Matrix Class Reference

This reference page is linked to from the following overview topics: Math and Geometry Utilities.



Detailed Description

This class represents a 4x4 transformation matrix.

Definition at line 1062 of file math.h.

#include <math.h>

List of all members.

Public Member Functions

  Matrix (void)
  Construct a matrix without initializing its elements. The values stored in the matrix are undefined.
  Matrix (const Matrix &m)
  Matrix (float f11, float f12, float f13, float f14, float f21, float f22, float f23, float f24, float f31, float f32, float f33, float f34, float f41, float f42, float f43, float f44)
  Construct the matrix by passing all the 16 values.
  Matrix (const double *pMatrix)
  Construct a matrix from an array of double values. At least 16 values should be contained in the array.
float &  operator() (int iRow, int iColumn)
  Returns a reference to a specific element in the matrix.
float  operator() (int iRow, int iColumn) const
  Returns the value of a specific element in the matrix.
  operator const float * (void) const
  Returns a pointer to the matrix data as a pointer to float values.
  operator float * (void)
  Returns a pointer to the constant matrix data as a pointer to float values.
Matrix SetIdentity (void)
  Sets this matrix to be the identity matrix.
bool  IsIdentity (void) const
  Return true if the matrix is the identity matrix.
bool  IsRigid (void) const
  Returns true if the transformation represented by the matrix is rigid (contains only translation and rotation, not scale).
Matrix operator*= (float)
  Multiplies the matrix with a scalar value.
Matrix  operator* (const Matrix &m) const
  Multiplies two matrices.
Matrix  operator* (float) const
  Returns the multiplication of a matrix and a scalar.
Matrix  operator+ (const Matrix &) const
  Returns the sum of two matrices.
Matrix operator*= (const Matrix &m)
  Multiplies the matrix with another matrix.
bool  operator== (const Matrix &m) const
  Return true if the two matrices are identical.
void  SetRow (int iRowIndex, const Vector &vValue)
  Sets the values in a row of the matrix.
Matrix Transpose (void)
  Transposes the matrix and returns it.
Matrix Invert (void)
  Inverts the matrix and returns it.
Matrix FromEuler (const Vector &vAngles)
  Creates a rotation matrix from the given euler values stored in the vector and returns it.
Vector  ToEuler (void) const
  Converts a rotation matrix to euler values returns them in a vector.
Matrix FromAxisAngle (const Vector &vAxis, float fAngle)
  Calculates a rotation matrix from an axis and angle and returns it.
Vector  Transform (const Vector &v, float fW=1.0f) const
  Transforms a vector by the matrix and returns the result.
Vector  ProjectedTransform (const Vector &v, float fW=1.0f) const
  Transforms a point (represented by a Vector) by the matrix and returns the result.
Vector  Transform (const Vector &v, float fW, float &fRW) const
  Transforms a point (represented by a Vector) by the matrix, and returns all four homogeneous coordinates.
Vector  TransformDirection (const Vector &v) const
  Transform a direction vector by the matrix.

Public Attributes

union {
   float   m_fData [16]
   struct {
      float   _11
      float   _12
      float   _13
      float   _14
      float   _21
      float   _22
      float   _23
      float   _24
      float   _31
      float   _32
      float   _33
      float   _34
      float   _41
      float   _42
      float   _43
      float   _44
   } 
   double   m_fAlignDummy [8]
   __m128   m_vAlignDummy [4]
}; 

Constructor & Destructor Documentation

Matrix ( void  ) [inline]

Construct a matrix without initializing its elements. The values stored in the matrix are undefined.

Definition at line 1067 of file math.h.

{};
Matrix ( const Matrix m ) [inline]

Definition at line 1069 of file math.h.

                              :
        _11(m._11), _12(m._12), _13(m._13), _14(m._14), 
        _21(m._21), _22(m._22), _23(m._23), _24(m._24), 
        _31(m._31), _32(m._32), _33(m._33), _34(m._34), 
        _41(m._41), _42(m._42), _43(m._43), _44(m._44) {};
Matrix ( float  f11,
float  f12,
float  f13,
float  f14,
float  f21,
float  f22,
float  f23,
float  f24,
float  f31,
float  f32,
float  f33,
float  f34,
float  f41,
float  f42,
float  f43,
float  f44 
) [inline]

Construct the matrix by passing all the 16 values.

Definition at line 1076 of file math.h.

                                                         :
        _11(f11), _12(f12), _13(f13), _14(f14), 
        _21(f21), _22(f22), _23(f23), _24(f24), 
        _31(f31), _32(f32), _33(f33), _34(f34), 
        _41(f41), _42(f42), _43(f43), _44(f44) {};
Matrix ( const double *  pMatrix )

Construct a matrix from an array of double values. At least 16 values should be contained in the array.


Member Function Documentation

float& operator() ( int  iRow,
int  iColumn 
) [inline]

Returns a reference to a specific element in the matrix.

Definition at line 1089 of file math.h.

    { 
        return m_fData[iRow*4+iColumn]; 
    };
float operator() ( int  iRow,
int  iColumn 
) const [inline]

Returns the value of a specific element in the matrix.

Definition at line 1095 of file math.h.

    { 
        return m_fData[iRow*4+iColumn]; 
    };
operator const float * ( void  ) const [inline]

Returns a pointer to the matrix data as a pointer to float values.

Do not delete this pointer.

Definition at line 1102 of file math.h.

{ return m_fData; };
operator float * ( void  ) [inline]

Returns a pointer to the constant matrix data as a pointer to float values.

Definition at line 1106 of file math.h.

