diff --git a/src/osgPlugins/dxf/dxfBlock.h b/src/osgPlugins/dxf/dxfBlock.h
index 820b2ab29..8d568f8db 100644
--- a/src/osgPlugins/dxf/dxfBlock.h
+++ b/src/osgPlugins/dxf/dxfBlock.h
@@ -19,6 +19,7 @@
 
 #include <osg/Referenced>
 #include <osg/Vec3d>
+#include <osg/ref_ptr>
 
 class dxfFile;
 class codeValue;
@@ -27,17 +28,17 @@ class dxfEntity;
 class dxfBlock : public osg::Referenced
 {
 public:
-	dxfBlock() : _currentEntity(NULL) {}
-	virtual ~dxfBlock() {}
-	inline const std::string& getName() const { return _name; }
-	virtual void assign(dxfFile* dxf, codeValue& cv);
-	std::vector<dxfEntity*> getEntityList() { return _entityList; }
-	const osg::Vec3d& getPosition() const;
+    dxfBlock() : _currentEntity(NULL) {}
+    virtual ~dxfBlock() {}
+    inline const std::string& getName() const { return _name; }
+    virtual void assign(dxfFile* dxf, codeValue& cv);
+    std::vector<osg::ref_ptr<dxfEntity> > & getEntityList() { return _entityList; }
+    const osg::Vec3d& getPosition() const;
 protected:
-	std::vector<dxfEntity*> _entityList;
-	dxfEntity* _currentEntity;
-	std::string _name;
-	osg::Vec3d _position;
+    std::vector<osg::ref_ptr<dxfEntity> > _entityList;
+    dxfEntity* _currentEntity;
+    std::string _name;
+    osg::Vec3d _position;
 };
 
 #endif
diff --git a/src/osgPlugins/dxf/dxfEntity.cpp b/src/osgPlugins/dxf/dxfEntity.cpp
index 959eb249f..7881cf570 100644
--- a/src/osgPlugins/dxf/dxfEntity.cpp
+++ b/src/osgPlugins/dxf/dxfEntity.cpp
@@ -418,8 +418,8 @@ dxfPolyline::drawScene(scene* sc)
         Vec3d nr;
         bool nset = false;
         //dxfVertex* v = NULL;
-        unsigned short ncount;
-        unsigned short mcount;
+        unsigned int ncount;
+        unsigned int mcount;
         if (_surfacetype == 6) { 
             // I dont have examples of type 5 and 8, but they may be the same as 6
             mcount = _mdensity;
@@ -428,8 +428,8 @@ dxfPolyline::drawScene(scene* sc)
             mcount = _mcount;
             ncount = _ncount;
         }
-        for (unsigned short n = 0; n < ncount-1; n++) {
-            for (unsigned short m = 1; m < mcount; m++) {
+        for (unsigned int n = 0; n < ncount-1; n++) {
+            for (unsigned int m = 1; m < mcount; m++) {
                 // 0
                 a = _vertices[(m-1)*ncount+n].get()->getVertex();
                 // 1
@@ -463,7 +463,7 @@ dxfPolyline::drawScene(scene* sc)
             }
         }
         if (_flag & 1) {
-            for (unsigned short n = 0; n < ncount-1; n++) {
+            for (unsigned int n = 0; n < ncount-1; n++) {
                 // 0
                 a = _vertices[(mcount-1)*ncount+n].get()->getVertex();
                 // 1
@@ -492,7 +492,7 @@ dxfPolyline::drawScene(scene* sc)
             }
         }
         if (_flag & 32) {
-            for (unsigned short m = 1; m < mcount; m++) {
+            for (unsigned int m = 1; m < mcount; m++) {
                 // 0
                 a = _vertices[(m-1)*ncount+(ncount-1)].get()->getVertex();
                 // 1
@@ -553,7 +553,7 @@ dxfPolyline::drawScene(scene* sc)
     } else if (_flag & 64) { 
         unsigned short _facetype = 3;
 
-        for (unsigned short i = 0; i < _indices.size(); i++) {
+        for (unsigned int i = 0; i < _indices.size(); i++) {
             dxfVertex* vindice = _indices[i].get();
             if (!vindice) continue;
             if (vindice->getIndice4()) {
@@ -751,8 +751,8 @@ dxfInsert::drawScene(scene* sc)
     sc->pushMatrix(m);
     sc->pushMatrix(back);
 
