object-snapper.cpp revision 41c4ddd6064c35b849f347c88f4e39bb31d4ce62
/*
* Snapping things to objects.
*
* Authors:
* Carl Hetherington <inkscape@carlh.net>
* Diederik van Lierop <mail@diedenrezi.nl>
* Jon A. Cruz <jon@joncruz.org>
* Abhishek Sharma
*
* Copyright (C) 2005 - 2012 Authors
*
* Released under GNU GPL, read the file 'COPYING' for more information
*/
#include "document.h"
#include "sp-namedview.h"
#include "sp-image.h"
#include "sp-item-group.h"
#include "sp-item.h"
#include "sp-use.h"
#include "inkscape.h"
#include "preferences.h"
#include "sp-text.h"
#include "sp-flowtext.h"
#include "text-editing.h"
#include "sp-clippath.h"
#include "sp-mask.h"
#include "helper/geom-curves.h"
#include "desktop.h"
#include "sp-root.h"
{
}
{
_candidates->clear();
delete _candidates;
delete _points_to_snap_to;
_clear_paths();
delete _paths_to_snap_to;
}
{
}
{
return _snapmanager->snapprefs.getObjectTolerance() == 10000; //TODO: Replace this threshold of 10000 by a constant; see also tolerance-slider.cpp
}
bool const &first_point,
bool const clip_or_mask,
{
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();
}
// 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 */
++i;
}
}
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
}
}
}
} else {
// 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)) ?
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)
} else {
}
if (bbox_of_item) {
// See if the item is within range
|| (_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
// For debugging: print the id of the candidate to the console
// SPObject *obj = (SPObject*)item;
// std::cout << "Snap candidate added: " << obj->getId() << std::endl;
break;
}
}
}
}
}
}
}
}
}
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) {
// Determine the type of bounding box we should snap to
bool p_is_a_node = t & SNAPSOURCE_NODE_CATEGORY;
bool p_is_a_bbox = t & SNAPSOURCE_BBOX_CATEGORY;
// A point considered for snapping should be either a node, a bbox corner or a guide/other. Pick only ONE!
g_warning("Snap warning: node type is ambiguous");
}
if (_snapmanager->snapprefs.isTargetSnappable(SNAPTARGET_BBOX_CORNER, SNAPTARGET_BBOX_EDGE_MIDPOINT, SNAPTARGET_BBOX_MIDPOINT)) {
bbox_type = !prefs_bbox ?
}
// Consider the page border for snapping to
}
for (std::vector<SnapCandidateItem>::const_iterator i = _candidates->begin(); i != _candidates->end(); ++i) {
//Geom::Affine i2doc(Geom::identity());
if (use) {
}
//Collect all nodes so we can snap to them
// 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()
// 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
}
// 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())
if (old_pref2) {
for ( std::vector<SPItem*>::const_iterator itemlist = rotationSource.begin(); itemlist != rotationSource.end(); ++itemlist) {
// don't snap to this item's rotation center
break;
}
}
}
// restore the original snap preferences
}
//Collect the bounding box's corners so we can snap to them
// 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) {
getBBoxPoints(b, _points_to_snap_to, true,
}
}
}
}
}
SnapCandidatePoint const &p,
SnapConstraint const &c,
{
// Iterate through all nodes, find out which one is the closest to p, and snap to it!
_points_to_snap_to->insert(_points_to_snap_to->end(), unselected_nodes->begin(), unselected_nodes->end());
}
SnappedPoint s;
bool success = false;
for (std::vector<SnapCandidatePoint>::const_iterator k = _points_to_snap_to->begin(); k != _points_to_snap_to->end(); ++k) {
if (!c.isUndefined()) {
// We're snapping to nodes along a constraint only, so find out if this node
// is at the constraint, while allowing for a small margin
// The distance from the target point to its projection on the constraint
// is too large, so this point is not on the constraint. Skip it!
continue;
}
}
s = SnappedPoint(target_pt, p.getSourceType(), p.getSourceNum(), (*k).getTargetType(), dist, getSnapperTolerance(), getSnapperAlwaysSnap(), false, true, (*k).getTargetBBox());
success = true;
}
}
}
if (success) {
}
}
{
// Iterate through all nodes, find out which one is the closest to this guide, and snap to it!
