#include "snapped-curve.h"

#include "libnr/nr-values.h"

#include <2geom/crossing.h>

#include <2geom/path-intersection.h>

#include <libnr/nr-convert2geom.h>

#include "desktop.h"

#include "inkscape.h"

Inkscape::SnappedCurve::SnappedCurve(Geom::Point const &snapped_point, Geom::Coord const &snapped_distance, Geom::Coord const &snapped_tolerance, bool const &always_snap, Geom::Curve const *curve)

{

_distance = snapped_distance;

_tolerance = snapped_tolerance;

_always_snap = always_snap;

_curve = curve;

_second_distance = NR_HUGE;

_second_tolerance = 0;

_second_always_snap = false;

_point = snapped_point;

_at_intersection = false;

}

Inkscape::SnappedCurve::SnappedCurve()

{

_distance = NR_HUGE;

_tolerance = 0;

_always_snap = false;

_curve = NULL;

_second_distance = NR_HUGE;

_second_tolerance = 0;

_second_always_snap = false;

_point = Geom::Point(0,0);

_at_intersection = false;

}

Inkscape::SnappedCurve::~SnappedCurve()

{

}

Inkscape::SnappedPoint Inkscape::SnappedCurve::intersect(SnappedCurve const &curve, Geom::Point const &p) const

{

// Calculate the intersections of two curves, which are both within snapping range, and

// return only the closest intersection

// The point of intersection should be considered for snapping, but might be outside the snapping range

// PS: We need p (the location of the mouse pointer) for find out which intersection is the

// closest, as there might be multiple intersections of two curves

Geom::Crossings cs = crossings(*(this->_curve), *(curve._curve));

if (cs.size() > 0) {

// There might be multiple intersections: find the closest

Geom::Coord best_dist = NR_HUGE;

Geom::Point best_p = Geom::Point(NR_HUGE, NR_HUGE);

for (std::vector<Geom::Crossing>::const_iterator i = cs.begin(); i != cs.end(); i++) {

Geom::Point p_ix = this->_curve->pointAt((*i).ta);

Geom::Coord dist = Geom::distance(p_ix, p);

if (dist < best_dist) {

best_dist = dist;

best_p = p_ix;

}

}

// Now we've found the closests intersection, return it as a SnappedPoint

bool const use_this_as_primary = _distance < curve.getDistance();

Inkscape::SnappedCurve const *primaryC = use_this_as_primary ? this : &curve;

Inkscape::SnappedCurve const *secondaryC = use_this_as_primary ? &curve : this;

// The intersection should in fact be returned in desktop coordinates, but for this

// we need a desktop: this is a dirty hack

SPDesktop const *desktop = SP_ACTIVE_DESKTOP;

best_p = desktop->dt2doc(best_p);

// TODO: Investigate whether it is possible to use document coordinates everywhere

// in the snapper code. Only the mouse position should be in desktop coordinates, I guess.

// All paths are already in document coords and we are certainly not going to change THAT.

return SnappedPoint(from_2geom(best_p), Inkscape::SNAPTARGET_PATH_INTERSECTION, primaryC->getDistance(), primaryC->getTolerance(), primaryC->getAlwaysSnap(), true,

secondaryC->getDistance(), secondaryC->getTolerance(), secondaryC->getAlwaysSnap());

}

// No intersection

return SnappedPoint(Geom::Point(NR_HUGE, NR_HUGE), SNAPTARGET_UNDEFINED, NR_HUGE, 0, false, false, NR_HUGE, 0, false);

}

bool getClosestCurve(std::list<Inkscape::SnappedCurve> const &list, Inkscape::SnappedCurve &result)

{

bool success = false;

for (std::list<Inkscape::SnappedCurve>::const_iterator i = list.begin(); i != list.end(); i++) {

if ((i == list.begin()) || (*i).getDistance() < result.getDistance()) {

result = *i;

success = true;

}

}

return success;

}

bool getClosestIntersectionCS(std::list<Inkscape::SnappedCurve> const &list, Geom::Point const &p, Inkscape::SnappedPoint &result)

{

bool success = false;

for (std::list<Inkscape::SnappedCurve>::const_iterator i = list.begin(); i != list.end(); i++) {

std::list<Inkscape::SnappedCurve>::const_iterator j = i;

j++;

for (; j != list.end(); j++) {

Inkscape::SnappedPoint sp = (*i).intersect(*j, p);

if (sp.getAtIntersection()) {

// if it's the first point

bool const c1 = !success;

// or, if it's closer

bool const c2 = sp.getDistance() < result.getDistance();

// or, if it's just then look at the other distance

// (only relevant for snapped points which are at an intersection

bool const c3 = (sp.getDistance() == result.getDistance()) && (sp.getSecondDistance() < result.getSecondDistance());

// then prefer this point over the previous one

if (c1 || c2 || c3) {

result = sp;

success = true;

}

}

}

}

return success;

}