Merge branch 'master' into color-priority

19 files changed, 377 insertions, 263 deletions

diff --git a/boost.pri b/boost.pri
index c2f5d8e..02e4247 100644
--- a/boost.pri
+++ b/boost.pri
@@ -6,35 +6,64 @@ boost {
   !isEmpty(BOOST_DIR) {
     QMAKE_INCDIR += $$BOOST_DIR
     message("boost location: $$BOOST_DIR")
-    win32:QMAKE_LIBDIR += -L$$BOOST_DIR/lib
+    win32: QMAKE_LIBDIR += -L$$BOOST_DIR/lib
   }
 
-  win32:!CONFIG(mingw-cross-env) {
-    LIBS += -llibboost_thread-vc90-mt-s-1_46_1 -llibboost_program_options-vc90-mt-s-1_46_1
-  } 
-
   CONFIG(mingw-cross-env) {
     DEFINES += BOOST_STATIC
     DEFINES += BOOST_THREAD_USE_LIB
     DEFINES += Boost_USE_STATIC_LIBS
-    LIBS += -lboost_thread_win32-mt -lboost_program_options-mt
+    BOOST_LINK_FLAGS = -lboost_thread_win32-mt -lboost_program_options-mt
   } 
 
-  unix {
-    BMT_TEST1 = /usr/lib64/libboost*thread-mt*
-    BMT_TEST2 = /usr/lib/libboost*thread-mt*
-    BMT_TEST3 = $$BOOST_DIR/lib/libboost*thread-mt*
+  isEmpty(BOOST_LINK_FLAGS):win32 {
+    BOOST_LINK_FLAGS = -llibboost_thread-vc90-mt-s-1_46_1 -llibboost_program_options-vc90-mt-s-1_46_1
+  } 
 
-    exists($$BMT_TEST1)|exists($$BMT_TEST2)|exists($$BMT_TEST3) {
-      LIBS += -lboost_thread-mt -lboost_program_options-mt
-      BOOST_IS_MT = true
-    } 
+  # check for OPENSCAD_LIBDIR + multithread
+  isEmpty(BOOST_LINK_FLAGS) {
+    OPENSCAD_LIBDIR = $$(OPENSCAD_LIBRARIES)
+    !isEmpty(OPENSCAD_LIBDIR) {
+      exists($$OPENSCAD_LIBDIR/lib/libboost*thread-mt*) {
+        BOOST_LINK_FLAGS = -lboost_thread-mt -lboost_program_options-mt
+      } else {
+        exists($$OPENSCAD_LIBDIR/lib/libboost*thread*) {
+          BOOST_LINK_FLAGS = -lboost_thread -lboost_program_options
+        }
+      }
+    }
   }
 
-  unix|macx {
-    isEmpty(BOOST_IS_MT) { 
-      LIBS += -lboost_thread -lboost_program_options
+  # check for BOOSTDIR + multithread
+  isEmpty(BOOST_LINK_FLAGS) {
+    BOOST_DIR = $$(BOOSTDIR)
+    !isEmpty(BOOST_DIR) {
+      exists($$BOOST_DIR/lib/libboost*thread-mt*) {
+        BOOST_LINK_FLAGS = -lboost_thread-mt -lboost_program_options-mt
+      } else {
+        exists($$BOOST_DIR/lib/libboost*thread*) {
+          BOOST_LINK_FLAGS = -lboost_thread -lboost_program_options
+        }
+      }
     }
   }
 
+  isEmpty(BOOST_LINK_FLAGS) {
+    unix {
+      BMT_TEST1 = /usr/lib64/libboost*thread-mt*
+      BMT_TEST2 = /usr/lib/libboost*thread-mt*
+      exists($$BMT_TEST1)|exists($$BMT_TEST2) {
+        BOOST_LINK_FLAGS = -lboost_thread-mt -lboost_program_options-mt
+      }
+    }
+  }
+
+  isEmpty(BOOST_LINK_FLAGS) {
+    unix|macx {
+      BOOST_LINK_FLAGS = -lboost_thread -lboost_program_options
+    }
+  }
+
+  LIBS += $$BOOST_LINK_FLAGS
+
 }
diff --git a/doc/TODO.txt b/doc/TODO.txt
index 4fac889..8f6d257 100644
--- a/doc/TODO.txt
+++ b/doc/TODO.txt
@@ -259,7 +259,6 @@ o variants of module transparent() { %child(); }
 o define modules
 o define functions
 o built-in variables and constants (builtin-tests.scad)
-o Write a regression test for the hexagonal cylinder orientation issue
 o Caching
   - Test that caching is actually performed (speedup + same results)
   - Test the modifier characters correctly influence the cache (also when
diff --git a/doc/testing.txt b/doc/testing.txt
index 4623a96..a50c95f 100644
--- a/doc/testing.txt
+++ b/doc/testing.txt
@@ -50,26 +50,33 @@ Adding a new regression test:
 Troubleshooting:
 ------------------------------
 
-0. Headless unix servers (no X11)
+0. Headless unix servers
 
-$ Xvfb :5 -screen 0 800x600x24 &        
+If you are attempting to run the tests on a unix-like system but only
+have shell-console access, you may be able to run the tests by using a 
+virtual framebuffer program like Xvnc or Xvfb. For example:
+
+$ Xvfb :5 -screen 0 800x600x24 &
 $ DISPLAY=:5 ctest
 
-1. Trouble finding libraries
+Some versions of Xvfb may fail, however. 
+
+1. Trouble finding libraries on unix
 
  To help CMAKE find eigen2, OpenCSG, CGAL, Boost, and GLEW, you can use 
  environment variables, just like for the main qmake & openscad.pro. Examples:
 
- OPENCSGDIR=~/OpenCSG-1.3.2 EIGEN2DIR=~/eigen2 cmake .
+ OPENSCAD_LIBRARIES=~ cmake .
+ CGALDIR=~/CGAL-3.9 BOOSTDIR=~/boost-1.47.0 cmake .
 
