--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/OrthancStone/Sources/Toolbox/AffineTransform2D.h	Tue Jul 07 16:21:02 2020 +0200
@@ -0,0 +1,103 @@
+/**
+ * Stone of Orthanc
+ * Copyright (C) 2012-2016 Sebastien Jodogne, Medical Physics
+ * Department, University Hospital of Liege, Belgium
+ * Copyright (C) 2017-2020 Osimis S.A., Belgium
+ *
+ * This program is free software: you can redistribute it and/or
+ * modify it under the terms of the GNU Affero General Public License
+ * as published by the Free Software Foundation, either version 3 of
+ * the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ **/
+
+
+#pragma once
+
+#include "../StoneEnumerations.h"
+#include "LinearAlgebra.h"
+
+#include <Images/ImageAccessor.h>
+
+namespace OrthancStone
+{
+  class AffineTransform2D
+  {
+  private:
+    Matrix  matrix_;
+
+  public:
+    AffineTransform2D();
+
+    // The matrix must be 3x3, without perspective effects
+    AffineTransform2D(const Matrix& m);
+
+    AffineTransform2D(const AffineTransform2D& other) :
+      matrix_(other.matrix_)
+    {
+    }
+    
+    const Matrix& GetHomogeneousMatrix() const
+    {
+      return matrix_;
+    }
+
+    void Apply(double& x /* inout */,
+               double& y /* inout */) const;
+
+    void Apply(Orthanc::ImageAccessor& target,
+               const Orthanc::ImageAccessor& source,
+               ImageInterpolation interpolation,
+               bool clear) const;
+
+    void ConvertToOpenGLMatrix(float target[16],
+                               unsigned int canvasWidth,
+                               unsigned int canvasHeight) const;
+
+    double ComputeZoom() const;
+    
+    static AffineTransform2D Invert(const AffineTransform2D& a);
+
+    static AffineTransform2D Combine(const AffineTransform2D& a,
+                                     const AffineTransform2D& b);
+      
+    static AffineTransform2D Combine(const AffineTransform2D& a,
+                                     const AffineTransform2D& b,
+                                     const AffineTransform2D& c);
+      
+    static AffineTransform2D Combine(const AffineTransform2D& a,
+                                     const AffineTransform2D& b,
+                                     const AffineTransform2D& c,
+                                     const AffineTransform2D& d);
+
+    // transformations are applied right to left: 
+    // `e` is the first transformation applied and `a` is the last one
+    static AffineTransform2D Combine(const AffineTransform2D& a,
+                                     const AffineTransform2D& b,
+                                     const AffineTransform2D& c,
+                                     const AffineTransform2D& d,
+                                     const AffineTransform2D& e);
+
+    static AffineTransform2D CreateOffset(double dx,
+                                          double dy);
+
+    static AffineTransform2D CreateScaling(double sx,
+                                           double sy);
+
+    static AffineTransform2D CreateRotation(double angle); // CW rotation in radians
+
+    static AffineTransform2D CreateRotation(double angle, // CW rotation in radians
+                                            double cx,    // rotation center
+                                            double cy);   // rotation center
+
+    static AffineTransform2D CreateOpenGLClipspace(unsigned int canvasWidth,
+                                                   unsigned int canvasHeight);
+  };
+}