-    std::vector<dxfEntity*> l = _block->getEntityList();
-    for (std::vector<dxfEntity*>::iterator itr = l.begin(); itr != l.end(); ++itr) {
+    std::vector<osg::ref_ptr<dxfEntity> > l = _block->getEntityList();
+    for (std::vector<osg::ref_ptr<dxfEntity> >::iterator itr = l.begin(); itr != l.end(); ++itr) {
         dxfBasicEntity* e = (*itr)->getEntity();
         if (e) {
             e->drawScene(sc);
diff --git a/src/osgPlugins/dxf/dxfEntity.h b/src/osgPlugins/dxf/dxfEntity.h
index 95787f5ca..b6591c0f1 100644
--- a/src/osgPlugins/dxf/dxfEntity.h
+++ b/src/osgPlugins/dxf/dxfEntity.h
@@ -147,14 +147,14 @@ public:
     virtual void assign(dxfFile* dxf, codeValue& cv);
     void getVertex(double &x, double &y, double &z) { x=_vertex.x();y=_vertex.y();z=_vertex.z(); }
     const osg::Vec3d& getVertex() const { return _vertex; }
-    const unsigned short getIndice1() const { return _indice1; }
-    const unsigned short getIndice2() const { return _indice2; }
-    const unsigned short getIndice3() const { return _indice3; }
-    const unsigned short getIndice4() const { return _indice4; }
+    const unsigned int getIndice1() const { return _indice1; }
+    const unsigned int getIndice2() const { return _indice2; }
+    const unsigned int getIndice3() const { return _indice3; }
+    const unsigned int getIndice4() const { return _indice4; }
 
 protected:
     osg::Vec3d    _vertex;
-    unsigned short _indice1, _indice2, _indice3, _indice4;
+    unsigned int _indice1, _indice2, _indice3, _indice4;
 };
 
 class dxfPolyline : public dxfBasicEntity
@@ -185,11 +185,11 @@ protected:
     std::vector<osg::ref_ptr<dxfVertex> >        _indices;
     double                        _elevation;
     unsigned short                _flag;
-    unsigned short                _mcount;
-    unsigned short                _ncount;
+    unsigned int                  _mcount;
+    unsigned int                  _ncount;
     unsigned short                _nstart; // 71
     unsigned short                _nend; //72
-    osg::Vec3d                        _ocs; //210 220 230
+    osg::Vec3d                    _ocs; //210 220 230
     unsigned short                _mdensity; // 73
     unsigned short                _ndensity; // 74
     unsigned short                _surfacetype; //75
@@ -246,8 +246,8 @@ protected:
                 // entities (dxf garble things) in the sequence
     double            _rotation;
     osg::Vec3d        _scale;
-    osg::Vec3d            _point;
-    osg::Vec3d            _ocs;
+    osg::Vec3d        _point;
+    osg::Vec3d        _ocs;
 };
 
 class dxfEntity : public osg::Referenced
diff --git a/src/osgPlugins/dxf/dxfSection.cpp b/src/osgPlugins/dxf/dxfSection.cpp
index 1e2bc8670..92bd682b9 100644
--- a/src/osgPlugins/dxf/dxfSection.cpp
+++ b/src/osgPlugins/dxf/dxfSection.cpp
@@ -78,7 +78,7 @@ void dxfEntities::assign(dxfFile* dxf, codeValue& cv)
 void 
 dxfEntities::drawScene(scene* sc)
 {
-    for (std::vector<dxfEntity*>::iterator itr = _entityList.begin();
+    for (std::vector<osg::ref_ptr<dxfEntity> >::iterator itr = _entityList.begin();
         itr != _entityList.end(); ++itr)
         (*itr)->drawScene(sc);
 }
diff --git a/src/osgPlugins/dxf/dxfSection.h b/src/osgPlugins/dxf/dxfSection.h
index 276c67092..15a52dfcb 100644
--- a/src/osgPlugins/dxf/dxfSection.h
+++ b/src/osgPlugins/dxf/dxfSection.h
@@ -11,10 +11,10 @@
  */
 
