C++ PathVector::push_back方法代码示例

/*
 * Converts all segments in all paths to Geom::LineSegment or Geom::HLineSegment or
 * Geom::VLineSegment or Geom::CubicBezier.
 */
Geom::PathVector
pathv_to_linear_and_cubic_beziers( Geom::PathVector const &pathv )
{
    Geom::PathVector output;

    for (Geom::PathVector::const_iterator pit = pathv.begin(); pit != pathv.end(); ++pit) {
        output.push_back( Geom::Path() );
        output.back().start( pit->initialPoint() );
        output.back().close( pit->closed() );

        for (Geom::Path::const_iterator cit = pit->begin(); cit != pit->end_open(); ++cit) {
            if (is_straight_curve(*cit)) {
                Geom::LineSegment l(cit->initialPoint(), cit->finalPoint());
                output.back().append(l);
            } else {
                Geom::BezierCurve const *curve = dynamic_cast<Geom::BezierCurve const *>(&*cit);
                if (curve && curve->order() == 3) {
                    Geom::CubicBezier b((*curve)[0], (*curve)[1], (*curve)[2], (*curve)[3]);
                    output.back().append(b);
                } else {
                    // convert all other curve types to cubicbeziers
                    Geom::Path cubicbezier_path = Geom::cubicbezierpath_from_sbasis(cit->toSBasis(), 0.1);
                    output.back().append(cubicbezier_path);
                }
            }
        }
    }
    
    return output;
}

/**
 * Returns a list of new curves corresponding to the subpaths in \a curve.
 * 2geomified
 */
GSList *
SPCurve::split() const
{
    GSList *l = NULL;

    for (Geom::PathVector::const_iterator path_it = _pathv.begin(); path_it != _pathv.end(); ++path_it) {
        Geom::PathVector newpathv;
        newpathv.push_back(*path_it);
        SPCurve * newcurve = new SPCurve(newpathv);
        l = g_slist_prepend(l, newcurve);
    }

    return l;
}

/*
 * Converts all segments in all paths to Geom::LineSegment.  There is an intermediate
 * stage where some may be converted to beziers.  maxdisp is the maximum displacement from
 * the line segment to the bezier curve; ** maxdisp is not used at this moment **.
 *
 * This is NOT a terribly fast method, but it should give a solution close to the one with the
 * fewest points.
 */
Geom::PathVector
pathv_to_linear( Geom::PathVector const &pathv, double /*maxdisp*/)
{
    Geom::PathVector output;
    Geom::PathVector tmppath = pathv_to_linear_and_cubic_beziers(pathv);
    
    // Now all path segments are either already lines, or they are beziers.

    for (Geom::PathVector::const_iterator pit = tmppath.begin(); pit != tmppath.end(); ++pit) {
        output.push_back( Geom::Path() );
        output.back().start( pit->initialPoint() );
        output.back().close( pit->closed() );

        for (Geom::Path::const_iterator cit = pit->begin(); cit != pit->end_open(); ++cit) {
            if (is_straight_curve(*cit)) {
                Geom::LineSegment ls(cit->initialPoint(), cit->finalPoint());
                output.back().append(ls);
            } 
            else { /* all others must be Bezier curves */
                Geom::BezierCurve const *curve = dynamic_cast<Geom::BezierCurve const *>(&*cit);
                Geom::CubicBezier b((*curve)[0], (*curve)[1], (*curve)[2], (*curve)[3]);
                std::vector<Geom::Point> bzrpoints = b.points();
                Geom::Point A = bzrpoints[0];
                Geom::Point B = bzrpoints[1];
                Geom::Point C = bzrpoints[2];
                Geom::Point D = bzrpoints[3];
                std::vector<Geom::Point> pointlist;
                pointlist.push_back(A);
                recursive_bezier4(
                   A[X], A[Y], 
                   B[X], B[Y], 
                   C[X], C[Y], 
                   D[X], D[Y],
                   pointlist, 
                   0);
                pointlist.push_back(D);
                Geom::Point r1 = pointlist[0];
                for (unsigned int i=1; i<pointlist.size();i++){
                   Geom::Point prev_r1 = r1;
                   r1 = pointlist[i];
                   Geom::LineSegment ls(prev_r1, r1);
                   output.back().append(ls);
                }
                pointlist.clear();
           }
        }
    }
    
    return output;
}

/// @todo investigate why Geom::Point p is passed in but ignored.
void Inkscape::ObjectSnapper::_collectPaths(Geom::Point /*p*/,
                                         SnapSourceType const source_type,
                                         bool const &first_point) const
{
    // Now, let's first collect all paths to snap to. If we have a whole bunch of points to snap,
    // e.g. when translating an item using the selector tool, then we will only do this for the
    // first point and store the collection for later use. This significantly improves the performance
    if (first_point) {
        _clear_paths();

