diff --git a/changes.txt b/changes.txt
index ee898830..44b62408 100644
--- a/changes.txt
+++ b/changes.txt
@@ -1,7 +1,7 @@
 --------------------------
 Changes in 1.9 (not yet released)
 
-- IAttributes interface changed. Most parameters are not passed by const-ref instead of per value.
+- IAttributes interface changed. Parameters are now passed by const-ref instead of per value.
 - Fix c::b project obj folder names. Some static builds had used the shared folders (thx @ gerdb for reporting)
 - Add ITexture::getSource which can be used to check where the last IVideoDriver::getTexture call found the texture.
 - Add IMeshTextureLoader interface and replace texture-loading algorithms in most meshloaders.
diff --git a/include/IAttributes.h b/include/IAttributes.h
index 79d689b4..6ddf571b 100644
--- a/include/IAttributes.h
+++ b/include/IAttributes.h
@@ -482,10 +482,10 @@ public:
 	*/
 
 	//! Adds an attribute as rectangle
-	virtual void addRect(const c8* attributeName, core::rect<s32> value) = 0;
+	virtual void addRect(const c8* attributeName, const core::rect<s32>& value) = 0;
 
 	//! Sets an attribute as rectangle
-	virtual void setAttribute(const c8* attributeName, core::rect<s32> v) = 0;
+	virtual void setAttribute(const c8* attributeName, const core::rect<s32>& v) = 0;
 
 	//! Gets an attribute as rectangle
 	//! \param attributeName: Name of the attribute to get.
@@ -498,7 +498,7 @@ public:
 	virtual core::rect<s32> getAttributeAsRect(s32 index) = 0;
 
 	//! Sets an attribute as rectangle
-	virtual void setAttribute(s32 index, core::rect<s32> v) = 0;
+	virtual void setAttribute(s32 index, const core::rect<s32>& v) = 0;
 
 
 	/*
@@ -508,10 +508,10 @@ public:
 	*/
 
 	//! Adds an attribute as dimension2d
-	virtual void addDimension2d(const c8* attributeName, core::dimension2d<u32> value) = 0;
+	virtual void addDimension2d(const c8* attributeName, const core::dimension2d<u32>& value) = 0;
 
 	//! Sets an attribute as dimension2d
-	virtual void setAttribute(const c8* attributeName, core::dimension2d<u32> v) = 0;
+	virtual void setAttribute(const c8* attributeName, const core::dimension2d<u32>& v) = 0;
 
 	//! Gets an attribute as dimension2d
 	//! \param attributeName: Name of the attribute to get.
@@ -524,7 +524,7 @@ public:
 	virtual core::dimension2d<u32> getAttributeAsDimension2d(s32 index) = 0;
 
 	//! Sets an attribute as dimension2d
-	virtual void setAttribute(s32 index, core::dimension2d<u32> v) = 0;
+	virtual void setAttribute(s32 index, const core::dimension2d<u32>& v) = 0;
 
 
 	/*
@@ -556,10 +556,10 @@ public:
 	*/
 
 	//! Adds an attribute as quaternion
-	virtual void addQuaternion(const c8* attributeName, core::quaternion v) = 0;
+	virtual void addQuaternion(const c8* attributeName, const core::quaternion& v) = 0;
 
 	//! Sets an attribute as quaternion
-	virtual void setAttribute(const c8* attributeName, core::quaternion v) = 0;
+	virtual void setAttribute(const c8* attributeName, const core::quaternion& v) = 0;
 
 	//! Gets an attribute as a quaternion
 	//! \param attributeName: Name of the attribute to get.
@@ -572,7 +572,7 @@ public:
 	virtual core::quaternion getAttributeAsQuaternion(s32 index) = 0;
 
 	//! Sets an attribute as quaternion
-	virtual void setAttribute(s32 index, core::quaternion v) = 0;
+	virtual void setAttribute(s32 index, const core::quaternion& v) = 0;
 