- Valid variables are as follows (see CMakeLists.txt for more info):
+ Valid variables are as follows:
 
  BOOSTDIR, CGALDIR, EIGEN2DIR, GLEWDIR, OPENCSGDIR, OPENSCAD_LIBRARIES
 
-2. Logs
+2. Location of logs
  
 Logs of test runs are found in tests/build/Testing/Temporary
-Pretty-printed index.html is in a subdir of tests/build/Testing/Temporary
+A pretty-printed index.html is in a subdir of tests/build/Testing/Temporary
 Expected results are found in tests/regression/*
 Actual results are found in tests/build/testname-output/*
 
@@ -77,28 +84,23 @@ Actual results are found in tests/build/testname-output/*
 
 Cross-compiling of tests has not been automated nor tested
 
-4. Image-based tests takes a long time, they fail, and it says 'return -11'
+4. Image-based tests takes a long time, they fail, and the log says 'return -11'
 
-Imagemagick may have crashed. You can try using the alternate IM comparator
-based on Normalized Cross Correlation. Pass -DCOMPARATOR=ncc to cmake
+Imagemagick may have crashed while comparing the expected images to the 
+test-run generated (actual) images. You can try using the alternate 
+ImageMagick comparison method by by erasing CMakeCache, and re-running 
+cmake with -DCOMPARATOR=ncc. This will enable the Normalized Cross 
+Comparison method.
 
-5. Testing images fails with 'morphology' not found for ImageMagick
+5. Testing images fails with 'morphology not found" for ImageMagick in the log
 
 Your version of imagemagick is old. Upgrade, or pass -DCOMPARATOR=old to 
 cmake. The comparison will be of lowered reliability.
 
-6. Unexplained or bizarre errors. 
-
-This can happen on dynamic-library systems (linux) where you try to use 
-your own version of a library while the system still has another version 
-under the system paths. You can diagnose this by looking at your cmake 
-log as well as your sysinfo.txt file, as well as running 'ldd' against 
-your binaries, to make sure that the proper versions of libraries are
-getting compiled and linked with the test binaries. 
-
-7. Other issues
+6. Other issues
 
-The OpenSCAD User Manual has a section on buildling. Check there for updates:
+The OpenSCAD User Manual has a section on buildling. Please check there 
+for updates:
 
 http://en.wikibooks.org/wiki/OpenSCAD_User_Manual
 
diff --git a/eigen2.pri b/eigen2.pri
index 44649f8..6062c76 100644
--- a/eigen2.pri
+++ b/eigen2.pri
@@ -1,20 +1,36 @@
 eigen2 {
+
+  CONFIG(mingw-cross-env) {
+    EIGEN2_INCLUDEPATH = mingw-cross-env/include/eigen2
+  }
+
   # Optionally specify location of Eigen2 using the 
-  # EIGEN2DIR env. variable
-  EIGEN2_DIR = $$(EIGEN2DIR)
-  !isEmpty(EIGEN2_DIR) {
-    EIGEN2_INCLUDEPATH = $$EIGEN2_DIR
+  # OPENSCAD_LIBRARIES env. variable
+  isEmpty(EIGEN2_INCLUDEPATH) {
+    OPENSCAD_LIBRARIES_DIR = $$(OPENSCAD_LIBRARIES)
+    !isEmpty(OPENSCAD_LIBRARIES_DIR) {
+      exists($$OPENSCAD_LIBRARIES_DIR/include/eigen2) {
+        EIGEN2_INCLUDEPATH = $$OPENSCAD_LIBRARIES_DIR/include/eigen2
+      }
+    }
   }
-  else {
-    CONFIG(mingw-cross-env) {
-      EIGEN2_INCLUDEPATH = mingw-cross-env/include/eigen2
-    } else {
-      freebsd-g++: EIGEN2_INCLUDEPATH *= /usr/local/include/eigen2
-      macx: EIGEN2_INCLUDEPATH *= /opt/local/include/eigen2
-      !macx:!freebsd-g++:!win32:EIGEN2_INCLUDEPATH *= /usr/include/eigen2
+
+  # Optionally specify location of Eigen2 using the 
+  # EIGEN2DIR env. variable
+  isEmpty(EIGEN2_INCLUDEPATH) {
+    EIGEN2_DIR = $$(EIGEN2DIR)
+    !isEmpty(EIGEN2_DIR) { 
+      EIGEN2_INCLUDEPATH = $$EIGEN2_DIR
+      message("EIGEN2 location: $$EIGEN2_INCLUDEPATH")
     }
   }
 
+  isEmpty(EIGEN2_INCLUDEPATH) {
+    freebsd-g++: EIGEN2_INCLUDEPATH = /usr/local/include/eigen2
+    macx: EIGEN2_INCLUDEPATH = /opt/local/include/eigen2
+    linux*: EIGEN2_INCLUDEPATH = /usr/include/eigen2
+  }
+
   # eigen2 being under 'include/eigen2' needs special prepending
   QMAKE_INCDIR_QT = $$EIGEN2_INCLUDEPATH $$QMAKE_INCDIR_QT
 
diff --git a/openscad.pro b/openscad.pro
index 344363a..0feca74 100644
--- a/openscad.pro
+++ b/openscad.pro
@@ -146,6 +146,7 @@ HEADERS += src/renderer.h \
            src/builtin.h \
            src/context.h \
            src/csgterm.h \
+           src/csgtermnormalizer.h \
            src/dxfdata.h \
            src/dxfdim.h \
            src/dxftess.h \
@@ -197,6 +198,7 @@ SOURCES += src/mathc99.cc \
            src/node.cc \
            src/context.cc \
            src/csgterm.cc \
+           src/csgtermnormalizer.cc \
            src/polyset.cc \
            src/csgops.cc \
            src/transform.cc \
diff --git a/src/CGALCache.cc b/src/CGALCache.cc
index 6bdad41..84de722 100644
--- a/src/CGALCache.cc
+++ b/src/CGALCache.cc
@@ -7,7 +7,9 @@ CGALCache *CGALCache::inst = NULL;
 void CGALCache::insert(const std::string &id, const CGAL_Nef_polyhedron &N)
 {
 	this->cache.insert(id, new CGAL_Nef_polyhedron(N), N.weight());
+#ifdef DEBUG
 	PRINTF("CGAL Cache insert: %s (%d verts)", id.substr(0, 40).c_str(), N.weight());
+#endif
 }
 
 void CGALCache::print()
diff --git a/src/csgterm.cc b/src/csgterm.cc
index 890b0c9..4e6912b 100644
--- a/src/csgterm.cc
+++ b/src/csgterm.cc
@@ -139,127 +139,6 @@ void CSGTerm::initBoundingBox()
 	}
 }
 