        // Determine the type of bounding box we should snap to
        SPItem::BBoxType bbox_type = SPItem::GEOMETRIC_BBOX;

        bool p_is_a_node = source_type & SNAPSOURCE_NODE_CATEGORY;
        bool p_is_a_bbox = source_type & SNAPSOURCE_BBOX_CATEGORY;
        bool p_is_other = (source_type & SNAPSOURCE_OTHERS_CATEGORY) || (source_type & SNAPSOURCE_DATUMS_CATEGORY);

        if (_snapmanager->snapprefs.isTargetSnappable(SNAPTARGET_BBOX_EDGE)) {
            Preferences *prefs = Preferences::get();
            int prefs_bbox = prefs->getBool("/tools/bounding_box", 0);
            bbox_type = !prefs_bbox ?
                SPItem::VISUAL_BBOX : SPItem::GEOMETRIC_BBOX;
        }

        // Consider the page border for snapping
        if (_snapmanager->snapprefs.isTargetSnappable(SNAPTARGET_PAGE_BORDER) && _snapmanager->snapprefs.isAnyCategorySnappable()) {
            Geom::PathVector *border_path = _getBorderPathv();
            if (border_path != NULL) {
                _paths_to_snap_to->push_back(SnapCandidatePath(border_path, SNAPTARGET_PAGE_BORDER, Geom::OptRect()));
            }
        }

        for (std::vector<SnapCandidateItem>::const_iterator i = _candidates->begin(); i != _candidates->end(); ++i) {

            /* Transform the requested snap point to this item's coordinates */
            Geom::Affine i2doc(Geom::identity());
            SPItem *root_item = NULL;
            /* We might have a clone at hand, so make sure we get the root item */
            if (SP_IS_USE((*i).item)) {
                i2doc = SP_USE((*i).item)->get_root_transform();
                root_item = SP_USE((*i).item)->root();
                g_return_if_fail(root_item);
            } else {
                i2doc = (*i).item->i2doc_affine();
                root_item = (*i).item;
            }

            //Build a list of all paths considered for snapping to

            //Add the item's path to snap to
            if (_snapmanager->snapprefs.isTargetSnappable(SNAPTARGET_PATH, SNAPTARGET_PATH_INTERSECTION, SNAPTARGET_TEXT_BASELINE)) {
                if (p_is_other || p_is_a_node || (!_snapmanager->snapprefs.getStrictSnapping() && p_is_a_bbox)) {
                    if (SP_IS_TEXT(root_item) || SP_IS_FLOWTEXT(root_item)) {
                        if (_snapmanager->snapprefs.isTargetSnappable(SNAPTARGET_TEXT_BASELINE)) {
                            // Snap to the text baseline
                            Text::Layout const *layout = te_get_layout(static_cast<SPItem *>(root_item));
                            if (layout != NULL && layout->outputExists()) {
                                Geom::PathVector *pv = new Geom::PathVector();
                                pv->push_back(layout->baseline() * root_item->i2dt_affine() * (*i).additional_affine * _snapmanager->getDesktop()->doc2dt());
                                _paths_to_snap_to->push_back(SnapCandidatePath(pv, SNAPTARGET_TEXT_BASELINE, Geom::OptRect()));
                            }
                        }
                    } else {
                        // Snapping for example to a traced bitmap is very stressing for
                        // the CPU, so we'll only snap to paths having no more than 500 nodes
                        // This also leads to a lag of approx. 500 msec (in my lousy test set-up).
                        bool very_complex_path = false;
                        if (SP_IS_PATH(root_item)) {
                            very_complex_path = SP_PATH(root_item)->nodesInPath() > 500;
                        }

                        if (!very_complex_path && root_item && _snapmanager->snapprefs.isTargetSnappable(SNAPTARGET_PATH, SNAPTARGET_PATH_INTERSECTION)) {
                            SPCurve *curve = NULL;
                            if (SP_IS_SHAPE(root_item)) {
                               curve = SP_SHAPE(root_item)->getCurve();
                            }/* else if (SP_IS_TEXT(root_item) || SP_IS_FLOWTEXT(root_item)) {
                               curve = te_get_layout(root_item)->convertToCurves();
                            }*/
                            if (curve) {
                                // We will get our own copy of the pathvector, which must be freed at some point

                                // Geom::PathVector *pv = pathvector_for_curve(root_item, curve, true, true, Geom::identity(), (*i).additional_affine);

                                Geom::PathVector *pv = new Geom::PathVector(curve->get_pathvector());
                                (*pv) *= root_item->i2dt_affine() * (*i).additional_affine * _snapmanager->getDesktop()->doc2dt(); // (_edit_transform * _i2d_transform);

                                _paths_to_snap_to->push_back(SnapCandidatePath(pv, SNAPTARGET_PATH, Geom::OptRect())); // Perhaps for speed, get a reference to the Geom::pathvector, and store the transformation besides it.
                                curve->unref();
                            }
                        }
                    }
                }
            }

            //Add the item's bounding box to snap to
            if (_snapmanager->snapprefs.isTargetSnappable(SNAPTARGET_BBOX_EDGE)) {
                if (p_is_other || p_is_a_bbox || (!_snapmanager->snapprefs.getStrictSnapping() && p_is_a_node)) {
                    // Discard the bbox of a clipped path / mask, because we don't want to snap to both the bbox
                    // of the item AND the bbox of the clipping path at the same time
//.........这里部分代码省略.........