#include "libnr/n-art-bpath.h"

#include "libnr/nr-path.h"

#include "libnr/nr-rect-ops.h"

#include "libnr/nr-point-fns.h"

#include "live_effects/n-art-bpath-2geom.h"

#include "2geom/path-intersection.h"

#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 "display/curve.h"

#include "desktop.h"

#include "inkscape.h"

#include "prefs-utils.h"

#include "sp-text.h"

#include "sp-flowtext.h"

#include "text-editing.h"

Inkscape::ObjectSnapper::ObjectSnapper(SPNamedView const *nv, NR::Coord const d)

: Snapper(nv, d), _snap_to_itemnode(true), _snap_to_itempath(true),

_snap_to_bboxnode(true), _snap_to_bboxpath(true), _strict_snapping(true),

_include_item_center(false)

{

_candidates = new std::vector<SPItem*>;

_points_to_snap_to = new std::vector<NR::Point>;

_bpaths_to_snap_to = new std::vector<NArtBpath*>;

_paths_to_snap_to = new std::vector<Path*>;

}

Inkscape::ObjectSnapper::~ObjectSnapper()

{

_candidates->clear(); //Don't delete the candidates themselves, as these are not ours!

delete _candidates;

_points_to_snap_to->clear();

delete _points_to_snap_to;

_clear_paths();

delete _paths_to_snap_to;

delete _bpaths_to_snap_to;

}

void Inkscape::ObjectSnapper::_findCandidates(SPObject* r,

std::list<SPItem const *> const &it,

bool const &first_point,

std::vector<NR::Point> &points_to_snap,

DimensionToSnap const snap_dim) const

{

if (ThisSnapperMightSnap()) {

SPDesktop const *desktop = SP_ACTIVE_DESKTOP;

if (first_point) {

_candidates->clear();

}

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(o, it, false, points_to_snap, snap_dim);

} else {

// Now let's see if any of the snapping points is within

// snapping range of this object

NR::Maybe<NR::Rect> b = sp_item_bbox_desktop(SP_ITEM(o));

if (b) {

for (std::vector<NR::Point>::const_iterator i = points_to_snap.begin(); i != points_to_snap.end(); i++) {

NR::Point b_min = b->min();

NR::Point b_max = b->max();

NR::Coord t = getSnapperTolerance();

bool withinX = ((*i)[NR::X] >= b_min[NR::X] - t) && ((*i)[NR::X] <= b_max[NR::X] + t);

bool withinY = ((*i)[NR::Y] >= b_min[NR::Y] - t) && ((*i)[NR::Y] <= b_max[NR::Y] + t);

bool c1 = snap_dim == GUIDE_TRANSL_SNAP_X && withinX;

bool c2 = snap_dim == GUIDE_TRANSL_SNAP_Y && withinY;

bool c3 = snap_dim == TRANSL_SNAP_XY && withinX && withinY;

// For an angled guide at e.g 45 deg., the bbox is very large and might even span

// the full desktop. Therefore we will simply return _any_ candidate, without looking at

// the bbox and the snapping distance.

bool c4 = snap_dim == ANGLED_GUIDE_TRANSL_SNAP || snap_dim == ANGLED_GUIDE_ROT_SNAP;

if ( c1 || c2 || c3 || c4) {

//We've found a point that is within snapping range

//of this object, so record it as a candidate

_candidates->push_back(SP_ITEM(o));

break;

}

}

}

}

}

}

}

}

}

void Inkscape::ObjectSnapper::_collectNodes(Inkscape::Snapper::PointType 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 & Inkscape::Snapper::SNAPPOINT_NODE;

bool p_is_a_bbox = t & Inkscape::Snapper::SNAPPOINT_BBOX;

bool p_is_a_guide = t & Inkscape::Snapper::SNAPPOINT_GUIDE;

// A point considered for snapping should be either a node, a bbox corner or a guide. Pick only ONE!

g_assert(!(p_is_a_node && p_is_a_bbox || p_is_a_bbox && p_is_a_guide || p_is_a_node && p_is_a_guide));

if (_snap_to_bboxnode) {

gchar const *prefs_bbox = prefs_get_string_attribute("tools.select", "bounding_box");

bbox_type = (prefs_bbox != NULL && strcmp(prefs_bbox, "geometric")==0)? SPItem::GEOMETRIC_BBOX : SPItem::APPROXIMATE_BBOX;

}

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

//NR::Matrix i2doc(NR::identity());

SPItem *root_item = *i;

if (SP_IS_USE(*i)) {

root_item = sp_use_root(SP_USE(*i));

}

//Collect all nodes so we can snap to them

if (_snap_to_itemnode) {

if (!(_strict_snapping && !p_is_a_node) || p_is_a_guide) {

sp_item_snappoints(root_item, _include_item_center, SnapPointsIter(*_points_to_snap_to));

