include/wx/matrix.h

   1 /////////////////////////////////////////////////////////////////////////////
   2 // Name:        matrix.h
   3 // Purpose:     wxTransformMatrix class. NOT YET USED
   4 //! Author:      Chris Breeze, Julian Smart
   5 // Modified by:  Klaas Holwerda
   6 // Created:     01/02/97
   7 // RCS-ID:      $Id$
   8 // Copyright:   (c) Julian Smart and Markus Holzem
   9 // Licence:     wxWindows licence
  10 /////////////////////////////////////////////////////////////////////////////
  11
  12 #ifndef _WX_MATRIXH__
  13 #define _WX_MATRIXH__
  14
  15 #ifdef __GNUG__
  16 #pragma interface "matrix.h"
  17 #endif
  18
  19 //! headerfiles="matrix.h wx/object.h"
  20 #include "wx/object.h"
  21
  22 //! codefiles="matrix.cpp"
  23
  24 // A simple 3x3 matrix. This may be replaced by a more general matrix
  25 // class some day.
  26 //
  27 // Note: this is intended to be used in wxDC at some point to replace
  28 // the current system of scaling/translation. It is not yet used.
  29
  30 //:defenition
  31 //  A 3x3 matrix to do 2D transformations.
  32 //  It can be used to map data to window coordinates.
  33 //  But also for manipulating your own data.
  34 //  For example drawing a picture (composed of several primitives)
  35 //  at a certain coordinate and angle within another parent picture.
  36 //  At all times m_isIdentity is set if the matrix itself is an Identity matrix.
  37 //  It is used where possible to optimize calculations.
  38 class WXDLLEXPORT wxTransformMatrix: public wxObject
  39 {
  40 public:
  41     wxTransformMatrix(void);
  42     wxTransformMatrix(const wxTransformMatrix& mat);
  43
  44     //get the value in the matrix at col,row
  45     //rows are horizontal (second index of m_matrix member)
  46     //columns are vertical (first index of m_matrix member)
  47     double GetValue(int col, int row) const;
  48
  49     //set the value in the matrix at col,row
  50     //rows are horizontal (second index of m_matrix member)
  51     //columns are vertical (first index of m_matrix member)
  52     void SetValue(int col, int row, double value);
  53
  54     void operator = (const wxTransformMatrix& mat);
  55     bool operator == (const wxTransformMatrix& mat);
  56     bool operator != (const wxTransformMatrix& mat);
  57
  58     //multiply every element by t
  59     wxTransformMatrix&          operator*=(const double& t);
  60     //divide every element by t
  61     wxTransformMatrix&          operator/=(const double& t);
  62     //add matrix m to this t
  63     wxTransformMatrix&          operator+=(const wxTransformMatrix& m);
  64     //subtract matrix m from this
  65     wxTransformMatrix&          operator-=(const wxTransformMatrix& m);
  66     //multiply matrix m with this
  67     wxTransformMatrix&          operator*=(const wxTransformMatrix& m);
  68
  69     // constant operators
  70
  71     //multiply every element by t  and return result
  72     wxTransformMatrix           operator*(const double& t) const;
  73     //divide this matrix by t and return result
  74     wxTransformMatrix           operator/(const double& t) const;
  75     //add matrix m to this and return result
  76     wxTransformMatrix           operator+(const wxTransformMatrix& m) const;
  77     //subtract matrix m from this and return result
  78     wxTransformMatrix           operator-(const wxTransformMatrix& m) const;
  79     //multiply this by matrix m and return result
  80     wxTransformMatrix           operator*(const wxTransformMatrix& m) const;
  81     wxTransformMatrix           operator-() const;
  82
  83     //rows are horizontal (second index of m_matrix member)
  84     //columns are vertical (first index of m_matrix member)
  85     double& operator()(int col, int row);
  86
  87     //rows are horizontal (second index of m_matrix member)
  88     //columns are vertical (first index of m_matrix member)
  89     double operator()(int col, int row) const;
  90
  91     // Invert matrix
  92     bool Invert(void);
  93
  94     // Make into identity matrix
  95     bool Identity(void);
  96
  97     // Is the matrix the identity matrix?
  98     // Only returns a flag, which is set whenever an operation
  99     // is done.
 100     inline bool IsIdentity(void) const { return m_isIdentity; };
 101
 102     // This does an actual check.
