// SPDX-FileCopyrightText: 2003 Dominique Devriese <devriese@kde.org>

// SPDX-License-Identifier: GPL-2.0-or-later

#include "special_constructors.h"

#include <math.h>

#include "calcpaths.h"
#include "common.h"
#include "conic-common.h"
#include "guiaction.h"
#include "kigpainter.h"

#include "../kig/kig_document.h"
#include "../kig/kig_part.h"
#include "../modes/construct_mode.h"
#include "../objects/bezier_imp.h"
#include "../objects/bezier_type.h"
#include "../objects/bogus_imp.h"
#include "../objects/centerofcurvature_type.h"
#include "../objects/circle_imp.h"
#include "../objects/conic_imp.h"
#include "../objects/conic_types.h"
#include "../objects/cubic_imp.h"
#include "../objects/intersection_types.h"
#include "../objects/inversion_type.h"
#include "../objects/line_imp.h"
#include "../objects/line_type.h"
#include "../objects/locus_imp.h"
#include "../objects/object_calcer.h"
#include "../objects/object_drawer.h"
#include "../objects/object_factory.h"
#include "../objects/object_holder.h"
#include "../objects/object_imp.h"
#include "../objects/object_type.h"
#include "../objects/other_imp.h"
#include "../objects/other_type.h"
#include "../objects/point_imp.h"
#include "../objects/point_type.h"
#include "../objects/polygon_imp.h"
#include "../objects/polygon_type.h"
#include "../objects/special_imptypes.h"
#include "../objects/tangent_type.h"
#include "../objects/text_imp.h"
#include "../objects/transform_types.h"

#include <QPen>

#include <algorithm>
#include <functional>
#include <iterator>

/*
 * conic-line and circle-circle intersection (with search for already computed
 * intersections)
 * the previous "ConicLineIntersectionConstructor" is now
 * dead code, which could be remove in the future
 */

TwoOrOneIntersectionConstructor::TwoOrOneIntersectionConstructor(const ArgsParserObjectType *t_std,
                                                                 const ArgsParserObjectType *t_special,
                                                                 const char *iconfile,
                                                                 const struct ArgsParser::spec argsspecv[])
    : StandardConstructorBase({}, {}, iconfile, margsparser)
    , mtype_std(t_std)
    , mtype_special(t_special)
    , margsparser(argsspecv, 2)
{
}

TwoOrOneIntersectionConstructor::~TwoOrOneIntersectionConstructor()
{
}

void TwoOrOneIntersectionConstructor::drawprelim(const ObjectDrawer &drawer,
                                                 KigPainter &p,
                                                 const std::vector<ObjectCalcer *> &parents,
                                                 const KigDocument &doc) const
{
    Args args;
    if (parents.size() != 2)
        return;
    transform(parents.begin(), parents.end(), back_inserter(args), std::mem_fn(&ObjectCalcer::imp));

    for (int i = -1; i <= 1; i += 2) {
        IntImp param(i);
        args.push_back(&param);
        ObjectImp *data = mtype_std->calc(args, doc);
        drawer.draw(*data, p, true);
        delete data;
        args.pop_back();
    }
}

std::vector<ObjectCalcer *> removeDuplicatedPoints(std::vector<ObjectCalcer *> points)
{
    std::vector<ObjectCalcer *> ret;

    for (std::vector<ObjectCalcer *>::iterator i = points.begin(); i != points.end(); ++i) {
        for (std::vector<ObjectCalcer *>::iterator j = ret.begin(); j != ret.end(); ++j) {
            if (coincidentPoints((*i)->imp(), (*j)->imp()))
                break;
        }
        ret.push_back(*i);
    }
    return ret;
}

bool coincidentPoints(const ObjectImp *p1, const ObjectImp *p2)
{
    const PointImp *pt1 = dynamic_cast<const PointImp *>(p1);
    if (!pt1)
        return false;
    const PointImp *pt2 = dynamic_cast<const PointImp *>(p2);
    if (!pt2)
        return false;

    Coordinate diff = pt1->coordinate() - pt2->coordinate();
    if (diff.squareLength() < 1e-12)
        return true;
    return false;
}

std::vector<ObjectHolder *> TwoOrOneIntersectionConstructor::build(const std::vector<ObjectCalcer *> &parents, KigDocument &doc, KigWidget &) const
{
    std::vector<ObjectHolder *> ret;
    assert(parents.size() == 2);

    std::vector<ObjectCalcer *> points = doc.findIntersectionPoints(parents[0], parents[1]);
    std::vector<ObjectCalcer *> uniquepoints = removeDuplicatedPoints(points);

    if (uniquepoints.size() == 1) {
        std::vector<ObjectCalcer *> args(parents);
        args.push_back(uniquepoints[0]);
        ret.push_back(new ObjectHolder(new ObjectTypeCalcer(mtype_special, args)));
        return ret;
    }
    for (int i = -1; i <= 1; i += 2) {
        ObjectConstCalcer *d = new ObjectConstCalcer(new IntImp(i));
        std::vector<ObjectCalcer *> args(parents);
        args.push_back(d);

        ret.push_back(new ObjectHolder(new ObjectTypeCalcer(mtype_std, args)));
    }
    return ret;
}

void TwoOrOneIntersectionConstructor::plug(KigPart *, KigGUIAction *)
{
}

bool TwoOrOneIntersectionConstructor::isTransform() const
{
    return false;
}

ThreeTwoOneIntersectionConstructor::ThreeTwoOneIntersectionConstructor(const ArgsParserObjectType *t_std,
                                                                       const ArgsParserObjectType *t_special,
                                                                       const char *iconfile,
                                                                       const struct ArgsParser::spec argsspecv[])
    : StandardConstructorBase({}, {}, iconfile, margsparser)
    , mtype_std(t_std)
    , mtype_special(t_special)
    , margsparser(argsspecv, 2)
{
}

ThreeTwoOneIntersectionConstructor::~ThreeTwoOneIntersectionConstructor()
{
}

void ThreeTwoOneIntersectionConstructor::drawprelim(const ObjectDrawer &drawer,
                                                    KigPainter &p,
                                                    const std::vector<ObjectCalcer *> &parents,
                                                    const KigDocument &doc) const
{
    Args args;
    if (parents.size() != 2)
        return;
    transform(parents.begin(), parents.end(), back_inserter(args), std::mem_fn(&ObjectCalcer::imp));

    for (int i = 1; i <= 3; i += 1) {
        IntImp param(i);
        args.push_back(&param);
        ObjectImp *data = mtype_std->calc(args, doc);
        drawer.draw(*data, p, true);
        delete data;
        args.pop_back();
    }
}

std::vector<ObjectHolder *> ThreeTwoOneIntersectionConstructor::build(const std::vector<ObjectCalcer *> &parents, KigDocument &doc, KigWidget &) const
{
    std::vector<ObjectHolder *> ret;
    assert(parents.size() == 2);

    std::vector<ObjectCalcer *> points = doc.findIntersectionPoints(parents[0], parents[1]);
    std::vector<ObjectCalcer *> uniquepoints = removeDuplicatedPoints(points);

    if (uniquepoints.size() == 2) {
        std::vector<ObjectCalcer *> args(parents);
        args.push_back(uniquepoints[0]);
        args.push_back(uniquepoints[1]);
        ret.push_back(new ObjectHolder(new ObjectTypeCalcer(mtype_special, args)));
        return ret;
    }
    if (uniquepoints.size() == 1) {
        for (int i = -1; i <= 1; i += 2) {
            std::vector<ObjectCalcer *> args(parents);
            args.push_back(uniquepoints[0]);
            ObjectConstCalcer *d = new ObjectConstCalcer(new IntImp(i));
            args.push_back(d);

            ret.push_back(new ObjectHolder(new ObjectTypeCalcer(CubicLineTwoIntersectionType::instance(), args)));
            args.clear();
        }
        return ret;
    }
    for (int i = 1; i <= 3; i += 1) {
        ObjectConstCalcer *d = new ObjectConstCalcer(new IntImp(i));
        std::vector<ObjectCalcer *> args(parents);
        args.push_back(d);

        ret.push_back(new ObjectHolder(new ObjectTypeCalcer(mtype_std, args)));
    }
    return ret;
}

void ThreeTwoOneIntersectionConstructor::plug(KigPart *, KigGUIAction *)
{
}

bool ThreeTwoOneIntersectionConstructor::isTransform() const
{
    return false;
}

/*
 * conic-conic intersection
 */

class ConicConicIntersectionConstructor : public StandardConstructorBase
{
protected:
    ArgsParser mparser;

public:
    ConicConicIntersectionConstructor();
    ~ConicConicIntersectionConstructor();

    void drawprelim(const ObjectDrawer &drawer, KigPainter &p, const std::vector<ObjectCalcer *> &parents, const KigDocument &) const override;
    std::vector<ObjectHolder *> build(const std::vector<ObjectCalcer *> &os, KigDocument &d, KigWidget &w) const override;
    void plug(KigPart *doc, KigGUIAction *kact) override;

    bool isTransform() const override;
};

class ConicLineIntersectionConstructor : public MultiObjectTypeConstructor
{
public:
    ConicLineIntersectionConstructor();
    ~ConicLineIntersectionConstructor();
};

class ArcLineIntersectionConstructor : public MultiObjectTypeConstructor
{
public:
    ArcLineIntersectionConstructor();
    ~ArcLineIntersectionConstructor();
};

