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/*
* ***** BEGIN GPL LICENSE BLOCK *****
*
* This program 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 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software Foundation,
* Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*
* The Original Code is Copyright (C) 2010 Blender Foundation.
* All rights reserved.
*
* The Original Code is: all of this file.
*
* Contributor(s): none yet.
*
* ***** END GPL LICENSE BLOCK *****
*/
#ifndef __SWEEPLINE_H__
#define __SWEEPLINE_H__
/** \file blender/freestyle/intern/geometry/SweepLine.h
* \ingroup freestyle
* \brief Class to define a Sweep Line
* \author Stephane Grabli
* \date 29/08/2002
*/
#include <list>
#include <vector>
/*! Class to define the intersection berween two segments*/
template<class Edge>
class Intersection
{
public:
template<class EdgeClass>
Intersection(EdgeClass* eA, real ta, EdgeClass* eB, real tb)
{
EdgeA = eA;
EdgeB = eB;
tA = ta;
tB = tb;
userdata = 0;
}
Intersection(const Intersection& iBrother)
{
EdgeA = iBrother.EdgeA;
EdgeB = iBrother.EdgeB;
tA = iBrother.tA;
tB = iBrother.tB;
userdata = 0;
}
/*! returns the parameter giving the intersection, for the edge iEdge */
real getParameter(Edge *iEdge)
{
if (iEdge == EdgeA)
return tA;
if (iEdge == EdgeB)
return tB;
return 0;
}
public:
void * userdata; // FIXME
Edge *EdgeA; // first segment
Edge *EdgeB; // second segment
real tA; // parameter defining the intersection point with respect to the segment EdgeA.
real tB; // parameter defining the intersection point with respect to the segment EdgeB.
};
template<class T, class Point>
class Segment
{
public:
Segment()
{
}
Segment(T& s, const Point& iA, const Point& iB)
{
_edge = s;
if (iA < iB) {
A = iA;
B = iB;
_order = true;
}
else {
A = iB;
B = iA;
_order = false;
}
}
Segment(Segment<T,Point>& iBrother)
{
_edge = iBrother.edge();
A = iBrother.A;
B = iBrother.B;
_Intersections = iBrother._Intersections;
_order = iBrother._order;
}
Segment(const Segment<T,Point>& iBrother)
{
_edge = iBrother._edge;
A = iBrother.A;
B = iBrother.B;
_Intersections = iBrother._Intersections;
_order = iBrother._order;
}
~Segment()
{
_Intersections.clear();
}
inline Point operator[](const unsigned short int& i) const
{
return (i % 2 == 0) ? A : B;
}
inline bool operator==(const Segment<T,Point>& iBrother)
{
if (_edge == iBrother._edge)
return true;
return false;
}
/* Adds an intersection for this segment */
inline void AddIntersection(Intersection<Segment<T,Point> > *i)
{
_Intersections.push_back(i);
}
/*! Checks for a common vertex with another edge */
inline bool CommonVertex(const Segment<T,Point>& S, Point& CP)
{
if ((A == S[0]) || (A == S[1])) {
CP = A;
return true;
}
if ((B == S[0]) || (B == S[1])) {
CP = B;
return true;
}
return false;
}
inline vector<Intersection<Segment<T,Point> >*>& intersections()
{
return _Intersections;
}
inline bool order()
{
return _order;
}
inline T& edge()
{
return _edge;
}
private:
T _edge;
Point A;
Point B;
std::vector<Intersection<Segment<T,Point> >*> _Intersections; // list of intersections parameters
bool _order; // true if A and B are in the same order than _edge.A and _edge.B. false otherwise.