 	/*
 
diff --git a/source/Irrlicht/CAttributeImpl.h b/source/Irrlicht/CAttributeImpl.h
index 5258ec07..115d0746 100644
--- a/source/Irrlicht/CAttributeImpl.h
+++ b/source/Irrlicht/CAttributeImpl.h
@@ -242,7 +242,7 @@ public:
 		ValueF.push_back(value.Z);
 	}
 
-	CNumbersAttribute(const char* name, core::rect<s32> value) :
+	CNumbersAttribute(const char* name, const core::rect<s32>& value) :
 		ValueI(), ValueF(), Count(4), IsFloat(false)
 	{
 		Name = name;
@@ -252,7 +252,7 @@ public:
 		ValueI.push_back(value.LowerRightCorner.Y);
 	}
 
-	CNumbersAttribute(const char* name, core::rect<f32> value) :
+	CNumbersAttribute(const char* name, const core::rect<f32>& value) :
 		ValueI(), ValueF(), Count(4), IsFloat(true)
 	{
 		Name = name;
@@ -262,7 +262,7 @@ public:
 		ValueF.push_back(value.LowerRightCorner.Y);
 	}
 
-	CNumbersAttribute(const char* name, core::matrix4 value) :
+	CNumbersAttribute(const char* name, const core::matrix4& value) :
 		ValueI(), ValueF(), Count(16), IsFloat(true)
 	{
 		Name = name;
@@ -271,7 +271,7 @@ public:
 				ValueF.push_back(value(r,c));
 	}
 
-	CNumbersAttribute(const char* name, core::quaternion value) :
+	CNumbersAttribute(const char* name, const core::quaternion& value) :
 		ValueI(), ValueF(), Count(4), IsFloat(true)
 	{
 		Name = name;
@@ -318,7 +318,7 @@ public:
 		ValueF.push_back(value.pointC.Z);
 	}
 
-	CNumbersAttribute(const char* name, core::vector2df value) :
+	CNumbersAttribute(const char* name, const core::vector2df& value) :
 		ValueI(), ValueF(), Count(2), IsFloat(true)
 	{
 		Name = name;
@@ -326,7 +326,7 @@ public:
 		ValueF.push_back(value.Y);
 	}
 
-	CNumbersAttribute(const char* name, core::vector2di value) :
+	CNumbersAttribute(const char* name, const core::vector2di& value) :
 		ValueI(), ValueF(), Count(2), IsFloat(false)
 	{
 		Name = name;
@@ -334,7 +334,7 @@ public:
 		ValueI.push_back(value.Y);
 	}
 
-	CNumbersAttribute(const char* name, core::line2di value) :
+	CNumbersAttribute(const char* name, const core::line2di& value) :
 		ValueI(), ValueF(), Count(4), IsFloat(false)
 	{
 		Name = name;
@@ -344,7 +344,7 @@ public:
 		ValueI.push_back(value.end.Y);
 	}
 
-	CNumbersAttribute(const char* name, core::line2df value) :
+	CNumbersAttribute(const char* name, const core::line2df& value) :
 		ValueI(), ValueF(), Count(4), IsFloat(true)
 	{
 		Name = name;
@@ -366,7 +366,7 @@ public:
 		ValueF.push_back(value.end.Z);
 	}
 
-	CNumbersAttribute(const char* name, core::dimension2du value) :
+	CNumbersAttribute(const char* name, const core::dimension2du& value) :
 		ValueI(), ValueF(), Count(2), IsFloat(false)
 	{
 		Name = name;
@@ -375,7 +375,7 @@ public:
 	}
 
 
-	CNumbersAttribute(const char* name, core::dimension2df value) :
+	CNumbersAttribute(const char* name, const core::dimension2df& value) :
 		ValueI(), ValueF(), Count(2), IsFloat(true)
 	{
 		Name = name;
@@ -832,7 +832,7 @@ public:
 		//}
 	}
 
-	virtual void setPosition(core::position2di v) _IRR_OVERRIDE_
+	virtual void setPosition(const core::position2di& v) _IRR_OVERRIDE_
 	{
 		reset();
 		if (IsFloat)
@@ -903,7 +903,7 @@ public:
 		}
 	}
 
