src/map/transform.cpp

   1 #include "matrix.h"
   2 #include "transform.h"
   3
   4
   5 #define NULL_QTRANSFORM 0,0,0,0,0,0,0,0,0
   6
   7 void Transform::simple(const ReferencePoint &p1, const ReferencePoint &p2)
   8 {
   9         if (p1.xy().x() == p2.xy().x() || p1.xy().y() == p2.xy().y()) {
  10                 _errorString = "Invalid reference points tuple";
  11                 return;
  12         }
  13
  14         double sX = (p1.xy().x() - p2.xy().x()) / (p1.pp().x() - p2.pp().x());
  15         double sY = (p2.xy().y() - p1.xy().y()) / (p2.pp().y() - p1.pp().y());
  16         double dX = p2.xy().x() - p2.pp().x() * sX;
  17         double dY = p1.xy().y() - p1.pp().y() * sY;
  18
  19         _proj2img = QTransform(sX, 0, 0, sY, dX, dY);
  20         _img2proj = _proj2img.inverted();
  21 }
  22
  23 void Transform::affine(const QList<ReferencePoint> &points)
  24 {
  25         Matrix c(3, 2);
  26         for (size_t i = 0; i < c.h(); i++) {
  27                 for (size_t j = 0; j < c.w(); j++) {
  28                         for (int k = 0; k < points.size(); k++) {
  29                                 double f[3], t[2];
  30
  31                                 f[0] = points.at(k).pp().x();
  32                                 f[1] = points.at(k).pp().y();
  33                                 f[2] = 1.0;
  34                                 t[0] = points.at(k).xy().x();
  35                                 t[1] = points.at(k).xy().y();
  36                                 c.m(i,j) += f[i] * t[j];
  37                         }
  38                 }
  39         }
  40
  41         Matrix Q(3, 3);
  42         for (int qi = 0; qi < points.size(); qi++) {
  43                 double v[3];
  44
  45                 v[0] = points.at(qi).pp().x();
  46                 v[1] = points.at(qi).pp().y();
  47                 v[2] = 1.0;
  48                 for (size_t i = 0; i < Q.h(); i++)
  49                         for (size_t j = 0; j < Q.w(); j++)
  50                                 Q.m(i,j) += v[i] * v[j];
  51         }
  52
  53         Matrix M(Q.augemented(c));
  54         if (!M.eliminate()) {
  55                 _errorString = "Singular transformation matrix";
  56                 return;
  57         }
  58
  59         _proj2img = QTransform(M.m(0,3), M.m(0,4), M.m(1,3), M.m(1,4), M.m(2,3),
  60           M.m(2,4));
  61         _img2proj = _proj2img.inverted();
  62 }
  63
  64 Transform::Transform()
  65   : _proj2img(NULL_QTRANSFORM), _img2proj(NULL_QTRANSFORM)
  66 {
  67 }
  68
  69 Transform::Transform(const QList<ReferencePoint> &points)
  70   : _proj2img(NULL_QTRANSFORM), _img2proj(NULL_QTRANSFORM)
  71 {
  72         if (points.count() < 2)
  73                 _errorString = "Insufficient number of reference points";
  74         else if (points.size() == 2)
  75                 simple(points.at(0), points.at(1));
  76         else
  77                 affine(points);
  78 }
  79
  80 Transform::Transform(const ReferencePoint &p1, const ReferencePoint &p2)
  81   : _proj2img(NULL_QTRANSFORM), _img2proj(NULL_QTRANSFORM)
  82 {
  83         simple(p1, p2);
  84 }
  85
  86 Transform::Transform(const ReferencePoint &p, const PointD &scale)
  87   : _proj2img(NULL_QTRANSFORM), _img2proj(NULL_QTRANSFORM)
  88 {
  89         if (scale.x() == 0.0 || scale.y() == 0.0) {
  90                 _errorString = "Invalid scale factor";
  91                 return;
  92         }
  93
  94         _img2proj = QTransform(scale.x(), 0, 0, -scale.y(), p.pp().x() - p.xy().x()
  95           / scale.x(), p.pp().y() + p.xy().x() / scale.y());
  96         _proj2img = _img2proj.inverted();
  97 }
  98
  99 Transform::Transform(double matrix[16])
 100   : _proj2img(NULL_QTRANSFORM), _img2proj(NULL_QTRANSFORM)
 101 {
 102         _img2proj = QTransform(matrix[0], matrix[1], matrix[4], matrix[5],
 103           matrix[3], matrix[7]);
 104         if (!_img2proj.isInvertible())
 105                 _errorString = "Singular transformation matrix";
 106         else
 107                 _proj2img = _img2proj.inverted();
 108 }
 109
 110 #ifndef QT_NO_DEBUG
 111 QDebug operator<<(QDebug dbg, const ReferencePoint &p)
 112 {
 113         dbg.nospace() << "ReferencePoint(" << p.xy() << ", " << p.pp() << ")";
 114         return dbg.space();
 115 }
 116 #endif // QT_NO_DEBUG