};
/*! defines a binary function that can be overload by the user to specify at each condition the intersection
* between 2 edges must be computed
*/
template<class T1, class T2>
struct binary_rule
{
binary_rule() {}
template<class T3,class T4> binary_rule(const binary_rule<T3,T4>& brother) {}
virtual ~binary_rule() {}
virtual bool operator()(T1&, T2&)
{
return true;
}
};
template<class T,class Point>
class SweepLine
{
public:
SweepLine() {}
~SweepLine()
{
for (typename vector<Intersection<Segment<T,Point> >*>::iterator i = _Intersections.begin(),
iend = _Intersections.end();
i != iend;
i++)
{
delete (*i);
}
}
inline void process(Point& p, vector<Segment<T,Point>*>& segments,
#if 0
binary_rule<Segment<T,Point>,Segment<T,Point> >& binrule = \
binary_rule<Segment<T,Point>,Segment<T,Point> >(),
#else
binary_rule<Segment<T,Point>,Segment<T,Point> >& binrule,
#endif
real epsilon = M_EPSILON)
{
// first we remove the segments that need to be removed and then we add the segments to add
vector<Segment<T,Point>*> toadd;
typename vector<Segment<T,Point>*>::iterator s, send;
for (s = segments.begin(), send = segments.end(); s != send; s++) {
if (p == (*(*s))[0])
toadd.push_back((*s));
else
remove((*s));
}
for (s = toadd.begin(), send = toadd.end(); s != send; s++) {
add((*s), binrule, epsilon);
}
}
inline void add(Segment<T,Point>* S,
#if 0
binary_rule<Segment<T,Point>,Segment<T,Point> >& binrule = \
binary_rule<Segment<T,Point>, Segment<T,Point> >(),
#else
binary_rule<Segment<T,Point>,Segment<T,Point> >& binrule,
#endif
real epsilon)
{
real t,u;
Point CP;
Vec2r v0, v1, v2, v3;
if (true == S->order()) {
v0[0] = ((*S)[0])[0];
v0[1] = ((*S)[0])[1];
v1[0] = ((*S)[1])[0];
v1[1] = ((*S)[1])[1];
}
else {
v1[0] = ((*S)[0])[0];
v1[1] = ((*S)[0])[1];
v0[0] = ((*S)[1])[0];
v0[1] = ((*S)[1])[1];
}
for (typename std::list<Segment<T,Point>* >::iterator s = _set.begin(), send = _set.end(); s != send; s++) {
Segment<T,Point>* currentS = (*s);
if (true != binrule(*S, *currentS))
continue;
if (true == currentS->order()) {
v2[0] = ((*currentS)[0])[0];
v2[1] = ((*currentS)[0])[1];
v3[0] = ((*currentS)[1])[0];
v3[1] = ((*currentS)[1])[1];
}
else {
v3[0] = ((*currentS)[0])[0];
v3[1] = ((*currentS)[0])[1];
v2[0] = ((*currentS)[1])[0];
v2[1] = ((*currentS)[1])[1];
}
if (S->CommonVertex(*currentS, CP))
continue; // the two edges have a common vertex->no need to check
if (GeomUtils::intersect2dSeg2dSegParametric(v0, v1, v2, v3, t, u, epsilon) == GeomUtils::DO_INTERSECT) {
// create the intersection
Intersection<Segment<T,Point> > *inter = new Intersection<Segment<T,Point> >(S,t,currentS,u);
// add it to the intersections list
_Intersections.push_back(inter);
// add this intersection to the first edge intersections list
S->AddIntersection(inter);
// add this intersection to the second edge intersections list
currentS->AddIntersection(inter);
}
}
// add the added segment to the list of active segments
_set.push_back(S);
}
inline void remove(Segment<T,Point>* s)
{
if (s->intersections().size() > 0)
_IntersectedEdges.push_back(s);
_set.remove(s);
}
vector<Segment<T,Point>* >& intersectedEdges()
{
return _IntersectedEdges;
}
vector<Intersection<Segment<T,Point> >*>& intersections()
{
return _Intersections;
}
private:
std::list<Segment<T,Point>* > _set; // set of active edges for a given position of the sweep line
std::vector<Segment<T,Point>* > _IntersectedEdges; // the list of intersected edges
std::vector<Intersection<Segment<T,Point> >*> _Intersections; // the list of all intersections.
};
#endif // __SWEEPLINE_H__
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