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#define INKSCAPE_LPE_INTERPOLATE_CPP
/** \file
* LPE interpolate implementation
*/
/*
* Authors:
* Johan Engelen
*
* Copyright (C) Johan Engelen 2007-2008 <j.b.c.engelen@utwente.nl>
*
* Released under GNU GPL, read the file 'COPYING' for more information
*/
#include "live_effects/lpe-interpolate.h"
#include <2geom/path.h>
#include <2geom/sbasis-to-bezier.h>
#include <2geom/d2-sbasis.h>
#include <2geom/piecewise.h>
#include <2geom/sbasis-geometric.h>
#include "sp-path.h"
#include "display/curve.h"
namespace Inkscape {
namespace LivePathEffect {
LPEInterpolate::LPEInterpolate(LivePathEffectObject *lpeobject) :
Effect(lpeobject),
trajectory_path(_("Trajectory"), _("Path along which intermediate steps are created."), "trajectory", &wr, this, "M0,0 L0,0"),
number_of_steps(_("Steps"), _("Determines the number of steps from start to end path."), "steps", &wr, this, 5),
equidistant_spacing(_("Equidistant spacing"), _("If true, the spacing between intermediates is constant along the length of the path. If false, the distance depends on the location of the nodes of the trajectory path."), "equidistant_spacing", &wr, this, true)
{
show_orig_path = true;
registerParameter( dynamic_cast<Parameter *>(&trajectory_path) );
registerParameter( dynamic_cast<Parameter *>(&equidistant_spacing) );
registerParameter( dynamic_cast<Parameter *>(&number_of_steps) );
number_of_steps.param_make_integer();
number_of_steps.param_set_range(2, NR_HUGE);
}
LPEInterpolate::~LPEInterpolate()
{
}
/*
* interpolate path_in[0] to path_in[1]
*/
Geom::PathVector
LPEInterpolate::doEffect_path (Geom::PathVector const & path_in)
{
if ( (path_in.size() < 2) || (number_of_steps < 2))
return path_in;
std::vector<Geom::Path> path_out;
Geom::Piecewise<Geom::D2<Geom::SBasis> > pwd2_A = path_in[0].toPwSb();
Geom::Piecewise<Geom::D2<Geom::SBasis> > pwd2_B = path_in[1].toPwSb();
// Transform both paths to (0,0) midpoint, so they can easily be positioned along interpolate_path
pwd2_A -= Geom::bounds_exact(pwd2_A).midpoint();
pwd2_B -= Geom::bounds_exact(pwd2_B).midpoint();
// Make sure both paths have the same number of segments and cuts at the same locations
pwd2_B.setDomain(pwd2_A.domain());
Geom::Piecewise<Geom::D2<Geom::SBasis> > pA = Geom::partition(pwd2_A, pwd2_B.cuts);
Geom::Piecewise<Geom::D2<Geom::SBasis> > pB = Geom::partition(pwd2_B, pwd2_A.cuts);
Geom::Piecewise<Geom::D2<Geom::SBasis> > trajectory = trajectory_path.get_pathvector()[0].toPwSb();
if (equidistant_spacing)
trajectory = Geom::arc_length_parametrization(trajectory);
Geom::Interval trajectory_domain = trajectory.domain();
for (int i = 0; i < number_of_steps; ++i) {
double fraction = i / (number_of_steps-1);
Geom::Piecewise<Geom::D2<Geom::SBasis> > pResult = pA*(1-fraction) + pB*fraction;
pResult += trajectory.valueAt(trajectory_domain.min() + fraction*trajectory_domain.extent());
Geom::PathVector pathv = Geom::path_from_piecewise(pResult, LPE_CONVERSION_TOLERANCE);
path_out.push_back( pathv[0] );
}
return path_out;
}
void
LPEInterpolate::resetDefaults(SPItem * item)
{
if (!SP_IS_PATH(item))
return;
SPCurve const *crv = sp_path_get_curve_reference(SP_PATH(item));
Geom::PathVector const &pathv = crv->get_pathvector();
if ( (pathv.size() < 2) )
return;
Geom::Rect bounds_A = pathv[0].boundsExact();
Geom::Rect bounds_B = pathv[1].boundsExact();
Geom::PathVector traj_pathv;
traj_pathv.push_back( Geom::Path() );
traj_pathv[0].start( bounds_A.midpoint() );
traj_pathv[0].appendNew<Geom::LineSegment>( bounds_B.midpoint() );
trajectory_path.set_new_value( traj_pathv, true );
}
} //namespace LivePathEffect
} /* namespace Inkscape */
/*
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 :
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