}

}

//Collect the bounding box's corners so we can snap to them

if (_snap_to_bboxnode) {

if (!(_strict_snapping && !p_is_a_bbox) || p_is_a_guide) {

NR::Maybe<NR::Rect> b = sp_item_bbox_desktop(root_item, bbox_type);

if (b) {

for ( unsigned k = 0 ; k < 4 ; k++ ) {

_points_to_snap_to->push_back(b->corner(k));

}

}

}

}

}

}

}

void Inkscape::ObjectSnapper::_snapNodes(SnappedConstraints &sc,

Inkscape::Snapper::PointType const &t,

NR::Point const &p,

bool const &first_point) const

{

// Iterate through all nodes, find out which one is the closest to p, and snap to it!

_collectNodes(t, first_point);

SnappedPoint s;

bool success = false;

for (std::vector<NR::Point>::const_iterator k = _points_to_snap_to->begin(); k != _points_to_snap_to->end(); k++) {

NR::Coord dist = NR::L2(*k - p);

if (dist < getSnapperTolerance() && dist < s.getDistance()) {

s = SnappedPoint(*k, dist, getSnapperTolerance(), getSnapperAlwaysSnap());

success = true;

}

}

if (success) {

sc.points.push_back(s);

}

}

void Inkscape::ObjectSnapper::_snapTranslatingGuideToNodes(SnappedConstraints &sc,

Inkscape::Snapper::PointType const &t,

NR::Point const &p,

NR::Point const &guide_normal) const

{

// Iterate through all nodes, find out which one is the closest to this guide, and snap to it!

_collectNodes(t, true);

SnappedPoint s;

bool success = false;

for (std::vector<NR::Point>::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)

NR::Point p_proj = project_on_linesegment(*k, p, p + NR::rot90(guide_normal));

NR::Coord dist = NR::L2(*k - p_proj);

if (dist < getSnapperTolerance() && dist < s.getDistance()) {

s = SnappedPoint(*k, dist, getSnapperTolerance(), getSnapperAlwaysSnap());

success = true;

}

}

if (success) {

sc.points.push_back(s);

}

}

void Inkscape::ObjectSnapper::_collectPaths(Inkscape::Snapper::PointType const &t,

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 = t & Inkscape::Snapper::SNAPPOINT_NODE;

if (_snap_to_bboxpath) {

gchar const *prefs_bbox = prefs_get_string_attribute("tools.select", "bounding_box");

bbox_type = (prefs_bbox != NULL && strcmp(prefs_bbox, "geometric")==0)? SPItem::GEOMETRIC_BBOX : SPItem::APPROXIMATE_BBOX;

}

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

/* Transform the requested snap point to this item's coordinates */

NR::Matrix i2doc(NR::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)) {

i2doc = sp_use_get_root_transform(SP_USE(*i));

root_item = sp_use_root(SP_USE(*i));

} else {

i2doc = sp_item_i2doc_affine(*i);

root_item = *i;

}

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

//Add the item's path to snap to

if (_snap_to_itempath) {

if (!(_strict_snapping && !p_is_a_node)) {

// Snapping to the path of characters is very cool, but for a large

// chunk of text this will take ages! So limit snapping to text paths

// containing max. 240 characters. Snapping the bbox will not be affected

bool very_lenghty_prose = false;

if (SP_IS_TEXT(root_item) || SP_IS_FLOWTEXT(root_item)) {

very_lenghty_prose = sp_text_get_length(SP_TEXT(root_item)) > 240;

}

// On my AMD 3000+, the snapping lag becomes annoying at approx. 240 chars

// which corresponds to a lag of 500 msec. This is for snapping a rect

// to a single line of text.

// Snapping for example to a traced bitmap is also 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_nodes_in_path(SP_PATH(root_item)) > 500;

}

if (!very_lenghty_prose && !very_complex_path) {

SPCurve *curve = curve_for_item(root_item);

if (curve) {

NArtBpath *bpath = bpath_for_curve(root_item, curve, true, true);

_bpaths_to_snap_to->push_back(bpath);

// Because in bpath_for_curve we set doTransformation to true, we

// will get a dupe of the path, which must be freed at some point

sp_curve_unref(curve);

}

}

}

}

//Add the item's bounding box to snap to

if (_snap_to_bboxpath) {

if (!(_strict_snapping && p_is_a_node)) {

NRRect rect;

sp_item_invoke_bbox(root_item, &rect, i2doc, TRUE, bbox_type);

NArtBpath *bpath = nr_path_from_rect(rect);

_bpaths_to_snap_to->push_back(bpath);

}

}

}

}

}

void Inkscape::ObjectSnapper::_snapPaths(SnappedConstraints &sc,

Inkscape::Snapper::PointType const &t,

NR::Point const &p,

bool const &first_point) const

{

_collectPaths(t, first_point);

