[geos-devel] Perl bindings via SWIG

[Ari Jolma]

Hello,

Here's a report on building Perl bindings for GEOS on MinGW using the 2.2.3
release. 

Configuration, compilation and installation of GEOS went without problems. Then
I created perl subdir under swig and tried building the bindings. After the
effort a simple test script runs ok. Here's what I did:

1. added 

#ifdef SWIGPERL
%include ../perl/perl.i
#endif

to geos.i

2. created perl.i with just one line (taken from ruby.i):

%rename(next_) geos::GeometryCollectionIterator::next();

3. ran swig (in msys) with arguments: -c++ -perl5 -o geos_wrap.cxx ../geos.i

The resulting geos_wrap.cxx had to be fixed by adding 

#ifdef select
  #undef select
#endif

Around "Workaround perl5 global namespace..."

4. created the test script test.pl (this is one of the python tests):

use Test::More qw(no_plan);

BEGIN{ use_ok( 'geos' ); }

$gf = geos::GeometryFactory->new();
$x = 492187.0;
$y = 4493034.0;
$z = 1500.0;
$c = geos::Coordinate->new($x, $y, $z);
$p = $gf->createPoint($c);
ok($p->{x} == $x);
ok($p->{y} == $y);

5. created very standard Makefile.PL:

use ExtUtils::MakeMaker;

WriteMakefile( 
	       NAME => 'geos',
	       LD => "g++",
	       LIBS => "-lgeos.dll",
	       INC => '-I../../source/headers',
	       OBJECT => 'geos_wrap.o'
	       );

and ran "perl Makefile.PL", which produces the Makefile. That I had to fix with
-Wl,--enable-runtime-pseudo-reloc in the dynamic_lib section in the $(LD)
commands (this could perhaps be fixed already in the Makefile.PL)

Then I just ran "dmake test", which builds the Perl module and runs the test script.

I'll probably do more tests with the module later, but this looks promising --
and the annoying things that I had to fix are assumably non-problems under
Linux. Thanks for Sean and Charlie for setting up the environment.

Regards,

Ari

-- 
Prof. Ari Jolma
Kartografia ja Geoinformatiikka / Cartography and Geoinformatics
Teknillinen Korkeakoulu / Helsinki University of Technology
POBox 1200, 02015 TKK, Finland
Email: ari.jolma at tkk.fi URL: http://www.tkk.fi/~jolma