ConicRadicalConstructor::ConicRadicalConstructor()
    : StandardConstructorBase(i18n("Radical Lines for Conics"),
                              i18n("The lines constructed through the intersections "
                                   "of two conics.  This is also defined for "
                                   "non-intersecting conics."),
                              "conicsradicalline",
                              mparser)
    , mtype(ConicRadicalType::instance())
    , mparser(mtype->argsParser().without(IntImp::stype()))
{
}

ConicRadicalConstructor::~ConicRadicalConstructor()
{
}

void ConicRadicalConstructor::drawprelim(const ObjectDrawer &drawer, KigPainter &p, const std::vector<ObjectCalcer *> &parents, const KigDocument &doc) const
{
    if (parents.size() == 2 && parents[0]->imp()->inherits(ConicImp::stype()) && parents[1]->imp()->inherits(ConicImp::stype())) {
        Args args;
        std::transform(parents.begin(), parents.end(), std::back_inserter(args), std::mem_fn(&ObjectCalcer::imp));
        for (int i = -1; i < 2; i += 2) {
            IntImp root(i);
            IntImp zeroindex(1);
            args.push_back(&root);
            args.push_back(&zeroindex);
            ObjectImp *data = mtype->calc(args, doc);
            drawer.draw(*data, p, true);
            delete data;
            data = nullptr;
            args.pop_back();
            args.pop_back();
        };
    };
}

std::vector<ObjectHolder *> ConicRadicalConstructor::build(const std::vector<ObjectCalcer *> &os, KigDocument &, KigWidget &) const
{
    using namespace std;
    std::vector<ObjectHolder *> ret;
    ObjectCalcer *zeroindexcalcer = new ObjectConstCalcer(new IntImp(1));
    for (int i = -1; i < 2; i += 2) {
        std::vector<ObjectCalcer *> args;
        std::copy(os.begin(), os.end(), back_inserter(args));
        args.push_back(new ObjectConstCalcer(new IntImp(i)));
        // we use only one zeroindex dataobject, so that if you switch one
        // radical line around, then the other switches along..
        args.push_back(zeroindexcalcer);
        ret.push_back(new ObjectHolder(new ObjectTypeCalcer(mtype, args)));
    };
    return ret;
}

static const struct ArgsParser::spec argsspecpp[] = {
    {PointImp::stype(), kli18n("Moving Point"), kli18n("Select the moving point, which will be moved around while drawing the locus..."), false},
    {PointImp::stype(), kli18n("Following Point"), kli18n("Select the following point, whose locations the locus will be drawn through..."), true}};

LocusConstructor::LocusConstructor()
    : StandardConstructorBase(i18n("Locus"), i18n("A locus"), "locus", margsparser)
    , margsparser(argsspecpp, 2)
{
}

LocusConstructor::~LocusConstructor()
{
}

void LocusConstructor::drawprelim(const ObjectDrawer &drawer, KigPainter &p, const std::vector<ObjectCalcer *> &parents, const KigDocument &) const
{
    // this function is rather ugly, but it is necessary to do it this
    // way in order to play nice with Kig's design..

    if (parents.size() != 2)
        return;
    const ObjectTypeCalcer *constrained = dynamic_cast<ObjectTypeCalcer *>(parents.front());
    const ObjectCalcer *moving = parents.back();
    if (!constrained || !constrained->type()->inherits(ObjectType::ID_ConstrainedPointType)) {
        // moving is in fact the constrained point. swap them.
        moving = parents.front();
        constrained = dynamic_cast<const ObjectTypeCalcer *>(parents.back());
        assert(constrained);
    };
    assert(constrained->type()->inherits(ObjectType::ID_ConstrainedPointType));

    const ObjectImp *oimp = constrained->parents().back()->imp();
    if (!oimp->inherits(CurveImp::stype()))
        oimp = constrained->parents().front()->imp();
    assert(oimp->inherits(CurveImp::stype()));
    const CurveImp *cimp = static_cast<const CurveImp *>(oimp);

    ObjectHierarchy hier(constrained, moving);

    LocusImp limp(cimp->copy(), hier);
    drawer.draw(limp, p, true);
}

int LocusConstructor::wantArgs(const std::vector<ObjectCalcer *> &os, const KigDocument &, const KigWidget &) const
{
    int ret = margsparser.check(os);
    if (ret == ArgsParser::Invalid)
        return ret;
    else if (os.size() != 2)
        return ret;
    if (dynamic_cast<ObjectTypeCalcer *>(os.front()) && static_cast<ObjectTypeCalcer *>(os.front())->type()->inherits(ObjectType::ID_ConstrainedPointType)) {
        std::set<ObjectCalcer *> children = getAllChildren(os.front());
        return children.find(os.back()) != children.end() ? ret : ArgsParser::Invalid;
    }
    if (dynamic_cast<ObjectTypeCalcer *>(os.back()) && static_cast<ObjectTypeCalcer *>(os.back())->type()->inherits(ObjectType::ID_ConstrainedPointType)) {
        std::set<ObjectCalcer *> children = getAllChildren(os.back());
        return children.find(os.front()) != children.end() ? ret : ArgsParser::Invalid;
    }
    return ArgsParser::Invalid;
}

std::vector<ObjectHolder *> LocusConstructor::build(const std::vector<ObjectCalcer *> &parents, KigDocument &, KigWidget &) const
{
    std::vector<ObjectHolder *> ret;
    assert(parents.size() == 2);

    ObjectTypeCalcer *constrained = dynamic_cast<ObjectTypeCalcer *>(parents.front());
    ObjectCalcer *moving = parents.back();
    if (!constrained || !constrained->type()->inherits(ObjectType::ID_ConstrainedPointType)) {
        // moving is in fact the constrained point. swap them.
        moving = parents.front();
        constrained = dynamic_cast<ObjectTypeCalcer *>(parents.back());
        assert(constrained);
    };
    assert(constrained->type()->inherits(ObjectType::ID_ConstrainedPointType));

    ret.push_back(ObjectFactory::instance()->locus(constrained, moving));
    return ret;
}

QString LocusConstructor::useText(const ObjectCalcer &o, const std::vector<ObjectCalcer *> &os, const KigDocument &, const KigWidget &) const
{
    if (dynamic_cast<const ObjectTypeCalcer *>(&o) && static_cast<const ObjectTypeCalcer &>(o).type()->inherits(ObjectType::ID_ConstrainedPointType)
        && (os.empty() || !dynamic_cast<ObjectTypeCalcer *>(os[0])
            || !static_cast<const ObjectTypeCalcer *>(os[0])->type()->inherits(ObjectType::ID_ConstrainedPointType)))
        return i18n("Moving Point");
    else
        return i18n("Dependent Point");
}

void ConicRadicalConstructor::plug(KigPart *, KigGUIAction *)
{
}

void LocusConstructor::plug(KigPart *, KigGUIAction *)
{
}

bool ConicRadicalConstructor::isTransform() const
{
    return mtype->isTransform();
}

bool LocusConstructor::isTransform() const
{
    return false;
}

/*
 * generic sequence of points constructor
 */

PointSequenceConstructor::PointSequenceConstructor(const QString &descname, const QString &desc, const QString &iconfile, const ObjectType *type)
    : mdescname(descname)
    , mdesc(desc)
    , miconfile(iconfile)
    , mtype(type)
{
}

const QString PointSequenceConstructor::descriptiveName() const
{
    return mdescname;
}

const QString PointSequenceConstructor::description() const
{
    return mdesc;
}

const QString PointSequenceConstructor::iconFileName(const bool) const
{
    return miconfile;
}

void PointSequenceConstructor::handleArgs(const std::vector<ObjectCalcer *> &os, KigPart &d, KigWidget &v) const
{
    std::vector<ObjectHolder *> bos = build(os, d.document(), v);
    for (std::vector<ObjectHolder *>::iterator i = bos.begin(); i != bos.end(); ++i) {
        (*i)->calc(d.document());
    }

    d.addObjects(bos);
}

void PointSequenceConstructor::handlePrelim(KigPainter &p, const std::vector<ObjectCalcer *> &os, const KigDocument &d, const KigWidget &) const
{
    uint count = os.size();
    if (count < 2)
        return;

    for (uint i = 0; i < count; i++) {
        assert(os[i]->imp()->inherits(PointImp::stype()));
    }

    std::vector<ObjectCalcer *> args = os;
    p.setBrushStyle(Qt::NoBrush);
    p.setBrushColor(Qt::red);
    p.setPen(QPen(Qt::red, 1));
    p.setWidth(-1); // -1 means the default width for the object being
                    // drawn..