-shared_ptr<CSGTerm> CSGTerm::normalize(shared_ptr<CSGTerm> term)
-{
-	// This function implements the CSG normalization
-  // Reference:
-	// Goldfeather, J., Molnar, S., Turk, G., and Fuchs, H. Near
-	// Realtime CSG Rendering Using Tree Normalization and Geometric
-	// Pruning. IEEE Computer Graphics and Applications, 9(3):20-28,
-	// 1989.
-  // http://www.cc.gatech.edu/~turk/my_papers/pxpl_csg.pdf
-
-	if (term->type == TYPE_PRIMITIVE) {
-		return term;
-	}
-
-	do {
-		while (term && normalize_tail(term)) { }
-		if (!term || term->type == TYPE_PRIMITIVE) return term;
-		term->left = normalize(term->left);
-	} while (term->type != TYPE_UNION &&
-					 (term->right->type != TYPE_PRIMITIVE || term->left->type == TYPE_UNION));
-	term->right = normalize(term->right);
-
-	// FIXME: Do we need to take into account any transformation of item here?
-	if (!term->right) {
-		if (term->type == TYPE_UNION || term->type == TYPE_DIFFERENCE) return term->left;
-		else return term->right;
-	}
-	if (!term->left) {
-		if (term->type == TYPE_UNION) return term->right;
-		else return term->left;
-	}
-
-	return term;
-}
-
-bool CSGTerm::normalize_tail(shared_ptr<CSGTerm> &term)
-{
-	if (term->type == TYPE_UNION || term->type == TYPE_PRIMITIVE) return false;
-
-	// Part A: The 'x . (y . z)' expressions
-
-	shared_ptr<CSGTerm> x = term->left;
-	shared_ptr<CSGTerm> y = term->right->left;
-	shared_ptr<CSGTerm> z = term->right->right;
-
-	shared_ptr<CSGTerm> result = term;
-
-	// 1.  x - (y + z) -> (x - y) - z
-	if (term->type == TYPE_DIFFERENCE && term->right->type == TYPE_UNION) {
-		term = createCSGTerm(TYPE_DIFFERENCE, 
-												 createCSGTerm(TYPE_DIFFERENCE, x, y),
-												 z);
-		return true;
-	}
-	// 2.  x * (y + z) -> (x * y) + (x * z)
-	else if (term->type == TYPE_INTERSECTION && term->right->type == TYPE_UNION) {
-		term = createCSGTerm(TYPE_UNION, 
-												 createCSGTerm(TYPE_INTERSECTION, x, y), 
-												 createCSGTerm(TYPE_INTERSECTION, x, z));
-		return true;
-	}
-	// 3.  x - (y * z) -> (x - y) + (x - z)
-	else if (term->type == TYPE_DIFFERENCE && term->right->type == TYPE_INTERSECTION) {
-		term = createCSGTerm(TYPE_UNION, 
-												 createCSGTerm(TYPE_DIFFERENCE, x, y), 
-												 createCSGTerm(TYPE_DIFFERENCE, x, z));
-		return true;
-	}
-	// 4.  x * (y * z) -> (x * y) * z
-	else if (term->type == TYPE_INTERSECTION && term->right->type == TYPE_INTERSECTION) {
-		term = createCSGTerm(TYPE_INTERSECTION, 
-												 createCSGTerm(TYPE_INTERSECTION, x, y),
-												 z);
-		return true;
-	}
-	// 5.  x - (y - z) -> (x - y) + (x * z)
-	else if (term->type == TYPE_DIFFERENCE && term->right->type == TYPE_DIFFERENCE) {
-		term = createCSGTerm(TYPE_UNION, 
-												 createCSGTerm(TYPE_DIFFERENCE, x, y), 
-												 createCSGTerm(TYPE_INTERSECTION, x, z));
-		return true;
-	}
-	// 6.  x * (y - z) -> (x * y) - z
-	else if (term->type == TYPE_INTERSECTION && term->right->type == TYPE_DIFFERENCE) {
-		term = createCSGTerm(TYPE_DIFFERENCE, 
-												 createCSGTerm(TYPE_INTERSECTION, x, y),
-												 z);
-		return true;
-	}
-
-	// Part B: The '(x . y) . z' expressions
-
-	x = term->left->left;
-	y = term->left->right;
-	z = term->right;
-
-	// 7. (x - y) * z  -> (x * z) - y
-	if (term->left->type == TYPE_DIFFERENCE && term->type == TYPE_INTERSECTION) {
-		term = createCSGTerm(TYPE_DIFFERENCE, 
-												 createCSGTerm(TYPE_INTERSECTION, x, z), 
-												 y);
-		return true;
-	}
-	// 8. (x + y) - z  -> (x - z) + (y - z)
-	else if (term->left->type == TYPE_UNION && term->type == TYPE_DIFFERENCE) {
-		term = createCSGTerm(TYPE_UNION, 
-												 createCSGTerm(TYPE_DIFFERENCE, x, z), 
-												 createCSGTerm(TYPE_DIFFERENCE, y, z));
-		return true;
-	}
-	// 9. (x + y) * z  -> (x * z) + (y * z)
-	else if (term->left->type == TYPE_UNION && term->type == TYPE_INTERSECTION) {
-		term = createCSGTerm(TYPE_UNION, 
-												 createCSGTerm(TYPE_INTERSECTION, x, z), 
-												 createCSGTerm(TYPE_INTERSECTION, y, z));
-		return true;
-	}
-
-	return false;
-}
-
 std::string CSGTerm::dump()
 {
 	std::stringstream dump;
diff --git a/src/csgterm.h b/src/csgterm.h
index 570af53..4278d85 100644
--- a/src/csgterm.h
+++ b/src/csgterm.h
@@ -33,9 +33,6 @@ public:
 
