#include "libnr/n-art-bpath.h"

#include "libnr/nr-rect-ops.h"

#include "document.h"

#include "sp-namedview.h"

#include "sp-path.h"

#include "sp-item-group.h"

#include "display/curve.h"

#include "desktop.h"

#include "inkscape.h"

#include "splivarot.h"

Inkscape::ObjectSnapper::ObjectSnapper(SPNamedView const *nv, NR::Coord const d)

: Snapper(nv, d), _snap_to_nodes(true), _snap_to_paths(true)

{

}

void Inkscape::ObjectSnapper::_findCandidates(std::list<SPItem*>& c,

SPObject* r,

std::list<SPItem const *> const &it,

NR::Point const &p) const

{

if (willSnapSomething()) {

SPDesktop const *desktop = SP_ACTIVE_DESKTOP;

for (SPObject* o = sp_object_first_child(r); o != NULL; o = SP_OBJECT_NEXT(o)) {

if (SP_IS_ITEM(o) && !SP_ITEM(o)->isLocked() && !desktop->itemIsHidden(SP_ITEM(o))) {

/* See if this item is on the ignore list */

std::list<SPItem const *>::const_iterator i = it.begin();

while (i != it.end() && *i != o) {

i++;

}

if (i == it.end()) {

/* See if the item is within range */

if (SP_IS_GROUP(o)) {

_findCandidates(c, o, it, p);

} else {

NR::Maybe<NR::Rect> b = sp_item_bbox_desktop(SP_ITEM(o));

if ( b && NR::expand(*b, -getDistance()).contains(p) ) {

c.push_back(SP_ITEM(o));

}

}

}

}

}

}

}

void Inkscape::ObjectSnapper::_snapNodes(Inkscape::SnappedPoint &s,

NR::Point const &p,

std::list<SPItem*> const &cand) const

{

/* FIXME: this seems like a hack. Perhaps Snappers should be

SPDesktop const *desktop = SP_ACTIVE_DESKTOP;

for (std::list<SPItem*>::const_iterator i = cand.begin(); i != cand.end(); i++) {

if (SP_IS_SHAPE(*i)) {

SPShape const *sh = SP_SHAPE(*i);

if (sh->curve) {

int j = 0;

NR::Matrix const i2doc = sp_item_i2doc_affine(*i);

while (SP_CURVE_BPATH(sh->curve)[j].code != NR_END) {

/* Get this node in desktop coordinates */

NArtBpath const &bp = SP_CURVE_BPATH(sh->curve)[j];

NR::Point const n = desktop->doc2dt(bp.c(3) * i2doc);

/* Try to snap to this node of the path */

NR::Coord const dist = NR::L2(n - p);

if (dist < getDistance() && dist < s.getDistance()) {

s = SnappedPoint(n, dist);

}

j++;

}

}

}

}

}

void Inkscape::ObjectSnapper::_snapPaths(Inkscape::SnappedPoint &s,

NR::Point const &p,

std::list<SPItem*> const &cand) const

{

/* FIXME: this seems like a hack. Perhaps Snappers should be

SPDesktop const *desktop = SP_ACTIVE_DESKTOP;

NR::Point const p_doc = desktop->dt2doc(p);

for (std::list<SPItem*>::const_iterator i = cand.begin(); i != cand.end(); i++) {

/* Transform the requested snap point to this item's coordinates */

NR::Matrix const i2doc = sp_item_i2doc_affine(*i);

NR::Point const p_it = p_doc * i2doc.inverse();

Path *livarot_path = Path_for_item(*i, true, true);

if (!livarot_path)

continue;

livarot_path->ConvertWithBackData(0.01);

/* Look for the nearest position on this SPItem to our snap point */

NR::Maybe<Path::cut_position> const o = get_nearest_position_on_Path(livarot_path, p_it);

if (o && o->t >= 0 && o->t <= 1) {

/* Convert the nearest point back to desktop coordinates */

NR::Point const o_it = get_point_on_Path(livarot_path, o->piece, o->t);

NR::Point const o_dt = desktop->doc2dt(o_it * i2doc);

NR::Coord const dist = NR::L2(o_dt - p);

if (dist < getDistance() && dist < s.getDistance()) {

s = SnappedPoint(o_dt, dist);

}

}

delete livarot_path;

}

}

Inkscape::SnappedPoint Inkscape::ObjectSnapper::_doFreeSnap(NR::Point const &p,

std::list<SPItem const *> const &it) const

{

if ( NULL == _named_view ) {

return SnappedPoint(p, NR_HUGE);

}

/* Get a list of all the SPItems that we will try to snap to */

std::list<SPItem*> cand;

_findCandidates(cand, sp_document_root(_named_view->document), it, p);

SnappedPoint s(p, NR_HUGE);

if (_snap_to_nodes) {

_snapNodes(s, p, cand);

}

if (_snap_to_paths) {

_snapPaths(s, p, cand);

}

return s;

}

Inkscape::SnappedPoint Inkscape::ObjectSnapper::_doConstrainedSnap(NR::Point const &p,

ConstraintLine const &c,

std::list<SPItem const *> const &it) const

{

/* FIXME: this needs implementing properly; I think we have to do the

return _doFreeSnap(p, it);

}

bool Inkscape::ObjectSnapper::willSnapSomething() const

{

return (_enabled && _snap_to != 0 && (_snap_to_paths || _snap_to_nodes));

}