    ObjectDrawer drawer(Qt::red);
    drawprelim(drawer, p, args, d);
}

std::vector<ObjectHolder *> PointSequenceConstructor::build(const std::vector<ObjectCalcer *> &parents, KigDocument &, KigWidget &) const
{
    uint count = parents.size() - 1;
    assert(count >= 3);
    std::vector<ObjectCalcer *> args;
    for (uint i = 0; i < count; ++i)
        args.push_back(parents[i]);
    ObjectTypeCalcer *calcer = new ObjectTypeCalcer(mtype, args);
    ObjectHolder *h = new ObjectHolder(calcer);
    std::vector<ObjectHolder *> ret;
    ret.push_back(h);
    return ret;
}

void PointSequenceConstructor::plug(KigPart *, KigGUIAction *)
{
}

bool PointSequenceConstructor::isTransform() const
{
    return false;
}

/*
 * generic polygon constructor
 */

PolygonBNPTypeConstructor::PolygonBNPTypeConstructor()
    : PointSequenceConstructor(i18n("Polygon by Its Vertices"), i18n("Construct a polygon by giving its vertices"), "kig_polygon", PolygonBNPType::instance())
{
}

PolygonBNPTypeConstructor::~PolygonBNPTypeConstructor()
{
}

bool PolygonBNPTypeConstructor::isAlreadySelectedOK(const std::vector<ObjectCalcer *> &os, const uint &pos) const
{
    if (pos == 0 && os.size() >= 3)
        return true;
    return false;
}

int PolygonBNPTypeConstructor::wantArgs(const std::vector<ObjectCalcer *> &os, const KigDocument &, const KigWidget &) const
{
    int count = os.size() - 1;

    for (int i = 0; i <= count; i++) {
        if (!(os[i]->imp()->inherits(PointImp::stype())))
            return ArgsParser::Invalid;
    }
    if (count < 3)
        return ArgsParser::Valid;
    if (os[0] == os[count])
        return ArgsParser::Complete;
    return ArgsParser::Valid;
}

QString PolygonBNPTypeConstructor::useText(const ObjectCalcer &, const std::vector<ObjectCalcer *> &os, const KigDocument &, const KigWidget &) const
{
    if (os.size() > 3)
        return i18n("... with this vertex (click on the first vertex to terminate construction)");
    else
        return i18n("Construct a polygon with this vertex");
}

QString PolygonBNPTypeConstructor::selectStatement(const std::vector<ObjectCalcer *> &, const KigDocument &, const KigWidget &) const
{
    return i18n("Select a point to be a vertex of the new polygon...");
}

void PolygonBNPTypeConstructor::drawprelim(const ObjectDrawer &drawer, KigPainter &p, const std::vector<ObjectCalcer *> &parents, const KigDocument &) const
{
    if (parents.size() < 2)
        return;

    std::vector<Coordinate> points;

    for (uint i = 0; i < parents.size(); ++i) {
        const Coordinate vertex = static_cast<const PointImp *>(parents[i]->imp())->coordinate();
        points.push_back(vertex);
    }

    if (parents.size() == 2) {
        SegmentImp segment = SegmentImp(points[0], points[1]);
        drawer.draw(segment, p, true);
    } else {
        FilledPolygonImp polygon = FilledPolygonImp(points);
        drawer.draw(polygon, p, true);
    }
}

/*
 * open polygon (polyline) constructor
 */

OpenPolygonTypeConstructor::OpenPolygonTypeConstructor()
    : PointSequenceConstructor(i18n("Open Polygon (Polygonal Line)"), i18n("Construct an open polygon"), "openpolygon", OpenPolygonType::instance())
{
}

OpenPolygonTypeConstructor::~OpenPolygonTypeConstructor()
{
}

bool OpenPolygonTypeConstructor::isAlreadySelectedOK(const std::vector<ObjectCalcer *> &os, const uint &pos) const
{
    if (pos == os.size() - 1 && os.size() >= 2)
        return true;
    return false;
}

int OpenPolygonTypeConstructor::wantArgs(const std::vector<ObjectCalcer *> &os, const KigDocument &, const KigWidget &) const
{
    int count = os.size() - 1;

    for (int i = 0; i <= count; i++) {
        if (!(os[i]->imp()->inherits(PointImp::stype())))
            return ArgsParser::Invalid;
    }
    if (count < 2)
        return ArgsParser::Valid;
    if (os[count] == os[count - 1])
        return ArgsParser::Complete;
    return ArgsParser::Valid;
}

QString OpenPolygonTypeConstructor::useText(const ObjectCalcer &, const std::vector<ObjectCalcer *> &os, const KigDocument &, const KigWidget &) const
{
    if (os.size() > 2)
        return i18n("... with this vertex (click again on the last vertex to terminate construction)");
    else
        return i18n("Construct a polygonal line with this vertex");
}

QString OpenPolygonTypeConstructor::selectStatement(const std::vector<ObjectCalcer *> &, const KigDocument &, const KigWidget &) const
{
    return i18n("Select a point to be a vertex of the new polygonal line...");
}

void OpenPolygonTypeConstructor::drawprelim(const ObjectDrawer &drawer, KigPainter &p, const std::vector<ObjectCalcer *> &parents, const KigDocument &) const
{
    if (parents.size() < 2)
        return;

    std::vector<Coordinate> points;

    for (uint i = 0; i < parents.size(); ++i) {
        const Coordinate vertex = static_cast<const PointImp *>(parents[i]->imp())->coordinate();
        points.push_back(vertex);
    }

    if (parents.size() == 2) {
        SegmentImp segment = SegmentImp(points[0], points[1]);
        drawer.draw(segment, p, true);
    } else {
        OpenPolygonalImp polygon = OpenPolygonalImp(points);
        drawer.draw(polygon, p, true);
    }
}

/*
 * construction of polygon vertices
 */

static const struct ArgsParser::spec argsspecpv[] = {
    {FilledPolygonImp::stype(), kli18n("Polygon"), kli18n("Construct the vertices of this polygon..."), true}};

PolygonVertexTypeConstructor::PolygonVertexTypeConstructor()
    : StandardConstructorBase(i18n("Vertices of a Polygon"), i18n("The vertices of a polygon."), "polygonvertices", margsparser)
    , mtype(PolygonVertexType::instance())
    , margsparser(argsspecpv, 1)
{
}

PolygonVertexTypeConstructor::~PolygonVertexTypeConstructor()
{
}

void PolygonVertexTypeConstructor::drawprelim(const ObjectDrawer &drawer, KigPainter &p, const std::vector<ObjectCalcer *> &parents, const KigDocument &) const
{
    if (parents.size() != 1)
        return;

    const FilledPolygonImp *polygon = dynamic_cast<const FilledPolygonImp *>(parents.front()->imp());
    const std::vector<Coordinate> points = polygon->points();

    int sides = points.size();
    for (int i = 0; i < sides; ++i) {
        PointImp point = PointImp(points[i]);
        drawer.draw(point, p, true);
    }
}

std::vector<ObjectHolder *> PolygonVertexTypeConstructor::build(const std::vector<ObjectCalcer *> &parents, KigDocument &, KigWidget &) const
{
    std::vector<ObjectHolder *> ret;
    assert(parents.size() == 1);
    const FilledPolygonImp *polygon = dynamic_cast<const FilledPolygonImp *>(parents.front()->imp());
    const std::vector<Coordinate> points = polygon->points();

    int sides = points.size();

    for (int i = 0; i < sides; ++i) {
        ObjectConstCalcer *d = new ObjectConstCalcer(new IntImp(i));
        std::vector<ObjectCalcer *> args(parents);
        args.push_back(d);
        ret.push_back(new ObjectHolder(new ObjectTypeCalcer(mtype, args)));
    }
    return ret;
}

void PolygonVertexTypeConstructor::plug(KigPart *, KigGUIAction *)
{
}

bool PolygonVertexTypeConstructor::isTransform() const
{
    return false;
}

/*
 * construction of polygon sides
 */

static const struct ArgsParser::spec argsspecps[] = {
    {FilledPolygonImp::stype(), kli18n("Polygon"), kli18n("Construct the sides of this polygon..."), false}};

PolygonSideTypeConstructor::PolygonSideTypeConstructor()
    : StandardConstructorBase(i18n("Sides of a Polygon"), i18n("The sides of a polygon."), "polygonsides", margsparser)
    , mtype(PolygonSideType::instance())
    , margsparser(argsspecps, 1)
{
}

PolygonSideTypeConstructor::~PolygonSideTypeConstructor()
{
}

void PolygonSideTypeConstructor::drawprelim(const ObjectDrawer &drawer, KigPainter &p, const std::vector<ObjectCalcer *> &parents, const KigDocument &) const
{
    if (parents.size() != 1)
        return;

    const FilledPolygonImp *polygon = dynamic_cast<const FilledPolygonImp *>(parents.front()->imp());
    const std::vector<Coordinate> points = polygon->points();

    uint sides = points.size();
    for (uint i = 0; i < sides; ++i) {
        uint nexti = (i + 1 < sides) ? (i + 1) : 0;
        SegmentImp segment = SegmentImp(points[i], points[nexti]);
        drawer.draw(segment, p, true);
    }
}

std::vector<ObjectHolder *> PolygonSideTypeConstructor::build(const std::vector<ObjectCalcer *> &parents, KigDocument &, KigWidget &) const
{
    std::vector<ObjectHolder *> ret;
    assert(parents.size() == 1);
    const FilledPolygonImp *polygon = dynamic_cast<const FilledPolygonImp *>(parents.front()->imp());
    const std::vector<Coordinate> points = polygon->points();

    uint sides = points.size();

    for (uint i = 0; i < sides; ++i) {
        ObjectConstCalcer *d = new ObjectConstCalcer(new IntImp(i));
        std::vector<ObjectCalcer *> args(parents);
        args.push_back(d);
        ret.push_back(new ObjectHolder(new ObjectTypeCalcer(mtype, args)));
    }
    return ret;
}

void PolygonSideTypeConstructor::plug(KigPart *, KigGUIAction *)
{
}

bool PolygonSideTypeConstructor::isTransform() const
{
    return false;
}

/*
 * polygon by center and vertex
 */

PolygonBCVConstructor::PolygonBCVConstructor()
    : mtype(PolygonBCVType::instance())
{
}

