diff -r d8475431bbbb -r 8e85e6bbefdf lemon/bezier.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/lemon/bezier.h	Mon May 23 04:48:14 2005 +0000
@@ -0,0 +1,147 @@
+/* -*- C++ -*-
+ * lemon/bezier.h - Part of LEMON, a generic C++ optimization library
+ *
+ * Copyright (C) 2005 Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport
+ * (Egervary Research Group on Combinatorial Optimization, EGRES).
+ *
+ * Permission to use, modify and distribute this software is granted
+ * provided that this copyright notice appears in all copies. For
+ * precise terms see the accompanying LICENSE file.
+ *
+ * This software is provided "AS IS" with no warranty of any kind,
+ * express or implied, and with no claim as to its suitability for any
+ * purpose.
+ *
+ */
+
+#ifndef LEMON_BEZIER_H
+#define LEMON_BEZIER_H
+
+///\ingroup misc
+///\file
+///\brief Classes to compute with Bezier curves.
+///
+///Up to now this file is used internally by \ref graph_to_eps.h
+///
+///\author Alpar Juttner
+
+#include<lemon/xy.h>
+
+namespace lemon {
+
+class BezierBase {
+public:
+  typedef xy<double> xy;
+protected:
+  static xy conv(xy x,xy y,double t) {return (1-t)*x+t*y;}
+};
+
+class Bezier1 : public BezierBase
+{
+public:
+  xy p1,p2;
+
+  Bezier1() {}
+  Bezier1(xy _p1, xy _p2) :p1(_p1), p2(_p2) {}
+  
+  xy operator()(double t) const
+  {
+    //    return conv(conv(p1,p2,t),conv(p2,p3,t),t);
+    return conv(p1,p2,t);
+  }
+  Bezier1 before(double t) const
+  {
+    return Bezier1(p1,conv(p1,p2,t));
+  }
+  
+  Bezier1 after(double t) const
+  {
+    return Bezier1(conv(p1,p2,t),p2);
+  }
+  Bezier1 revert() { return Bezier1(p2,p1);}
+  Bezier1 operator()(double a,double b) { return before(b).after(a/b); }
+  xy grad() { return p2-p1; }
+  xy grad(double t) { return grad(); }
+
+};
+
+class Bezier2 : public BezierBase
+{
+public:
+  xy p1,p2,p3;
+
+  Bezier2() {}
+  Bezier2(xy _p1, xy _p2, xy _p3) :p1(_p1), p2(_p2), p3(_p3) {}
+  Bezier2(const Bezier1 &b) : p1(b.p1), p2(conv(b.p1,b.p2,.5)), p3(b.p2) {}
+  xy operator()(double t) const
+  {
+    //    return conv(conv(p1,p2,t),conv(p2,p3,t),t);
+    return ((1-t)*(1-t))*p1+(2*(1-t)*t)*p2+(t*t)*p3;
+  }
+  Bezier2 before(double t) const
+  {
+    xy q(conv(p1,p2,t));
+    xy r(conv(p2,p3,t));
+    return Bezier2(p1,q,conv(q,r,t));
+  }
+  
+  Bezier2 after(double t) const
+  {
+    xy q(conv(p1,p2,t));
+    xy r(conv(p2,p3,t));
+    return Bezier2(conv(q,r,t),r,p3);
+  }
+  Bezier2 revert() { return Bezier2(p3,p2,p1);}
+  Bezier2 operator()(double a,double b) { return before(b).after(a/b); }
+  Bezier1 grad() { return Bezier1(2.0*(p2-p1),2.0*(p3-p2)); }
+  xy grad(double t) { return grad()(t); }  
+};
+
+class Bezier3 : public BezierBase
+{
+public:
+  xy p1,p2,p3,p4;
+
+  Bezier3() {}
+  Bezier3(xy _p1, xy _p2, xy _p3, xy _p4) :p1(_p1), p2(_p2), p3(_p3), p4(_p4) {}
+  Bezier3(const Bezier1 &b) : p1(b.p1), p2(conv(b.p1,b.p2,1.0/3.0)), 
+			      p3(conv(b.p1,b.p2,2.0/3.0)), p4(b.p2) {}
+  Bezier3(const Bezier2 &b) : p1(b.p1), p2(conv(b.p1,b.p2,2.0/3.0)),
+			      p3(conv(b.p2,b.p3,1.0/3.0)), p4(b.p3) {}
+  
+  xy operator()(double t) const 
+    {
+      //    return Bezier2(conv(p1,p2,t),conv(p2,p3,t),conv(p3,p4,t))(t);
+      return ((1-t)*(1-t)*(1-t))*p1+(3*t*(1-t)*(1-t))*p2+
+	(3*t*t*(1-t))*p3+(t*t*t)*p4;
+    }
+  Bezier3 before(double t) const
+    {
+      xy p(conv(p1,p2,t));
+      xy q(conv(p2,p3,t));
+      xy r(conv(p3,p4,t));
+      xy a(conv(p,q,t));
+      xy b(conv(q,r,t));
+      xy c(conv(a,b,t));
+      return Bezier3(p1,p,a,c);
+    }
+  
+  Bezier3 after(double t) const
+    {
+      xy p(conv(p1,p2,t));
+      xy q(conv(p2,p3,t));
+      xy r(conv(p3,p4,t));
+      xy a(conv(p,q,t));
+      xy b(conv(q,r,t));
+      xy c(conv(a,b,t));
+      return Bezier3(c,b,r,p4);
+    }
+  Bezier3 revert() { return Bezier3(p4,p3,p2,p1);}
+  Bezier3 operator()(double a,double b) { return before(b).after(a/b); }
+  Bezier2 grad() { return Bezier2(3.0*(p2-p1),3.0*(p3-p2),3.0*(p4-p3)); }
+  xy grad(double t) { return grad()(t); }
+};
+
+} //END OF NAMESPACE LEMON
+
+#endif // LEMON_BEZIER_H