gmsh : added fltk support

var/spack/packages/fltk/font.patch

@@ -0,0 +1,44 @@
+Index: FL/x.H
+===================================================================
+--- a/FL/x.H	(revision 10476)
++++ b/FL/x.H	(working copy)
+@@ -132,6 +132,7 @@
+   XFontStruct *ptr;
+ };
+ extern FL_EXPORT Fl_XFont_On_Demand fl_xfont;
++extern FL_EXPORT XFontStruct* fl_core_font();
+
+ // this object contains all X-specific stuff about a window:
+ // Warning: this object is highly subject to change!
+Index: src/fl_font.cxx
+===================================================================
+--- a/src/fl_font.cxx	(revision 10476)
++++ b/src/fl_font.cxx	(working copy)
+@@ -55,6 +55,14 @@
+ #  include "fl_font_x.cxx"
+ #endif // WIN32
+
++#ifdef WIN32
++#elif defined(__APPLE__)
++#else
++XFontStruct *fl_core_font()
++{
++  return fl_xfont.value();
++}
++#endif
+
+ double fl_width(const char* c) {
+   if (c) return fl_width(c, (int) strlen(c));
+Index: src/gl_draw.cxx
+===================================================================
+--- a/src/gl_draw.cxx	(revision 10476)
++++ b/src/gl_draw.cxx	(working copy)
+@@ -84,7 +84,7 @@
+  * then sorting through them at draw time (for normal X rendering) to find which one can
+  * render the current glyph... But for now, just use the first font in the list for GL...
+  */
+-    XFontStruct *font = fl_xfont;
++    XFontStruct *font = fl_core_font();
+     int base = font->min_char_or_byte2;
+     int count = font->max_char_or_byte2-base+1;
+     fl_fontsize->listbase = glGenLists(256);

var/spack/packages/fltk/package.py

@@ -0,0 +1,58 @@
+##############################################################################
+# Copyright (c) 2013-2015, Lawrence Livermore National Security, LLC.
+# Produced at the Lawrence Livermore National Laboratory.
+#
+# This file is part of Spack.
+# Written 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 General Public License (as published by
+# the Free Software Foundation) version 2.1 dated 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 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 Fltk(Package):
+    """
+    FLTK (pronounced "fulltick") is a cross-platform C++ GUI toolkit for UNIX/Linux (X11), Microsoft Windows, and
+    MacOS X. FLTK provides modern GUI functionality without the bloat and supports 3D graphics via OpenGL and its
+    built-in GLUT emulation.
+
+    FLTK is designed to be small and modular enough to be statically linked, but works fine as a shared library. FLTK
+    also includes an excellent UI builder called FLUID that can be used to create applications in minutes.
+    """
+    homepage = 'http://www.fltk.org/'
+    url = 'http://fltk.org/pub/fltk/1.3.3/fltk-1.3.3-source.tar.gz'
+
+    version('1.3.3', '9ccdb0d19dc104b87179bd9fd10822e3')
+
+    patch('font.patch', when='@1.3.3')
+
+    variant('shared', default=True, description='Enables the build of shared libraries')
+
+    def install(self, spec, prefix):
+        options = ['--prefix=%s' % prefix,
+                   '--enable-localjpeg',
+                   '--enable-localpng',
+                   '--enable-localzlib']
+
+        if '+shared' in spec:
+            options.append('--enable-shared')
+
+        # FLTK needs to be built in-source
+        configure(*options)
+        make()
+        make('install')

var/spack/packages/gmsh/package.py

@@ -27,7 +27,7 @@
 
 class Gmsh(Package):
     """
-    Gmsh is a free 3D finite element grid generator with a build-in CAD engine and post-processor. Its design goal is
+    Gmsh is a free 3D finite element grid generator with a built-in CAD engine and post-processor. Its design goal is
     to provide a fast, light and user-friendly meshing tool with parametric input and advanced visualization
     capabilities. Gmsh is built around four modules: geometry, mesh, solver and post-processing. The specification of
     any input to these modules is done either interactively using the graphical user interface or in ASCII text files
@@ -38,17 +38,19 @@ class Gmsh(Package):
 
     version('2.11.0', 'f15b6e7ac9ca649c9a74440e1259d0db')
 
-    # FIXME : Misses dependencies on gmm, FLTK, PetsC, TetGen, HDF5
+    # FIXME : Misses dependencies on gmm, PetsC, TetGen, HDF5
 
     variant('shared', default=True, description='Enables the build of shared libraries')
     variant('debug', default=False, description='Builds the library in debug mode')
     variant('mpi', default=False, description='Builds MPI support for parser and solver')
+    variant('fltk', default=False, description='Enables the build of the FLTK GUI')
     variant('compression', default=True, description='Enables IO compression through zlib')
 
     depends_on('blas')
     depends_on('lapack')
     depends_on('gmp')
     depends_on('mpi', when='+mpi')
+    depends_on('fltk', when='+fltk')  # Assumes OpenGL with GLU is already provided by the system
     depends_on('zlib', when='+compression')
 
     def install(self, spec, prefix):