PolygonBCVConstructor::~PolygonBCVConstructor()
{
}

const QString PolygonBCVConstructor::descriptiveName() const
{
    return i18n("Regular Polygon with Given Center");
}

const QString PolygonBCVConstructor::description() const
{
    return i18n("Construct a regular polygon with a given center and vertex");
}

const QString PolygonBCVConstructor::iconFileName(const bool) const
{
    return QStringLiteral("hexagonbcv");
}

bool PolygonBCVConstructor::isAlreadySelectedOK(const std::vector<ObjectCalcer *> &, const uint &) const
{
    return false;
}

int PolygonBCVConstructor::wantArgs(const std::vector<ObjectCalcer *> &os, const KigDocument &, const KigWidget &) const
{
    if (os.size() > 3)
        return ArgsParser::Invalid;

    uint imax = (os.size() <= 2) ? os.size() : 2;
    for (uint i = 0; i < imax; ++i)
        if (!(os[i]->imp()->inherits(PointImp::stype())))
            return ArgsParser::Invalid;

    if (os.size() < 3)
        return ArgsParser::Valid;

    if (!(os[2]->imp()->inherits(BogusPointImp::stype())))
        return ArgsParser::Invalid;

    return ArgsParser::Complete;
}

void PolygonBCVConstructor::handleArgs(const std::vector<ObjectCalcer *> &os, KigPart &d, KigWidget &v) const
{
    std::vector<ObjectHolder *> bos = build(os, d.document(), v);
    for (std::vector<ObjectHolder *>::iterator i = bos.begin(); i != bos.end(); ++i) {
        (*i)->calc(d.document());
    }

    d.addObjects(bos);
}

void PolygonBCVConstructor::handlePrelim(KigPainter &p, const std::vector<ObjectCalcer *> &os, const KigDocument &d, const KigWidget &) const
{
    if (os.size() < 2)
        return;

    for (uint i = 0; i < 2; i++) {
        assert(os[i]->imp()->inherits(PointImp::stype()));
    }

    Coordinate c = static_cast<const PointImp *>(os[0]->imp())->coordinate();
    Coordinate v = static_cast<const PointImp *>(os[1]->imp())->coordinate();

    int nsides = 6;
    bool moreinfo = false;
    int winding = 0; // 0 means allow winding > 1
    if (os.size() == 3) {
        assert(os[2]->imp()->inherits(BogusPointImp::stype()));
        Coordinate cntrl = static_cast<const PointImp *>(os[2]->imp())->coordinate();
        nsides = computeNsides(c, v, cntrl, winding);
        moreinfo = true;
    }

    std::vector<ObjectCalcer *> args;
    args.push_back(os[0]);
    args.push_back(os[1]);
    ObjectConstCalcer *ns = new ObjectConstCalcer(new IntImp(nsides));
    args.push_back(ns);
    if (winding > 1) {
        ns = new ObjectConstCalcer(new IntImp(winding));
        args.push_back(ns);
    }

    p.setBrushStyle(Qt::NoBrush);
    p.setBrushColor(Qt::red);
    p.setPen(QPen(Qt::red, 1));
    p.setWidth(-1); // -1 means the default width for the object being
                    // drawn..

    ObjectDrawer drawer(Qt::red);
    drawprelim(drawer, p, args, d);
    if (moreinfo) {
        p.setPointStyle(Kig::RoundEmpty);
        p.setWidth(6);
        double ro = 1.0 / (2.5);
        Coordinate where = getRotatedCoord(c, (1 - ro) * c + ro * v, 4 * M_PI / 5.0);
        PointImp ptn = PointImp(where);
        TextImp text = TextImp(QStringLiteral("(5,2)"), where, false);
        ptn.draw(p);
        text.draw(p);
        for (int i = 3; i < 9; ++i) {
            where = getRotatedCoord(c, v, 2.0 * M_PI / i);
            ptn = PointImp(where);
            ptn.draw(p);
            if (i > 5)
                continue;
            text = TextImp(QStringLiteral("(%1)").arg(i), where, false);
            text.draw(p);
        }
        p.setStyle(Qt::DotLine);
        p.setWidth(1);
        double radius = (v - c).length();
        CircleImp circle = CircleImp(c, radius);
        circle.draw(p);
        for (int i = 2; i < 5; i++) {
            ro = 1.0 / (i + 0.5);
            CircleImp circle = CircleImp(c, ro * radius);
            circle.draw(p);
        }
    }
    delete_all(args.begin() + 2, args.end());
}

std::vector<ObjectHolder *> PolygonBCVConstructor::build(const std::vector<ObjectCalcer *> &parents, KigDocument &, KigWidget &) const
{
    assert(parents.size() == 3);
    std::vector<ObjectCalcer *> args;

    Coordinate c = static_cast<const PointImp *>(parents[0]->imp())->coordinate();
    Coordinate v = static_cast<const PointImp *>(parents[1]->imp())->coordinate();
    Coordinate cntrl = static_cast<const PointImp *>(parents[2]->imp())->coordinate();

    args.push_back(parents[0]);
    args.push_back(parents[1]);
    int winding = 0;
    int nsides = computeNsides(c, v, cntrl, winding);
    ObjectConstCalcer *d = new ObjectConstCalcer(new IntImp(nsides));
    args.push_back(d);
    if (winding > 1) {
        d = new ObjectConstCalcer(new IntImp(winding));
        args.push_back(d);
    }

    ObjectTypeCalcer *calcer = new ObjectTypeCalcer(mtype, args);
    ObjectHolder *h = new ObjectHolder(calcer);
    std::vector<ObjectHolder *> ret;
    ret.push_back(h);
    return ret;
}

QString PolygonBCVConstructor::useText(const ObjectCalcer &, const std::vector<ObjectCalcer *> &os, const KigDocument &, const KigWidget &) const
{
    switch (os.size()) {
    case 1:
        return i18n("Construct a regular polygon with this center");
        break;

    case 2:
        return i18n("Construct a regular polygon with this vertex");
        break;

    case 3:
        Coordinate c = static_cast<const PointImp *>(os[0]->imp())->coordinate();
        Coordinate v = static_cast<const PointImp *>(os[1]->imp())->coordinate();
        Coordinate cntrl = static_cast<const PointImp *>(os[2]->imp())->coordinate();
        int winding = 0;
        int nsides = computeNsides(c, v, cntrl, winding);

        if (winding > 1) {
            QString result = i18n("Adjust the number of sides (%1/%2)", nsides, winding);
            return result;
        } else {
            QString result = i18n("Adjust the number of sides (%1)", nsides);
            return result;
        }
        break;
    }

    return QLatin1String("");
}

QString PolygonBCVConstructor::selectStatement(const std::vector<ObjectCalcer *> &os, const KigDocument &, const KigWidget &) const
{
    switch (os.size()) {
    case 1:
        return i18n("Select the center of the new polygon...");
        break;

    case 2:
        return i18n("Select a vertex for the new polygon...");
        break;

    case 3:
        return i18n("Move the cursor to get the desired number of sides...");
        break;
    }

    return QLatin1String("");
}

void PolygonBCVConstructor::drawprelim(const ObjectDrawer &drawer, KigPainter &p, const std::vector<ObjectCalcer *> &parents, const KigDocument &doc) const
{
    if (parents.size() < 3 || parents.size() > 4)
        return;

    assert(parents[0]->imp()->inherits(PointImp::stype()) && parents[1]->imp()->inherits(PointImp::stype()) && parents[2]->imp()->inherits(IntImp::stype()));

    if (parents.size() == 4)
        assert(parents[3]->imp()->inherits(IntImp::stype()));

    Args args;
    std::transform(parents.begin(), parents.end(), std::back_inserter(args), std::mem_fn(&ObjectCalcer::imp));

    ObjectImp *data = mtype->calc(args, doc);
    drawer.draw(*data, p, true);
    delete data;
    data = nullptr;
}

void PolygonBCVConstructor::plug(KigPart *, KigGUIAction *)
{
}

bool PolygonBCVConstructor::isTransform() const
{
    return false;
}

Coordinate PolygonBCVConstructor::getRotatedCoord(const Coordinate &c, const Coordinate &v, double alpha) const
{
    double cosalpha = cos(alpha);
    double sinalpha = sin(alpha);
    double dx = v.x - c.x;
    double dy = v.y - c.y;
    return c + Coordinate(cosalpha * dx - sinalpha * dy, sinalpha * dx + cosalpha * dy);
}

int PolygonBCVConstructor::computeNsides(const Coordinate &c, const Coordinate &v, const Coordinate &cntrl, int &winding) const
{
    Coordinate lvect = v - c;
    Coordinate rvect = cntrl - c;

    double angle = atan2(rvect.y, rvect.x) - atan2(lvect.y, lvect.x);
    angle = fabs(angle / (2 * M_PI));
    while (angle > 1)
        angle -= 1;
    if (angle > 0.5)
        angle = 1 - angle;

    double realsides = 1.0 / angle; // this is bigger that 2
    if (angle == 0.)
        realsides = 3;
    if (winding <= 0) // free to compute winding
    {
        winding = 1;
        double ratio = lvect.length() / rvect.length();
        winding = int(ratio);
        if (winding < 1)
            winding = 1;
        if (winding > 50)
            winding = 50;
    }
    int nsides = int(winding * realsides + 0.5); // nsides/winding should be reduced!
    if (nsides > 100)
        nsides = 100; // well, 100 seems large enough!
    if (nsides < 3)
        nsides = 3;
    while (!relativePrimes(nsides, winding))
        ++nsides;
    return nsides;
}

/*
 * generic Bézier curve constructor
 */

BezierCurveTypeConstructor::BezierCurveTypeConstructor()
    : PointSequenceConstructor(i18n("Bézier Curve by its Control Points"),
                               i18n("Construct a Bézier curve by giving its control points"),
                               "bezierN",
                               BezierCurveType::instance())
{
}