 /**
-	Classes used to parse each section of a DXF file. Not all
-	types of section has been defined here, just the ones
-	I found of interest, ie HEADER, TABLES, BLOCKS, and ENTITIES.
-	Yet to be implemented: CLASSES, OBJECTS, and THUMBNAILIMAGE.
+    Classes used to parse each section of a DXF file. Not all
+    types of section has been defined here, just the ones
+    I found of interest, ie HEADER, TABLES, BLOCKS, and ENTITIES.
+    Yet to be implemented: CLASSES, OBJECTS, and THUMBNAILIMAGE.
 */
 #ifndef DXF_SECTION
 #define DXF_SECTION 1
@@ -24,6 +24,8 @@
 #include "dxfTable.h"
 #include "codeValue.h"
 #include "scene.h"
+#include "dxfEntity.h"
+#include "dxfBlock.h"
 
 #include <map>
 #include <vector>
@@ -31,77 +33,75 @@
 #include <string>
 
 class dxfFile;
-class dxfEntity;
-class dxfBlock;
 
 
 class dxfSection : public dxfSectionBase
 {
 public:
-	dxfSection() {}
-	virtual ~dxfSection() {}
+    dxfSection() {}
+    virtual ~dxfSection() {}
 };
 
 class dxfHeader : public dxfSection
 {
 public:
-	dxfHeader() : _inVariable(false) {}
-	virtual ~dxfHeader() {}
-	virtual void assign(dxfFile* dxf, codeValue& cv);
-	VariableList& getVariable(std::string inVar) { return _variables[inVar]; }
+    dxfHeader() : _inVariable(false) {}
+    virtual ~dxfHeader() {}
+    virtual void assign(dxfFile* dxf, codeValue& cv);
+    VariableList& getVariable(std::string inVar) { return _variables[inVar]; }
 protected:
-	std::map<std::string, VariableList> _variables;
-	bool _inVariable;
-	std::string _currentVariable;
+    std::map<std::string, VariableList> _variables;
+    bool _inVariable;
+    std::string _currentVariable;
 };
 
 
 class dxfTables : public dxfSection
 {
 public:
-	dxfTables() : _inLayerTable(false) {}
-	virtual ~dxfTables() {}
-	virtual void assign(dxfFile* dxf, codeValue& cv);
-	dxfLayerTable*	getOrCreateLayerTable() 
-	{ 
-		if (!_layerTable.get())
-			_layerTable = new dxfLayerTable;
-		return _layerTable.get(); 
-	}
+    dxfTables() : _inLayerTable(false) {}
+    virtual ~dxfTables() {}
+    virtual void assign(dxfFile* dxf, codeValue& cv);
+    dxfLayerTable*    getOrCreateLayerTable() 
+    { 
+        if (!_layerTable.get())
+            _layerTable = new dxfLayerTable;
+        return _layerTable.get(); 
+    }
 
 protected:
-	bool _inLayerTable;
-	osg::ref_ptr<dxfLayerTable>				_layerTable;
-	std::vector<osg::ref_ptr<dxfTable> >	_others;
-	osg::ref_ptr<dxfTable>				_currentTable;
+    bool _inLayerTable;
+    osg::ref_ptr<dxfLayerTable>                _layerTable;
+    std::vector<osg::ref_ptr<dxfTable> >    _others;
+    osg::ref_ptr<dxfTable>                _currentTable;
 };
 
 class dxfEntities : public dxfSection
 {
 public:
-	dxfEntities() : _currentEntity(NULL) {}
-	virtual ~dxfEntities() {}
-	virtual void assign(dxfFile* dxf, codeValue& cv);
-	virtual void drawScene(scene* sc);
+    dxfEntities() : _currentEntity(NULL) {}
+    virtual ~dxfEntities() {}
+    virtual void assign(dxfFile* dxf, codeValue& cv);
+    virtual void drawScene(scene* sc);
 
 protected:
-	dxfEntity*				_currentEntity;
-	std::vector<dxfEntity*> _entityList;
+    dxfEntity*                _currentEntity;
+    std::vector<osg::ref_ptr<dxfEntity> > _entityList;
 
 };
 
 class dxfBlocks : public dxfSection
 {
 public:
-	dxfBlocks() : _currentBlock(NULL) {}
-	virtual ~dxfBlocks() {}
-	virtual void assign(dxfFile* dxf, codeValue& cv);
-	dxfBlock* findBlock(std::string s);
+    dxfBlocks() : _currentBlock(NULL) {}
+    virtual ~dxfBlocks() {}
+    virtual void assign(dxfFile* dxf, codeValue& cv);
+    dxfBlock* findBlock(std::string s);
 
 protected:
-	dxfBlock*	_currentBlock;
-	std::map<std::string, dxfBlock*> _blockNameList;
-	std::vector<dxfBlock*> _blockList;
+    dxfBlock*    _currentBlock;
+    std::map<std::string, dxfBlock*> _blockNameList;
+    std::vector<osg::ref_ptr<dxfBlock> > _blockList;
 };
 
