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/**
* \file object-snapper.cpp
* \brief Snapping things to objects.
*
* Authors:
* Carl Hetherington <inkscape@carlh.net>
*
* Copyright (C) 2005 Authors
*
* Released under GNU GPL, read the file 'COPYING' for more information
*/
#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)
{
}
/**
* \param p Point we are trying to snap (desktop coordinates)
*/
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
** in SPDesktop rather than SPNamedView?
*/
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
** in SPDesktop rather than SPNamedView?
*/
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
** intersection of c with the objects.
*/
return _doFreeSnap(p, it);
}
/**
* \return true if this Snapper will snap at least one kind of point.
*/
bool Inkscape::ObjectSnapper::willSnapSomething() const
{
return (_enabled && _snap_to != 0 && (_snap_to_paths || _snap_to_nodes));
}
/*
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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