--- a/SConstruct	Sun Apr 27 22:55:17 2008 +0200
+++ b/SConstruct	Mon Apr 28 11:44:11 2008 +0200
@@ -48,6 +48,9 @@
 opt.Save('.optioncache', env)
 Help(opt.GenerateHelpText(env))
 
+
+### configure
+
 platform = 'unknown'
 def CheckPlatform(context):
 	global platform
@@ -104,11 +107,9 @@
 conf.CheckGCC()
 conf.CheckIntelC()
 conf.CheckCPUFlags()
-env = conf.Finish()
 
-
-if intelc and env['intelc']:
-	Tool("intelc").generate(env)
+if intelc and conf.env['intelc']:
+	Tool("intelc").generate(conf.env)
 	cc = 'intelc'
 elif gcc:
 	cc = 'gcc'
@@ -119,17 +120,17 @@
 if cc == 'intelc':
 	add_flags += cpuflags_intelc + ' '
 
-if env['precision'] == 'double':
+if conf.env['precision'] == 'double':
 	add_flags += '-DPYRIT_DOUBLE '
 elif cc == 'gcc':
 	add_flags += '-fsingle-precision-constant '
 
-add_flags += env['flags']
+add_flags += conf.env['flags']
 
 if cc == 'intelc':
-	env.Append(CCFLAGS="-O3 -w1 " + add_flags)
+	conf.env.Append(CCFLAGS="-O3 -w1 " + add_flags)
 elif cc == 'gcc':
-	env.Append(CCFLAGS="-O3 -Wall -pipe " + add_flags)
+	conf.env.Append(CCFLAGS="-O3 -Wall -pipe " + add_flags)
 	# CCFLAGS= -fno-strict-aliasing
 else:
 	print "No supported compiler found."
@@ -138,11 +139,19 @@
 print "Using compiler: " + cc
 print "Additional flags: " + add_flags
 
-# pthread
-if env['PLATFORM'] == 'win32':
-	env.Append(LIBS=["pthreadGC2"])
+if conf.CheckLibWithHeader('png', 'png.h', 'C'):
+	conf.env.Append(CCFLAGS='-DHAVE_PNG')
+	conf.env.Append(LIBS=['png'])
+
+if conf.env['PLATFORM'] == 'win32':
+	conf.env.Append(LIBS=["pthreadGC2"])
 else:
-	env.Append(CCFLAGS="-pthread ")
+	conf.env.Append(CCFLAGS="-pthread ")
+
+env = conf.Finish()
+
+
+### build targets
 
 (lib, pymodule) = SConscript('src/SConscript', build_dir='build/lib', duplicate=0, exports='env')