From 2da15511294d2f89f2337ee0330db9062a4cfdce Mon Sep 17 00:00:00 2001
From: clifford <clifford@b57f626f-c46c-0410-a088-ec61d464b74c>
Date: Sat, 30 Jan 2010 18:30:54 +0000
Subject: Clifford Wolf: 	Started to use eigen2 for linear algebra
 problems

git-svn-id: http://svn.clifford.at/openscad/trunk@376 b57f626f-c46c-0410-a088-ec61d464b74c

diff --git a/README b/README
index 86669bb..9288811 100644
--- a/README
+++ b/README
@@ -52,6 +52,9 @@ development. Other versions may or may not work as well..
 * GLEW (bundled with OpenCSG)
   http://glew.sourceforge.net/
 
+* Eigen2 (2.0.11)
+  http://eigen.tuxfamily.org/
+
 * GCC C++ Compiler (4.0, 4.2, 4.3.1):
   http://gcc.gnu.org/
 
diff --git a/openscad.pro b/openscad.pro
index cb8afe7..60b9ab4 100644
--- a/openscad.pro
+++ b/openscad.pro
@@ -39,6 +39,13 @@ mdi {
 include(cgal.pri)
 include(opencsg.pri)
 
+!isEmpty(EIGEN2_DIR) {
+  QMAKE_CXXFLAGS += -I$$EIGEN2_DIR
+}
+else {
+  QMAKE_CXXFLAGS += -I/usr/include/eigen2
+}
+
 QMAKE_CXXFLAGS_RELEASE = -O3 -march=pentium
 QMAKE_CXXFLAGS_DEBUG = -O0 -ggdb
 
@@ -46,8 +53,6 @@ QMAKE_CXXFLAGS_DEBUG = -O0 -ggdb
 # QMAKE_CXXFLAGS += -pg
 # QMAKE_LFLAGS   += -pg
 
-
-
 LEXSOURCES += src/lexer.l
 YACCSOURCES += src/parser.y
 
diff --git a/src/polyset.cc b/src/polyset.cc
index 7110f95..83c1cfc 100644
--- a/src/polyset.cc
+++ b/src/polyset.cc
@@ -25,6 +25,9 @@
 #include "printutils.h"
 #include "Preferences.h"
 
+#include <Eigen/Core>
+#include <Eigen/LU>
+
 QCache<QString,PolySet::ps_cache_entry> PolySet::ps_cache(100);
 
 PolySet::ps_cache_entry::ps_cache_entry(PolySet *ps) :
@@ -129,10 +132,11 @@ static void gl_draw_triangle(GLint *shaderinfo, const PolySet::Point *p0, const
 
 void PolySet::render_surface(colormode_e colormode, csgmode_e csgmode, double *m, GLint *shaderinfo) const
 {
-	double m_scale_rotate_det =
-		m[0]*m[5]*m[10] + m[4]*m[9]*m[2] + m[8]*m[1]*m[6] -
-		(m[8]*m[5]*m[2] + m[4]*m[1]*m[10] + m[0]*m[9]*m[6]);
-	bool mirrored = m_scale_rotate_det < 0;
+	Eigen::Matrix3f m3f;
+	m3f << m[0], m[4], m[8],
+		m[1], m[5], m[9],
+		m[2], m[6], m[10];
+	bool mirrored = m3f.determinant() < 0;
 
 	if (colormode == COLORMODE_MATERIAL) {
 		const QColor &col = Preferences::inst()->color(Preferences::OPENCSG_FACE_FRONT_COLOR);
-- 
cgit v0.10.1