_collectNodes(SNAPSOURCE_GUIDE, true);
if (_snapmanager->snapprefs.isTargetSnappable(SNAPTARGET_PATH, SNAPTARGET_PATH_INTERSECTION, SNAPTARGET_BBOX_EDGE, SNAPTARGET_PAGE_BORDER, SNAPTARGET_TEXT_BASELINE)) {
_collectPaths(p, SNAPSOURCE_GUIDE, true);
}
SnappedPoint s;
for (std::vector<SnapCandidatePoint>::const_iterator k = _points_to_snap_to->begin(); k != _points_to_snap_to->end(); ++k) {
// Project each node (*k) on the guide line (running through point p)
Geom::Coord dist2 = Geom::L2(p - p_proj); // distance from projection of node on the guide, to the mouse location
s = SnappedPoint(target_pt, SNAPSOURCE_GUIDE, 0, (*k).getTargetType(), dist, tol, getSnapperAlwaysSnap(), false, true, (*k).getTargetBBox());
}
}
}
/// @todo investigate why Geom::Point p is passed in but ignored.
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
bool p_is_other = (source_type & SNAPSOURCE_OTHERS_CATEGORY) || (source_type & SNAPSOURCE_DATUMS_CATEGORY);
bbox_type = !prefs_bbox ?
}
// Consider the page border for snapping
if (_snapmanager->snapprefs.isTargetSnappable(SNAPTARGET_PAGE_BORDER) && _snapmanager->snapprefs.isAnyCategorySnappable()) {
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 */
/* We might have a clone at hand, so make sure we get the root item */
if (use) {
} else {
}
//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)) {
// Snap to the text baseline
pv->push_back(layout->baseline() * root_item->i2dt_affine() * (*i).additional_affine * _snapmanager->getDesktop()->doc2dt());
}
}
} 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 (path) {
}
if (!very_complex_path && root_item && _snapmanager->snapprefs.isTargetSnappable(SNAPTARGET_PATH, SNAPTARGET_PATH_INTERSECTION)) {
if (shape) {
}/* else if (dynamic_cast<SPText *>(root_item) || dynamic_cast<SPFlowtext *>(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);
(*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.
}
}
}
}
}
//Add the item's bounding box to snap to
// 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) {
if (rect) {
}
}
}
}
}
}
}
SnapCandidatePoint const &p,
SPPath const *selected_path) const
{
// Now we can finally do the real snapping, using the paths collected above
bool const node_tool_active = _snapmanager->snapprefs.isTargetSnappable(SNAPTARGET_PATH, SNAPTARGET_PATH_INTERSECTION) && selected_path != NULL;
if (p.getSourceNum() <= 0) {
/* findCandidates() is used for snapping to both paths and nodes. It ignores the path that is
* currently being edited, because that path requires special care: when snapping to nodes
* only the unselected nodes of that path should be considered, and these will be passed on separately.
* This path must not be ignored however when snapping to the paths, so we add it here
* manually when applicable.
* */
if (node_tool_active) {
// TODO fix the function to be const correct:
if (curve) {
true,
true,
}
}
}
int num_path = 0; // _paths_to_snap_to contains multiple path_vectors, each containing multiple paths.
