Detailed Description

See also:: Class Point2, Class Point3, Class Matrix3.

Description:: This class defines a 3x2 2D transformation matrix. Methods are provided to zero the matrix, set it to the identity matrix, translate, rotate and scale it, and compute its inverse. Operators are available for matrix addition, subtraction and multiplication. All methods of this class are implemented by the system.

Data Members:: float m[3][2];

#include <matrix2.h>

Inheritance diagram for Matrix2:

Public Member Functions
	Matrix2 ()
	Matrix2 (BOOL init)
GEOMEXPORT	Matrix2 (float(*fp)[2])
GEOMEXPORT Matrix2 &	operator-= (const Matrix2 &M)
GEOMEXPORT Matrix2 &	operator+= (const Matrix2 &M)
GEOMEXPORT Matrix2 &	operator*= (const Matrix2 &M)
	operator float * ()
GEOMEXPORT void	IdentityMatrix ()
GEOMEXPORT void	Zero ()
Point2	GetRow (int i) const
GEOMEXPORT void	SetRow (int i, Point2 p)
GEOMEXPORT Point3	GetColumn (int i)
GEOMEXPORT void	SetColumn (int i, Point3 col)
GEOMEXPORT Point2	GetColumn2 (int i)
void	SetTrans (const Point2 p)
void	SetTrans (int i, float v)
Point2	GetTrans ()
GEOMEXPORT void	Translate (const Point2 &p)
GEOMEXPORT void	Rotate (float angle)
GEOMEXPORT void	Scale (const Point2 &s, BOOL trans=FALSE)
GEOMEXPORT void	PreTranslate (const Point2 &p)
GEOMEXPORT void	PreRotate (float angle)
GEOMEXPORT void	PreScale (const Point2 &s, BOOL trans=FALSE)
GEOMEXPORT void	SetTranslate (const Point2 &s)
GEOMEXPORT void	SetRotate (float angle)
GEOMEXPORT void	Invert ()
GEOMEXPORT Matrix2	operator* (const Matrix2 &B) const
GEOMEXPORT Matrix2	operator+ (const Matrix2 &B) const
GEOMEXPORT Matrix2	operator- (const Matrix2 &B) const
GEOMEXPORT IOResult	Save (ISave *isave)
GEOMEXPORT IOResult	Load (ILoad *iload)
Public Attributes
float	m [3][2]
Static Public Attributes
static const Matrix2	Identity

Constructor & Destructor Documentation

Matrix2 ( ) [inline]

Remarks:: Constructor. No initialization is done in this constructor. Use Zero() or IdentityMatrix() to initialize the matrix.

{}   // NO INITIALIZATION done in this constructor!! (can use Zero or IdentityMatrix)

Matrix2 ( BOOL init ) [inline]

{ UNUSED_PARAM(init); IdentityMatrix(); } // An option to initialize

GEOMEXPORT Matrix2 ( float(*) fp[2] )

Remarks:: Constructor. The matrix is initialized using fp.

Member Function Documentation

GEOMEXPORT Matrix2& operator-= ( const Matrix2 & M )

Remarks:: Subtracts a Matrix2 from this Matrix2.

GEOMEXPORT Matrix2& operator+= ( const Matrix2 & M )

Remarks:: Adds a Matrix2 to this Matrix2.

GEOMEXPORT Matrix2& operator*= ( const Matrix2 & M )

Remarks:: Matrix multiplication between this Matrix2 and M.

operator float * ( ) [inline]

Remarks:: Returns the address of the Matrix2.

{ return(&m[0][0]); }

GEOMEXPORT void IdentityMatrix ( )

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Remarks:: Sets this Matrix2 to the Identity Matrix.

GEOMEXPORT void Zero ( )

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Remarks:: Set all elements of this Matrix2 to 0.0f

Point2 GetRow ( int i ) const [inline]

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Remarks:: Returns the specified row of this matrix.

Parameters:: int i

Specifies the row to retrieve (0-2).

{ return (*this)[i]; }

GEOMEXPORT void SetRow	(	int	i,
		Point2	p
	)		`[inline]`

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Remarks:: Sets the specified row of this matrix.

Parameters:: int i

Specifies the row to set (0-2).

Point2 p

The values to set.

{ (*this)[i] = p; }

GEOMEXPORT Point3 GetColumn ( int i )

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Remarks:: Returns the specified column of this matrix.

Parameters:: int i

Specifies the column to retrieve (0 or 1).

GEOMEXPORT void SetColumn	(	int	i,
		Point3	col
	)

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Remarks:: Sets the specified column of this matrix.

Parameters:: int i

Specifies the column to set (0 or 1).

Point3 col

The values to set.

GEOMEXPORT Point2 GetColumn2 ( int i )

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Remarks:: This method returns a Point2 containing the upper two rows of the specified column.

Parameters:: int i

Specifies the column to get (0 or 1).

void SetTrans ( const Point2 p ) [inline]

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Remarks:: Sets the translation row of the matrix to the specified values.

Parameters:: const Point2 p

The values to set.

{ (*this)[2] = p;  }

void SetTrans	(	int	i,
		float	v
	)		`[inline]`

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Remarks:: Sets the specified element of the translation row of this matrix to the specified value.

Parameters:: int i

Specifies which column to set (0 or 1)

float v

The value to store.

{ (*this)[2][i] = v;  }

Point2 GetTrans ( ) [inline]

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Remarks:: Returns the translation row of this matrix.

{ return (*this)[2]; }

GEOMEXPORT void Translate ( const Point2 & p )

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Remarks:: Apply an incremental translation to this matrix.

Parameters:: const Point2& p

Specifies the amount to translate the matrix.

GEOMEXPORT void Rotate ( float angle )

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Remarks:: Apply an incremental rotation to this matrix using the specified angle.

Parameters:: float angle

Specifies the angle of rotation.

GEOMEXPORT void Scale	(	const Point2 &	s,
		BOOL	trans = `FALSE`
	)

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Remarks:: Apply an incremental scaling to this matrix using the specified scale factors.

Parameters:: const Point2& s

The scale factors.

BOOL trans = FALSE

If set to TRUE, the translation component is scaled. If trans = FALSE the translation component is unaffected. When 3ds Max was originally written there was a bug in the code for this method where the translation portion of the matrix was not being scaled. This meant that when a matrix was scaled the bottom row was not scaled. Thus it would always scale about the local origin of the object, but it would scale the world axes. When this bug was discovered, dependencies existed in the code upon this bug. Thus it could not simply be fixed because it would break the existing code that depended upon it working the incorrect way. To correct this the trans parameter was added. If this is set to TRUE, the translation component will be scaled correctly. The existing plug-ins don't use this parameter, it defaults to FALSE, and the code behaves the old way.