 	const BoundingBox &getBoundingBox() const { return this->bbox; }
 
-	static shared_ptr<CSGTerm> normalize(shared_ptr<CSGTerm> term);
-	static bool normalize_tail(shared_ptr<CSGTerm> &term);
-
 	std::string dump();
 private:
 	CSGTerm(type_e type, shared_ptr<CSGTerm> left, shared_ptr<CSGTerm> right);
diff --git a/src/csgtermnormalizer.cc b/src/csgtermnormalizer.cc
new file mode 100644
index 0000000..a830422
--- /dev/null
+++ b/src/csgtermnormalizer.cc
@@ -0,0 +1,150 @@
+#include "csgtermnormalizer.h"
+#include "csgterm.h"
+#include "printutils.h"
+
+shared_ptr<CSGTerm> CSGTermNormalizer::normalize(const shared_ptr<CSGTerm> &root)
+{
+	shared_ptr<CSGTerm> temp = root;
+	while (1) {
+		shared_ptr<CSGTerm> n = normalizePass(temp);
+		if (temp == n) break;
+		temp = n;
+
+		int num = count(temp);
+#ifdef DEBUG
+		PRINTF("Normalize count: %d\n", num);
+#endif
+		if (num > 5000) {
+			PRINTF("WARNING: Normalized tree is growing past 5000 elements. Aborting normalization.\n");
+			return root;
+		}
+	}
+	return temp;
+}
+
+shared_ptr<CSGTerm> CSGTermNormalizer::normalizePass(shared_ptr<CSGTerm> term)
+{
+	// This function implements the CSG normalization
+  // Reference:
+	// Goldfeather, J., Molnar, S., Turk, G., and Fuchs, H. Near
+	// Realtime CSG Rendering Using Tree Normalization and Geometric
+	// Pruning. IEEE Computer Graphics and Applications, 9(3):20-28,
+	// 1989.
+  // http://www.cc.gatech.edu/~turk/my_papers/pxpl_csg.pdf
+
+	if (term->type == CSGTerm::TYPE_PRIMITIVE) {
+		return term;
+	}
+
+	do {
+		while (term && normalize_tail(term)) { }
+		if (!term || term->type == CSGTerm::TYPE_PRIMITIVE) return term;
+		term->left = normalizePass(term->left);
+	} while (term->type != CSGTerm::TYPE_UNION &&
+					 (term->right->type != CSGTerm::TYPE_PRIMITIVE || term->left->type == CSGTerm::TYPE_UNION));
+	term->right = normalizePass(term->right);
+
+	// FIXME: Do we need to take into account any transformation of item here?
+	if (!term->right) {
+		if (term->type == CSGTerm::TYPE_UNION || term->type == CSGTerm::TYPE_DIFFERENCE) return term->left;
+		else return term->right;
+	}
+	if (!term->left) {
+		if (term->type == CSGTerm::TYPE_UNION) return term->right;
+		else return term->left;
+	}
+
+	return term;
+}
+
+bool CSGTermNormalizer::normalize_tail(shared_ptr<CSGTerm> &term)
+{
+	if (term->type == CSGTerm::TYPE_UNION || term->type == CSGTerm::TYPE_PRIMITIVE) return false;
+
+	// Part A: The 'x . (y . z)' expressions
+
+	shared_ptr<CSGTerm> x = term->left;
+	shared_ptr<CSGTerm> y = term->right->left;
+	shared_ptr<CSGTerm> z = term->right->right;
+
+	shared_ptr<CSGTerm> result = term;
+
+	// 1.  x - (y + z) -> (x - y) - z
+	if (term->type == CSGTerm::TYPE_DIFFERENCE && term->right->type == CSGTerm::TYPE_UNION) {
+		term = CSGTerm::createCSGTerm(CSGTerm::TYPE_DIFFERENCE, 
+												 CSGTerm::createCSGTerm(CSGTerm::TYPE_DIFFERENCE, x, y),
+												 z);
+		return true;
+	}
+	// 2.  x * (y + z) -> (x * y) + (x * z)
+	else if (term->type == CSGTerm::TYPE_INTERSECTION && term->right->type == CSGTerm::TYPE_UNION) {
+		term = CSGTerm::createCSGTerm(CSGTerm::TYPE_UNION, 
+												 CSGTerm::createCSGTerm(CSGTerm::TYPE_INTERSECTION, x, y), 
+												 CSGTerm::createCSGTerm(CSGTerm::TYPE_INTERSECTION, x, z));
+		return true;
+	}
+	// 3.  x - (y * z) -> (x - y) + (x - z)
+	else if (term->type == CSGTerm::TYPE_DIFFERENCE && term->right->type == CSGTerm::TYPE_INTERSECTION) {
+		term = CSGTerm::createCSGTerm(CSGTerm::TYPE_UNION, 
+												 CSGTerm::createCSGTerm(CSGTerm::TYPE_DIFFERENCE, x, y), 
+												 CSGTerm::createCSGTerm(CSGTerm::TYPE_DIFFERENCE, x, z));
+		return true;
+	}
+	// 4.  x * (y * z) -> (x * y) * z
+	else if (term->type == CSGTerm::TYPE_INTERSECTION && term->right->type == CSGTerm::TYPE_INTERSECTION) {
+		term = CSGTerm::createCSGTerm(CSGTerm::TYPE_INTERSECTION, 
+												 CSGTerm::createCSGTerm(CSGTerm::TYPE_INTERSECTION, x, y),
+												 z);
+		return true;
+	}
+	// 5.  x - (y - z) -> (x - y) + (x * z)
+	else if (term->type == CSGTerm::TYPE_DIFFERENCE && term->right->type == CSGTerm::TYPE_DIFFERENCE) {
+		term = CSGTerm::createCSGTerm(CSGTerm::TYPE_UNION, 
+												 CSGTerm::createCSGTerm(CSGTerm::TYPE_DIFFERENCE, x, y), 
+												 CSGTerm::createCSGTerm(CSGTerm::TYPE_INTERSECTION, x, z));
+		return true;
+	}
+	// 6.  x * (y - z) -> (x * y) - z
+	else if (term->type == CSGTerm::TYPE_INTERSECTION && term->right->type == CSGTerm::TYPE_DIFFERENCE) {
+		term = CSGTerm::createCSGTerm(CSGTerm::TYPE_DIFFERENCE, 
+												 CSGTerm::createCSGTerm(CSGTerm::TYPE_INTERSECTION, x, y),
+												 z);
+		return true;
+	}
+
+	// Part B: The '(x . y) . z' expressions
+
+	x = term->left->left;
+	y = term->left->right;
+	z = term->right;
+
+	// 7. (x - y) * z  -> (x * z) - y
+	if (term->left->type == CSGTerm::TYPE_DIFFERENCE && term->type == CSGTerm::TYPE_INTERSECTION) {
+		term = CSGTerm::createCSGTerm(CSGTerm::TYPE_DIFFERENCE, 
+												 CSGTerm::createCSGTerm(CSGTerm::TYPE_INTERSECTION, x, z), 
+												 y);
+		return true;
+	}
+	// 8. (x + y) - z  -> (x - z) + (y - z)
+	else if (term->left->type == CSGTerm::TYPE_UNION && term->type == CSGTerm::TYPE_DIFFERENCE) {
+		term = CSGTerm::createCSGTerm(CSGTerm::TYPE_UNION, 
+												 CSGTerm::createCSGTerm(CSGTerm::TYPE_DIFFERENCE, x, z), 
+												 CSGTerm::createCSGTerm(CSGTerm::TYPE_DIFFERENCE, y, z));
+		return true;
+	}
+	// 9. (x + y) * z  -> (x * z) + (y * z)
+	else if (term->left->type == CSGTerm::TYPE_UNION && term->type == CSGTerm::TYPE_INTERSECTION) {
+		term = CSGTerm::createCSGTerm(CSGTerm::TYPE_UNION, 
+												 CSGTerm::createCSGTerm(CSGTerm::TYPE_INTERSECTION, x, z), 
+												 CSGTerm::createCSGTerm(CSGTerm::TYPE_INTERSECTION, y, z));
+		return true;
+	}
+
+	return false;
+}
+
+int CSGTermNormalizer::count(const shared_ptr<CSGTerm> &term) const
+{
+	if (!term) return 0;
+	return term->type == CSGTerm::TYPE_PRIMITIVE ? 1 : 0 + count(term->left) + count(term->right);
+}
diff --git a/src/csgtermnormalizer.h b/src/csgtermnormalizer.h
new file mode 100644
index 0000000..df37441
--- /dev/null
+++ b/src/csgtermnormalizer.h
@@ -0,0 +1,22 @@
+#ifndef CSGTERMNORMALIZER_H_
+#define CSGTERMNORMALIZER_H_
+
+#include "memory.h"
+
+class CSGTermNormalizer
+{
+public:
+	CSGTermNormalizer() : counter(0) {}
+	~CSGTermNormalizer() {}
+
+	shared_ptr<class CSGTerm> normalize(const shared_ptr<CSGTerm> &term);
+
+private:
+	shared_ptr<CSGTerm> normalizePass(shared_ptr<CSGTerm> term) ;
+	bool normalize_tail(shared_ptr<CSGTerm> &term);
+	int count(const shared_ptr<CSGTerm> &term) const;
+
+	int counter;
+};
+
+#endif
diff --git a/src/mainwin.cc b/src/mainwin.cc
index a169ab1..1b90b60 100644
--- a/src/mainwin.cc
+++ b/src/mainwin.cc
@@ -45,6 +45,7 @@
 #include "ProgressWidget.h"
 #endif
 #include "ThrownTogetherRenderer.h"
+#include "csgtermnormalizer.h"
 
