Add Package : OpenSceneGraph (#2075)

* Created the initial version of the 'OpenSceneGraph' package.

* Added 'zlib' as a dependency and linked it during the build step.

* Fixed a few minor PEP8 style violations in the 'OpenSceneGraph' package.

* Added cmake as a build dependency and improved the build procedure.

* Made a few important argument updates to improve package compatibility.

* Fixed up a few remaining style issues in the 'openscenegraph' package.

* Added a description for the 'openscenegraph' package.

* Fixed a bug that was causing some 'openscenegraph@3.2.3%gcc' installs to fail.

* Fixed a number of small issues with the 'openscenegraph' package.

* Removed a number of superfluous flags from the 'openscenegraph' install.

var/spack/repos/builtin/packages/openscenegraph/package.py

+##############################################################################
+# Copyright (c) 2013-2016, Lawrence Livermore National Security, LLC.
+# Produced at the Lawrence Livermore National Laboratory.
+#
+# This file is part of Spack.
+# Created by Todd Gamblin, tgamblin@llnl.gov, All rights reserved.
+# LLNL-CODE-647188
+#
+# For details, see https://github.com/llnl/spack
+# Please also see the LICENSE file for our notice and the LGPL.
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU Lesser General Public License (as
+# published by the Free Software Foundation) version 2.1, February 1999.
+#
+# This program is distributed in the hope that it will be useful, but
+# WITHOUT ANY WARRANTY; without even the IMPLIED WARRANTY OF
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the terms and
+# conditions of the GNU Lesser General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public
+# License along with this program; if not, write to the Free Software
+# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+##############################################################################
+
+from spack import *
+
+
+class Openscenegraph(Package):
+    """OpenSceneGraph is an open source, high performance 3D graphics toolkit
+       that's used in a variety of visual simulation applications."""
+
+    homepage = "http://www.openscenegraph.org"
+    url      = "http://trac.openscenegraph.org/downloads/developer_releases/OpenSceneGraph-3.2.3.zip"
+
+    version('3.2.3', '02ffdad7744c747d8fad0d7babb58427')
+    version('3.1.5', '1c90b851b109849c985006486ef59822')
+
+    variant('debug', default=False, description='Builds a debug version of the library')
+    variant('shared', default=True, description='Builds a shared version of the library')
+
+    depends_on('cmake@2.8.7:', type='build')
+    depends_on('qt@4:')
+    depends_on('zlib')
+
+    def install(self, spec, prefix):
+        build_type = 'Debug' if '+debug' in spec else 'Release'
+        shared_status = 'ON' if '+shared' in spec else 'OFF'
+
+        cmake_args = std_cmake_args[:]
+        cmake_args.extend([
+            '-DCMAKE_BUILD_TYPE={0}'.format(build_type),
+            '-DDYNAMIC_OPENSCENEGRAPH={0}'.format(shared_status),
+            '-DDYNAMIC_OPENTHREADS={0}'.format(shared_status),
+        ])
+
+        # NOTE: This is necessary in order to allow OpenSceneGraph to compile
+        # despite containing a number of implicit bool to int conversions.
+        if spec.satisfies('%gcc'):
+            cmake_args.extend([
+                '-DCMAKE_C_FLAGS=-fpermissive',
+                '-DCMAKE_CXX_FLAGS=-fpermissive',
+            ])
+
+        with working_dir('spack-build', create=True):
+            cmake(
+                '..',
+                '-DZLIB_INCLUDE_DIR={0}'.format(spec['zlib'].prefix.include),
+                '-DZLIB_LIBRARY={0}/libz.{1}'.format(spec['zlib'].prefix.lib,
+                                                     dso_suffix),
+                '-DBUILD_OSG_APPLICATIONS=OFF',
+                '-DOSG_NOTIFY_DISABLED=ON',
+                '-DLIB_POSTFIX=',
+                *cmake_args
+            )
+            make()
+            make('install')