// num_path will count the paths, and will not be zeroed for each path_vector. It will
// continue counting
//dt->snapindicator->remove_debugging_points();
for (std::vector<SnapCandidatePath >::const_iterator it_p = _paths_to_snap_to->begin(); it_p != _paths_to_snap_to->end(); ++it_p) {
//if true then this pathvector it_pv is currently being edited in the node tool
for(Geom::PathVector::iterator it_pv = (it_p->path_vector)->begin(); it_pv != (it_p->path_vector)->end(); ++it_pv) {
// Find a nearest point for each curve within this path
// n curves will return n time values with 0 <= t <= 1
//std::cout << "#nearest points = " << anp.size() << " | p = " << p.getPoint() << std::endl;
// Now we will examine each of the nearest points, and determine whether it's within snapping range and if we should snap to it
unsigned int index = 0;
//dt->snapindicator->set_new_debugging_point(sp_doc*dt->doc2dt());
bool c1 = true;
bool c2 = true;
if (being_edited) {
/* If the path is being edited, then we should only snap though to stationary pieces of the path
* and not to the pieces that are being dragged around. This way we avoid
* self-snapping. For this we check whether the nodes at both ends of the current
* piece are unselected; if they are then this piece must be stationary
*/
/* Unfortunately, this might yield false positives for coincident nodes. Inkscape might therefore mistakenly
* snap to path segments that are not stationary. There are at least two possible ways to overcome this:
* - Linking the individual nodes of the SPPath we have here, to the nodes of the NodePath::SubPath class as being
* used in sp_nodepath_selected_nodes_move. This class has a member variable called "selected". For this the nodes
* should be in the exact same order for both classes, so we can index them
* - Replacing the SPPath being used here by the NodePath::SubPath class; but how?
*/
}
// std::cout << " dist -> " << dist << std::endl;
if (dist < getSnapperTolerance()) {
// Add the curve we have snapped to
// We currently only use the tangent when snapping guides, so only in this case we will
// actually calculate the tangent to avoid wasting CPU cycles
}
isr.curves.push_back(SnappedCurve(sp_dt, sp_tangent_dt, num_path, index, dist, getSnapperTolerance(), getSnapperAlwaysSnap(), false, curve, p.getSourceType(), p.getSourceNum(), it_p->target_type, it_p->target_bbox));
// For each curve that's within snapping range, we will now also search for tangential and perpendicular snaps
}
}
}
}
num_path++;
} // End of: for (Geom::PathVector::iterator ....)
}
}
}
/* Returns true if point is coincident with one of the unselected nodes */
bool Inkscape::ObjectSnapper::isUnselectedNode(Geom::Point const &point, std::vector<SnapCandidatePoint> const *unselected_nodes) const
{
if (unselected_nodes == NULL) {
return false;
}
if (unselected_nodes->size() == 0) {
return false;
}
for (std::vector<SnapCandidatePoint>::const_iterator i = unselected_nodes->begin(); i != unselected_nodes->end(); ++i) {
return true;
}
}
return false;
}
SnapCandidatePoint const &p,
SnapConstraint const &c,
{
// Now we can finally do the real snapping, using the paths collected above
if (!is_zero(direction_vector)) {
}
// The intersection point of the constraint line with any path, must lie within two points on the
// SnapConstraint: p_min_on_cl and p_max_on_cl. The distance between those points is twice the snapping tolerance
Geom::Point const p_min_on_cl = dt->dt2doc(p_proj_on_constraint - getSnapperTolerance() * direction_vector);
Geom::Point const p_max_on_cl = dt->dt2doc(p_proj_on_constraint + getSnapperTolerance() * direction_vector);
// PS: Because the paths we're about to snap to are all expressed relative to document coordinate system, we will have