BezierCurveTypeConstructor::~BezierCurveTypeConstructor()
{
}

bool BezierCurveTypeConstructor::isAlreadySelectedOK(const std::vector<ObjectCalcer *> &os, const uint &pos) const
{
    if (pos == os.size() - 1 && os.size() >= 3)
        return true;
    return false;
}

int BezierCurveTypeConstructor::wantArgs(const std::vector<ObjectCalcer *> &os, const KigDocument &, const KigWidget &) const
{
    int count = os.size() - 1;

    for (int i = 0; i <= count; i++) {
        if (!(os[i]->imp()->inherits(PointImp::stype())))
            return ArgsParser::Invalid;
    }
    if (count < 3)
        return ArgsParser::Valid;
    if (os[count] == os[count - 1])
        return ArgsParser::Complete;
    return ArgsParser::Valid;
}

QString BezierCurveTypeConstructor::useText(const ObjectCalcer &, const std::vector<ObjectCalcer *> &os, const KigDocument &, const KigWidget &) const
{
    if (os.size() > 3)
        return i18n("... with this control point (click again on the last control point to terminate construction)");
    else
        return i18n("Construct a Bézier curve with this control point");
}

QString BezierCurveTypeConstructor::selectStatement(const std::vector<ObjectCalcer *> &, const KigDocument &, const KigWidget &) const
{
    return i18n("Select a point to be a control point of the new Bézier curve...");
}

void BezierCurveTypeConstructor::drawprelim(const ObjectDrawer &, KigPainter &p, const std::vector<ObjectCalcer *> &parents, const KigDocument &) const
{
    if (parents.size() < 2)
        return;

    std::vector<Coordinate> points;

    for (uint i = 0; i < parents.size(); ++i) {
        const Coordinate vertex = static_cast<const PointImp *>(parents[i]->imp())->coordinate();
        points.push_back(vertex);
    }

    BezierImp B = BezierImp(points);
    B.draw(p);
}

/*
 * generic rational Bézier curve constructor
 */

RationalBezierCurveTypeConstructor::RationalBezierCurveTypeConstructor()
{
}

RationalBezierCurveTypeConstructor::~RationalBezierCurveTypeConstructor()
{
}

const QString RationalBezierCurveTypeConstructor::descriptiveName() const
{
    return i18n("Rational Bézier Curve by its Control Points");
}

const QString RationalBezierCurveTypeConstructor::description() const
{
    return i18n("Construct a Bézier curve by giving its control points and positive weights");
}

const QString RationalBezierCurveTypeConstructor::iconFileName(const bool) const
{
    return QStringLiteral("rbezierN");
}

bool RationalBezierCurveTypeConstructor::isAlreadySelectedOK(const std::vector<ObjectCalcer *> &os, const uint &pos) const
{
    if (pos % 2 == 1)
        return true;
    if (pos == os.size() - 2 && os.size() >= 3)
        return true;
    return false;
}

int RationalBezierCurveTypeConstructor::wantArgs(const std::vector<ObjectCalcer *> &os, const KigDocument &, const KigWidget &) const
{
    int count = os.size() - 1;

    for (int i = 0; i <= count; i++) {
        if (!(os[i]->imp()->inherits(i % 2 == 0 ? PointImp::stype() : &weightimptypeinstance)))
            return ArgsParser::Invalid;
    }
    if (count < 6)
        return ArgsParser::Valid;
    if (count % 2 == 0 && (os[count] == os[count - 2]))
        return ArgsParser::Complete;
    return ArgsParser::Valid;
}

std::vector<ObjectHolder *> RationalBezierCurveTypeConstructor::build(const std::vector<ObjectCalcer *> &parents, KigDocument &, KigWidget &) const
{
    uint count = parents.size() - 1;
    assert(count >= 3);
    std::vector<ObjectCalcer *> args;
    for (uint i = 0; i < count; ++i)
        args.push_back(parents[i]);
    ObjectTypeCalcer *calcer = new ObjectTypeCalcer(RationalBezierCurveType::instance(), args);
    ObjectHolder *h = new ObjectHolder(calcer);
    std::vector<ObjectHolder *> ret;
    ret.push_back(h);
    return ret;
}

void RationalBezierCurveTypeConstructor::handleArgs(const std::vector<ObjectCalcer *> &os, KigPart &d, KigWidget &v) const
{
    std::vector<ObjectHolder *> bos = build(os, d.document(), v);
    for (std::vector<ObjectHolder *>::iterator i = bos.begin(); i != bos.end(); ++i) {
        (*i)->calc(d.document());
    }

    d.addObjects(bos);
}

QString RationalBezierCurveTypeConstructor::useText(const ObjectCalcer &, const std::vector<ObjectCalcer *> &os, const KigDocument &, const KigWidget &) const
{
    if (os.size() % 2 == 0)
        return i18n("... assign this weight to last selected control point");

    if (os.size() > 6)
        return i18n("... with this control point (click again on the last control point or weight to terminate construction)");
    else
        return i18n("Construct a rational Bézier curve with this control point");
}

QString RationalBezierCurveTypeConstructor::selectStatement(const std::vector<ObjectCalcer *> &os, const KigDocument &, const KigWidget &) const
{
    if (os.size() % 2 == 0)
        return i18n("Select a point to be a control point of the new rational Bézier curve...");
    else
        return i18n("Select a numeric label to be a weight of last selected point...");
}

void RationalBezierCurveTypeConstructor::drawprelim(const ObjectDrawer &, KigPainter &p, const std::vector<ObjectCalcer *> &parents, const KigDocument &) const
{
    if (parents.size() < 5)
        return;

    std::vector<Coordinate> points;
    std::vector<double> weights;

    uint count = parents.size();
    for (uint i = 0; i < count; i += 2) {
        bool valid;
        assert(parents[i]->imp()->inherits(PointImp::stype()));
        const Coordinate vertex = static_cast<const PointImp *>(parents[i]->imp())->coordinate();
        points.push_back(vertex);
        if (i + 1 >= count)
            break;
        assert(parents[i + 1]->imp()->inherits(&weightimptypeinstance));
        const double weight = getDoubleFromImp(parents[i + 1]->imp(), valid);
        assert(valid);
        weights.push_back(weight);
    }

    if (count % 2 == 1) {
        // point was selected, we
        weights.push_back(1); // don't have its weight so far
    }

    assert(points.size() == weights.size());

    RationalBezierImp rB = RationalBezierImp(points, weights);
    rB.draw(p);
}

void RationalBezierCurveTypeConstructor::handlePrelim(KigPainter &p, const std::vector<ObjectCalcer *> &os, const KigDocument &d, const KigWidget &) const
{
    uint count = os.size();
    if (count < 5)
        return;

    for (uint i = 0; i < count; i += 2) {
        assert(os[i]->imp()->inherits(PointImp::stype()));
        if (i + 1 >= count)
            break;
        assert(os[i + 1]->imp()->inherits(&weightimptypeinstance));
    }

    std::vector<ObjectCalcer *> args = os;
    p.setBrushStyle(Qt::NoBrush);
    p.setBrushColor(Qt::red);
    p.setPen(QPen(Qt::red, 1));
    p.setWidth(-1); // -1 means the default width for the object being
                    // drawn..

    ObjectDrawer drawer(Qt::red);
    drawprelim(drawer, p, args, d);
}

void RationalBezierCurveTypeConstructor::plug(KigPart *, KigGUIAction *)
{
}

bool RationalBezierCurveTypeConstructor::isTransform() const
{
    return false;
}

/*
 * ConicConic intersection...
 */

static const ArgsParser::spec argsspectc[] = {{ConicImp::stype(), {}, {}, true},
                                              {ConicImp::stype(), {}, {}, true}};

ConicConicIntersectionConstructor::ConicConicIntersectionConstructor()
    : StandardConstructorBase({}, {}, "curvelineintersection", mparser)
    , mparser(argsspectc, 2)
{
}

ConicConicIntersectionConstructor::~ConicConicIntersectionConstructor()
{
}

void ConicConicIntersectionConstructor::drawprelim(const ObjectDrawer &drawer,
                                                   KigPainter &p,
                                                   const std::vector<ObjectCalcer *> &parents,
                                                   const KigDocument &) const
{
    if (parents.size() != 2)
        return;
    assert(parents[0]->imp()->inherits(ConicImp::stype()) && parents[1]->imp()->inherits(ConicImp::stype()));
    const ConicCartesianData conica = static_cast<const ConicImp *>(parents[0]->imp())->cartesianData();
    const ConicCartesianData conicb = static_cast<const ConicImp *>(parents[1]->imp())->cartesianData();
    bool ok = true;
    for (int wr = -1; wr < 2; wr += 2) {
        LineData radical = calcConicRadical(conica, conicb, wr, 1, ok);
        if (ok) {
            for (int wi = -1; wi < 2; wi += 2) {
                Coordinate c = calcConicLineIntersect(conica, radical, 0.0, wi);
                if (c.valid()) {
                    PointImp pi(c);
                    drawer.draw(pi, p, true);
                }
            };
        };
    };
}

std::vector<ObjectHolder *> ConicConicIntersectionConstructor::build(const std::vector<ObjectCalcer *> &os, KigDocument &doc, KigWidget &) const
{
    assert(os.size() == 2);
    std::vector<ObjectHolder *> ret;
    ObjectCalcer *conica = os[0];
    ObjectConstCalcer *zeroindexdo = new ObjectConstCalcer(new IntImp(1));

    for (int wr = -1; wr < 2; wr += 2) {
        std::vector<ObjectCalcer *> args = os;
        args.push_back(new ObjectConstCalcer(new IntImp(wr)));
        args.push_back(zeroindexdo);
        ObjectTypeCalcer *radical = new ObjectTypeCalcer(ConicRadicalType::instance(), args);
        radical->calc(doc);
        for (int wi = -1; wi < 2; wi += 2) {
            args.clear();
            args.push_back(conica);
            args.push_back(radical);
            args.push_back(new ObjectConstCalcer(new IntImp(wi)));
            ret.push_back(new ObjectHolder(new ObjectTypeCalcer(ConicLineIntersectionType::instance(), args)));
        };
    };
    return ret;
}

void ConicConicIntersectionConstructor::plug(KigPart *, KigGUIAction *)
{
}

bool ConicConicIntersectionConstructor::isTransform() const
{
    return false;
}

