Shaping
=======

Layout Driver
=============

The PangoLayout object is a highlevel driver that takes an attributed
string and produces lines of glyphs.

* Figure out better ways of doing line breaks. (This may involve
  implementing the TeX/Raph x0-x1 stuff for line breaks.)

* Add spacing parameter as illustrated; this should be a quick
  (10 minute) addition.

* Although PangoLayout isn't intended to handle large amounts
  of text, it should be able to handle embedded "\n" and simple
  multiple paragraphs. This could be done entirely within 
  pango_layout_check_lines()

* pango_layout_context_changed() is a hack. Either the context
  should have change-notification, or else the layout should 
  make a copy of the context when the context is set.

* optimize right alignment for width == -1 and only a single 
  line. (Currently this causes a useless call to gtk_layout_get_extents.)

X rendering
===========

* Right now we assume a single resolution for all fonts on a display;
  but in theory, the resolution could be per-screen. To solve 
  this, we would probably want to add a window argument to 
  pango_x_get_context() and then have some sort of X specific font 
  loading interface.

* It is not clear that X is interpreting the ink_rect the same way
  as we are. There is a bit of fudging in the underline drawing
  code to deal with this and make the underlines look symetric.

* pangox.c/get_font_metrics_from_string() needs to gutted and
  replaced with using pango_itemize(); to support this, we need 
  the ability to specifiy a particular font to use when itemizing.
  This probably means adding a attribute type which contains
  a PangoFont *, and overrides the description.

* pangox.c needs to be split into at least two separate files.

  (
   Probably along the lines of 

   1) font map
   2) font 
   3) rendering
  )


Other rendering engines
=======================

* Somebody should start working on a libart font-system / renderer
  soon, to make sure that the interfaces are suitable.

* FreeType-2.0 support could be very interesting, with the OpenType 
  that it has.

Engines
=======

* Switch engines to be indentified by properties, instead
  of hardcoded role/language. (?)

Language Modules
================

 * It would be nice to have X based shapers for a few more scripts;
   Hindi is one obvious need. (Actually, there may be a need for
   a generic framework for Indic shapers to be developed. A
   libpango-indic...)

 * Once we have a libart renderer, porting Raph's devanagari shaper
   to Pango and C (from Perl) would be a cool demo and test case.
  
 * The clusters set by the current modules need to be set.

 * Tamil module should be switched over to libunicode from utils.c stuff.

Documentation
=============

* Much or all of the X Fonts document from pango.org needs to be moved
  into the API reference.

Fonts
=====

* Add handling for baseline adjustment

* pango_context_list_fonts() does not properly suppress duplicates
  when multiple font maps are involved

General
=======

* unicode_next_utf8() is extensively used on strings which are not
  guaranteed to be NULL terminated. This is a BUG. Once I agree
  with Tom Tromey on a change to libunicode to make the operation
  more efficient, these need to be gone through one-by-one.

* Remove the extraneous font argument from the script_shape virtual function
  in ShapeEngine.

* rename pango_context_set_size() to pango_context_set_font_size()
* settle on either _free or _destroy

* PangoAttrList currently takes the policy of "most recent wins"
  when multiple attributes of the same type are present for a range. 
  It would map better on the TkText tag-based API if attributes
  also had a depth/priority and "most recent wins" only applied
  for attributes of the same priority. 

* Add a "make test" target to examples/, add environment variables
  to point to module and font alias files, remove the code that
  loads these from the current directory.  (There are security
  implications with the current stuff)

* Report errors from functions, these errors include such things.

  - Invalid string
  - Font does not match 

 Probably the right thing to do here is to use something very close
 to the GConf API ... see Havoc's GException proposal.

* Allow UTF8 strings with embedded NULLs.

* Write a small default shaping engine that only
  draws a placeholder character ... and does that in
  a way that always works.

* Finish coverting over from utils.c to Tom Tromey's libunicode.
  Add the remaining useful functions from utils.c into libunicode.

* s/num_chars/n_chars/ etc. (Always use n_ as enumeration prefix)

* Fix handling of 'trailing' in x_to_index() to handle clusters 
  with more than one character where positioning is not allowed
  inside the cluster. Uniscript sets trailing as 0 or number of j
  characters in the glyph. (Trailing is currently a boolean
  for us.)

* pango_font_get_metrics() currently takes a language tag, but
  really uses that to find out one or more _scripts_; should we
  define script tags and put those (optionally?) in the 
  interface?