 #include <QMenu>
 #include <QTime>
@@ -782,15 +783,8 @@ void MainWindow::compileCSG(bool procevents)
 		if (procevents)
 			QApplication::processEvents();
 		
-		this->root_norm_term = this->root_raw_term;
-		
-		// CSG normalization
-		while (1) {
-			shared_ptr<CSGTerm> n = CSGTerm::normalize(this->root_norm_term);
-			if (this->root_norm_term == n) break;
-			this->root_norm_term = n;
-		}
-		
+		CSGTermNormalizer normalizer;
+		this->root_norm_term = normalizer.normalize(this->root_raw_term);
 		assert(this->root_norm_term);
 
 		root_chain = new CSGChain();
@@ -804,11 +798,7 @@ void MainWindow::compileCSG(bool procevents)
 			
 			highlights_chain = new CSGChain();
 			for (unsigned int i = 0; i < highlight_terms.size(); i++) {
-				while (1) {
-					shared_ptr<CSGTerm> n = CSGTerm::normalize(highlight_terms[i]);
-					if (highlight_terms[i] == n) break;
-					highlight_terms[i] = n;
-				}
+				highlight_terms[i] = normalizer.normalize(highlight_terms[i]);
 				highlights_chain->import(highlight_terms[i]);
 			}
 		}
@@ -821,11 +811,7 @@ void MainWindow::compileCSG(bool procevents)
 			