 #endif
diff --git a/src/osgPlugins/dxf/scene.cpp b/src/osgPlugins/dxf/scene.cpp
index 064b1c30d..6075e9617 100644
--- a/src/osgPlugins/dxf/scene.cpp
+++ b/src/osgPlugins/dxf/scene.cpp
@@ -52,7 +52,7 @@ Vec3d scene::addNormal(Vec3d v)
 }
 
 void 
-scene::addLine(std::string l, unsigned short color, Vec3d s, Vec3d e) 
+scene::addLine(const std::string & l, unsigned short color, Vec3d & s, Vec3d & e) 
 {
     dxfLayer* layer = _layerTable->findOrCreateLayer(l);
     if (layer->getFrozen()) return;
@@ -61,7 +61,7 @@ scene::addLine(std::string l, unsigned short color, Vec3d s, Vec3d e)
     ly->_lines[correctedColorIndex(l, color)].push_back(a);
     ly->_lines[correctedColorIndex(l, color)].push_back(b);
 }
-void scene::addLineStrip(std::string l, unsigned short color, std::vector<Vec3d> vertices) 
+void scene::addLineStrip(const std::string & l, unsigned short color, std::vector<Vec3d> & vertices) 
 {
     dxfLayer* layer = _layerTable->findOrCreateLayer(l);
     if (layer->getFrozen()) return;
@@ -73,7 +73,7 @@ void scene::addLineStrip(std::string l, unsigned short color, std::vector<Vec3d>
     }
     ly->_linestrips[correctedColorIndex(l, color)].push_back(converted);
 }
-void scene::addLineLoop(std::string l, unsigned short color, std::vector<Vec3d> vertices) 
+void scene::addLineLoop(const std::string & l, unsigned short color, std::vector<Vec3d> & vertices) 
 {
     dxfLayer* layer = _layerTable->findOrCreateLayer(l);
     if (layer->getFrozen()) return;
@@ -88,7 +88,7 @@ void scene::addLineLoop(std::string l, unsigned short color, std::vector<Vec3d>
 }
 
 
-void scene::addTriangles(std::string l, unsigned short color, std::vector<Vec3d> vertices, bool inverted) 
+void scene::addTriangles(const std::string & l, unsigned short color, std::vector<Vec3d> & vertices, bool inverted) 
 {
     dxfLayer* layer = _layerTable->findOrCreateLayer(l);
     if (layer->getFrozen()) return;
@@ -119,7 +119,7 @@ void scene::addTriangles(std::string l, unsigned short color, std::vector<Vec3d>
             }
     }
 }
-void scene::addQuads(std::string l, unsigned short color, std::vector<Vec3d> vertices, bool inverted) 
+void scene::addQuads(const std::string & l, unsigned short color, std::vector<Vec3d> & vertices, bool inverted) 
 {
     dxfLayer* layer = _layerTable->findOrCreateLayer(l);
     if (layer->getFrozen()) return;
@@ -170,7 +170,7 @@ void scene::addQuads(std::string l, unsigned short color, std::vector<Vec3d> ver
 
 
 unsigned short 
-scene::correctedColorIndex(std::string l, unsigned short color)
+scene::correctedColorIndex(const std::string & l, unsigned short color)
 {
     if (color >= aci::MIN && color <= aci::MAX)
     {
diff --git a/src/osgPlugins/dxf/scene.h b/src/osgPlugins/dxf/scene.h
index 188b648be..d6370daf2 100644
--- a/src/osgPlugins/dxf/scene.h
+++ b/src/osgPlugins/dxf/scene.h
@@ -32,7 +32,7 @@ class dxfLayerTable;
 class bounds {
 public:
     bounds() : _min(DBL_MAX, DBL_MAX, DBL_MAX), _max(-DBL_MAX, -DBL_MAX, -DBL_MAX) {}
-    inline void expandBy(osg::Vec3d v) {
+    inline void expandBy(const osg::Vec3d & v) {
         if(v.x()<_min.x()) _min.x() = v.x();
         if(v.x()>_max.x()) _max.x() = v.x();
 
