/// @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
if (!(*i).clip_or_mask) {
Geom::OptRect rect = root_item->bounds(bbox_type, i2doc);
if (rect) {
Geom::PathVector *path = _getPathvFromRect(*rect);
rect = root_item->desktopBounds(bbox_type);
_paths_to_snap_to->push_back(SnapCandidatePath(path, SNAPTARGET_BBOX_EDGE, rect));
}
}
}
}
}
}
}
void Inkscape::ObjectSnapper::_findCandidates(SPObject* parent,
std::vector<SPItem const *> const *it,
bool const &first_point,
Geom::Rect const &bbox_to_snap,
bool const clip_or_mask,
Geom::Affine const additional_affine) const // transformation of the item being clipped / masked
{
SPDesktop const *dt = _snapmanager->getDesktop();
if (dt == NULL) {
g_warning("desktop == NULL, so we cannot snap; please inform the developers of this bug");
// Apparently the setup() method from the SnapManager class hasn't been called before trying to snap.
}
if (first_point) {
_candidates->clear();
}
Geom::Rect bbox_to_snap_incl = bbox_to_snap; // _incl means: will include the snapper tolerance
bbox_to_snap_incl.expandBy(getSnapperTolerance()); // see?
for ( SPObject *o = parent->firstChild(); o; o = o->getNext() ) {
g_assert(dt != NULL);
if (SP_IS_ITEM(o) && !(dt->itemIsHidden(SP_ITEM(o)) && !clip_or_mask)) {
// Snapping to items in a locked layer is allowed
// Don't snap to hidden objects, unless they're a clipped path or a mask
/* See if this item is on the ignore list */
std::vector<SPItem const *>::const_iterator i;
if (it != NULL) {
i = it->begin();
while (i != it->end() && *i != o) {
++i;
}
}
if (it == NULL || i == it->end()) {
SPItem *item = SP_ITEM(o);
if (item) {
if (!clip_or_mask) { // cannot clip or mask more than once
// The current item is not a clipping path or a mask, but might
// still be the subject of clipping or masking itself ; if so, then
// we should also consider that path or mask for snapping to
SPObject *obj = SP_OBJECT(item->clip_ref ? item->clip_ref->getObject() : NULL);
if (obj && _snapmanager->snapprefs.isTargetSnappable(SNAPTARGET_PATH_CLIP)) {
_findCandidates(obj, it, false, bbox_to_snap, true, item->i2doc_affine());
}
obj = SP_OBJECT(item->mask_ref ? item->mask_ref->getObject() : NULL);
if (obj && _snapmanager->snapprefs.isTargetSnappable(SNAPTARGET_PATH_MASK)) {
_findCandidates(obj, it, false, bbox_to_snap, true, item->i2doc_affine());
}
}
}
if (SP_IS_GROUP(o)) {
_findCandidates(o, it, false, bbox_to_snap, clip_or_mask, additional_affine);
} else {
Geom::OptRect bbox_of_item;
Preferences *prefs = Preferences::get();
int prefs_bbox = prefs->getBool("/tools/bounding_box", 0);
// We'll only need to obtain the visual bounding box if the user preferences tell
// us to, AND if we are snapping to the bounding box itself. If we're snapping to
// paths only, then we can just as well use the geometric bounding box (which is faster)
SPItem::BBoxType bbox_type = (!prefs_bbox && _snapmanager->snapprefs.isTargetSnappable(SNAPTARGET_BBOX_CATEGORY)) ?
SPItem::VISUAL_BBOX : SPItem::GEOMETRIC_BBOX;
if (clip_or_mask) {
// Oh oh, this will get ugly. We cannot use sp_item_i2d_affine directly because we need to
// insert an additional transformation in document coordinates (code copied from sp_item_i2d_affine)
bbox_of_item = item->bounds(bbox_type, item->i2doc_affine() * additional_affine * dt->doc2dt());
} else {
bbox_of_item = item->desktopBounds(bbox_type);
}
if (bbox_of_item) {
// See if the item is within range
if (bbox_to_snap_incl.intersects(*bbox_of_item)
|| (_snapmanager->snapprefs.isTargetSnappable(SNAPTARGET_ROTATION_CENTER) && bbox_to_snap_incl.contains(item->getCenter()))) { // rotation center might be outside of the bounding box
// This item is within snapping range, so record it as a candidate
_candidates->push_back(SnapCandidateItem(item, clip_or_mask, additional_affine));
// For debugging: print the id of the candidate to the console
// SPObject *obj = (SPObject*)item;
// std::cout << "Snap candidate added: " << obj->getId() << std::endl;
}
}
}
}
}
}
}
void Inkscape::ObjectSnapper::_collectNodes(SnapSourceType const &t,
bool const &first_point) const
{
// Now, let's first collect all points 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) {
_points_to_snap_to->clear();
// Determine the type of bounding box we should snap to
SPItem::BBoxType bbox_type = SPItem::GEOMETRIC_BBOX;
bool p_is_a_node = t & SNAPSOURCE_NODE_CATEGORY;
bool p_is_a_bbox = t & SNAPSOURCE_BBOX_CATEGORY;
bool p_is_other = (t & SNAPSOURCE_OTHERS_CATEGORY) || (t & SNAPSOURCE_DATUMS_CATEGORY);
// A point considered for snapping should be either a node, a bbox corner or a guide/other. Pick only ONE!