ConicLineIntersectionConstructor::ConicLineIntersectionConstructor()
    : MultiObjectTypeConstructor(ConicLineIntersectionType::instance(), {}, {}, "curvelineintersection", -1, 1)
{
}

ConicLineIntersectionConstructor::~ConicLineIntersectionConstructor()
{
}

ArcLineIntersectionConstructor::ArcLineIntersectionConstructor()
    : MultiObjectTypeConstructor(ArcLineIntersectionType::instance(), {}, {}, "curvelineintersection", -1, 1)
{
}

ArcLineIntersectionConstructor::~ArcLineIntersectionConstructor()
{
}

QString ConicRadicalConstructor::useText(const ObjectCalcer &o, const std::vector<ObjectCalcer *> &, const KigDocument &, const KigWidget &) const
{
    if (o.imp()->inherits(CircleImp::stype()))
        return i18n("Construct the Radical Lines of This Circle");
    else
        return i18n("Construct the Radical Lines of This Conic");
}

/*
 * generic affinity and generic projectivity.  A unique affinity can be
 * obtained by specifying the image of three points (four for projectivity)
 * in the end we need, besides the object to be transformed, a total of
 * six point or (alternatively) two triangles; our affinity will map the
 * first triangle onto the second with corresponding ordering of their
 * vertices.  Since we allow for two different ways of specifying the six
 * points we shall use a Generic constructor, like that for intersections.
 */

GenericAffinityConstructor::GenericAffinityConstructor()
    : MergeObjectConstructor(i18n("Generic Affinity"),
                             i18n("The unique affinity that maps three points (or a triangle) onto three other points (or a triangle)"),
                             "genericaffinity")
{
    SimpleObjectTypeConstructor *b2tr = new SimpleObjectTypeConstructor(AffinityB2TrType::instance(), {}, {}, "genericaffinity");

    SimpleObjectTypeConstructor *gi3p = new SimpleObjectTypeConstructor(AffinityGI3PType::instance(), {}, {}, "genericaffinity");

    merge(b2tr);
    merge(gi3p);
}

GenericAffinityConstructor::~GenericAffinityConstructor()
{
}

bool GenericAffinityConstructor::isAlreadySelectedOK(const std::vector<ObjectCalcer *> &, const uint &) const
{
    return true;
}

GenericProjectivityConstructor::GenericProjectivityConstructor()
    : MergeObjectConstructor(
        i18n("Generic Projective Transformation"),
        i18n("The unique projective transformation that maps four points (or a quadrilateral) onto four other points (or a quadrilateral)"),
        "genericprojectivity")
{
    SimpleObjectTypeConstructor *b2qu =
        new SimpleObjectTypeConstructor(ProjectivityB2QuType::instance(), {}, {}, "genericprojectivity");

    SimpleObjectTypeConstructor *gi4p =
        new SimpleObjectTypeConstructor(ProjectivityGI4PType::instance(), {}, {}, "genericprojectivity");

    merge(b2qu);
    merge(gi4p);
}

GenericProjectivityConstructor::~GenericProjectivityConstructor()
{
}

bool GenericProjectivityConstructor::isAlreadySelectedOK(const std::vector<ObjectCalcer *> &, const uint &) const
{
    return true;
}

/*
 * inversion of points, lines with respect to a circle
 */

InversionConstructor::InversionConstructor()
    : MergeObjectConstructor(i18n("Inversion of Point, Line or Circle"), i18n("The inversion of a point, line or circle with respect to a circle"), "inversion")
{
    SimpleObjectTypeConstructor *pointobj = new SimpleObjectTypeConstructor(InvertPointType::instance(), {}, {}, "inversion");

    SimpleObjectTypeConstructor *curveobj =
        new SimpleObjectTypeConstructor(CircularInversionType::instance(), {}, {}, "inversion");

    //  SimpleObjectTypeConstructor* lineobj =
    //     new SimpleObjectTypeConstructor(
    //      InvertLineType::instance(),
    //      {}, {},
    //      "inversion" );
    //
    //  SimpleObjectTypeConstructor* segmentobj =
    //     new SimpleObjectTypeConstructor(
    //      InvertSegmentType::instance(),
    //      {}, {},
    //      "inversion" );
    //
    //  SimpleObjectTypeConstructor* circleobj =
    //     new SimpleObjectTypeConstructor(
    //      InvertCircleType::instance(),
    //      {}, {},
    //      "inversion" );
    //
    //  SimpleObjectTypeConstructor* arcobj =
    //     new SimpleObjectTypeConstructor(
    //      InvertArcType::instance(),
    //      {}, {},
    //      "inversion" );

    //  merge( arcobj );
    //  merge( circleobj );
    merge(curveobj);
    merge(pointobj);
    //  merge( segmentobj );
    //  merge( lineobj );
}

InversionConstructor::~InversionConstructor()
{
}

/*
 * Transport of Measure
 */

MeasureTransportConstructor::MeasureTransportConstructor()
    : mtype(MeasureTransportType::instance())
{
}

MeasureTransportConstructor::~MeasureTransportConstructor()
{
}

const QString MeasureTransportConstructor::descriptiveName() const
{
    return i18n("Measure Transport");
}

const QString MeasureTransportConstructor::description() const
{
    return i18n("Transport the measure of a segment or arc over a line or circle.");
}

const QString MeasureTransportConstructor::iconFileName(const bool) const
{
    return QStringLiteral("measuretransport");
}

bool MeasureTransportConstructor::isAlreadySelectedOK(const std::vector<ObjectCalcer *> &, const uint &) const
{
    return false;
}

/*
 * we want the arguments in the exact order, this makes
 * the code simpler, but I guess it is also less confusing
 * to the user
 */

int MeasureTransportConstructor::wantArgs(const std::vector<ObjectCalcer *> &os, const KigDocument &doc, const KigWidget &) const
{
    if (os.size() == 0)
        return ArgsParser::Valid;

    if (!os[0]->imp()->inherits(&lengthimptypeinstance))
        return ArgsParser::Invalid;

    if (os.size() == 1)
        return ArgsParser::Valid;

    if (!os[1]->imp()->inherits(LineImp::stype()) && !os[1]->imp()->inherits(CircleImp::stype()))
        return ArgsParser::Invalid;
    const CurveImp *c = static_cast<const CurveImp *>(os[1]->imp());

    if (os.size() == 2)
        return ArgsParser::Valid;

    if (!os[2]->imp()->inherits(PointImp::stype()))
        return ArgsParser::Invalid;
    const PointImp *p = static_cast<const PointImp *>(os[2]->imp());

    // we have two choices:
    // - using "isPointOnCurve" produces a "by construction" incidence
    //   test.  This would be fine, but doesn't always work; e.g. if we
    //   have two points A, B, the segment s = AB and we construct the
    //   support line of the segment (property of segments), then kig
    //   is not able to understand that A is "by construction" on the
    //   constructed line.
    //   Moreover there are problems when hovering the cursor over points
    //   that are on both a segment and its support line.
    //      if ( ! isPointOnCurve( os[2], os[1] ) )
    // - using "containsPoint", which is actually the test performed
    //   when calc-ing the TransportOfMeasure; the risk here is to
    //   be able to select points that are only coincidentally on the line.

    if (!c->containsPoint(p->coordinate(), doc))
        return ArgsParser::Invalid;

    if (os.size() == 3)
        return ArgsParser::Complete;

    return ArgsParser::Invalid;
}

void MeasureTransportConstructor::handleArgs(const std::vector<ObjectCalcer *> &os, KigPart &d, KigWidget &v) const
{
    std::vector<ObjectHolder *> bos = build(os, d.document(), v);
    for (std::vector<ObjectHolder *>::iterator i = bos.begin(); i != bos.end(); ++i) {
        (*i)->calc(d.document());
    }

    d.addObjects(bos);
}

void MeasureTransportConstructor::handlePrelim(KigPainter &p, const std::vector<ObjectCalcer *> &os, const KigDocument &d, const KigWidget &) const
{
    p.setBrushStyle(Qt::NoBrush);
    p.setBrushColor(Qt::red);
    p.setPen(QPen(Qt::red, 1));
    p.setWidth(-1); // -1 means the default width for the object being
                    // drawn..