// to convert the snapper coordinates from the desktop coordinates to document coordinates
if (c.isCircular()) {
} else {
}
// Find all intersections of the constrained path with the snap target candidates
for (std::vector<SnapCandidatePath >::const_iterator k = _paths_to_snap_to->begin(); k != _paths_to_snap_to->end(); ++k) {
if (k->path_vector && _allowSourceToSnapToTarget(p.getSourceType(), (*k).target_type, strict_snapping)) {
// Do the intersection math
// Convert the collected intersections to snapped points
for (std::vector<Geom::PVIntersection>::const_iterator i = inters.begin(); i != inters.end(); ++i) {
// Convert to desktop coordinates
// Construct a snapped point
SnappedPoint s = SnappedPoint(p_inters, p.getSourceType(), p.getSourceNum(), k->target_type, dist, getSnapperTolerance(), getSnapperAlwaysSnap(), true, false, k->target_bbox);
// Store the snapped point
}
}
}
}
}
SnapCandidatePoint const &p,
{
if (_snap_enabled == false || _snapmanager->snapprefs.isSourceSnappable(p.getSourceType()) == false || ThisSnapperMightSnap() == false) {
return;
}
/* Get a list of all the SPItems that we will try to snap to */
if (p.getSourceNum() <= 0) {
Geom::Rect const local_bbox_to_snap = bbox_to_snap ? *bbox_to_snap : Geom::Rect(p.getPoint(), p.getPoint());
_findCandidates(_snapmanager->getDocument()->getRoot(), it, p.getSourceNum() <= 0, local_bbox_to_snap, false, Geom::identity());
}
if (_snapmanager->snapprefs.isTargetSnappable(SNAPTARGET_PATH, SNAPTARGET_PATH_INTERSECTION, SNAPTARGET_BBOX_EDGE, SNAPTARGET_PAGE_BORDER, SNAPTARGET_TEXT_BASELINE)) {
if (n > 0) {
/* While editing a path in the node tool, findCandidates must ignore that path because
* of the node snapping requirements (i.e. only unselected nodes must be snapable).
* That path must not be ignored however when snapping to the paths, so we add it here
* manually when applicable
*/
} // else: *it->begin() might be a SPGroup, e.g. when editing a LPE of text that has been converted to a group of paths
// as reported in bug #356743. In that case we can just ignore it, i.e. not snap to this item
}
} else {
}
}
}
SnapCandidatePoint const &p,
SnapConstraint const &c,
{
if (_snap_enabled == false || _snapmanager->snapprefs.isSourceSnappable(p.getSourceType()) == false || ThisSnapperMightSnap() == false) {
return;
}
// project the mouse pointer onto the constraint. Only the projected point will be considered for snapping
/* Get a list of all the SPItems that we will try to snap to */
if (p.getSourceNum() <= 0) {
_findCandidates(_snapmanager->getDocument()->getRoot(), it, p.getSourceNum() <= 0, local_bbox_to_snap, false, Geom::identity());
}
// A constrained snap, is a snap in only one degree of freedom (specified by the constraint line).
// This is useful for example when scaling an object while maintaining a fixed aspect ratio. It's
// nodes are only allowed to move in one direction (i.e. in one degree of freedom).
if (_snapmanager->snapprefs.isTargetSnappable(SNAPTARGET_PATH, SNAPTARGET_PATH_INTERSECTION, SNAPTARGET_BBOX_EDGE, SNAPTARGET_PAGE_BORDER, SNAPTARGET_TEXT_BASELINE)) {
}
}
{
return true;
}
{
for (std::vector<SnapCandidatePath >::const_iterator k = _paths_to_snap_to->begin(); k != _paths_to_snap_to->end(); ++k) {
delete k->path_vector;
}
}
{
Geom::Rect const border_rect = Geom::Rect(Geom::Point(0,0), Geom::Point((_snapmanager->getDocument())->getWidth().value("px"),(_snapmanager->getDocument())->getHeight().value("px")));
return _getPathvFromRect(border_rect);
}
{
if (border_curve) {
return dummy;
} else {
return NULL;
}
}
{
points->push_back(SnapCandidatePoint(Geom::Point(0,0), SNAPSOURCE_UNDEFINED, SNAPTARGET_PAGE_CORNER));
points->push_back(SnapCandidatePoint(Geom::Point(0,h), SNAPSOURCE_UNDEFINED, SNAPTARGET_PAGE_CORNER));