-	virtual void setRect(core::rect<s32> value) _IRR_OVERRIDE_
+	virtual void setRect(const core::rect<s32>& value) _IRR_OVERRIDE_
 	{
 		reset();
 		if (IsFloat)
@@ -922,7 +922,7 @@ public:
 		}
 	}
 
-	virtual void setMatrix(core::matrix4 value) _IRR_OVERRIDE_
+	virtual void setMatrix(const core::matrix4& value) _IRR_OVERRIDE_
 	{
 		reset();
 		if (IsFloat)
@@ -941,7 +941,7 @@ public:
 		}
 	}
 
-	virtual void setQuaternion(core::quaternion value)
+	virtual void setQuaternion(const core::quaternion& value)
 	{
 		reset();
 		if (IsFloat)
@@ -1031,7 +1031,7 @@ public:
 		}
 	}
 
-	virtual void setVector2d(core::vector2df v) _IRR_OVERRIDE_
+	virtual void setVector2d(const core::vector2df& v) _IRR_OVERRIDE_
 	{
 		reset();
 		if (IsFloat)
@@ -1046,7 +1046,7 @@ public:
 		}
 	}
 
-	virtual void setVector2d(core::vector2di v)
+	virtual void setVector2d(const core::vector2di& v)
 	{
 		reset();
 		if (IsFloat)
@@ -1061,7 +1061,7 @@ public:
 		}
 	}
 
-	virtual void setLine2d(core::line2di v) _IRR_OVERRIDE_
+	virtual void setLine2d(const core::line2di& v) _IRR_OVERRIDE_
 	{
 		reset();
 		if (IsFloat)
@@ -1080,7 +1080,7 @@ public:
 		}
 	}
 
-	virtual void setLine2d(core::line2df v) _IRR_OVERRIDE_
+	virtual void setLine2d(const core::line2df& v) _IRR_OVERRIDE_
 	{
 		reset();
 		if (IsFloat)
@@ -1099,7 +1099,7 @@ public:
 		}
 	}
 
-	virtual void setDimension2d(core::dimension2du v) _IRR_OVERRIDE_
+	virtual void setDimension2d(const core::dimension2du& v) _IRR_OVERRIDE_
 	{
 		reset();
 		if (IsFloat)
@@ -1332,7 +1332,7 @@ class CVector2DAttribute : public CNumbersAttribute
 {
 public:
 
-	CVector2DAttribute(const char* name, core::vector2df value) : CNumbersAttribute(name, value) {}
+	CVector2DAttribute(const char* name, const core::vector2df& value) : CNumbersAttribute(name, value) {}
 
 	virtual E_ATTRIBUTE_TYPE getType() const _IRR_OVERRIDE_
 	{
@@ -1350,7 +1350,7 @@ class CPosition2DAttribute : public CNumbersAttribute
 {
 public:
 
-	CPosition2DAttribute(const char* name, core::position2di value) : CNumbersAttribute(name, value) {}
+	CPosition2DAttribute(const char* name, const core::position2di& value) : CNumbersAttribute(name, value) {}
 
 	virtual E_ATTRIBUTE_TYPE getType() const _IRR_OVERRIDE_
 	{
@@ -1370,7 +1370,7 @@ class CRectAttribute : public CNumbersAttribute
 {
 public:
 
-	CRectAttribute(const char* name, core::rect<s32> value) : CNumbersAttribute(name, value) { }
+	CRectAttribute(const char* name, const core::rect<s32>& value) : CNumbersAttribute(name, value) { }
 
 	virtual E_ATTRIBUTE_TYPE getType() const _IRR_OVERRIDE_
 	{
@@ -1389,7 +1389,7 @@ class CDimension2dAttribute : public CNumbersAttribute
 {
 public:
 
-	CDimension2dAttribute (const char* name, core::dimension2d<u32> value) : CNumbersAttribute(name, value) { }
+	CDimension2dAttribute (const char* name, const core::dimension2d<u32>& value) : CNumbersAttribute(name, value) { }
 
 	virtual E_ATTRIBUTE_TYPE getType() const _IRR_OVERRIDE_
 	{
@@ -1407,7 +1407,7 @@ class CMatrixAttribute : public CNumbersAttribute
 {
 public:
 
