From 02966b735b1245e1d036d1a7eb5a1f554d281d5d Mon Sep 17 00:00:00 2001
From: ponchio <federico.ponchio@isti.cnr.it>
Date: Fri, 5 Mar 2004 15:15:11 +0000
Subject: [PATCH] Created.

---
 vcg/math/similar.h | 105 +++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 105 insertions(+)
 create mode 100644 vcg/math/similar.h

diff --git a/vcg/math/similar.h b/vcg/math/similar.h
new file mode 100644
index 00000000..020a556c
--- /dev/null
+++ b/vcg/math/similar.h
@@ -0,0 +1,105 @@
+#ifndef SIMILAR_H
+#define SIMILAR_H
+
+#include <vcg/math/quaternion.h>
+#include <vcg/math/matrix44.h>
+
+namespace vcg {
+
+template <class S> class Similar {
+public:
+  Similar() {}
+  
+  Similar operator*(const Similar &affine) const;
+  Similar &operator*=(const Similar &affine);
+  Point3<S> operator*(const Point3<S> &p) const;
+  
+  
+  void SetIdentity();
+  void SetScale(const S s);
+	Similar &SetTranslate(const Point3<S> &t);	
+  ///use radiants for angle.
+  void SetRotate(S angle, const Point3<S> & axis); 
+
+  Matrix44<S> Matrix() const;
+
+  Quaternion<S> rot;
+  Point3<S> tra;
+  S sca;  
+};
+
+template <class S> Similar<S> Similar<S>::operator*(const Similar &a) const {
+  Similar<S> r;
+  r.rot = rot * a.rot;
+  r.sca = sca * a.sca;
+  r.tra = (rot.Rotate(a.tra)) * sca + tra;
+  return r;
+}
+
+template <class S> Similar<S> &Similar<S>::operator*=(const Similar &a) {  
+  rot = rot * a.rot;
+  sca = sca * a.sca;
+  tra = (rot.Rotate(a.tra)) * sca + tra;
+  return *this;
+}
+
+template <class S> Point3<S> Similar<S>::operator*(const Point3<S> &p) const {
+  Point3<S> r = rot.Rotate(p);
+  r *= sca;
+  r += tra;
+  return r;
+}
+  
+template <class S> void Similar<S>::SetIdentity() {
+  rot.FromAxis(0, Point3<S>(1, 0, 0));
+  tra = Point3<S>(0, 0, 0);
+  sca = 1;
+}
+
+template <class S> void Similar<S>::SetScale(const S s) {
+  SetIdentity();
+  sca = s;
+}
+
+template <class S> Similar<S> &Similar<S>::SetTranslate(const Point3<S> &t) {
+  SetIdentity();
+  tra = t;
+  return *this;
+}
+
+template <class S> void Similar<S>::SetRotate(S angle, const Point3<S> &axis) {
+  SetIdentity();
+  rot.FromAxis(angle, axis);
+}
+
+template <class S> Matrix44<S> Similar<S>::Matrix() const {
+  Matrix44<S> r;
+  rot.ToMatrix(r);
+  r *= Matrix44<S>().SetScale(sca, sca, sca);
+  Matrix44<S> t = Matrix44<S>().SetTranslate(tra[0], tra[1], tra[2]);
+  r *= t;
+  return r;
+}
+
+template <class S> Similar<S> &invert(Similar<S> &a) {
+  //WARNING:: TEST THIS!!!
+  a.rot.Invert();
+  a.sca = 1/a.sca;
+  a.tra = a.rot.Rotate(-a.tra)*a.sca;
+  return a;
+}
+
+template <class S> Similar<S> interpolate(const Similar<S> &a, const Similar<S> &b, const S t) {
+  Similar<S> r;
+  r.rot = interpolate(a.rot, b.rot, t);
+  r.tra = t * a.tra + (1-t) * b.tra;
+  r.sca = t * a.sca + (1-t) * b.sca;
+  return r;
+}
+
+typedef Similar<float> Similarf;
+typedef Similar<double>Similard;
+
+} //namespace
+
+#endif
\ No newline at end of file