 			background_chain = new CSGChain();
 			for (unsigned int i = 0; i < background_terms.size(); i++) {
-				while (1) {
-					shared_ptr<CSGTerm> n = CSGTerm::normalize(background_terms[i]);
-					if (background_terms[i] == n) break;
-					background_terms[i] = n;
-				}
+				background_terms[i] = normalizer.normalize(background_terms[i]);
 				background_chain->import(background_terms[i]);
 			}
 		}
diff --git a/src/openscad.cc b/src/openscad.cc
index 0d5b25e..c6dd7b6 100644
--- a/src/openscad.cc
+++ b/src/openscad.cc
@@ -364,6 +364,10 @@ int main(int argc, char **argv)
 			}
 			
 			if (dxf_output_file) {
+				if (root_N.dim != 2) {
+					fprintf(stderr, "Current top level object is not a 2D object.\n");
+					exit(1);
+				}
 				std::ofstream fstream(dxf_output_file);
 				if (!fstream.is_open()) {
 					PRINTF("Can't open file \"%s\" for export", dxf_output_file);
diff --git a/testdata/scad/features/cylinder-tests.scad b/testdata/scad/features/cylinder-tests.scad
index 54e88cd..71f43a6 100644
--- a/testdata/scad/features/cylinder-tests.scad
+++ b/testdata/scad/features/cylinder-tests.scad
@@ -12,4 +12,9 @@ translate([22,-11,0]) cylinder(h=5, r=5, r1=0, center=true);
 translate([22,0,0]) cylinder(h=5, r=5, r2=0);
 translate([22,11,0]) cylinder(h=15, r=5, r2=5);
 
+// This tests for hexagonal cylinder orientation, since people
+// tend to "abuse" this for captured nut slots
+translate([-10,0,0]) cylinder(h=2, r=3, $fn=6);
+
+
 // FIXME: We could test $fs, $fa, $fn as well
diff --git a/tests/CMakeLists.txt b/tests/CMakeLists.txt
index b374188..21cee6b 100644
--- a/tests/CMakeLists.txt
+++ b/tests/CMakeLists.txt
@@ -64,43 +64,64 @@ endif()
 # Build test apps
 #
 
+function(inclusion user_set_path found_paths)
+  # This function exists as a wrapper for INCLUDE_DIRECTORIES
+  # to deal with systems in which some libraries are found 
+  # in the system paths, (/usr) but others are found in customized 
+  # paths set in environment variables (CGAL_DIR). 
+  # message(STATUS "inclusion ${user_set_path} ${found_paths}")
+  # message(STATUS "inclusion ${${user_set_path}} ${${found_paths}}")
+  set( inclusion_match 0 )
+  foreach( found_path ${${found_paths}} )
+    if (${found_path} MATCHES ${${user_set_path}}.*)
+      set( inclusion_match 1 )
+    endif()
+  endforeach()
+  if (user_set_path AND inclusion_match)
+    include_directories(BEFORE ${${found_paths}})
+    # message(STATUS "inclusion prepend ${${found_paths}} for ${user_set_path}")
+  else()
+    include_directories(AFTER ${${found_paths}})
+    # message(STATUS "inclusion append ${${found_paths}} for ${user_set_path}")
+  endif()
+  set( inclusion_match 0 )
+endfunction()
+
 # Boost
+# Update this if FindBoost.cmake gets out of sync with the current boost release
+# set(Boost_ADDITIONAL_VERSIONS "1.47.0" "1.46.0")
+
+if (WIN32)
+  set(Boost_USE_STATIC_LIBS TRUE)
+  set(BOOST_STATIC TRUE)
+  set(BOOST_THREAD_USE_LIB TRUE)
+endif()
+
 if (NOT $ENV{OPENSCAD_LIBRARIES} STREQUAL "")
   set(BOOST_ROOT "$ENV{OPENSCAD_LIBRARIES}")
+  if (EXISTS ${BOOST_ROOT}/include/boost)
+    # if boost is under OPENSCAD_LIBRARIES, then 
+    # don't look in the system paths (workaround FindBoost.cmake bug)
+    set(Boost_NO_SYSTEM_PATHS "TRUE")
+    message(STATUS "BOOST_ROOT: " ${BOOST_ROOT})
+  endif()
 endif()
 
 if (NOT $ENV{BOOSTDIR} STREQUAL "")
-  set(BOOST_DIR "$ENV{BOOSTDIR}")
-endif()
-
-if (NOT ${BOOST_DIR} STREQUAL "")
-  set(BOOST_ROOT ${BOOST_DIR})
-  message(STATUS "BOOST_ROOT: " ${BOOST_ROOT})
+  set(BOOST_ROOT "$ENV{BOOSTDIR}")
   set(Boost_NO_SYSTEM_PATHS "TRUE")
   set(Boost_DEBUG TRUE)
+  message(STATUS "BOOST_ROOT: " ${BOOST_ROOT})
 endif()
 
-
-if (WIN32)
-  set(Boost_USE_STATIC_LIBS TRUE)
-  set(BOOST_STATIC TRUE)
-  set(BOOST_THREAD_USE_LIB TRUE)
-endif()
-
-# Update this if FindBoost.cmake gets out of sync with the current boost release
-# set(Boost_ADDITIONAL_VERSIONS "1.47.0" "1.46.0")
 find_package( Boost 1.35.0 COMPONENTS thread program_options REQUIRED)
-if(Boost_FOUND)
-  message(STATUS "Boost includes found: " ${Boost_INCLUDE_DIRS})
-  message(STATUS "Boost libraries found:")
-  foreach(boostlib ${Boost_LIBRARIES})
-    message(STATUS "  " ${boostlib})
-  endforeach()
-  include_directories(${Boost_INCLUDE_DIRS})
-else()
-  message(STATUS "BOOST_ROOT: ${BOOST_ROOT}")
-  message(FATAL_ERROR "Boost not found.")
-endif()
+message(STATUS "Boost includes found: " ${Boost_INCLUDE_DIRS})
+message(STATUS "Boost libraries found:")
+foreach(boostlib ${Boost_LIBRARIES})
+  message(STATUS "  " ${boostlib})
+endforeach()
+
+inclusion(BOOST_ROOT Boost_INCLUDE_DIRS)
 