    ObjectDrawer drawer(Qt::red);
    drawprelim(drawer, p, os, d);
}

void MeasureTransportConstructor::drawprelim(const ObjectDrawer &drawer,
                                             KigPainter &p,
                                             const std::vector<ObjectCalcer *> &parents,
                                             const KigDocument &doc) const
{
    Args args;
    using namespace std;
    transform(parents.begin(), parents.end(), back_inserter(args), std::mem_fn(&ObjectCalcer::imp));
    ObjectImp *data = mtype->calc(args, doc);
    drawer.draw(*data, p, true);
    delete data;
}

QString MeasureTransportConstructor::useText(const ObjectCalcer &o, const std::vector<ObjectCalcer *> &os, const KigDocument &, const KigWidget &) const
{
    if (o.imp()->inherits(SegmentImp::stype()))
        return i18n("Segment to transport");
    if (o.imp()->inherits(ArcImp::stype()))
        return i18n("Arc to transport");
    if (o.imp()->inherits(NumericTextImp::stype()))
        return i18n("Value to transport");
    if (o.imp()->inherits(LineImp::stype()))
        return i18n("Transport a measure on this line");
    if (o.imp()->inherits(CircleImp::stype()))
        return i18n("Transport a measure on this circle");
    if (o.imp()->inherits(PointImp::stype())) {
        if (os[1]->imp()->inherits(CircleImp::stype()))
            return i18n("Start transport from this point of the circle");
        if (os[1]->imp()->inherits(LineImp::stype()))
            return i18n("Start transport from this point of the line");
        else
            return i18n("Start transport from this point of the curve");
        // well, this isn't impemented yet, should never get here
    }
    return QLatin1String("");
}

QString MeasureTransportConstructor::selectStatement(const std::vector<ObjectCalcer *> &os, const KigDocument &, const KigWidget &) const
{
    switch (os.size()) {
    case 0:
        return i18n("Select a segment, arc or numeric label to be transported...");
        break;

    case 1:
        return i18n("Select a destination line or circle...");
        break;

    case 2:
        return i18n("Choose a starting point on the line/circle...");
        break;
    }

    return QLatin1String("");
}

std::vector<ObjectHolder *> MeasureTransportConstructor::build(const std::vector<ObjectCalcer *> &parents, KigDocument &, KigWidget &) const
{
    assert(parents.size() == 3);
    //  std::vector<ObjectCalcer*> args;
    //  for ( uint i = 0; i < count; ++i ) args.push_back( parents[i] );
    ObjectTypeCalcer *calcer = new ObjectTypeCalcer(mtype, parents);
    ObjectHolder *h = new ObjectHolder(calcer);
    std::vector<ObjectHolder *> ret;
    ret.push_back(h);
    return ret;
}

void MeasureTransportConstructor::plug(KigPart *, KigGUIAction *)
{
}

bool MeasureTransportConstructor::isTransform() const
{
    return false;
}

/*
 * Generic intersection
 */

/*
 * these two argsparser spec vectors are used for the special
 * construction of conic-line and circle-circle constructions
 */

static const struct ArgsParser::spec argsspeccli[] = {{ConicImp::stype(), kli18n("Intersect with this conic"), {}, true},
                                                      {AbstractLineImp::stype(), kli18n("Intersect with this line"), {}, true}};

static const struct ArgsParser::spec argsspeccbli[] = {{CubicImp::stype(), kli18n("Intersect with this cubic"), {}, true},
                                                       {AbstractLineImp::stype(), kli18n("Intersect with this line"), {}, true}};

static const struct ArgsParser::spec argsspeccci[] = {{CircleImp::stype(), kli18n("Intersect with this circle"), {}, true},
                                                      {CircleImp::stype(), kli18n("Intersect with this circle"), {}, true}};

GenericIntersectionConstructor::GenericIntersectionConstructor()
    : MergeObjectConstructor(i18n("Intersect"), i18n("The intersection of two objects"), "curvelineintersection")
{
    // intersection type..
    // There is one "toplevel" object_constructor, that is composed
    // of multiple subconstructors.  First we build the
    // subconstructors:
    SimpleObjectTypeConstructor *lineline =
        new SimpleObjectTypeConstructor(LineLineIntersectionType::instance(), {}, {}, "curvelineintersection");

    ObjectConstructor *lineconic =
        //    new ConicLineIntersectionConstructor();
        new TwoOrOneIntersectionConstructor(ConicLineIntersectionType::instance(),
                                            ConicLineOtherIntersectionType::instance(),
                                            "curvelineintersection",
                                            argsspeccli);

    ObjectConstructor *arcline = new ArcLineIntersectionConstructor();

    ObjectConstructor *linecubic = new ThreeTwoOneIntersectionConstructor(CubicLineIntersectionType::instance(),
                                                                          CubicLineOtherIntersectionType::instance(),
                                                                          "curvelineintersection",
                                                                          argsspeccbli);

    ObjectConstructor *conicconic = new ConicConicIntersectionConstructor();

    //  MultiObjectTypeConstructor* circlecircle =
    //    new MultiObjectTypeConstructor(
    //      CircleCircleIntersectionType::instance(),
    //      {}, {},
    //      "circlecircleintersection", -1, 1 );
    ObjectConstructor *circlecircle = new TwoOrOneIntersectionConstructor(CircleCircleIntersectionType::instance(),
                                                                          CircleCircleOtherIntersectionType::instance(),
                                                                          "circlecircleintersection",
                                                                          argsspeccci);

    SimpleObjectTypeConstructor *polygonline =
        new SimpleObjectTypeConstructor(PolygonLineIntersectionType::instance(), {}, {}, "curvelineintersection");

    SimpleObjectTypeConstructor *polygonpolygon =
        new SimpleObjectTypeConstructor(PolygonPolygonIntersectionType::instance(), {}, {}, "curvelineintersection");

    MultiObjectTypeConstructor *opolygonalline =
        new MultiObjectTypeConstructor(OPolygonalLineIntersectionType::instance(), {}, {}, "curvelineintersection", -1, 1);

    MultiObjectTypeConstructor *cpolygonalline =
        new MultiObjectTypeConstructor(CPolygonalLineIntersectionType::instance(), {}, {}, "curvelineintersection", -1, 1);

    merge(lineline);
    merge(circlecircle);
    merge(lineconic);
    merge(linecubic);
    merge(conicconic);
    merge(arcline);
    merge(polygonline);
    merge(opolygonalline);
    merge(cpolygonalline);
    merge(polygonpolygon);
}

GenericIntersectionConstructor::~GenericIntersectionConstructor()
{
}

bool GenericIntersectionConstructor::isIntersection() const
{
    return true;
}

QString GenericIntersectionConstructor::useText(const ObjectCalcer &o, const std::vector<ObjectCalcer *> &os, const KigDocument &, const KigWidget &) const
{
    QString preamble;
    switch (os.size()) {
    case 1:
        if (o.imp()->inherits(CircleImp::stype()))
            return i18n("Intersect this Circle");
        else if (o.imp()->inherits(ConicImp::stype()))
            return i18n("Intersect this Conic");
        else if (o.imp()->inherits(SegmentImp::stype()))
            return i18n("Intersect this Segment");
        else if (o.imp()->inherits(RayImp::stype()))
            return i18n("Intersect this Half-line");
        else if (o.imp()->inherits(LineImp::stype()))
            return i18n("Intersect this Line");
        else if (o.imp()->inherits(CubicImp::stype()))
            return i18n("Intersect this Cubic Curve");
        else if (o.imp()->inherits(ArcImp::stype()))
            return i18n("Intersect this Arc");
        else if (o.imp()->inherits(FilledPolygonImp::stype()))
            return i18n("Intersect this Polygon");
        else if (o.imp()->inherits(AbstractPolygonImp::stype()))
            return i18n("Intersect this Polygonal");
        else
            assert(false);
        break;
    case 2:
        if (o.imp()->inherits(CircleImp::stype()))
            return i18n("with this Circle");
        else if (o.imp()->inherits(ConicImp::stype()))
            return i18n("with this Conic");
        else if (o.imp()->inherits(SegmentImp::stype()))
            return i18n("with this Segment");
        else if (o.imp()->inherits(RayImp::stype()))
            return i18n("with this Half-line");
        else if (o.imp()->inherits(LineImp::stype()))
            return i18n("with this Line");
        else if (o.imp()->inherits(CubicImp::stype()))
            return i18n("with this Cubic Curve");
        else if (o.imp()->inherits(ArcImp::stype()))
            return i18n("with this Arc");
        else if (o.imp()->inherits(FilledPolygonImp::stype()))
            return i18n("with this Polygon");
        else if (o.imp()->inherits(AbstractPolygonImp::stype()))
            return i18n("with this Polygonal");
        else
            assert(false);
        break;
    }

    return QString();
}

static const ArgsParser::spec argsspecMidPointOfTwoPoints[] = {{PointImp::stype(),
                                                                kli18n("Construct midpoint of this point and another one"),
                                                                kli18n("Select the first of the points of which you want to construct the midpoint..."),
                                                                false},
                                                               {PointImp::stype(),
                                                                kli18n("Construct the midpoint of this point and another one"),
                                                                kli18n("Select the other of the points of which to construct the midpoint..."),
                                                                false}};

MidPointOfTwoPointsConstructor::MidPointOfTwoPointsConstructor()
    : StandardConstructorBase("Mid Point", "Construct the midpoint of two points", "bisection", mparser)
    , mparser(argsspecMidPointOfTwoPoints, 2)
{
}

