bugfix: Fix crash bug when using zero scale factors. Reported by Alan Cox

6 files changed, 61 insertions, 42 deletions

diff --git a/src/CGALEvaluator.cc b/src/CGALEvaluator.cc
index 15fa746..0e849a8 100644
--- a/src/CGALEvaluator.cc
+++ b/src/CGALEvaluator.cc
@@ -252,31 +252,45 @@ Response CGALEvaluator::visit(State &state, const TransformNode &node)
 				// objects. So we convert in to our internal 2d data format, transform it,
 				// tesselate it and create a new CGAL_Nef_polyhedron2 from it.. What a hack!
 				
-				CGAL_Aff_transformation2 t(
-					node.matrix(0,0), node.matrix(0,1), node.matrix(0,3),
-					node.matrix(1,0), node.matrix(1,1), node.matrix(1,3), node.matrix(3,3));
-				
-				DxfData *dd = N.convertToDxfData();
-				for (size_t i=0; i < dd->points.size(); i++) {
-					CGAL_Kernel2::Point_2 p = CGAL_Kernel2::Point_2(dd->points[i][0], dd->points[i][1]);
-					p = t.transform(p);
-					dd->points[i][0] = to_double(p.x());
-					dd->points[i][1] = to_double(p.y());
+				Eigen::Matrix2f testmat;
+				testmat << node.matrix(0,0), node.matrix(0,1), node.matrix(1,0), node.matrix(1,1);
+				if (testmat.determinant() == 0) {
+					PRINT("Warning: Scaling a 2D object with 0 - removing object");
+					N.p2.reset();
+				}
+				else {
+					CGAL_Aff_transformation2 t(
+						node.matrix(0,0), node.matrix(0,1), node.matrix(0,3),
+						node.matrix(1,0), node.matrix(1,1), node.matrix(1,3), node.matrix(3,3));
+					
+					DxfData *dd = N.convertToDxfData();
+					for (size_t i=0; i < dd->points.size(); i++) {
+						CGAL_Kernel2::Point_2 p = CGAL_Kernel2::Point_2(dd->points[i][0], dd->points[i][1]);
+						p = t.transform(p);
+						dd->points[i][0] = to_double(p.x());
+						dd->points[i][1] = to_double(p.y());
+					}
+					
+					PolySet ps;
+					ps.is2d = true;
+					dxf_tesselate(&ps, *dd, 0, true, false, 0);
+					
+					N = evaluateCGALMesh(ps);
+					delete dd;
 				}
-				
-				PolySet ps;
-				ps.is2d = true;
-				dxf_tesselate(&ps, *dd, 0, true, false, 0);
-				
-				N = evaluateCGALMesh(ps);
-				delete dd;
 			}
 			else if (N.dim == 3) {
-				CGAL_Aff_transformation t(
-					node.matrix(0,0), node.matrix(0,1), node.matrix(0,2), node.matrix(0,3),
-					node.matrix(1,0), node.matrix(1,1), node.matrix(1,2), node.matrix(1,3),
-					node.matrix(2,0), node.matrix(2,1), node.matrix(2,2), node.matrix(2,3), node.matrix(3,3));
-				N.p3->transform(t);
+				if (node.matrix.matrix().determinant() == 0) {
+					PRINT("Warning: Scaling a 3D object with 0 - removing object");
+					N.p3.reset();
+				}
+				else {
+					CGAL_Aff_transformation t(
+						node.matrix(0,0), node.matrix(0,1), node.matrix(0,2), node.matrix(0,3),
+						node.matrix(1,0), node.matrix(1,1), node.matrix(1,2), node.matrix(1,3),
+						node.matrix(2,0), node.matrix(2,1), node.matrix(2,2), node.matrix(2,3), node.matrix(3,3));
+					N.p3->transform(t);
+				}
 			}
 		}
 		else {
diff --git a/src/CGAL_Nef_polyhedron.cc b/src/CGAL_Nef_polyhedron.cc
index 04783e5..ba298ad 100644
--- a/src/CGAL_Nef_polyhedron.cc
+++ b/src/CGAL_Nef_polyhedron.cc
@@ -61,6 +61,8 @@ CGAL_Nef_polyhedron &CGAL_Nef_polyhedron::minkowski(const CGAL_Nef_polyhedron &o
 