 # Mac OS X
 if(${CMAKE_SYSTEM_NAME} MATCHES "Darwin")
@@ -109,18 +130,11 @@ endif(${CMAKE_SYSTEM_NAME} MATCHES "Darwin")
 
 # Qt4
 
-if(${CMAKE_SYSTEM_NAME} MATCHES "FreeBSD")
-  # make /usr/local/include/qt4 come before /usr/local/include (QT4 vs QT3)
-  set(CMAKE_INCLUDE_DIRECTORIES_BEFORE ON)
-endif()
-
+set(CMAKE_INCLUDE_DIRECTORIES_BEFORE ON)
 find_package(OpenGL REQUIRED)
 find_package(Qt4 COMPONENTS QtCore QtGui QtOpenGL REQUIRED)
 include(${QT_USE_FILE})
-
-if(${CMAKE_SYSTEM_NAME} MATCHES "FreeBSD")
-  set(CMAKE_INCLUDE_DIRECTORIES_BEFORE OFF)
-endif()
+set(CMAKE_INCLUDE_DIRECTORIES_BEFORE OFF)
 
 # Eigen2
 
@@ -131,24 +145,32 @@ if(NOT ${CMAKE_SYSTEM_NAME} MATCHES "Darwin")
   endif()
 endif()
 
+if (NOT $ENV{EIGEN2DIR} STREQUAL "")
+  set(EIGEN2_DIR "$ENV{EIGEN2DIR}")
+elseif (NOT $ENV{OPENSCAD_LIBRARIES} STREQUAL "")
+  set(EIGEN2_DIR "$ENV{OPENSCAD_LIBRARIES}")
+endif()
+
 if (NOT EIGEN2_INCLUDE_DIR)
+  if (EIGEN2_DIR)
+    set(EIGEN2_FIND_HINTS "${EIGEN2_DIR}/include/eigen2")
+  endif()
+  if (${CMAKE_SYSTEM_NAME} MATCHES "FreeBSD")
+    set(EIGEN2_FIND_PATHS /usr/local/include/eigen2)
+  else()
+    set(EIGEN2_FIND_PATHS /opt/local/include/eigen2 /usr/include/eigen2)
+  endif()
   find_path(EIGEN2_INCLUDE_DIR
             Eigen/Core 
-            HINTS $ENV{EIGEN2DIR}
-            PATHS /opt/local/include/eigen2 /usr/include/eigen2)
-  if (${CMAKE_SYSTEM_NAME} MATCHES "FreeBSD") 
-    find_path(EIGEN2_INCLUDE_DIR 
-              Eigen/Core 
-              HINTS $ENV{EIGEN2DIR}
-              PATHS /usr/local/include/eigen2 )
-  endif()
+            HINTS ${EIGEN2_FIND_HINTS}
+            PATHS ${EIGEN2_FIND_PATHS})
   if (NOT EIGEN2_INCLUDE_DIR)
     message(FATAL_ERROR "Eigen2 not found")
   else()
     message(STATUS "Eigen2 found in " ${EIGEN2_INCLUDE_DIR})
   endif()
 endif()
-include_directories(${EIGEN2_INCLUDE_DIR})
+inclusion(EIGEN2_DIR EIGEN2_INCLUDE_DIR)
 
 # OpenCSG
 if (NOT $ENV{OPENCSGDIR} STREQUAL "")
@@ -171,10 +193,14 @@ if (NOT OPENCSG_INCLUDE_DIR)
     message(STATUS "OpenCSG library found in " ${OPENCSG_LIBRARY})
   endif()
 endif()
-include_directories(${OPENCSG_INCLUDE_DIR})
+inclusion(OPENCSG_DIR OPENCSG_INCLUDE_DIR)
 
 # GLEW
 
+if(WIN32_STATIC_BUILD)
+  set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -DGLEW_STATIC")
+endif()
+
 if (NOT $ENV{GLEWDIR} STREQUAL "")
   set(GLEW_DIR "$ENV{GLEWDIR}")
 elseif (NOT $ENV{OPENSCAD_LIBRARIES} STREQUAL "")
@@ -182,11 +208,8 @@ elseif (NOT $ENV{OPENSCAD_LIBRARIES} STREQUAL "")
 endif()
 
 find_package(GLEW REQUIRED)
-include_directories(${GLEW_INCLUDE_PATH})
 
-if(WIN32_STATIC_BUILD)
-  set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -DGLEW_STATIC")
-endif()
+inclusion( GLEW_DIR GLEW_INCLUDE_PATH )
 
 # Flex/Bison
 find_package(BISON REQUIRED)
@@ -211,8 +234,13 @@ set_source_files_properties(${CMAKE_CURRENT_BINARY_DIR}/parser_yacc.c PROPERTIES
 if (NOT $ENV{CGALDIR} STREQUAL "")
   set(CGAL_DIR "$ENV{CGALDIR}")
 elseif (NOT $ENV{OPENSCAD_LIBRARIES} STREQUAL "")
-  set(CGAL_DIR "$ENV{OPENSCAD_LIBRARIES}/lib/CGAL")
-  set(CMAKE_MODULE_PATH "${CGAL_DIR}")
+  if (EXISTS "$ENV{OPENSCAD_LIBRARIES}/lib/CGAL")
+    set(CGAL_DIR "$ENV{OPENSCAD_LIBRARIES}/lib/CGAL")
+    set(CMAKE_MODULE_PATH "${CGAL_DIR}")
+  elseif (EXISTS "$ENV{OPENSCAD_LIBRARIES}/include/CGAL")
+    set(CGAL_DIR "$ENV{OPENSCAD_LIBRARIES}")
+    set(CMAKE_MODULE_PATH "${CGAL_DIR}")
+  endif()
 endif()
 message(STATUS "CGAL_DIR: " ${CGAL_DIR})
 find_package(CGAL REQUIRED)
@@ -224,7 +252,7 @@ message(STATUS "CGAL libraries found in " ${CGAL_LIBRARIES_DIR} )
 if("${CGAL_MAJOR_VERSION}.${CGAL_MINOR_VERSION}" VERSION_LESS 3.6)
   message(FATAL_ERROR "CGAL >= 3.6 required")
 endif()
-include_directories(${CGAL_INCLUDE_DIRS})
+inclusion(CGAL_DIR CGAL_INCLUDE_DIRS)
 