 103     inline bool IsIdentity1(void) const ;
 104
 105     //Scale by scale (isotropic scaling i.e. the same in x and y):
 106     //!ex:
 107     //!code:           | scale  0      0      |
 108     //!code: matrix' = |  0     scale  0      | x matrix
 109     //!code:           |  0     0      scale  |
 110     bool Scale(double scale);
 111
 112     //Scale with center point and x/y scale
 113     //
 114     //!ex:
 115     //!code:           |  xs    0      xc(1-xs) |
 116     //!code: matrix' = |  0    ys      yc(1-ys) | x matrix
 117     //!code:           |  0     0      1        |
 118     wxTransformMatrix&  Scale(const double &xs, const double &ys,const double &xc, const double &yc);
 119
 120     // mirror a matrix in x, y
 121     //!ex:
 122     //!code:           | -1     0      0 |
 123     //!code: matrix' = |  0    -1      0 | x matrix
 124     //!code:           |  0     0      1 |
 125     wxTransformMatrix&  Mirror(bool x=true, bool y=false);
 126
 127     // Translate by dx, dy:
 128     //!ex:
 129     //!code:           | 1  0 dx |
 130     //!code: matrix' = | 0  1 dy | x matrix
 131     //!code:           | 0  0  1 |
 132     bool Translate(double x, double y);
 133
 134     // Rotate clockwise by the given number of degrees:
 135     //!ex:
 136     //!code:           |  cos sin 0 |
 137     //!code: matrix' = | -sin cos 0 | x matrix
 138     //!code:           |   0   0  1 |
 139     bool Rotate(double angle);
 140
 141     //Rotate counter clockwise with point of rotation
 142     //
 143     //!ex:
 144     //!code:           |  cos(r) -sin(r)    x(1-cos(r))+y(sin(r)|
 145     //!code: matrix' = |  sin(r)  cos(r)    y(1-cos(r))-x(sin(r)| x matrix
 146     //!code:           |   0          0                       1 |
 147     wxTransformMatrix&  Rotate(const double &r, const double &x, const double &y);
 148
 149     // Transform X value from logical to device
 150     inline double TransformX(double x) const;
 151
 152     // Transform Y value from logical to device
 153     inline double TransformY(double y) const;
 154
 155     // Transform a point from logical to device coordinates
 156     bool TransformPoint(double x, double y, double& tx, double& ty) const;
 157
 158     // Transform a point from device to logical coordinates.
 159     // Example of use:
 160     //   wxTransformMatrix mat = dc.GetTransformation();
 161     //   mat.Invert();
 162     //   mat.InverseTransformPoint(x, y, x1, y1);
 163     // OR (shorthand:)
 164     //   dc.LogicalToDevice(x, y, x1, y1);
 165     // The latter is slightly less efficient if we're doing several
 166     // conversions, since the matrix is inverted several times.
 167     // N.B. 'this' matrix is the inverse at this point
 168     bool InverseTransformPoint(double x, double y, double& tx, double& ty) const;
 169
 170     double Get_scaleX();
 171     double Get_scaleY();
 172     double GetRotation();
 173     void   SetRotation(double rotation);
 174
 175
 176 public:
 177     double  m_matrix[3][3];
 178     bool    m_isIdentity;
 179 };
 180
 181
 182 /*
 183 Chris Breeze reported, that
 184 some functions of wxTransformMatrix cannot work because it is not
 185 known if he matrix has been inverted. Be careful when using it.
 186 */
 187
 188 // Transform X value from logical to device
 189 // warning: this function can only be used for this purpose
 190 // because no rotation is involved when mapping logical to device coordinates
 191 // mirror and scaling for x and y will be part of the matrix
 192 // if you have a matrix that is rotated, eg a shape containing a matrix to place
 193 // it in the logical coordinate system, use TransformPoint
 194 inline double wxTransformMatrix::TransformX(double x) const
 195 {
 196     //normally like this, but since no rotation is involved (only mirror and scale)
 197     //we can do without Y -> m_matrix[1]{0] is -sin(rotation angle) and therefore zero
 198     //(x * m_matrix[0][0] + y * m_matrix[1][0] + m_matrix[2][0]))
 199     return (m_isIdentity ? x : (x * m_matrix[0][0] +  m_matrix[2][0]));
 200 }
 201
 202 // Transform Y value from logical to device
 203 // warning: this function can only be used for this purpose
 204 // because no rotation is involved when mapping logical to device coordinates
 205 // mirror and scaling for x and y will be part of the matrix
 206 // if you have a matrix that is rotated, eg a shape containing a matrix to place
 207 // it in the logical coordinate system, use TransformPoint
 208 inline double wxTransformMatrix::TransformY(double y) const
 209 {
 210     //normally like this, but since no rotation is involved (only mirror and scale)
 211     //we can do without X -> m_matrix[0]{1] is sin(rotation angle) and therefore zero
 212     //(x * m_matrix[0][1] + y * m_matrix[1][1] + m_matrix[2][1]))
 213     return (m_isIdentity ? y : (y * m_matrix[1][1] + m_matrix[2][1]));
 214 }
 215
 216
 217 // Is the matrix the identity matrix?
 218 // Each operation checks whether the result is still the identity matrix and sets a flag.
 219 inline bool wxTransformMatrix::IsIdentity1(void) const
 220 {
 221     return
 222      (m_matrix[0][0] == 1.0 &&
 223       m_matrix[1][1] == 1.0 &&
 224       m_matrix[2][2] == 1.0 &&
 225       m_matrix[1][0] == 0.0 &&
 226       m_matrix[2][0] == 0.0 &&
 227       m_matrix[0][1] == 0.0 &&
 228       m_matrix[2][1] == 0.0 &&
 229       m_matrix[0][2] == 0.0 &&
 230       m_matrix[1][2] == 0.0) ;
 231 }
 232
 233 // Calculates the determinant of a 2 x 2 matrix
 234 inline double wxCalculateDet(double a11, double a21, double a12, double a22)
 235 {
 236     return a11 * a22 - a12 * a21;
 237 }
 238
 239 #endif
 240     // _WX_MATRIXH__