// Now we can finally do the real snapping, using the paths collected above

SnappedPoint s;

bool success = false;

/* FIXME: this seems like a hack. Perhaps Snappers should be

SPDesktop const *desktop = SP_ACTIVE_DESKTOP;

NR::Point const p_doc = desktop->dt2doc(p);

// Convert all bpaths to Paths, because here we really must have Paths

// (whereas in _snapPathsConstrained we will use the original bpaths)

if (first_point) {

for (std::vector<NArtBpath*>::const_iterator k = _bpaths_to_snap_to->begin(); k != _bpaths_to_snap_to->end(); k++) {

Path *path = bpath_to_Path(*k);

if (path) {

path->ConvertWithBackData(0.01); //This is extremely time consuming!

_paths_to_snap_to->push_back(path);

}

}

}

for (std::vector<Path*>::const_iterator k = _paths_to_snap_to->begin(); k != _paths_to_snap_to->end(); k++) {

if (*k) {

/* Look for the nearest position on this SPItem to our snap point */

NR::Maybe<Path::cut_position> const o = get_nearest_position_on_Path(*k, p_doc);

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(*k, o->piece, o->t);

NR::Point const o_dt = desktop->doc2dt(o_it);

NR::Coord const dist = NR::L2(o_dt - p);

if (dist < getSnapperTolerance()) {

// if we snap to a straight line segment (within a path), then return this line segment

if ((*k)->IsLineSegment(o->piece)) {

NR::Point start_point;

NR::Point end_point;

(*k)->PointAt(o->piece, 0, start_point);

(*k)->PointAt(o->piece, 1, end_point);

start_point = desktop->doc2dt(start_point);

end_point = desktop->doc2dt(end_point);

sc.lines.push_back(Inkscape::SnappedLineSegment(o_dt, dist, getSnapperTolerance(), getSnapperAlwaysSnap(), start_point, end_point));

} else {

// for segments other than straight lines of a path, we'll return just the closest snapped point

if (dist < s.getDistance()) {

s = SnappedPoint(o_dt, dist, getSnapperTolerance(), getSnapperAlwaysSnap());

success = true;

}

}

}

}

}

}

if (success) {

sc.points.push_back(s);

}

}

void Inkscape::ObjectSnapper::_snapPathsConstrained(SnappedConstraints &sc,

Inkscape::Snapper::PointType const &t,

NR::Point const &p,

bool const &first_point,

ConstraintLine const &c) const

{

_collectPaths(t, first_point);

// Now we can finally do the real snapping, using the paths collected above

/* FIXME: this seems like a hack. Perhaps Snappers should be

SPDesktop const *desktop = SP_ACTIVE_DESKTOP;

NR::Point const p_doc = desktop->dt2doc(p);

NR::Point direction_vector = c.getDirection();

if (!is_zero(direction_vector)) {

direction_vector = NR::unit_vector(direction_vector);

}

NR::Point const p1_on_cl = c.hasPoint() ? c.getPoint() : p;

NR::Point const p2_on_cl = p1_on_cl + direction_vector;

// The intersection point of the constraint line with any path,

// must lie within two points on the constraintline: p_min_on_cl and p_max_on_cl

// The distance between those points is twice the snapping tolerance

NR::Point const p_proj_on_cl = project_on_linesegment(p, p1_on_cl, p2_on_cl);

NR::Point const p_min_on_cl = desktop->dt2doc(p_proj_on_cl - getSnapperTolerance() * direction_vector);

NR::Point const p_max_on_cl = desktop->dt2doc(p_proj_on_cl + getSnapperTolerance() * direction_vector);

Geom::Path cl;

cl.start(p_min_on_cl.to_2geom());

cl.appendNew<Geom::LineSegment>(p_max_on_cl.to_2geom());

for (std::vector<NArtBpath*>::const_iterator k = _bpaths_to_snap_to->begin(); k != _bpaths_to_snap_to->end(); k++) {

if (*k) {

// convert a Path object (see src/livarot/Path.h) to a 2geom's path object (see 2geom/path.h)

// TODO: (Diederik) Only do this once for the first point, needs some storage of pointers in a member variable

std::vector<Geom::Path> path_2geom = BPath_to_2GeomPath(*k);

for (std::vector<Geom::Path>::const_iterator l = path_2geom.begin(); l != path_2geom.end(); l++) {

Geom::SimpleCrosser sxr;

Geom::Crossings crossings = sxr.crossings(*l, cl);

for (std::vector<Geom::Crossing>::const_iterator m = crossings.begin(); m != crossings.end(); m++) {

// Reconstruct the point of intersection

NR::Point p_inters = p_min_on_cl + ((*m).tb) * (p_max_on_cl - p_min_on_cl);

