csTransform Class Reference
[Geometry utilities]

A class which defines a transformation from one coordinate system to another. More...

#include <csgeom/transfrm.h>

Inheritance diagram for csTransform:

Public Member Functions
	csTransform (const csMatrix3 &other2this, const csVector3 &origin_pos)
	Initialize with the given transformation.
	csTransform ()
	Initialize with the identity transformation.
csString	Description () const
	Return a textual representation of the transform.
csVector3	GetFront () const
	Get the front vector in 'other' space.
const csMatrix3 &	GetO2T () const
	Get 'other' to 'this' transformation matrix.
const csVector3 &	GetO2TTranslation () const
	Get 'other' to 'this' translation.
const csVector3 &	GetOrigin () const
	Get origin of transformed coordinate system.
csVector3	GetRight () const
	Get the right vector in 'other' space.
csVector3	GetUp () const
	Get the up vector in 'other' space.
void	Identity ()
	Reset this transform to the identity transform.
bool	IsIdentity () const
	Returns true if this transform is an identity transform.
csBox3	Other2This (const csBox3 &box) const
	Convert a box in 'other' space to 'this' space.
csSphere	Other2This (const csSphere &s) const
	Convert a sphere in 'other' space to 'this' space.
void	Other2This (const csPlane3 &p, const csVector3 &point, csPlane3 &result) const
	Convert a plane in 'other' space to 'this' space.
csPlane3	Other2This (const csPlane3 &p) const
	Convert a plane in 'other' space to 'this' space.
csVector3	Other2This (const csVector3 &v) const
	Transform vector in 'other' space v to a vector in 'this' space.
csPlane3	Other2ThisRelative (const csPlane3 &p) const
	Convert a plane in 'other' space to 'this' space.
csVector3	Other2ThisRelative (const csVector3 &v) const
	Convert vector v in 'other' space to a vector in 'this' space.
virtual void	SetO2T (const csMatrix3 &m)
	Set 'other' to 'this' transformation matrix.
virtual void	SetO2TTranslation (const csVector3 &v)
	Set 'world' to 'this' translation.
void	SetOrigin (const csVector3 &v)
	Set origin of transformed coordinate system.
void	Translate (const csVector3 &v)
	Move the 'other' to 'this' translation by a specified amount.
Static Public Member Functions
static csTransform	GetReflect (const csPlane3 &pl)
	Return a transform that represents a mirroring across a plane.
Protected Attributes
csMatrix3	m_o2t
	Transformation matrix from 'other' space to 'this' space.
csVector3	v_o2t
	Location of the origin for 'this' space.
Friends
csTransform	operator* (const csTransform &t1, const csReversibleTransform &t2)
	Combine two transforms, rightmost first.
csMatrix3	operator* (const csTransform &t, const csMatrix3 &m)
	Multiply a matrix with the transformation matrix.
csMatrix3	operator* (const csMatrix3 &m, const csTransform &t)
	Multiply a matrix with the transformation matrix.
csBox3	operator* (const csTransform &t, const csBox3 &p)
	Apply a transformation to a box.
csBox3	operator* (const csBox3 &p, const csTransform &t)
	Apply a transformation to a box.
csSphere	operator* (const csTransform &t, const csSphere &p)
	Apply a transformation to a sphere.
csSphere	operator* (const csSphere &p, const csTransform &t)
	Apply a transformation to a sphere.
csPlane3	operator* (const csTransform &t, const csPlane3 &p)
	Apply a transformation to a Plane.
csPlane3	operator* (const csPlane3 &p, const csTransform &t)
	Apply a transformation to a Plane.
csVector3	operator* (const csTransform &t, const csVector3 &v)
	Apply a transformation to a 3D vector.
csVector3	operator* (const csVector3 &v, const csTransform &t)
	Apply a transformation to a 3D vector.
csMatrix3 &	operator*= (csMatrix3 &m, const csTransform &t)
	Multiply a matrix with the transformation matrix.
csBox3 &	operator*= (csBox3 &p, const csTransform &t)
	Apply a transformation to a box.
csSphere &	operator*= (csSphere &p, const csTransform &t)
	Apply a transformation to a sphere.
csPlane3 &	operator*= (csPlane3 &p, const csTransform &t)
	Apply a transformation to a Plane.
csVector3 &	operator*= (csVector3 &v, const csTransform &t)
	Apply a transformation to a 3D vector.

Detailed Description

A class which defines a transformation from one coordinate system to another.

The two coordinate systems are refered to as 'other' and 'this'. The transform defines a transformation from 'other' to 'this'.

Definition at line 48 of file transfrm.h.

Constructor & Destructor Documentation

csTransform::csTransform ( ) [inline]

Initialize with the identity transformation.

Definition at line 63 of file transfrm.h.

csTransform::csTransform	(	const csMatrix3 &	other2this,
		const csVector3 &	origin_pos
	)			`[inline]`

Initialize with the given transformation.

The transformation is given as a 3x3 matrix and a vector. The transformation is defined to mean T=M*(O-V) with T the vector in 'this' space, O the vector in 'other' space, M the transformation matrix and V the transformation vector.

Definition at line 72 of file transfrm.h.

Member Function Documentation

csString csTransform::Description ( ) const

Return a textual representation of the transform.

csVector3 csTransform::GetFront ( ) const [inline]

Get the front vector in 'other' space.

This is basically equivalent to doing: tr.This2OtherRelative (csVector3 (0, 0, 1)) but it is more efficient.

Definition at line 337 of file transfrm.h.

const csMatrix3& csTransform::GetO2T ( ) const [inline]

Get 'other' to 'this' transformation matrix.