 int CGAL_Nef_polyhedron::weight() const
 {
+	if (this->empty()) return 0;
+
 	size_t memsize = sizeof(CGAL_Nef_polyhedron);
 	if (this->dim == 2) {
 		memsize += sizeof(CGAL_Nef_polyhedron2) +
diff --git a/src/PolySetCGALEvaluator.cc b/src/PolySetCGALEvaluator.cc
index 81ae31e..6ed1ab4 100644
--- a/src/PolySetCGALEvaluator.cc
+++ b/src/PolySetCGALEvaluator.cc
@@ -281,12 +281,14 @@ PolySet *PolySetCGALEvaluator::evaluatePolySet(const LinearExtrudeNode &node)
 		BOOST_FOREACH (AbstractNode * v, node.getChildren()) {
 			if (v->modinst->isBackground()) continue;
 			CGAL_Nef_polyhedron N = this->cgalevaluator.evaluateCGALMesh(*v);
-			if (N.dim != 2) {
-				PRINT("ERROR: linear_extrude() is not defined for 3D child objects!");
-			}
-			else {
-				if (sum.empty()) sum = N.copy();
-				else sum += N;
+			if (!N.empty()) {
+				if (N.dim != 2) {
+					PRINT("ERROR: linear_extrude() is not defined for 3D child objects!");
+				}
+				else {
+					if (sum.empty()) sum = N.copy();
+					else sum += N;
+				}
 			}
 		}
 
@@ -379,12 +381,14 @@ PolySet *PolySetCGALEvaluator::evaluatePolySet(const RotateExtrudeNode &node)
 		BOOST_FOREACH (AbstractNode * v, node.getChildren()) {
 			if (v->modinst->isBackground()) continue;
 			CGAL_Nef_polyhedron N = this->cgalevaluator.evaluateCGALMesh(*v);
-			if (N.dim != 2) {
-				PRINT("ERROR: rotate_extrude() is not defined for 3D child objects!");
-			}
-			else {
-				if (sum.empty()) sum = N.copy();
-				else sum += N;
+			if (!N.empty()) {
+				if (N.dim != 2) {
+					PRINT("ERROR: rotate_extrude() is not defined for 3D child objects!");
+				}
+				else {
+					if (sum.empty()) sum = N.copy();
+					else sum += N;
+				}
 			}
 		}
 
diff --git a/src/transform.cc b/src/transform.cc
index f5038b1..c2ac194 100644
--- a/src/transform.cc
+++ b/src/transform.cc
@@ -87,11 +87,10 @@ AbstractNode *TransformModule::evaluate(const Context *ctx, const ModuleInstanti
 	{
 		Vector3d scalevec(1,1,1);
 		Value v = c.lookup_variable("v");
-		v.getnum(scalevec[0]);
-		v.getnum(scalevec[1]);
-		v.getnum(scalevec[2]);
-		v.getv3(scalevec[0], scalevec[1], scalevec[2]);
-		if (scalevec[2] == 0) scalevec[2] = 1;
+		if (!v.getv3(scalevec[0], scalevec[1], scalevec[2], 1.0)) {
+			double num;
+			if (v.getnum(num)) scalevec.setConstant(num);
+		}
 		node->matrix.scale(scalevec);
 	}
 	else if (this->type == ROTATE)
diff --git a/src/value.cc b/src/value.cc
index c9dbd55..93c4d5e 100644
--- a/src/value.cc
+++ b/src/value.cc
@@ -359,11 +359,11 @@ bool Value::getv2(double &x, double &y) const
 	return true;
 }
 
-bool Value::getv3(double &x, double &y, double &z) const
+bool Value::getv3(double &x, double &y, double &z, double defaultval) const
 {
 	if (this->type == VECTOR && this->vec.size() == 2) {
 		if (getv2(x, y)) {
-			z = 0;
+			z = defaultval;
 			return true;
 		}
 		return false;
diff --git a/src/value.h b/src/value.h
index a2cfbdf..4a67fbc 100644
--- a/src/value.h
+++ b/src/value.h
@@ -73,7 +73,7 @@ public:
 
 	bool getnum(double &v) const;
 	bool getv2(double &x, double &y) const;
-	bool getv3(double &x, double &y, double &z) const;
+	bool getv3(double &x, double &y, double &z, double defaultval = 0.0) const;
 
 	std::string toString() const;