MidPointOfTwoPointsConstructor::~MidPointOfTwoPointsConstructor()
{
}

void MidPointOfTwoPointsConstructor::drawprelim(const ObjectDrawer &drawer,
                                                KigPainter &p,
                                                const std::vector<ObjectCalcer *> &parents,
                                                const KigDocument &) const
{
    if (parents.size() != 2)
        return;
    assert(parents[0]->imp()->inherits(PointImp::stype()));
    assert(parents[1]->imp()->inherits(PointImp::stype()));
    const Coordinate m = (static_cast<const PointImp *>(parents[0]->imp())->coordinate() + static_cast<const PointImp *>(parents[1]->imp())->coordinate()) / 2;
    drawer.draw(PointImp(m), p, true);
}

std::vector<ObjectHolder *> MidPointOfTwoPointsConstructor::build(const std::vector<ObjectCalcer *> &os, KigDocument &d, KigWidget &) const
{
    ObjectTypeCalcer *seg = new ObjectTypeCalcer(SegmentABType::instance(), os);
    seg->calc(d);
    //  int index = seg->imp()->propertiesInternalNames().indexOf( "mid-point" );
    //  assert( index != -1 );
    ObjectPropertyCalcer *prop = new ObjectPropertyCalcer(seg, "mid-point");
    prop->calc(d);
    std::vector<ObjectHolder *> ret;
    ret.push_back(new ObjectHolder(prop));
    return ret;
}

void MidPointOfTwoPointsConstructor::plug(KigPart *, KigGUIAction *)
{
}

bool MidPointOfTwoPointsConstructor::isTransform() const
{
    return false;
}

static const ArgsParser::spec argsspecGoldenPointOfTwoPoints[] = {
    {PointImp::stype(),
     kli18n("Construct golden ratio point of this point and another one"),
     kli18n("Select the first of the points of which you want to construct the golden ratio point..."),
     false},
    {PointImp::stype(),
     kli18n("Construct the golden ratio point of this point and another one"),
     kli18n("Select the other of the points of which to construct the golden ratio point..."),
     false}};

GoldenPointOfTwoPointsConstructor::GoldenPointOfTwoPointsConstructor()
    : StandardConstructorBase("Golden Ratio Point", "Construct the golden ratio point of two points", "bisection", mparser)
    , mparser(argsspecGoldenPointOfTwoPoints, 2)
{
}

GoldenPointOfTwoPointsConstructor::~GoldenPointOfTwoPointsConstructor()
{
}

void GoldenPointOfTwoPointsConstructor::drawprelim(const ObjectDrawer &drawer,
                                                   KigPainter &p,
                                                   const std::vector<ObjectCalcer *> &parents,
                                                   const KigDocument &) const
{
    if (parents.size() != 2)
        return;
    assert(parents[0]->imp()->inherits(PointImp::stype()));
    assert(parents[1]->imp()->inherits(PointImp::stype()));
    const Coordinate m =
        (static_cast<const PointImp *>(parents[0]->imp())->coordinate()
         + (sqrt(5) - 1) / 2
             * (static_cast<const PointImp *>(parents[1]->imp())->coordinate() - static_cast<const PointImp *>(parents[0]->imp())->coordinate()));
    drawer.draw(PointImp(m), p, true);
}

std::vector<ObjectHolder *> GoldenPointOfTwoPointsConstructor::build(const std::vector<ObjectCalcer *> &os, KigDocument &d, KigWidget &) const
{
    ObjectTypeCalcer *seg = new ObjectTypeCalcer(SegmentABType::instance(), os);
    seg->calc(d);
    //  int index = seg->imp()->propertiesInternalNames().indexOf( "golden-point" );
    //  assert( index != -1 );
    ObjectPropertyCalcer *prop = new ObjectPropertyCalcer(seg, "golden-point");
    prop->calc(d);
    std::vector<ObjectHolder *> ret;
    ret.push_back(new ObjectHolder(prop));
    return ret;
}

void GoldenPointOfTwoPointsConstructor::plug(KigPart *, KigGUIAction *)
{
}

bool GoldenPointOfTwoPointsConstructor::isTransform() const
{
    return false;
}

TestConstructor::TestConstructor(const ArgsParserObjectType *type, const QString &descname, const QString &desc, const QString &iconfile)
    : StandardConstructorBase(descname, desc, iconfile, type->argsParser())
    , mtype(type)
{
}

TestConstructor::~TestConstructor()
{
}

void TestConstructor::drawprelim(const ObjectDrawer &, KigPainter &, const std::vector<ObjectCalcer *> &, const KigDocument &) const
{
    // not used, only here because of the wrong
    // ObjectConstructor-GUIAction design.  See the TODO
}

std::vector<ObjectHolder *> TestConstructor::build(const std::vector<ObjectCalcer *> &, KigDocument &, KigWidget &) const
{
    // not used, only here because of the wrong
    // ObjectConstructor-GUIAction design.  See the TODO
    std::vector<ObjectHolder *> ret;
    return ret;
}

void TestConstructor::plug(KigPart *, KigGUIAction *)
{
}

bool TestConstructor::isTransform() const
{
    return false;
}

bool TestConstructor::isTest() const
{
    return true;
}

BaseConstructMode *TestConstructor::constructMode(KigPart &doc)
{
    return new TestConstructMode(doc, mtype);
}

int TestConstructor::wantArgs(const std::vector<ObjectCalcer *> &os, const KigDocument &d, const KigWidget &v) const
{
    int ret = StandardConstructorBase::wantArgs(os, d, v);
    if (ret == ArgsParser::Complete)
        ret = ArgsParser::Valid;
    return ret;
}

QString GenericIntersectionConstructor::selectStatement(const std::vector<ObjectCalcer *> &sel, const KigDocument &, const KigWidget &) const
{
    if (sel.size() == 0)
        return i18n("Select the first object to intersect...");
    else
        return i18n("Select the second object to intersect...");
}

TangentConstructor::TangentConstructor()
    : MergeObjectConstructor(i18n("Tangent"), i18n("The line tangent to a curve"), "tangent")
{
    SimpleObjectTypeConstructor *conic = new SimpleObjectTypeConstructor(TangentConicType::instance(), {}, {}, "tangentconic");

    SimpleObjectTypeConstructor *arc = new SimpleObjectTypeConstructor(TangentArcType::instance(), {}, {}, "tangentarc");

    SimpleObjectTypeConstructor *cubic = new SimpleObjectTypeConstructor(TangentCubicType::instance(), {}, {}, "tangentcubic");

    SimpleObjectTypeConstructor *curve = new SimpleObjectTypeConstructor(TangentCurveType::instance(), {}, {}, "tangentcurve");

    merge(conic);
    merge(arc);
    merge(cubic);
    merge(curve);
}

TangentConstructor::~TangentConstructor()
{
}

QString TangentConstructor::useText(const ObjectCalcer &o, const std::vector<ObjectCalcer *> &, const KigDocument &, const KigWidget &) const
{
    if (o.imp()->inherits(CircleImp::stype()))
        return i18n("Tangent to This Circle");
    else if (o.imp()->inherits(ConicImp::stype()))
        return i18n("Tangent to This Conic");
    else if (o.imp()->inherits(ArcImp::stype()))
        return i18n("Tangent to This Arc");
    else if (o.imp()->inherits(CubicImp::stype()))
        return i18n("Tangent to This Cubic Curve");
    else if (o.imp()->inherits(CurveImp::stype()))
        return i18n("Tangent to This Curve");
    else if (o.imp()->inherits(PointImp::stype()))
        return i18n("Tangent at This Point");
    //  else assert( false );
    return QString();
}

// QString TangentConstructor::selectStatement(
//   const std::vector<ObjectCalcer*>& sel, const KigDocument&,
//   const KigWidget& ) const
//{
//   if ( sel.size() == 0 )
//     return i18n( "Select the object..." );
//   else
//     return i18n( "Select the point for the tangent to go through..." );
// }

/*
 * center of curvature of a curve
 */

CocConstructor::CocConstructor()
    : MergeObjectConstructor(i18n("Center Of Curvature"), i18n("The center of the osculating circle to a curve"), "centerofcurvature")
{
    SimpleObjectTypeConstructor *conic = new SimpleObjectTypeConstructor(CocConicType::instance(), {}, {}, "cocconic");

    SimpleObjectTypeConstructor *cubic = new SimpleObjectTypeConstructor(CocCubicType::instance(), {}, {}, "coccubic");

    SimpleObjectTypeConstructor *curve = new SimpleObjectTypeConstructor(CocCurveType::instance(), {}, {}, "coccurve");

    merge(conic);
    merge(cubic);
    merge(curve);
}

CocConstructor::~CocConstructor()
{
}

QString CocConstructor::useText(const ObjectCalcer &o, const std::vector<ObjectCalcer *> &, const KigDocument &, const KigWidget &) const
{
    if (o.imp()->inherits(ConicImp::stype()))
        return i18n("Center of Curvature of This Conic");
    else if (o.imp()->inherits(CubicImp::stype()))
        return i18n("Center of Curvature of This Cubic Curve");
    else if (o.imp()->inherits(CurveImp::stype()))
        return i18n("Center of Curvature of This Curve");
    else if (o.imp()->inherits(PointImp::stype()))
        return i18n("Center of Curvature at This Point");
    return QString();
}

bool relativePrimes(int n, int p)
{
    if (p > n)
        return relativePrimes(p, n);
    assert(p >= 0);
    if (p == 0)
        return false;
    if (p == 1)
        return true;
    int d = int(n / p);
    return relativePrimes(p, n - d * p);
}

// QString CocConstructor::selectStatement(
//   const std::vector<ObjectCalcer*>& sel, const KigDocument&,
//   const KigWidget& ) const
//{
//   if ( sel.size() == 0 )
//     return i18n( "Select the object..." );
//   else
//     return i18n( "Select the point where to compute the center of curvature..." );
// }