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// SPDX-License-Identifier: GPL-2.0-or-later
/** \file
* LPE interpolate implementation
*/
/*
* Authors:
* Johan Engelen
*
* Copyright (C) Johan Engelen 2007-2008 <j.b.c.engelen@utwente.nl>
*
* Released under GNU GPL v2+, read the file 'COPYING' for more information.
*/
#include "live_effects/lpe-interpolate.h"
#include <2geom/sbasis-to-bezier.h>
#include "display/curve.h"
#include "object/sp-path.h"
// TODO due to internal breakage in glibmm headers, this must be last:
#include <glibmm/i18n.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(_("E_quidistant 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(&trajectory_path);
registerParameter(&equidistant_spacing);
registerParameter(&number_of_steps);
number_of_steps.param_make_integer();
number_of_steps.param_set_range(2, std::numeric_limits<gint>::max());
}
LPEInterpolate::~LPEInterpolate() = default;
bool
LPEInterpolate::doOnOpen(SPLPEItem const *lpeitem)
{
if (!is_load || is_applied) {
return false;
}
trajectory_path.reload();
return false;
}
void LPEInterpolate::transform_multiply(Geom::Affine const &postmul, bool /*set*/)
{
if (sp_lpe_item && sp_lpe_item->pathEffectsEnabled() && sp_lpe_item->optimizeTransforms()) {
trajectory_path.param_transform_multiply(postmul, false);
}
}
/*
* 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;
}
// Don't allow empty path parameter:
if (trajectory_path.get_pathvector().empty()) {
return path_in;
}
if (is_load) {
trajectory_path.reload();
}
Geom::PathVector 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
Geom::OptRect bounds_A = Geom::bounds_exact(pwd2_A);
if (bounds_A) {
pwd2_A -= bounds_A->midpoint();
}
Geom::OptRect bounds_B = Geom::bounds_exact(pwd2_B);
if (bounds_B) {
pwd2_B -= bounds_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);
auto trajectory = calculate_trajectory(bounds_A, bounds_B);
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;
}
// returns the lpe parameter trajectory_path, transformed so that it starts at the
// bounding box center of the first path and ends at the bounding box center of the
// second path
Geom::Piecewise<Geom::D2<Geom::SBasis> > LPEInterpolate::calculate_trajectory(Geom::OptRect bounds_A,
Geom::OptRect bounds_B)
{
Geom::Affine affine = trajectory_path.get_relative_affine();
Geom::Piecewise<Geom::D2<Geom::SBasis> > trajectory = trajectory_path.get_pathvector()[0].toPwSb() * affine;
if (equidistant_spacing) {
trajectory = Geom::arc_length_parametrization(trajectory);
}
if (!bounds_A || !bounds_B) {
return trajectory;
}
auto trajectory_start = trajectory.firstValue();
auto trajectory_end = trajectory.lastValue();
auto midpoint_A = bounds_A->midpoint();
auto midpoint_B = bounds_B->midpoint();
Geom::Ray original(trajectory_start, trajectory_end);
Geom::Ray transformed(midpoint_A, midpoint_B);
double rotation = transformed.angle() - original.angle();
double scale = Geom::distance(midpoint_A, midpoint_B) / Geom::distance(trajectory_start, trajectory_end);
Geom::Affine transformation;
transformation *= Geom::Translate(-trajectory_start);
transformation *= Geom::Scale(scale, scale);
transformation *= Geom::Rotate(rotation);
transformation *= Geom::Translate(midpoint_A);
return trajectory * transformation;
}
void LPEInterpolate::resetDefaults(SPItem const *item)
{
Effect::resetDefaults(item);
if (!SP_IS_PATH(item))
return;
SPCurve const *crv = SP_PATH(item)->curveForEdit();
Geom::PathVector const &pathv = crv->get_pathvector();
if ((pathv.size() < 2))
return;
Geom::OptRect bounds_A = pathv[0].boundsExact();
Geom::OptRect bounds_B = pathv[1].boundsExact();
if (bounds_A && bounds_B) {
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);
}
else {
trajectory_path.param_set_and_write_default();
}
}
} // 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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