points->push_back(SnapCandidatePoint(Geom::Point(w,h), SNAPSOURCE_UNDEFINED, SNAPTARGET_PAGE_CORNER));
points->push_back(SnapCandidatePoint(Geom::Point(w,0), SNAPSOURCE_UNDEFINED, SNAPTARGET_PAGE_CORNER));
}
bool const /*isTarget*/,
bool const includeCorners,
bool const includeLineMidpoints,
bool const includeObjectMidpoints)
{
if (bbox) {
// collect the corners of the bounding box
for ( unsigned k = 0 ; k < 4 ; k++ ) {
if (includeCorners) {
points->push_back(SnapCandidatePoint(bbox->corner(k), SNAPSOURCE_BBOX_CORNER, -1, SNAPTARGET_BBOX_CORNER, *bbox));
}
// optionally, collect the midpoints of the bounding box's edges too
if (includeLineMidpoints) {
points->push_back(SnapCandidatePoint((bbox->corner(k) + bbox->corner((k+1) % 4))/2, SNAPSOURCE_BBOX_EDGE_MIDPOINT, -1, SNAPTARGET_BBOX_EDGE_MIDPOINT, *bbox));
}
}
if (includeObjectMidpoints) {
points->push_back(SnapCandidatePoint(bbox->midpoint(), SNAPSOURCE_BBOX_MIDPOINT, -1, SNAPTARGET_BBOX_MIDPOINT, *bbox));
}
}
}
bool Inkscape::ObjectSnapper::_allowSourceToSnapToTarget(SnapSourceType source, SnapTargetType target, bool strict_snapping) const
{
bool allow_this_pair_to_snap = true;
if (strict_snapping) { // bounding boxes will not snap to nodes/paths and vice versa
allow_this_pair_to_snap = false;
}
}
return allow_this_pair_to_snap;
}
void Inkscape::ObjectSnapper::_snapPathsTangPerp(bool snap_tang, bool snap_perp, IntermSnapResults &isr, SnapCandidatePoint const &p, Geom::Curve const *curve, SPDesktop const *dt) const
{
// Here we will try to snap either tangentially or perpendicularly to a single path; for this we need to know where the origin is located of the line that is currently being rotated,
// or we need to know the vector of the guide which is currently being translated
// Now we will iterate over all the origins and vectors and see which of these will get use a tangential or perpendicular snap
for (std::vector<std::pair<Geom::Point, bool> >::const_iterator it_origin_or_vector = origins_and_vectors.begin(); it_origin_or_vector != origins_and_vectors.end(); ++it_origin_or_vector) {
Geom::Point origin_or_vector_doc = dt->dt2doc((*it_origin_or_vector).first); // "first" contains a Geom::Point, denoting either a point or vector
if ((*it_origin_or_vector).second) { // if "second" is true then "first" is a vector, otherwise it's a point
// So we have a vector, which tells us what tangential or perpendicular direction we're looking for
// When snapping to a point of a line segment that has a specific tangential or normal vector, then either all point
// along that line will be snapped to or no points at all will be snapped to. This is not very useful, so let's skip
// any line segments and lets only snap to higher order curves
continue;
}
// The vector is being treated as a point (relative to the origin), and has been translated to document coordinates accordingly
// We need however to make it a vector again, because also the origin has been transformed
}
if (snap_tang) { // Find all points that lead to a tangential snap
if ((*it_origin_or_vector).second) { // if "second" is true then "first" is a vector, otherwise it's a point
} else {
}
isr.points.push_back(SnappedPoint(point_dt, p.getSourceType(), p.getSourceNum(), SNAPTARGET_PATH_TANGENTIAL, dist, getSnapperTolerance(), getSnapperAlwaysSnap(), false, true));
}
}
if (snap_perp) { // Find all points that lead to a perpendicular snap
if ((*it_origin_or_vector).second) {
} else {
}
isr.points.push_back(SnappedPoint(point_dt, p.getSourceType(), p.getSourceNum(), SNAPTARGET_PATH_PERPENDICULAR, dist, getSnapperTolerance(), getSnapperAlwaysSnap(), false, true));
}
}
}
}
/*
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 :