geom-nodetype.cpp revision 13b2057922920384c8b51f3f944971f4ceab382b
#define INKSCAPE_HELPER_GEOM_NODETYPE_CPP
/**
* Specific nodetype geometry functions for Inkscape, not provided my lib2geom.
*
* Author:
* Johan Engelen <goejendaagh@zonnet.nl>
*
* Copyright (C) 2008 Johan Engelen
*
* Released under GNU GPL
*/
#include "helper/geom-nodetype.h"
#include <2geom/curve.h>
#include <2geom/point.h>
#include <vector>
namespace Geom {
/*
* NOTE: THIS METHOD NEVER RETURNS "NODE_SYMM".
* Returns the nodetype between c_incoming and c_outgoing. Location of the node is
* at c_incoming.pointAt(1) == c_outgoing.pointAt(0). If these two are unequal,
* the returned type is NODE_NONE.
* Comparison is based on the unitTangent, does not work for NODE_SYMM!
*/
NodeType get_nodetype(Curve const &c_incoming, Curve const &c_outgoing)
{
if ( !are_near(c_incoming.pointAt(1), c_outgoing.pointAt(0)) )
return NODE_NONE;
Geom::Point deriv_1 = c_incoming.unitTangentAt(1);
Geom::Point deriv_2 = c_outgoing.unitTangentAt(0);
double this_angle_L2 = Geom::L2(deriv_1);
double next_angle_L2 = Geom::L2(deriv_2);
double both_angles_L2 = Geom::L2(deriv_1 + deriv_2);
if ( (this_angle_L2 > 1e-6) &&
(next_angle_L2 > 1e-6) &&
((this_angle_L2 + next_angle_L2 - both_angles_L2) < 1e-3) )
{
return NODE_SMOOTH;
}
return NODE_CUSP;
}
} // end namespace Geom
/*
Local Variables:
mode:c++
c-file-style:"stroustrup"
c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
indent-tabs-mode:nil
fill-column:99
End:
*/
// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:encoding=utf-8:textwidth=99 :