Mercurial > hg > orthanc-stone

comparison Framework/Toolbox/AffineTransform2D.cpp @ 575:919226caca82

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
AffineTransform2D::ComputeZoom()
author Sebastien Jodogne <s.jodogne@gmail.com>
date Fri, 19 Apr 2019 09:08:15 +0200
parents 911297a277c4
children 7912de3a15e0
comparison
equal deleted inserted replaced
574:911297a277c4 575:919226caca82
128 target[14] = -z; 128 target[14] = -z;
129 target[15] = static_cast<float>(source(2, 2)); 129 target[15] = static_cast<float>(source(2, 2));
130 } 130 }
131 131
132 132
133 double AffineTransform2D::ComputeZoom() const
134 {
135 // Compute the length of the (0,0)-(1,1) diagonal (whose
136 // length is sqrt(2)) instead of the (0,0)-(1,0) unit segment,
137 // in order to cope with possible anisotropic zooming
138
139 double x1 = 0;
140 double y1 = 0;
141 Apply(x1, y1);
142
143 double x2 = 1;
144 double y2 = 1;
145 Apply(x2, y2);
146
147 double dx = x2 - x1;
148 double dy = y2 - y1;
149
150 double zoom = sqrt(dx * dx + dy * dy) / sqrt(2.0);
151
152 if (LinearAlgebra::IsCloseToZero(zoom))
153 {
154 return 1; // Default value if transform is ill-conditioned
155 }
156 else
157 {
158 return zoom;
159 }
160 }
161
162
133 AffineTransform2D AffineTransform2D::Invert(const AffineTransform2D& a) 163 AffineTransform2D AffineTransform2D::Invert(const AffineTransform2D& a)
134 { 164 {
135 AffineTransform2D t; 165 AffineTransform2D t;
136 LinearAlgebra::InvertMatrix(t.matrix_, a.matrix_); 166 LinearAlgebra::InvertMatrix(t.matrix_, a.matrix_);
137 return t; 167 return t;