// When it's within snapping range, then return it

// (within snapping range == between p_min_on_cl and p_max_on_cl == 0 < tb < 1)

if ((*m).tb >= 0 && (*m).tb <= 1 ) {

NR::Coord dist = NR::L2(desktop->dt2doc(p_proj_on_cl) - p_inters);

SnappedPoint s(desktop->doc2dt(p_inters), dist, getSnapperTolerance(), getSnapperAlwaysSnap());

sc.points.push_back(s);

}

}

}

}

}

}

void Inkscape::ObjectSnapper::_doFreeSnap(SnappedConstraints &sc,

Inkscape::Snapper::PointType const &t,

NR::Point const &p,

bool const &first_point,

std::vector<NR::Point> &points_to_snap,

std::list<SPItem const *> const &it) const

{

if ( NULL == _named_view ) {

return;

}

/* Get a list of all the SPItems that we will try to snap to */

if (first_point) {

_findCandidates(sp_document_root(_named_view->document), it, first_point, points_to_snap, TRANSL_SNAP_XY);

}

if (_snap_to_itemnode || _snap_to_bboxnode) {

_snapNodes(sc, t, p, first_point);

}

if (_snap_to_itempath || _snap_to_bboxpath) {

_snapPaths(sc, t, p, first_point);

}

}

void Inkscape::ObjectSnapper::_doConstrainedSnap( SnappedConstraints &sc,

Inkscape::Snapper::PointType const &t,

NR::Point const &p,

bool const &first_point,

std::vector<NR::Point> &points_to_snap,

ConstraintLine const &c,

std::list<SPItem const *> const &it) const

{

if ( NULL == _named_view ) {

return;

}

/* Get a list of all the SPItems that we will try to snap to */

if (first_point) {

_findCandidates(sp_document_root(_named_view->document), it, first_point, points_to_snap, TRANSL_SNAP_XY);

}

// A constrained snap, is a snap in only one degree of freedom (specified by the constraint line).

// This is usefull 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).

// When snapping to objects, we either snap to their nodes or their paths. It is however very

// unlikely that any node will be exactly at the constrained line, so for a constrained snap

// to objects we will only consider the object's paths. Beside, the nodes will be at these paths,

// so we will more or less snap to them anyhow.

if (_snap_to_itempath || _snap_to_bboxpath) {

_snapPathsConstrained(sc, t, p, first_point, c);

}

}

void Inkscape::ObjectSnapper::guideSnap(SnappedConstraints &sc,

NR::Point const &p,

NR::Point const &guide_normal) const

{

if ( NULL == _named_view ) {

return;

}

/* Get a list of all the SPItems that we will try to snap to */

std::vector<SPItem*> cand;

std::list<SPItem const *> const it; //just an empty list

std::vector<NR::Point> points_to_snap;

points_to_snap.push_back(p);

// This method is used to snap a guide to nodes, while dragging the guide around

DimensionToSnap snap_dim;

if (guide_normal == component_vectors[NR::Y]) {

snap_dim = GUIDE_TRANSL_SNAP_Y;

} else if (guide_normal == component_vectors[NR::X]) {

snap_dim = GUIDE_TRANSL_SNAP_X;

} else {

snap_dim = ANGLED_GUIDE_TRANSL_SNAP;

}

// We don't support ANGLED_GUIDE_ROT_SNAP yet.

// It would be cool to allow the user to rotate a guide by dragging it, instead of

// only translating it. (For example when CTRL is pressed). We will need an UI part

// for that first; and some important usability choices need to be made:

// E.g. which point should be used for pivoting? A previously snapped point,

// or a transformation center (which can be moved after clicking for the

// second time on an object; but should this point then be constrained to the

// line, or can it be located anywhere?)

_findCandidates(sp_document_root(_named_view->document), it, true, points_to_snap, snap_dim);

_snapTranslatingGuideToNodes(sc, Inkscape::Snapper::SNAPPOINT_GUIDE, p, guide_normal);

// _snapRotatingGuideToNodes has not been implemented yet.

}

bool Inkscape::ObjectSnapper::ThisSnapperMightSnap() const

{

bool snap_to_something = _snap_to_itempath || _snap_to_itemnode || _snap_to_bboxpath || _snap_to_bboxnode;

return (_snap_enabled && _snap_from != 0 && snap_to_something);

}

void Inkscape::ObjectSnapper::_clear_paths() const

{

for (std::vector<NArtBpath*>::const_iterator k = _bpaths_to_snap_to->begin(); k != _bpaths_to_snap_to->end(); k++) {

g_free(*k);

}

_bpaths_to_snap_to->clear();

for (std::vector<Path*>::const_iterator k = _paths_to_snap_to->begin(); k != _paths_to_snap_to->end(); k++) {

delete *k;

}

_paths_to_snap_to->clear();

}