-	CMatrixAttribute(const char* name, core::matrix4 value) : CNumbersAttribute(name, value) { }
+	CMatrixAttribute(const char* name, const core::matrix4& value) : CNumbersAttribute(name, value) { }
 
 	virtual E_ATTRIBUTE_TYPE getType() const _IRR_OVERRIDE_
 	{
@@ -1430,7 +1430,7 @@ class CQuaternionAttribute : public CNumbersAttribute
 {
 public:
 
-	CQuaternionAttribute(const char* name, core::quaternion value) : CNumbersAttribute(name, value) { }
+	CQuaternionAttribute(const char* name, const core::quaternion& value) : CNumbersAttribute(name, value) { }
 
 	virtual E_ATTRIBUTE_TYPE getType() const _IRR_OVERRIDE_
 	{
@@ -1514,7 +1514,7 @@ class CLine2dAttribute : public CNumbersAttribute
 {
 public:
 
-	CLine2dAttribute(const char* name, core::line2df value) : CNumbersAttribute(name, value) { }
+	CLine2dAttribute(const char* name, const core::line2df& value) : CNumbersAttribute(name, value) { }
 
 	virtual E_ATTRIBUTE_TYPE getType() const _IRR_OVERRIDE_
 	{
diff --git a/source/Irrlicht/CAttributes.cpp b/source/Irrlicht/CAttributes.cpp
index 3ecf6044..26ded3be 100644
--- a/source/Irrlicht/CAttributes.cpp
+++ b/source/Irrlicht/CAttributes.cpp
@@ -390,7 +390,7 @@ core::position2di CAttributes::getAttributeAsPosition2d(const c8* attributeName,
 }
 
 //! Sets a attribute as rectangle
-void CAttributes::setAttribute(const c8* attributeName, core::rect<s32> value)
+void CAttributes::setAttribute(const c8* attributeName, const core::rect<s32>& value)
 {
 	IAttribute* att = getAttributeP(attributeName);
 	if (att)
@@ -412,7 +412,7 @@ core::rect<s32> CAttributes::getAttributeAsRect(const c8* attributeName, const c
 }
 
 //! Sets a attribute as dimension2d
-void CAttributes::setAttribute(const c8* attributeName, core::dimension2d<u32> value)
+void CAttributes::setAttribute(const c8* attributeName, const core::dimension2d<u32>& value)
 {
 	IAttribute* att = getAttributeP(attributeName);
 	if (att)
@@ -869,13 +869,13 @@ void CAttributes::addPosition2d(const c8* attributeName, const core::position2di
 }
 
 //! Adds an attribute as rectangle
-void CAttributes::addRect(const c8* attributeName, core::rect<s32> value)
+void CAttributes::addRect(const c8* attributeName, const core::rect<s32>& value)
 {
 	Attributes.push_back(new CRectAttribute(attributeName, value));
 }
 
 //! Adds an attribute as dimension2d
-void CAttributes::addDimension2d(const c8* attributeName, core::dimension2d<u32> value)
+void CAttributes::addDimension2d(const c8* attributeName, const core::dimension2d<u32>& value)
 {
 	Attributes.push_back(new CDimension2dAttribute(attributeName, value));
 }
@@ -971,14 +971,14 @@ void CAttributes::setAttribute(s32 index, const core::position2di& v)
 }
 
 //! Sets a attribute as rectangle
-void CAttributes::setAttribute(s32 index, core::rect<s32> v)
+void CAttributes::setAttribute(s32 index, const core::rect<s32>& v)
 {
 	if ((u32)index < Attributes.size())
 		Attributes[index]->setRect(v);
 }
 
 //! Sets a attribute as dimension2d
-void CAttributes::setAttribute(s32 index, core::dimension2d<u32> v)
+void CAttributes::setAttribute(s32 index, const core::dimension2d<u32>& v)
 {
 	if ((u32)index < Attributes.size())
 		Attributes[index]->setDimension2d(v);
@@ -1054,14 +1054,14 @@ void CAttributes::setAttribute(s32 index, const core::matrix4& v)
 
