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#define INKSCAPE_LPE_TANGENT_TO_CURVE_CPP
/** \file
* Implementation of tangent-to-curve LPE.
*/
/*
* Authors:
* Johan Engelen
* Maximilian Albert
*
* Copyright (C) Johan Engelen 2007 <j.b.c.engelen@utwente.nl>
* Copyright (C) Maximilian Albert 2008 <maximilian.albert@gmail.com>
*
* Released under GNU GPL, read the file 'COPYING' for more information
*/
#include "live_effects/lpe-tangent_to_curve.h"
// FIXME: The following are only needed to convert the path's SPCurve* to pwd2.
// There must be a more convenient way to achieve this.
#include "sp-path.h"
#include "display/curve.h"
#include "libnr/n-art-bpath-2geom.h"
#include <2geom/path.h>
#include <2geom/transforms.h>
namespace Inkscape {
namespace LivePathEffect {
LPETangentToCurve::LPETangentToCurve(LivePathEffectObject *lpeobject) :
Effect(lpeobject),
angle(_("Angle"), _("Additional angle between tangent and curve"), "angle", &wr, this, 0.0),
t_attach(_("Location along curve"), _("Location of the point of attachment along the curve (between 0.0 and number-of-segments)"), "t_attach", &wr, this, 0.5),
length_left(_("Length left"), _("Specifies the left end of the tangent"), "length-left", &wr, this, 150),
length_right(_("Length right"), _("Specifies the right end of the tangent"), "length-right", &wr, this, 150)
{
registerParameter( dynamic_cast<Parameter *>(&angle) );
registerParameter( dynamic_cast<Parameter *>(&t_attach) );
registerParameter( dynamic_cast<Parameter *>(&length_left) );
registerParameter( dynamic_cast<Parameter *>(&length_right) );
}
LPETangentToCurve::~LPETangentToCurve()
{
}
Geom::Piecewise<Geom::D2<Geom::SBasis> >
LPETangentToCurve::doEffect_pwd2 (Geom::Piecewise<Geom::D2<Geom::SBasis> > const & pwd2_in)
{
using namespace Geom;
Piecewise<D2<SBasis> > output;
ptA = pwd2_in.valueAt(t_attach);
derivA = unit_vector(derivative(pwd2_in).valueAt(t_attach));
// TODO: Why are positive angles measured clockwise, not counterclockwise?
Geom::Rotate rot(Geom::Rotate::from_degrees(-angle));
derivA = derivA * rot;
C = ptA - derivA * length_left;
D = ptA + derivA * length_right;
output = Piecewise<D2<SBasis> >(D2<SBasis>(Linear(C[X], D[X]), Linear(C[Y], D[Y])));
return output;
}
class KnotHolderEntityAttachPt : public KnotHolderEntity
{
public:
virtual bool isLPEParam() { return true; }
virtual void knot_set(NR::Point const &p, NR::Point const &origin, guint state);
virtual NR::Point knot_get();
virtual void onKnotUngrabbed();
};
class KnotHolderEntityLeftEnd : public KnotHolderEntity
{
public:
virtual bool isLPEParam() { return true; }
virtual void knot_set(NR::Point const &p, NR::Point const &origin, guint state);
virtual NR::Point knot_get();
virtual void onKnotUngrabbed();
};
class KnotHolderEntityRightEnd : public KnotHolderEntity
{
public:
virtual bool isLPEParam() { return true; }
virtual void knot_set(NR::Point const &p, NR::Point const &origin, guint state);
virtual NR::Point knot_get();
virtual void onKnotUngrabbed();
};
void
LPETangentToCurve::addKnotHolderHandles(KnotHolder *knotholder, SPDesktop *desktop, SPItem *item)
{
KnotHolderEntityLeftEnd *entity_left_end = new KnotHolderEntityLeftEnd();
KnotHolderEntityRightEnd *entity_right_end = new KnotHolderEntityRightEnd();
KnotHolderEntityAttachPt *entity_attach_pt = new KnotHolderEntityAttachPt();
entity_left_end->create(desktop, item, knotholder,
_("Adjust the \"left\" end of the tangent"));
entity_right_end->create(desktop, item, knotholder,
_("Adjust the \"right\" end of the tangent"));
entity_attach_pt->create(desktop, item, knotholder,
_("Adjust the point of attachment of the tangent"));
knotholder->add(entity_left_end);
knotholder->add(entity_right_end);
knotholder->add(entity_attach_pt);
}
static LPETangentToCurve *
get_effect(SPItem *item)
{
Effect *effect = sp_lpe_item_get_current_lpe(SP_LPE_ITEM(item));
if (effect->effectType() != TANGENT_TO_CURVE) {
g_print ("Warning: Effect is not of type LPETangentToCurve!\n");
return NULL;
}
return static_cast<LPETangentToCurve *>(effect);
}
void
KnotHolderEntityAttachPt::knot_set(NR::Point const &p, NR::Point const &origin, guint state)
{
using namespace Geom;
LPETangentToCurve* lpe = get_effect(item);
// FIXME: There must be a better way of converting the path's SPCurve* to pwd2.
SPCurve *curve = sp_path_get_curve_for_edit (SP_PATH(item));
const NArtBpath *bpath = curve->get_bpath();
Piecewise<D2<SBasis> > pwd2;
std::vector<Geom::Path> pathv = BPath_to_2GeomPath(bpath);
for (unsigned int i=0; i < pathv.size(); i++) {
pwd2.concat(pathv[i].toPwSb());
}
double t0 = nearest_point(p.to_2geom(), pwd2);
lpe->t_attach.param_set_value(t0);
// FIXME: this should not directly ask for updating the item. It should write to SVG, which triggers updating.
sp_lpe_item_update_patheffect (SP_LPE_ITEM(item), true, true);
}
void
KnotHolderEntityLeftEnd::knot_set(NR::Point const &p, NR::Point const &origin, guint state)
{
LPETangentToCurve *lpe = get_effect(item);
double lambda = Geom::nearest_point(p.to_2geom(), lpe->ptA, lpe->derivA);
lpe->length_left.param_set_value(-lambda);
sp_lpe_item_update_patheffect (SP_LPE_ITEM(item), false, true);
}
void
KnotHolderEntityRightEnd::knot_set(NR::Point const &p, NR::Point const &origin, guint state)
{
LPETangentToCurve *lpe = get_effect(item);
double lambda = Geom::nearest_point(p.to_2geom(), lpe->ptA, lpe->derivA);
lpe->length_right.param_set_value(lambda);
sp_lpe_item_update_patheffect (SP_LPE_ITEM(item), false, true);
}
NR::Point
KnotHolderEntityAttachPt::knot_get()
{
LPETangentToCurve* lpe = get_effect(item);
return lpe->ptA;
}
NR::Point
KnotHolderEntityLeftEnd::knot_get()
{
LPETangentToCurve *lpe = get_effect(item);
return lpe->C;
}
NR::Point
KnotHolderEntityRightEnd::knot_get()
{
LPETangentToCurve *lpe = get_effect(item);
return lpe->D;
}
void
KnotHolderEntityAttachPt::onKnotUngrabbed()
{
LPETangentToCurve *lpe = get_effect(item);
lpe->t_attach.write_to_SVG();
}
void
KnotHolderEntityLeftEnd::onKnotUngrabbed()
{
LPETangentToCurve *lpe = get_effect(item);
lpe->length_left.write_to_SVG();
}
void
KnotHolderEntityRightEnd::onKnotUngrabbed()
{
LPETangentToCurve *lpe = get_effect(item);
lpe->length_right.write_to_SVG();
}
} //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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