if (((p_is_a_node && p_is_a_bbox) || (p_is_a_bbox && p_is_other) || (p_is_a_node && p_is_other))) {
g_warning("Snap warning: node type is ambiguous");
}
if (_snapmanager->snapprefs.isTargetSnappable(SNAPTARGET_BBOX_CORNER, SNAPTARGET_BBOX_EDGE_MIDPOINT, SNAPTARGET_BBOX_MIDPOINT)) {
Preferences *prefs = Preferences::get();
bool prefs_bbox = prefs->getBool("/tools/bounding_box");
bbox_type = !prefs_bbox ?
SPItem::VISUAL_BBOX : SPItem::GEOMETRIC_BBOX;
}
// Consider the page border for snapping to
if (_snapmanager->snapprefs.isTargetSnappable(SNAPTARGET_PAGE_CORNER)) {
_getBorderNodes(_points_to_snap_to);
}
for (std::vector<SnapCandidateItem>::const_iterator i = _candidates->begin(); i != _candidates->end(); ++i) {
//Geom::Affine i2doc(Geom::identity());
SPItem *root_item = (*i).item;
if (SP_IS_USE((*i).item)) {
root_item = SP_USE((*i).item)->root();
}
g_return_if_fail(root_item);
//Collect all nodes so we can snap to them
if (p_is_a_node || p_is_other || (p_is_a_bbox && !_snapmanager->snapprefs.getStrictSnapping())) {
// Note: there are two ways in which intersections are considered:
// Method 1: Intersections are calculated for each shape individually, for both the
// snap source and snap target (see sp_shape_snappoints)
// Method 2: Intersections are calculated for each curve or line that we've snapped to, i.e. only for
// the target (see the intersect() method in the SnappedCurve and SnappedLine classes)
// Some differences:
// - Method 1 doesn't find intersections within a set of multiple objects
// - Method 2 only works for targets
// When considering intersections as snap targets:
// - Method 1 only works when snapping to nodes, whereas
// - Method 2 only works when snapping to paths
// - There will be performance differences too!
// If both methods are being used simultaneously, then this might lead to duplicate targets!
// Well, here we will be looking for snap TARGETS. Both methods can therefore be used.
// When snapping to paths, we will get a collection of snapped lines and snapped curves. findBestSnap() will
// go hunting for intersections (but only when asked to in the prefs of course). In that case we can just
// temporarily block the intersections in sp_item_snappoints, we don't need duplicates. If we're not snapping to
// paths though but only to item nodes then we should still look for the intersections in sp_item_snappoints()
bool old_pref = _snapmanager->snapprefs.isTargetSnappable(SNAPTARGET_PATH_INTERSECTION);
if (_snapmanager->snapprefs.isTargetSnappable(SNAPTARGET_PATH)) {
// So if we snap to paths, then findBestSnap will find the intersections
// and therefore we temporarily disable SNAPTARGET_PATH_INTERSECTION, which will
// avoid root_item->getSnappoints() below from returning intersections
_snapmanager->snapprefs.setTargetSnappable(SNAPTARGET_PATH_INTERSECTION, false);
}
// We should not snap a transformation center to any of the centers of the items in the
// current selection (see the comment in SelTrans::centerRequest())
bool old_pref2 = _snapmanager->snapprefs.isTargetSnappable(SNAPTARGET_ROTATION_CENTER);
if (old_pref2) {
for ( GSList const *itemlist = _snapmanager->getRotationCenterSource(); itemlist != NULL; itemlist = g_slist_next(itemlist) ) {
if ((*i).item == reinterpret_cast<SPItem*>(itemlist->data)) {
// don't snap to this item's rotation center
_snapmanager->snapprefs.setTargetSnappable(SNAPTARGET_ROTATION_CENTER, false);
break;
}
}
}
root_item->getSnappoints(*_points_to_snap_to, &_snapmanager->snapprefs);
// restore the original snap preferences
_snapmanager->snapprefs.setTargetSnappable(SNAPTARGET_PATH_INTERSECTION, old_pref);
_snapmanager->snapprefs.setTargetSnappable(SNAPTARGET_ROTATION_CENTER, old_pref2);
}
//Collect the bounding box's corners so we can snap to them
if (p_is_a_bbox || (!_snapmanager->snapprefs.getStrictSnapping() && p_is_a_node) || p_is_other) {
// 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
if (!(*i).clip_or_mask) {
Geom::OptRect b = root_item->desktopBounds(bbox_type);
getBBoxPoints(b, _points_to_snap_to, true,
_snapmanager->snapprefs.isTargetSnappable(SNAPTARGET_BBOX_CORNER),
_snapmanager->snapprefs.isTargetSnappable(SNAPTARGET_BBOX_EDGE_MIDPOINT),
_snapmanager->snapprefs.isTargetSnappable(SNAPTARGET_BBOX_MIDPOINT));
}
}
}
}
}