 
 //! Adds an attribute as quaternion
-void CAttributes::addQuaternion(const c8* attributeName, core::quaternion v)
+void CAttributes::addQuaternion(const c8* attributeName, const core::quaternion& v)
 {
 	Attributes.push_back(new CQuaternionAttribute(attributeName, v));
 }
 
 
 //! Sets an attribute as quaternion
-void CAttributes::setAttribute(const c8* attributeName, core::quaternion v)
+void CAttributes::setAttribute(const c8* attributeName, const core::quaternion& v)
 {
 	IAttribute* att = getAttributeP(attributeName);
 	if (att)
@@ -1094,7 +1094,7 @@ core::quaternion CAttributes::getAttributeAsQuaternion(s32 index)
 }
 
 //! Sets an attribute as quaternion
-void CAttributes::setAttribute(s32 index, core::quaternion v)
+void CAttributes::setAttribute(s32 index, const core::quaternion& v)
 {
 if (index >= 0 && index < (s32)Attributes.size() )
 		Attributes[index]->setQuaternion(v);
@@ -1333,7 +1333,7 @@ void CAttributes::setAttribute(s32 index, const core::line3df& v)
 }
 
 
-//! Adds an attribute as user pointner
+//! Adds an attribute as user pointer
 void CAttributes::addUserPointer(const c8* attributeName, void* userPointer)
 {
 	Attributes.push_back(new CUserPointerAttribute(attributeName, userPointer));
diff --git a/source/Irrlicht/CAttributes.h b/source/Irrlicht/CAttributes.h
index f231c0f2..87b4d118 100644
--- a/source/Irrlicht/CAttributes.h
+++ b/source/Irrlicht/CAttributes.h
@@ -447,10 +447,10 @@ public:
 	*/
 
 	//! Adds an attribute as rectangle
-	virtual void addRect(const c8* attributeName, core::rect<s32> value) _IRR_OVERRIDE_;
+	virtual void addRect(const c8* attributeName, const core::rect<s32>& value) _IRR_OVERRIDE_;
 
 	//! Sets an attribute as rectangle
-	virtual void setAttribute(const c8* attributeName, core::rect<s32> v) _IRR_OVERRIDE_;
+	virtual void setAttribute(const c8* attributeName, const core::rect<s32>& v) _IRR_OVERRIDE_;
 
 	//! Gets an attribute as rectangle
 	//! \param attributeName: Name of the attribute to get.
@@ -463,7 +463,7 @@ public:
 	virtual core::rect<s32> getAttributeAsRect(s32 index) _IRR_OVERRIDE_;
 
 	//! Sets an attribute as rectangle
-	virtual void setAttribute(s32 index, core::rect<s32> v) _IRR_OVERRIDE_;
+	virtual void setAttribute(s32 index, const core::rect<s32>& v) _IRR_OVERRIDE_;
 
 
 	/*
@@ -473,10 +473,10 @@ public:
 	*/
 
 	//! Adds an attribute as dimension2d
-	virtual void addDimension2d(const c8* attributeName, core::dimension2d<u32> value) _IRR_OVERRIDE_;
+	virtual void addDimension2d(const c8* attributeName, const core::dimension2d<u32>& value) _IRR_OVERRIDE_;
 
 	//! Sets an attribute as dimension2d
-	virtual void setAttribute(const c8* attributeName, core::dimension2d<u32> v) _IRR_OVERRIDE_;
+	virtual void setAttribute(const c8* attributeName, const core::dimension2d<u32>& v) _IRR_OVERRIDE_;
 
 	//! Gets an attribute as dimension2d
 	//! \param attributeName: Name of the attribute to get.
@@ -489,7 +489,7 @@ public:
 	virtual core::dimension2d<u32> getAttributeAsDimension2d(s32 index) _IRR_OVERRIDE_;
 
