src/common/affinematrix2d.cpp

   1 ///////////////////////////////////////////////////////////////////////////////
   2 // Name:        affinematrix2d.cpp
   3 // Purpose:     implementation of wxAffineMatrix2D
   4 // Author:      Based on wxTransformMatrix by Chris Breeze, Julian Smart
   5 // Created:     2011-04-05
   6 // Copyright:   (c) wxWidgets team
   7 // Licence:     wxWidgets licence
   8 ///////////////////////////////////////////////////////////////////////////////
   9
  10 #include "wx/wxprec.h"
  11
  12 #ifdef __BORLANDC__
  13     #pragma hdrstop
  14 #endif
  15
  16 #include "wx/affinematrix2d.h"
  17 #include "wx/math.h"
  18
  19 // sets the matrix to the respective values
  20 void wxAffineMatrix2D::Set(const wxMatrix2D &mat2D, const wxPoint2DDouble &tr)
  21 {
  22     m_11 = mat2D.m_11;
  23     m_12 = mat2D.m_12;
  24     m_21 = mat2D.m_21;
  25     m_22 = mat2D.m_22;
  26     m_tx = tr.m_x;
  27     m_ty = tr.m_y;
  28 }
  29
  30 // gets the component valuess of the matrix
  31 void wxAffineMatrix2D::Get(wxMatrix2D *mat2D, wxPoint2DDouble *tr) const
  32 {
  33     mat2D->m_11 = m_11;
  34     mat2D->m_12 = m_12;
  35     mat2D->m_21 = m_21;
  36     mat2D->m_22 = m_22;
  37
  38     if ( tr )
  39     {
  40         tr->m_x = m_tx;
  41         tr->m_y = m_ty;
  42     }
  43 }
  44
  45 // concatenates the matrix
  46 // | t.m_11  t.m_12  0 |   | m_11  m_12   0 |
  47 // | t.m_21  t.m_22  0 | x | m_21  m_22   0 |
  48 // | t.m_tx  t.m_ty  1 |   | m_tx  m_ty   1 |
  49 void wxAffineMatrix2D::Concat(const wxAffineMatrix2DBase &t)
  50 {
  51     wxMatrix2D mat;
  52     wxPoint2DDouble tr;
  53     t.Get(&mat, &tr);
  54
  55     m_tx += tr.m_x*m_11 + tr.m_y*m_21;
  56     m_ty += tr.m_x*m_12 + tr.m_y*m_22;
  57     wxDouble e11 = mat.m_11*m_11 + mat.m_12*m_21;
  58     wxDouble e12 = mat.m_11*m_12 + mat.m_12*m_22;
  59     wxDouble e21 = mat.m_21*m_11 + mat.m_22*m_21;
  60     m_22 = mat.m_21*m_12 + mat.m_22*m_22;
  61     m_11 = e11;
  62     m_12 = e12;
  63     m_21 = e21;
  64 }
  65
  66 // makes this its inverse matrix.
  67 // Invert
  68 // | m_11  m_12   0 |
  69 // | m_21  m_22   0 |
  70 // | m_tx  m_ty   1 |
  71 bool wxAffineMatrix2D::Invert()
  72 {
  73     const wxDouble det = m_11*m_22 - m_12*m_21;
  74
  75     if ( !det )
  76         return false;
  77
  78     wxDouble ex = (m_21*m_ty - m_22*m_tx) / det;
  79     m_ty = (-m_11*m_ty + m_12*m_tx) / det;
  80     m_tx = ex;
  81     wxDouble e11 = m_22 / det;
  82     m_12 = -m_12 / det;
  83     m_21 = -m_21 / det;
  84     m_22 = m_11 / det;
  85     m_11 = e11;
  86
  87     return true;
  88 }
  89
  90 // returns true if the elements of the transformation matrix are equal
  91 bool wxAffineMatrix2D::IsEqual(const wxAffineMatrix2DBase& t) const
  92 {
  93     wxMatrix2D mat;
  94     wxPoint2DDouble tr;
  95     t.Get(&mat, &tr);
  96
  97     return m_11 == mat.m_11 && m_12 == mat.m_12 &&
  98            m_21 == mat.m_21 && m_22 == mat.m_22 &&
  99            m_tx == tr.m_x && m_ty == tr.m_y;
 100 }
 101
 102 //
 103 // transformations
 104 //
 105
 106 // add the translation to this matrix
 107 void wxAffineMatrix2D::Translate(wxDouble dx, wxDouble dy)
 108 {
 109     m_tx += dx;
 110     m_ty += dy;
 111 }
 112
 113 // add the scale to this matrix
 114 // | xScale   0      0 |   | m_11  m_12   0 |
 115 // |   0    yScale   0 | x | m_21  m_22   0 |
 116 // |   0      0      1 |   | m_tx  m_ty   1 |
 117 void wxAffineMatrix2D::Scale(wxDouble xScale, wxDouble yScale)
 118 {
 119     m_11 *= xScale;
 120     m_12 *= xScale;
 121     m_21 *= yScale;
 122     m_22 *= yScale;
 123 }
 124
 125 // add the rotation to this matrix (counter clockwise, radians)
 126 // | cos   -sin   0 |   | m_11  m_12   0 |
 127 // | sin    cos   0 | x | m_21  m_22   0 |
 128 // |  0      0    1 |   | m_tx  m_ty   1 |
 129 void wxAffineMatrix2D::Rotate(wxDouble ccRadians)
 130 {
 131     wxDouble c = cos(ccRadians);
 132     wxDouble s = sin(ccRadians);
 133
 134     wxDouble e11 = c*m_11 - s*m_21;
 135     wxDouble e12 = c*m_12 - s*m_22;
 136     m_21 = s*m_11 + c*m_21;
 137     m_22 = s*m_12 + c*m_22;
 138     m_11 = e11;
 139     m_12 = e12;
 140 }
 141
 142 //
 143 // apply the transforms
 144 //
 145
 146 // applies that matrix to the point
 147 //                           | m_11  m_12   0 |
 148 // | src.m_x  src._my  1 | x | m_21  m_22   0 |
 149 //                           | m_tx  m_ty   1 |
 150 wxPoint2DDouble
 151 wxAffineMatrix2D::DoTransformPoint(const wxPoint2DDouble& src) const
 152 {
 153     if ( IsIdentity() )
 154         return src;
 155
 156     return wxPoint2DDouble(src.m_x * m_11 + src.m_y * m_21 + m_tx,
 157                            src.m_y * m_12 + src.m_y * m_22 + m_ty);
 158 }
 159
 160 // applies the matrix except for translations
 161 //                           | m_11  m_12   0 |
 162 // | src.m_x  src._my  0 | x | m_21  m_22   0 |
 163 //                           | m_tx  m_ty   1 |
 164 wxPoint2DDouble
 165 wxAffineMatrix2D::DoTransformDistance(const wxPoint2DDouble& src) const
 166 {
 167     if ( IsIdentity() )
 168         return src;
 169
 170     return wxPoint2DDouble(src.m_x * m_11 + src.m_y * m_21,
 171                            src.m_y * m_12 + src.m_y * m_22);
 172 }
 173
 174 bool wxAffineMatrix2D::IsIdentity() const
 175 {
 176     return m_11 == 1 && m_12 == 0 &&
 177            m_21 == 0 && m_22 == 1 &&
 178            m_tx == 0 && m_ty == 0;
 179 }