FTGL.h not found

[John W. Eaton]

On 10-Jul-2008, John W. Eaton wrote:

| So do we agree that the configure script and sources should be changed
| to look for and use ftgl.h?

After taking a closer look, I don't see any FTGL headers included
anywhere in the Octave sources, and the configure test actually
includes FTGLTextureFont.h, so it seems we should check for that
instead.  I made that change, but then the check still failed, so I
finally looked in the config.log file and found that FTGLTextureFont.h
is deprecated, so ftgl.h should be used instead.  OK, changing the
test to use that, I now see:

  configure:11194: checking FTGL/ftgl.h usability
  configure:11211: g++ -c -ggdb3   conftest.cpp >&5
  In file included from /usr/include/FTGL/ftgl.h:32,
		   from conftest.cpp:76:
  /usr/include/ft2build.h:56:38: error: freetype/config/ftheader.h: No such file or directory
  In file included from conftest.cpp:76:
  /usr/include/FTGL/ftgl.h:33:10: error: #include expects "FILENAME" or <FILENAME>
  /usr/include/FTGL/ftgl.h:34:10: error: #include expects "FILENAME" or <FILENAME>
  /usr/include/FTGL/ftgl.h:35:10: error: #include expects "FILENAME" or <FILENAME>
  In file included from /usr/include/FTGL/ftgl.h:110,
		   from conftest.cpp:76:
  /usr/include/FTGL/FTPoint.h:75: error: expected ',' or '...' before '&' token
  /usr/include/FTGL/FTPoint.h: In constructor 'FTPoint::FTPoint(int)':
  /usr/include/FTGL/FTPoint.h:77: error: 'ft_vector' was not declared in this scope
  ...

in config.log.

This happens because on my system, /usr/include/FTGL/ftgl.h has the
lines

  /* We need the Freetype headers */
  #include <ft2build.h>
  #include FT_FREETYPE_H
  #include FT_GLYPH_H
  #include FT_OUTLINE_H

and, other than comments and a multiple-inclusion guard,
/usr/include/ft2build.h is just the line

    /* `<prefix>/include/freetype2' must be in your current inclusion path */
  #include <freetype/config/ftheader.h>

but the -I flags don't include the freetype2 directory.  So it looks
like we need to check for the location of the freetype2 directory and
add that to the include flags.  What is the best way to do that?  Will
someone please fix this and submit a changeset?

Thanks,

jwe