 # Imagemagick
 
@@ -253,6 +281,7 @@ set(CORE_SOURCES
   ../src/node.cc 
   ../src/context.cc 
   ../src/csgterm.cc 
+  ../src/csgtermnormalizer.cc 
   ../src/polyset.cc 
   ../src/csgops.cc 
   ../src/transform.cc 
@@ -453,8 +482,8 @@ endfunction()
 # comparison method to use
 if (NOT $ENV{COMPARATOR} STREQUAL "")
   set(COMPARATOR "$ENV{COMPARATOR}")
+  message(STATUS "ImageMagick method modified with COMPARATOR: " ${COMPARATOR})
 endif()
-message(STATUS "COMPARATOR: " ${COMPARATOR})
 
 #
 # This functions adds cmd-line tests given files.
diff --git a/tests/csgtestcore.cc b/tests/csgtestcore.cc
index c2be326..e8a6878 100644
--- a/tests/csgtestcore.cc
+++ b/tests/csgtestcore.cc
@@ -19,6 +19,7 @@
 #include "ThrownTogetherRenderer.h"
 
 #include "csgterm.h"
+#include "csgtermnormalizer.h"
 #include "OffscreenView.h"
 
 #include <QApplication>
@@ -315,12 +316,8 @@ int csgtestcore(int argc, char *argv[], test_type_e test_type)
 	}
 
 	// CSG normalization
-	csgInfo.root_norm_term = root_raw_term;
-	while (1) {
-		shared_ptr<CSGTerm> n = CSGTerm::normalize(csgInfo.root_norm_term);
-		if (csgInfo.root_norm_term == n) break;
-		csgInfo.root_norm_term = n;
-	}
+	CSGTermNormalizer normalizer;
+	csgInfo.root_norm_term = normalizer.normalize(root_raw_term);
 		
 	assert(csgInfo.root_norm_term);
 
@@ -333,11 +330,7 @@ int csgtestcore(int argc, char *argv[], test_type_e test_type)
 		
 		csgInfo.highlights_chain = new CSGChain();
 		for (unsigned int i = 0; i < csgInfo.highlight_terms.size(); i++) {
-			while (1) {
-				shared_ptr<CSGTerm> n = CSGTerm::normalize(csgInfo.highlight_terms[i]);
-				if (csgInfo.highlight_terms[i] == n) break;
-				csgInfo.highlight_terms[i] = n;
-			}
+			csgInfo.highlight_terms[i] = normalizer.normalize(csgInfo.highlight_terms[i]);
 			csgInfo.highlights_chain->import(csgInfo.highlight_terms[i]);
 		}
 	}
@@ -347,11 +340,7 @@ int csgtestcore(int argc, char *argv[], test_type_e test_type)
 		
 		csgInfo.background_chain = new CSGChain();
 		for (unsigned int i = 0; i < csgInfo.background_terms.size(); i++) {
-			while (1) {
-				shared_ptr<CSGTerm> n = CSGTerm::normalize(csgInfo.background_terms[i]);
-				if (csgInfo.background_terms[i] == n) break;
-				csgInfo.background_terms[i] = n;
-			}
+			csgInfo.background_terms[i] = normalizer.normalize(csgInfo.background_terms[i]);
 			csgInfo.background_chain->import(csgInfo.background_terms[i]);
 		}
 	}
diff --git a/tests/regression/cgalpngtest/cylinder-tests-expected.png b/tests/regression/cgalpngtest/cylinder-tests-expected.png
index 9d96df2..843d70f 100644
--- a/tests/regression/cgalpngtest/cylinder-tests-expected.png
+++ b/tests/regression/cgalpngtest/cylinder-tests-expected.png
diff --git a/tests/regression/dumptest/cylinder-tests-expected.txt b/tests/regression/dumptest/cylinder-tests-expected.txt
index 2ac2549..b1e8b6e 100644
--- a/tests/regression/dumptest/cylinder-tests-expected.txt
+++ b/tests/regression/dumptest/cylinder-tests-expected.txt
@@ -29,4 +29,7 @@
 	multmatrix([[1, 0, 0, 22], [0, 1, 0, 11], [0, 0, 1, 0], [0, 0, 0, 1]]) {
 		cylinder($fn = 0, $fa = 12, $fs = 2, h = 15, r1 = 5, r2 = 5, center = false);
 	}
+	multmatrix([[1, 0, 0, -10], [0, 1, 0, 0], [0, 0, 1, 0], [0, 0, 0, 1]]) {
+		cylinder($fn = 6, $fa = 12, $fs = 2, h = 2, r1 = 3, r2 = 3, center = false);
+	}
 
diff --git a/tests/regression/opencsgtest/cylinder-tests-expected.png b/tests/regression/opencsgtest/cylinder-tests-expected.png
index 17c10b8..4c7ab79 100644
--- a/tests/regression/opencsgtest/cylinder-tests-expected.png
+++ b/tests/regression/opencsgtest/cylinder-tests-expected.png
diff --git a/tests/regression/throwntogethertest/cylinder-tests-expected.png b/tests/regression/throwntogethertest/cylinder-tests-expected.png
index 0a3ed33..4c7ab79 100644
--- a/tests/regression/throwntogethertest/cylinder-tests-expected.png
+++ b/tests/regression/throwntogethertest/cylinder-tests-expected.png