--- /dev/null
+/*! ========================================================================
+** Extended Template and Library
+** B-Spline Class Implementation
+** $Id$
+**
+** Copyright (c) 2002 Robert B. Quattlebaum Jr.
+**
+** This package is free software; you can redistribute it and/or
+** modify it under the terms of the GNU General Public License as
+** published by the Free Software Foundation; either version 2 of
+** the License, or (at your option) any later version.
+**
+** This package 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
+** General Public License for more details.
+**
+** === N O T E S ===========================================================
+**
+** This is an internal header file, included by other ETL headers.
+** You should not attempt to use it directly.
+**
+** ========================================================================= */
+
+/* === S T A R T =========================================================== */
+
+#ifndef __ETL__BSPLINE_H
+#define __ETL__BSPLINE_H
+
+/* === H E A D E R S ======================================================= */
+
+#include <vector>
+#include <functional>
+#include "_curve_func.h"
+
+/* === M A C R O S ========================================================= */
+
+/* === T Y P E D E F S ===================================================== */
+
+/* === C L A S S E S & S T R U C T S ======================================= */
+
+_ETL_BEGIN_NAMESPACE
+
+template <class T, class K=float, class C=affine_combo<T,K>, class D=distance_func<T> >
+class bspline : public std::unary_function<K,T>
+{
+public:
+ typedef T value_type;
+ typedef K knot_type;
+ typedef std::vector<knot_type> knot_container;
+ typedef std::vector<value_type> cpoint_container;
+ typedef typename knot_container::iterator knot_iterator;
+ typedef typename cpoint_container::iterator cpoint_iterator;
+
+ typedef C affine_func_type;
+ typedef D distance_func_type;
+
+protected:
+ affine_func_type affine_func;
+ distance_func_type distance_func;
+
+private:
+ int m;
+ knot_container _knots;
+ cpoint_container _cpoints;
+ bool _loop;
+
+public:
+ bspline():m(2),_loop(false) { }
+
+ int get_m()const { return m-1; };
+ int set_m(int new_m) { m=new_m+1; return m-1; };
+
+ bool set_loop(bool x) { _loop=x; reset_knots(); return _loop; }
+
+ knot_container & knots() { return _knots; };
+ cpoint_container & cpoints() { return _cpoints; };
+
+ const knot_container & knots()const { return _knots; };
+ const cpoint_container & cpoints()const { return _cpoints; };
+
+ void reset_knots()
+ {
+ int i;
+
+ if(!_loop)
+ {
+ _knots.clear();
+ if(!_cpoints.size())
+ return;
+ while(m>(signed)_cpoints.size())
+ m--;
+ for(i=0;i<m;i++)
+ *_knots.insert(_knots.end())=0;
+ for(i=1;i<(signed)_cpoints.size()-m+1;i++)
+ *_knots.insert(_knots.end())=i;
+ for(i=0;i<m;i++)
+ *_knots.insert(_knots.end())=_cpoints.size()-m+1;
+ }
+ else
+ {
+ _knots.clear();
+ if(!_cpoints.size())
+ return;
+ while(m>(signed)_cpoints.size())
+ m--;
+ for(i=0;i<=(signed)_cpoints.size()-m+1;i++)
+ *_knots.insert(_knots.end())=i;
+ }
+ }
+
+ int calc_curve_segment(knot_type t)const
+ {
+ int k;
+ if(t<0)
+ t=0;
+ if(t>=_knots.back())
+ t=_knots.back()-0.0001;
+ for(k=0;_knots[k]>t || _knots[k+1]<=t;k++)
+ ;
+
+ return k;
+ }
+
+ knot_container get_segment_knots(int i)const
+ {
+ if(i+1<m)
+ {
+ knot_container ret(_knots.begin(),_knots.begin()+i+m+1);
+
+ return ret;
+ }
+ if(i+1>=(signed)_knots.size())
+ {
+ knot_container ret(_knots.begin()+i-m+1,_knots.end());
+ return ret;
+ }
+ return knot_container(_knots.begin()+i-m+1, _knots.begin()+i+m);
+ }
+
+ cpoint_container get_segment_cpoints(int i)const
+ {
+ if(i+1<m)
+ {
+ return cpoint_container();
+ }
+ if(i+1>=(signed)_knots.size())
+ {
+ return cpoint_container();
+ }
+ return cpoint_container(_cpoints.begin()+i-m+1, _cpoints.begin()+i+1);
+ }
+
+ cpoint_container calc_shell(knot_type t, int level)const
+ {
+ int
+ i=calc_curve_segment(t),
+ j,k;
+
+ knot_container u=get_segment_knots(i);
+
+ cpoint_container d=get_segment_cpoints(i);
+
+ if(!d.size())
+ return cpoint_container();
+
+ for(j=0;d.size()>1 && j<level;d.pop_back(),j++)
+ {
+ for(k=0;k<d.size()-1;k++)
+ {
+ d[k]=affine_func(d[k],d[k+1],((t-u[j+k+1])/(u[m+k]-u[j+k+1])));
+ }
+ }
+ return d;
+ }
+
+ value_type operator()(knot_type t)const
+ {
+ return get_curve_val(calc_curve_segment(t),t);
+ }
+
+ value_type get_curve_val(int i,knot_type t)const
+ {
+ int
+ j,k;
+
+ knot_container u=get_segment_knots(i);
+
+ cpoint_container d=get_segment_cpoints(i);
+
+ if(!d.size())
+ return value_type();
+
+ for(j=0;d.size()>1;d.pop_back(),j++)
+ {
+ for(k=0;k<(signed)d.size()-1;k++)
+ {
+ d[k]=affine_func(d[k],d[k+1],((t-u[j+k+1])/(u[m+k]-u[j+k+1])));
+ }
+ }
+ return d.front();
+ }
+
+ cpoint_iterator find_closest_cpoint(const value_type &point, typename distance_func_type::result_type max)
+ {
+ cpoint_iterator i=_cpoints.begin();
+ cpoint_iterator ret=i;
+ typename distance_func_type::result_type dist=distance_func(point,_cpoints[0]);
+
+ // The distance function returns "cooked" (ie: squared)
+ // distances, so we need to cook our max distance for
+ // the comparison to work correctly.
+ max=distance_func.cook(max);
+
+ for(++i;i<_cpoints.end();i++)
+ {
+ typename distance_func_type::result_type thisdist=distance_func(point,*i);
+
+ if(thisdist<dist)
+ {
+ dist=thisdist;
+ ret=i;
+ }
+ }
+ if(dist<max)
+ return ret;
+ return _cpoints.end();
+ }
+};
+
+_ETL_END_NAMESPACE
+
+/* -- F U N C T I O N S ----------------------------------------------------- */
+
+/* -- E N D ----------------------------------------------------------------- */
+
+#endif
projects / synfig.git / blobdiff