0 is now available for download at:

http://download.gnome.org/sources/pango/1.17/
or
ftp://ftp.gtk.org/pub/pango/1.17

c1b9b2e236a0d5fe208b532a4a792e7a pango-1.17.0.tar.bz2
7326429bb60bf02685aeee4b3ffbf64a pango-1.17.0.tar.gz

This is the first development release in what seems to be a exciting cycle in Pango development, leading to Pango-1.18.0, which will be released just in time for GNOME-2.20.

Notes:

* This is unstable development release. While it has had fairly extensive testing, there are likely bugs remaining to be found. This release should not be used in production.

* Installing this version will overwrite your existing copy of Pango. If you have problems, you'll need to reinstall Pango-1.16.x

* Bugs should be reported to http://bugzilla.gnome.org.

About Pango
===========

Pango is a library for layout and rendering of text, with an emphasis on internationalization. Pango can be used anywhere that text layout is needed, though most of the work on Pango so far has been done in the context of the GTK+ widget toolkit. Pango forms the core of text and font handling for GTK+-2.x.

Pango is designed to be modular; the core Pango layout engine can be used with different font backends. There are three basic backends, with multiple options for rendering with each.

- Client side fonts using the FreeType and fontconfig libraries. Rendering can be with with Cairo or Xft libraries, or directly to an in-memory buffer with no additional libraries.

- Native fonts on Microsoft Windows using Uniscribe for complex-text handling. Rendering can be done via Cairo or directly using the native Win32 API.

- Native fonts on MacOS X, rendering via Cairo.

The integration of Pango with Cairo (http://cairographics.org) provides a complete solution with high quality text handling and graphics rendering.

Dynamically loaded modules then handle text layout for particular combinations of script and font backend. Pango ships with a wide selection of modules, including modules for Hebrew, Arabic, Hangul, Thai, and a number of Indic scripts. Virtually all of the world's major scripts are supported.

As well as the low level layout rendering routines, Pango includes PangoLayout, a high level driver for laying out entire blocks of text, and routines to assist in editing internationalized text.

More information about Pango is available from http://www.pango.org/. Bugs should be reported to http://bugzilla.gnome.org.

Pango 1.17 depends on version 2.12.0 or newer of the GLib library and version 1.2.6 or newer of the cairo library (if the cairo backend is desired); more information about GLib and cairo can be found at http://www.gtk.org/ and http://cairographics.org/ respectively.

Overview of changes between 1.16.4 and 1.17.0
==============================================

General:

- Text justification. A simple justification algorithm is implemented that tries to justify by expanding spaces in the line, and if none found, by adjust letter spacing. [Based on patch by Mathias Hasselmann]

- The pango_script_get_sample_language() function is modified to use the value of environment variables PANGO_LANGUAGE or LANGUAGE (checked in that order) to make guess better languages for scripts. The env var should be a list of language tags, like "en:fa" for example where in effect makes Pango choose Persian (fa) fonts instead of Arabic (ar) fonts when a run of text in the Arabic script is found in an otherwise non-Arabic layout.

This trick is also useful for East Asian languages. For example a Japanese user that cannot set her primary language to Japanese can still set PANGO_LANGUAGE="ja" and Pango will map CJK characters to Japanese.

The LANGUAGE env var is a standard gettext variable listing languages the user wants to receive UI translated messages in. However, since most packages don't provide separate English translations, setting LANGUAGE="en:ja" doesn't have the intended effect and UI messages will be shown in Japanese. For these situations one can use LANGUAGE="en:C:ja". Pango skips the special language tag 'C'.

- Simplified embedded-shape rendering with pangocairo backends do. [Richard Hult]

- New header file: Moved PangoLanguage APIs into its own header pango-language.h, which is included from pango-types.h.

- ATSUI backend now lists synthesized italic faces like other

- Misc optimizations and fixes.

OpenType Layout Engine Improvements:

- Vertical glyph variants are not selected in vertical text if the font supports them.

- Instead of hardcoded OpenType script tag in each module, and using Default Language System unconditionally, Pango will now find and use the script/lang-sys pair that best matches the detected script and language of a run of text. Moreover, it also applies the OpenType 'locl' feature.


These, plus the PANGO_LANGUAGE env var, give font designers and users lots of options to provide/choose language-specific glyph variants.


Only basic, arabic, and syriac modules updated to take advantage of the new support so far.

New pango-view command line options:

--align
--justify
--language

Public API Changes:

- New public pangocairo API:

PangoCairoShapeRendererFunc
pango_cairo_context_set_shape_renderer()

pango_cairo_context_get_shape_renderer()


These are used by the default pangocairo renderer to render shape attributes (see examples/cairoshape.c). Cairo-based PangoRenderer implementations outside Pango may want to implement the draw_shape() method similarly to provide compatibility with these new APIs. (See bug #437533 for GdkPangoRenderer for example.)

- Other public API changes:

New is_expandable_space member in PangoLogAttr
New macro PANGO_UNITS_ROUND()

- New OpenType engine API. These are engine API, for use by Pango modules, and typically need not to be bound by language bindings:

PANGO_OT_NO_FEATURE
PANGO_OT_NO_SCRIPT
PANGO_OT_TAG_DEFAULT_SCRIPT
PANGO_OT_TAG_DEFAULT_LANGUAGE
PangoOTFeatureMap
PangoOTRulesetDescription
pango_ot_ruleset_get_for()
pango_ot_ruleset_new_for()
pango_ot_ruleset_maybe_add_feature()
pango_ot_ruleset_maybe_add_features()
pango_ot_ruleset_description_hash()
pango_ot_ruleset_description_equal()
pango_ot_ruleset_description_copy()
pango_ot_ruleset_description_free()
pango_ot_tag_from_script()
pango_ot_tag_to_script()
pango_ot_tag_from_language()
pango_ot_tag_to_language()

- Bugs fixed in this release:

Bug 64538 =E2=80" pango_layout_set_justify() doesn't work
Bug 325714 =E2=80" Pango should respect $LANGUAGE
Bug 414264 =E2=80" Pango vertical writing support is different with real
CJK usage.
Bug 416515 =E2=80" Time is not aligned with date on vertical panel
Bug 429397 =E2=80" Updated MS Mincho/Gothic are not listed in font dialo
g
properly on Vista/
Bug 433805 =E2=80" [Atsui] Approximate char/digit width width often 0
(worked around)
Bug 434160 - [atsui] Italic versions of some faces can't be created
Bug 435709 =E2=80" pango_cairo_context_[sg]et_shape_renderer()
Bug 355789 =E2=80" Pango misaligns word-wrapped text due to trailing
whitespace
Bug 436154 =E2=80" Error building the pango.modules file while cross
compiling
Bug 436988 =E2=80" Adding PangoScript to PangoAnalysis
Bug 437534 =E2=80" pango_language_includes_script is buggy

14 May 2007
Behdad Esfahbod


Printed from Linux Compatible (http://www.linuxcompatible.org/news/story/pango_1170_released.html)