 	//! Sets an attribute as dimension2d
-	virtual void setAttribute(s32 index, core::dimension2d<u32> v) _IRR_OVERRIDE_;
+	virtual void setAttribute(s32 index, const core::dimension2d<u32>& v) _IRR_OVERRIDE_;
 
 
 	/*
@@ -523,10 +523,10 @@ public:
 	*/
 
 	//! Adds an attribute as quaternion
-	virtual void addQuaternion(const c8* attributeName, core::quaternion v) _IRR_OVERRIDE_;
+	virtual void addQuaternion(const c8* attributeName, const core::quaternion& v) _IRR_OVERRIDE_;
 
 	//! Sets an attribute as quaternion
-	virtual void setAttribute(const c8* attributeName, core::quaternion v) _IRR_OVERRIDE_;
+	virtual void setAttribute(const c8* attributeName, const core::quaternion& v) _IRR_OVERRIDE_;
 
 	//! Gets an attribute as a quaternion
 	//! \param attributeName: Name of the attribute to get.
@@ -539,7 +539,7 @@ public:
 	virtual core::quaternion getAttributeAsQuaternion(s32 index) _IRR_OVERRIDE_;
 
 	//! Sets an attribute as quaternion
-	virtual void setAttribute(s32 index, core::quaternion v) _IRR_OVERRIDE_;
+	virtual void setAttribute(s32 index, const core::quaternion& v) _IRR_OVERRIDE_;
 
 	/*
 
@@ -601,7 +601,7 @@ public:
 	//! Adds an attribute as 3d triangle
 	virtual void addTriangle3d(const c8* attributeName, const core::triangle3df& v) _IRR_OVERRIDE_;
 
-	//! Sets an attribute as 3d trianle
+	//! Sets an attribute as 3d triangle
 	virtual void setAttribute(const c8* attributeName, const core::triangle3df& v) _IRR_OVERRIDE_;
 
 	//! Gets an attribute as a 3d triangle
@@ -702,7 +702,7 @@ public:
 
 	*/
 
-	//! Adds an attribute as user pointner
+	//! Adds an attribute as user pointer
 	virtual void addUserPointer(const c8* attributeName, void* userPointer) _IRR_OVERRIDE_;
 
 	//! Sets an attribute as user pointer
diff --git a/source/Irrlicht/IAttribute.h b/source/Irrlicht/IAttribute.h
index 1d35db37..4f917777 100644
--- a/source/Irrlicht/IAttribute.h
+++ b/source/Irrlicht/IAttribute.h
@@ -76,18 +76,18 @@ public:
 	virtual void setBool(bool boolValue)		{};
 	virtual void setBinary(void* data, s32 maxLenght) {};
 	virtual void setVector(const core::vector3df& v)	{};
-	virtual void setPosition(core::position2di v)	{};
-	virtual void setRect(core::rect<s32> v)		{};
-	virtual void setQuaternion(core::quaternion v) {};
-	virtual void setMatrix(core::matrix4 v) {};
+	virtual void setPosition(const core::position2di& v)	{};
+	virtual void setRect(const core::rect<s32>& v)		{};
+	virtual void setQuaternion(const core::quaternion& v) {};
+	virtual void setMatrix(const core::matrix4& v) {};
 	virtual void setTriangle(const core::triangle3df& v) {};
-	virtual void setVector2d(core::vector2df v) {};
-	virtual void setVector2d(core::vector2di v) {};
-	virtual void setLine2d(core::line2df v) {};
-	virtual void setLine2d(core::line2di v) {};
+	virtual void setVector2d(const core::vector2df& v) {};
+	virtual void setVector2d(const core::vector2di& v) {};
+	virtual void setLine2d(const core::line2df& v) {};
+	virtual void setLine2d(const core::line2di& v) {};
 	virtual void setLine3d(const core::line3df& v) {};
 	virtual void setLine3d(const core::line3di& v) {};
-	virtual void setDimension2d(core::dimension2du v) {};
+	virtual void setDimension2d(const core::dimension2du& v) {};
 	virtual void setBBox(const core::aabbox3d<f32>& v) {};
 	virtual void setPlane(const core::plane3df& v) {};
 	virtual void setUserPointer(void* v)	{};