@@ -57,7 +57,7 @@ public:
 
 
 static inline 
-osg::Geometry* createLnGeometry( osg::PrimitiveSet::Mode lineType, osg::Vec3Array* vertices, osg::Vec4 color)
+osg::Geometry* createLnGeometry( osg::PrimitiveSet::Mode lineType, osg::Vec3Array* vertices, const osg::Vec4 & color)
 {
     osg::Geometry* geom = new osg::Geometry;
     geom->setVertexArray(vertices);
@@ -75,7 +75,7 @@ osg::Geometry* createLnGeometry( osg::PrimitiveSet::Mode lineType, osg::Vec3Arra
 
 
 static inline 
-osg::Geometry* createTriGeometry( osg::Vec3Array* vertices, osg::Vec3Array* normals, osg::Vec4 color)
+osg::Geometry* createTriGeometry( osg::Vec3Array* vertices, osg::Vec3Array* normals, const osg::Vec4 & color)
 {
     osg::Geometry* geom = new osg::Geometry;
     geom->setVertexArray(vertices);
@@ -90,7 +90,7 @@ osg::Geometry* createTriGeometry( osg::Vec3Array* vertices, osg::Vec3Array* norm
 }
 
 static inline 
-osg::Geometry* createQuadGeometry( osg::Vec3Array* vertices, osg::Vec3Array* normals, osg::Vec4 color)
+osg::Geometry* createQuadGeometry( osg::Vec3Array* vertices, osg::Vec3Array* normals, const osg::Vec4 & color)
 {
     osg::Geometry* geom = new osg::Geometry;
     geom->setVertexArray(vertices);
@@ -103,8 +103,9 @@ osg::Geometry* createQuadGeometry( osg::Vec3Array* vertices, osg::Vec3Array* nor
     geom->setNormalBinding(osg::Geometry::BIND_PER_PRIMITIVE);
     return geom;
 }
+
 static inline 
-osg::Geode* createModel(std::string name, osg::Geometry* geom)
+osg::Geode* createModel(const std::string & name, osg::Geometry* geom)
 {
     osg::Geode* geom_geode = new osg::Geode;
     geom_geode->addDrawable(geom);
@@ -275,7 +276,7 @@ public:
 
     osg::Vec3d addVertex(osg::Vec3d v);
     osg::Vec3d addNormal(osg::Vec3d v);
-    sceneLayer* findOrCreateSceneLayer(std::string l)
+    sceneLayer* findOrCreateSceneLayer(const std::string & l)
     {
         sceneLayer* ly = _layers[l].get();
         if (!ly) {
@@ -284,13 +285,13 @@ public:
         }
         return ly;
     }
-    unsigned short correctedColorIndex(std::string l, unsigned short color);
+    unsigned short correctedColorIndex(const std::string & l, unsigned short color);
 
-    void addLine(std::string l, unsigned short color, osg::Vec3d s, osg::Vec3d e);
-    void addLineStrip(std::string l, unsigned short color, std::vector<osg::Vec3d> vertices);
-    void addLineLoop(std::string l, unsigned short color, std::vector<osg::Vec3d> vertices);
-    void addTriangles(std::string l, unsigned short color, std::vector<osg::Vec3d> vertices, bool inverted=false);
-    void addQuads(std::string l, unsigned short color, std::vector<osg::Vec3d> vertices, bool inverted=false);
+    void addLine(const std::string & l, unsigned short color, osg::Vec3d & s, osg::Vec3d & e);
+    void addLineStrip(const std::string & l, unsigned short color, std::vector<osg::Vec3d> & vertices);
+    void addLineLoop(const std::string & l, unsigned short color, std::vector<osg::Vec3d> & vertices);
+    void addTriangles(const std::string & l, unsigned short color, std::vector<osg::Vec3d> & vertices, bool inverted=false);
+    void addQuads(const std::string & l, unsigned short color, std::vector<osg::Vec3d> & vertices, bool inverted=false);
     osg::Group* scene2osg()
     {
         osg::Group* root = NULL;
@@ -324,12 +325,11 @@ public:
 protected:
     osg::Matrixd                _m;
     osg::Matrixd                _r;
-    osg::Vec3d                        _t;
-    bounds                        _b;
+    osg::Vec3d                  _t;
+    bounds                      _b;
     std::map<std::string, osg::ref_ptr<sceneLayer> >        _layers;
-    std::vector<osg::Matrixd>    _mStack;
-    dxfLayerTable* _layerTable;
-
+    std::vector<osg::Matrixd>   _mStack;
+    dxfLayerTable*              _layerTable;
 };
 
 #endif