{ return m_fData; };
Matrix& SetIdentity ( void  )

Sets this matrix to be the identity matrix.

bool IsIdentity ( void  ) const

Return true if the matrix is the identity matrix.

bool IsRigid ( void  ) const

Returns true if the transformation represented by the matrix is rigid (contains only translation and rotation, not scale).

Matrix& operator*= ( float  )

Multiplies the matrix with a scalar value.

Matrix operator* ( const Matrix m ) const

Multiplies two matrices.

Matrix operator* ( float  ) const

Returns the multiplication of a matrix and a scalar.

Matrix operator+ ( const Matrix ) const

Returns the sum of two matrices.

Matrix& operator*= ( const Matrix m )

Multiplies the matrix with another matrix.

bool operator== ( const Matrix m ) const

Return true if the two matrices are identical.

void SetRow ( int  iRowIndex,
const Vector vValue 
)

Sets the values in a row of the matrix.

The last value in the row remains unchanged.

Matrix& Transpose ( void  )

Transposes the matrix and returns it.

Matrix& Invert ( void  )

Inverts the matrix and returns it.

Matrix& FromEuler ( const Vector vAngles )

Creates a rotation matrix from the given euler values stored in the vector and returns it.

Vector ToEuler ( void  ) const

Converts a rotation matrix to euler values returns them in a vector.

Matrix& FromAxisAngle ( const Vector vAxis,
float  fAngle 
)

Calculates a rotation matrix from an axis and angle and returns it.

Vector Transform ( const Vector v,
float  fW = 1.0f 
) const [inline]

Transforms a vector by the matrix and returns the result.

The fourth component of the vector (if you are using homogeneous coordinates) can be passed in the fW parameter.

Parameters:
[in] v A Vector containing the x, y, z components of the point
[in] fW The w component of the point

Definition at line 1158 of file math.h.

    {
        return Vector( 
            v.m_fX*_11+v.m_fY*_21+v.m_fZ*_31+fW*_41,
            v.m_fX*_12+v.m_fY*_22+v.m_fZ*_32+fW*_42,
            v.m_fX*_13+v.m_fY*_23+v.m_fZ*_33+fW*_43 );
    };
Vector ProjectedTransform ( const Vector v,
float  fW = 1.0f 
) const [inline]

Transforms a point (represented by a Vector) by the matrix and returns the result.

This point is assumed to be represented in homogenous coordinates, with a fourth (W) value. After the transformation the result vector will be divided by the resulting W component.

Parameters:
[in] v A Vector containing the x, y, z components of the point
[in] fW The w component of the point

Definition at line 1173 of file math.h.

    {
        float fRW = v.m_fX*_14+v.m_fY*_24+v.m_fZ*_34+fW*_44;
        return (1/fRW)*Vector( 
            v.m_fX*_11+v.m_fY*_21+v.m_fZ*_31+fW*_41,
            v.m_fX*_12+v.m_fY*_22+v.m_fZ*_32+fW*_42,
            v.m_fX*_13+v.m_fY*_23+v.m_fZ*_33+fW*_43 );
    };
Vector Transform ( const Vector v,
float  fW,
float &  fRW 
) const [inline]

Transforms a point (represented by a Vector) by the matrix, and returns all four homogeneous coordinates.

Since Vectors only hold 3 coordinates, the W coordinate is passed in and out through parameters.

Parameters:
[in] v A Vector containing the x, y, z components of the point
[in] fW The w component of the point
[out] fRW The w component of the transformed point

Definition at line 1191 of file math.h.

    {
        fRW = v.m_fX*_14+v.m_fY*_24+v.m_fZ*_34+fW*_44;
        return Vector( 
            v.m_fX*_11+v.m_fY*_21+v.m_fZ*_31+fW*_41,
            v.m_fX*_12+v.m_fY*_22+v.m_fZ*_32+fW*_42,
            v.m_fX*_13+v.m_fY*_23+v.m_fZ*_33+fW*_43 );
    };
Vector TransformDirection ( const Vector v ) const [inline]

Transform a direction vector by the matrix.

Vector transformation is different than point transformation, in that it ignores the last row (translation) of the matrix during the transformation.

Definition at line 1208 of file math.h.

    {
        return Vector( 
            v.m_fX*_11+v.m_fY*_21+v.m_fZ*_31,
            v.m_fX*_12+v.m_fY*_22+v.m_fZ*_32,
            v.m_fX*_13+v.m_fY*_23+v.m_fZ*_33 );
    };

Member Data Documentation

float m_fData[16]

Definition at line 1217 of file math.h.

float _11

Definition at line 1219 of file math.h.

float _12

Definition at line 1219 of file math.h.

float _13

Definition at line 1219 of file math.h.

float _14

Definition at line 1219 of file math.h.

float _21

Definition at line 1220 of file math.h.

float _22

Definition at line 1220 of file math.h.

float _23

Definition at line 1220 of file math.h.

float _24

Definition at line 1220 of file math.h.

float _31

Definition at line 1221 of file math.h.

float _32

Definition at line 1221 of file math.h.

float _33

Definition at line 1221 of file math.h.

float _34

Definition at line 1221 of file math.h.

float _41

Definition at line 1222 of file math.h.

float _42

Definition at line 1222 of file math.h.

float _43

Definition at line 1222 of file math.h.

float _44

Definition at line 1222 of file math.h.

double m_fAlignDummy[8]

Definition at line 1224 of file math.h.

__m128 m_vAlignDummy[4]

Definition at line 1226 of file math.h.


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

Matrix Matrix Matrix Matrix Matrix Matrix Matrix Matrix Matrix Matrix
Matrix Matrix Matrix Matrix Matrix Matrix Matrix Matrix Matrix Matrix