This is the 3x3 matrix M from the transform equation T=M*(O-V).

Definition at line 112 of file transfrm.h.

const csVector3& csTransform::GetO2TTranslation ( ) const [inline]

Get 'other' to 'this' translation.

This is the vector V from the transform equation T=M*(O-V). This is equivalent to calling GetOrigin().

Definition at line 119 of file transfrm.h.

const csVector3& csTransform::GetOrigin ( ) const [inline]

Get origin of transformed coordinate system.

In other words, the vector that gets 0,0,0 after transforming with Other2This(). This is equivalent to calling GetO2TTranslation().

Definition at line 126 of file transfrm.h.

static csTransform csTransform::GetReflect ( const csPlane3 & pl ) [static]

Return a transform that represents a mirroring across a plane.

This function will return a csTransform which represents a reflection across the plane pl.

csVector3 csTransform::GetRight ( ) const [inline]

Get the right vector in 'other' space.

This is basically equivalent to doing: tr.This2OtherRelative (csVector3 (1, 0, 0)) but it is more efficient.

Definition at line 369 of file transfrm.h.

csVector3 csTransform::GetUp ( ) const [inline]

Get the up vector in 'other' space.

This is basically equivalent to doing: tr.This2OtherRelative (csVector3 (0, 1, 0)) but it is more efficient.

Definition at line 353 of file transfrm.h.

void csTransform::Identity ( ) [inline]

Reset this transform to the identity transform.

Definition at line 81 of file transfrm.h.

bool csTransform::IsIdentity ( ) const [inline]

Returns true if this transform is an identity transform.

This tests all fields so don't call this before every operation.

Definition at line 91 of file transfrm.h.

csBox3 csTransform::Other2This ( const csBox3 & box ) const

Convert a box in 'other' space to 'this' space.

csSphere csTransform::Other2This ( const csSphere & s ) const

Convert a sphere in 'other' space to 'this' space.

void csTransform::Other2This	(	const csPlane3 &	p,
		const csVector3 &	point,
		csPlane3 &	result
	)			const

Convert a plane in 'other' space to 'this' space.

This is an optimized version for which a point on the new plane is known (point). The result is stored in 'result'. If 'p' is expressed as (N,D) (with N a vector for the A,B,C components of 'p') then this will return a new plane in 'result' which looks like (M*N,-(M*N)*point).

csPlane3 csTransform::Other2This ( const csPlane3 & p ) const

Convert a plane in 'other' space to 'this' space.

If 'p' is expressed as (N,D) (with N a vector for the A,B,C components of 'p') then this will return a new plane which looks like (M*N,D+(M*N)*(M*V)).

csVector3 csTransform::Other2This ( const csVector3 & v ) const [inline]

Transform vector in 'other' space v to a vector in 'this' space.

This is the basic transform function. This will calculate and return M*(v-V).

Definition at line 159 of file transfrm.h.

csPlane3 csTransform::Other2ThisRelative ( const csPlane3 & p ) const

Convert a plane in 'other' space to 'this' space.

This version ignores translation. If 'p' is expressed as (N,D) (with N a vector for the A,B,C components of 'p') then this will return a new plane which looks like (M*N,D).

csVector3 csTransform::Other2ThisRelative ( const csVector3 & v ) const [inline]

Convert vector v in 'other' space to a vector in 'this' space.

Use the origin of 'other' space. This will calculate and return M*v (so the translation or V of this transform is ignored).

Definition at line 169 of file transfrm.h.

virtual void csTransform::SetO2T ( const csMatrix3 & m ) [inline, virtual]

Set 'other' to 'this' transformation matrix.

This is the 3x3 matrix M from the transform equation T=M*(O-V).

Reimplemented in csReversibleTransform, and csOrthoTransform.

Definition at line 132 of file transfrm.h.

virtual void csTransform::SetO2TTranslation ( const csVector3 & v ) [inline, virtual]

Set 'world' to 'this' translation.

This is the vector V from the transform equation T=M*(O-V). This is equivalent to calling SetOrigin().

Definition at line 139 of file transfrm.h.

void csTransform::SetOrigin ( const csVector3 & v ) [inline]

Set origin of transformed coordinate system.

This is equivalent to calling SetO2TTranslation().

Definition at line 145 of file transfrm.h.

void csTransform::Translate ( const csVector3 & v ) [inline]

Move the 'other' to 'this' translation by a specified amount.

Basically this will add 'v' to the origin or translation of this transform so that the new transform looks like T=M*(O-(V+v)).

Definition at line 152 of file transfrm.h.

Friends And Related Function Documentation

csTransform operator*	(	const csTransform &	t1,
		const csReversibleTransform &	t2
	)			`[friend]`

Combine two transforms, rightmost first.

Given the following definitions:

't1' expressed as T=t1.M*(O-t1.V)
't2' expressed as T=t2.M*(O-t2.V)
t2.Minv is the inverse of t2.M

Then this will return a new transform T=(t1.M*t2.M)*(O-(t2.V+t2.Minv*t1.V)).

csMatrix3 operator*	(	const csTransform &	t,
		const csMatrix3 &	m
	)			`[friend]`

Multiply a matrix with the transformation matrix.

This will calculate and return M*m.

csMatrix3 operator*	(	const csMatrix3 &	m,
		const csTransform &	t
	)			`[friend]`

Multiply a matrix with the transformation matrix.

This will calculate and return m*M.

csBox3 operator*	(	const csTransform &	t,
		const csBox3 &	p
	)			`[friend]`

Apply a transformation to a box.