Improving scons building system

external/obtain.py

+import urllib
+import os
+import sys
+import shutil
+
+# Check if the build dir exists
+if not os.path.exists('build'):
+	os.mkdir('build')
+#end
+
+# Download a file
+def download(url, filename):
+	urllib.urlretrieve(url, filename)
+#end
+
+# Uncompress the archive
+def uncompress(filename):
+	cmd = '';
+	if os.name == 'posix':
+		cmd = 'tar -xf '
+	elif os.name == 'nt':
+		cmd = '7zip '
+
+	cmd += filename
+	ret = os.system(cmd)
+#end
+
+# Obtain a package and uncompress it
+def obtain(name, rep, url, filename):
+	if not os.path.exists(rep):
+		print '<<INSTALL>> Obtaining ' + name
+
+		download(url, filename)
+		uncompress(filename)
+	else:
+		print '<<INSTALL>> ' + name + ' already available'
+	#end
+#end
+
+def configure_build(rep):
+	os.chdir(rep)
+	ret = os.system('./configure -q --prefix=' + os.getcwd() + os.sep + os.pardir + os.sep + 'build')
+	if ret != 0:
+		print '<<ERROR>> unable to configure package'
+		exit
+	#end
+	ret = os.system('make -s && make -s install')
+	if ret != 0:
+		print '<<ERROR>> unable to build & install package'
+		exit
+	#end
+	os.chdir(os.pardir)
+#end
+

external/obtain_ceres.py

-import urllib
+import obtain
 import os
 import sys
 import shutil
 
-# Download a file
-def download(url, filename):
-	urllib.urlretrieve(url, filename)
-#end
-
-# Uncompress the archive
-def uncompress(filename):
-	cmd = '';
-	if os.name == 'posix':
-		cmd = 'tar -xf '
-	elif os.name == 'nt':
-		cmd = '7zip '
-
-	cmd += filename
-	ret = os.system(cmd)
-#end
-
-# Obtain a package and uncompress it
-def obtain(name, rep, url, filename):
-	if not os.path.exists(rep):
-		print '<<INSTALL>> Obtaining ' + name
-
-		download(url, filename)
-		uncompress(filename)
-	else:
-		print '<<INSTALL>> ' + name + ' already available'
-	#end
-#end
-
-def configure_build(rep):
-	os.chdir(rep)
-	ret = os.system('./configure -q --prefix=' + os.getcwd() + os.sep + os.pardir + os.sep + 'build')
-	if ret != 0:
-		print '<<ERROR>> unable to configure package'
-		exit
-	#end
-	ret = os.system('make -s && make -s install')
-	if ret != 0:
-		print '<<ERROR>> unable to build & install package'
-		exit
-	#end
-	os.chdir(os.pardir)
-#end
-
-# Check if the build dir exists
-if not os.path.exists('build'):
-	os.mkdir('build')
-#end
 
 # Download GLOG
-obtain('GLOG v0.3.3', 'glog-0.3.3', 'http://google-glog.googlecode.com/files/glog-0.3.3.tar.gz', 'glog-0.3.3.tar.gz')
+obtain.obtain('GLOG v0.3.3', 'glog-0.3.3', 'http://google-glog.googlecode.com/files/glog-0.3.3.tar.gz', 'glog-0.3.3.tar.gz')
 if os.name == 'nt':
 	print '<<WARNING>> no automatic installation for this package'
 else:
 	print '<<INSTALL>> configure and build GLOG v0.3.3'
-	configure_build('glog-0.3.3')
+	obtain.configure_build('glog-0.3.3')
 #end
 
 # Download Eigen3
-obtain('Eigen v3.2.1', 'eigen-eigen-ffa86ffb5570', 'http://bitbucket.org/eigen/eigen/get/3.2.0.tar.gz', 'eigen-3.2.1.tar.gz')
-shutil.copytree('eigen-eigen-ffa86ffb5570' + os.sep + 'Eigen', 'build' + os.sep + 'include' + os.sep + 'Eigen')
+execfile('obtain_eigen.py')
  
 # Download CERES
-obtain('CERES v1.7.0', 'ceres-solver-1.7.0', 'http://ceres-solver.googlecode.com/files/ceres-solver-1.7.0.tar.gz', 'ceres-solver-1.7.0.tar.gz')
+obtain.obtain('CERES v1.7.0', 'ceres-solver-1.7.0', 'http://ceres-solver.googlecode.com/files/ceres-solver-1.7.0.tar.gz', 'ceres-solver-1.7.0.tar.gz')
 print '<<WARNING>> CERES installation requires CMake. You need to run it yourself'

external/obtain_eigen.py

+import obtain
+import os
+import sys
+import shutil
+
+# Download Eigen3
+obtain.obtain('Eigen v3.2.1', 'eigen-eigen-ffa86ffb5570', 'http://bitbucket.org/eigen/eigen/get/3.2.0.tar.gz', 'eigen-3.2.1.tar.gz')
+
+rep = 'build' + os.sep + 'include' + os.sep + 'Eigen'
+if not os.path.exists(rep):
+	shutil.copytree('eigen-eigen-ffa86ffb5570' + os.sep + 'Eigen', rep)
+#end

sources/core/SConscript

 env = Environment()
-env.Append(CPPPATH = '/home/belcour/Sources/eigen')
+env.Append(CPPPATH = '../../external/eigen-eigen-ffa86ffb5570')
 
 # Library sources
 sources = ['common.cpp',