xiiTransformTemplate< Type > Class Template Reference

A class that represents position, rotation and scaling via a position vector, a quaternion and a scale vector. More...

#include <Transform.h>

Public Types
using	ComponentType = Type

Public Member Functions
	XII_DECLARE_POD_TYPE ()
	xiiTransformTemplate ()=default
	Default constructor: Does not do any initialization.
	xiiTransformTemplate (const xiiVec3Template< Type > &vPosition, const xiiQuatTemplate< Type > &qRotation=xiiQuatTemplate< Type >::MakeIdentity(), const xiiVec3Template< Type > &vScale=xiiVec3Template< Type >(1))
	Initializes the transform from the given position, rotation and scale.
void	SetIdentity ()
	Sets the position to be zero and the rotation to identity.
Type	GetMaxScale () const
	Returns the scale component with maximum magnitude.
bool	ContainsNegativeScale () const
	Returns whether this transform contains negative scaling aka mirroring.
bool	ContainsUniformScale () const
	Returns whether this transform contains uniform scaling.
bool	IsValid () const
	Checks that all components are valid (no NaN, only finite numbers).
bool	IsIdentical (const xiiTransformTemplate &rhs) const
	Equality Check (bitwise)
bool	IsEqual (const xiiTransformTemplate &rhs, Type fEpsilon) const
	Equality Check with epsilon.
void	Invert ()
	Inverts this transform.
const xiiTransformTemplate	GetInverse () const
	Returns the inverse of this transform.
xiiVec3Template< Type >	TransformPosition (const xiiVec3Template< Type > &v) const
xiiVec3Template< Type >	TransformDirection (const xiiVec3Template< Type > &v) const
void	operator+= (const xiiVec3Template< Type > &v)
void	operator-= (const xiiVec3Template< Type > &v)
const xiiMat4Template< Type >	GetAsMat4 () const
	Returns the transformation as a matrix.

Static Public Member Functions
static xiiTransformTemplate< Type >	Make (const xiiVec3Template< Type > &vPosition, const xiiQuatTemplate< Type > &qRotation=xiiQuatTemplate< Type >::MakeIdentity(), const xiiVec3Template< Type > &vScale=xiiVec3Template< Type >(1))
	Creates a transform from the given position, rotation and scale.
static xiiTransformTemplate< Type >	MakeIdentity ()
	Creates an identity transform.
static xiiTransformTemplate< Type >	MakeFromMat4 (const xiiMat4Template< Type > &mMat)
	Creates a transform from the given matrix.
static xiiTransformTemplate< Type >	MakeLocalTransform (const xiiTransformTemplate &globalTransformParent, const xiiTransformTemplate &globalTransformChild)
	Creates a transform that is the local transformation needed to get from the parent's transform to the child's.
static xiiTransformTemplate< Type >	MakeGlobalTransform (const xiiTransformTemplate &globalTransformParent, const xiiTransformTemplate &localTransformChild)
	Creates a transform that is the global transform, that is reached by applying the child's local transform to the parent's global one.

Public Attributes
xiiVec3Template< Type >	m_vPosition
xiiQuatTemplate< Type >	m_qRotation
xiiVec3Template< Type >	m_vScale

Detailed Description

template<typename Type>
class xiiTransformTemplate< Type >

A class that represents position, rotation and scaling via a position vector, a quaternion and a scale vector.

Todo

Fix docs and unit tests

Scale is applied first, then rotation and finally translation is added. Thus scale and rotation are always in 'local space', i.e. applying a rotation to the xiiTransformTemplate will rotate objects in place around their local center. Since the translation is added afterwards, the translation component is always the global center position, around which objects rotate.

The functions SetLocalTransform() and SetGlobalTransform() allow to create transforms that either represent the full global transformation of an object, factoring its parent's transform in, or the local transformation that will get you from the parent's global transformation to the current global transformation of a child (i.e. only the difference). This is particularly useful when editing entities in a hierarchical structure.

This representation cannot handle shearing, which means rotations and scalings cannot be combined correctly. Many parts of game engine cannot handle shearing or non-uniform scaling across hierarchies anyway. Therefore this class implements a simplified way of combining scalings when multiplying two xiiTransform's. Instead of rotating scale into the proper space, the two values are simply multiplied component-wise.

In situations where this is insufficient, use a 3x3 or 4x4 matrix instead. Sometimes it is sufficient to use the matrix for the computation and the result can be stored in a transform again.

Member Function Documentation

MakeFromMat4()

template<typename Type>

xiiTransformTemplate< Type > xiiTransformTemplate< Type >::MakeFromMat4 ( const xiiMat4Template< Type > & mMat )

staticnodiscard

Creates a transform from the given matrix.

Note

This operation always succeeds, even though the matrix may be complete garbage (e.g. a zero matrix) or may not be representable as a transform (containing shearing). Also be careful with mirroring. The transform may or may not be able to represent that.

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The documentation for this class was generated from the following files:

• /home/runner/work/XII/XII/Source/Engine/Foundation/Math/Declarations.h
• /home/runner/work/XII/XII/Source/Engine/Foundation/Math/Transform.h
• /home/runner/work/XII/XII/Source/Engine/Foundation/Math/Implementation/Transform_inl.h