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/** \file
* Implementation of sp_item_notify_moveto().
*/
#include <sp-item.h>
#include <2geom/transforms.h>
#include <sp-guide.h>
#include <sp-item-rm-unsatisfied-cns.h>
using std::vector;
/**
* Called by sp_guide_moveto to indicate that the guide line corresponding to g has been moved, and
* that consequently this item should move with it.
*
* \pre exist [cn in item.constraints] g eq cn.g.
*/
void sp_item_notify_moveto(SPItem &item, SPGuide const &mv_g, int const snappoint_ix,
double const position, bool const commit)
{
g_return_if_fail(SP_IS_ITEM(&item));
g_return_if_fail( unsigned(snappoint_ix) < 8 );
Geom::Point const dir( mv_g.normal_to_line );
double const dir_lensq(dot(dir, dir));
g_return_if_fail( dir_lensq != 0 );
std::vector<Inkscape::SnapCandidatePoint> snappoints;
item.getSnappoints(snappoints, NULL);
g_return_if_fail( snappoint_ix < int(snappoints.size()) );
double const pos0 = dot(dir, snappoints[snappoint_ix].getPoint());
/// \todo effic: skip if mv_g is already satisfied.
/* Translate along dir to make dot(dir, snappoints(item)[snappoint_ix]) == position. */
/* Calculation:
dot(dir, snappoints[snappoint_ix] + s * dir) = position.
dot(dir, snappoints[snappoint_ix]) + dot(dir, s * dir) = position.
pos0 + s * dot(dir, dir) = position.
s * lensq(dir) = position - pos0.
s = (position - pos0) / dot(dir, dir). */
Geom::Translate const tr( ( position - pos0 )
* ( dir / dir_lensq ) );
item.set_i2d_affine(item.i2dt_affine() * tr);
/// \todo Reget snappoints, check satisfied.
if (commit) {
/// \todo Consider maintaining a set of dirty items.
/* Commit repr. */
{
item.doWriteTransform(item.getRepr(), item.transform);
}
sp_item_rm_unsatisfied_cns(item);
#if 0 /* nyi */
move_cn_to_front(mv_g, snappoint_ix, item.constraints);
/** \note If the guideline is connected to multiple snappoints of
* this item, then keeping those cns in order requires that the
* guide send notifications in order of increasing importance.
*/
#endif
}
}
/*
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:fileencoding=utf-8:textwidth=99 :
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