Inkscape::SnappedPoint SnapManager::constrainedAngularSnap(Inkscape::SnapCandidatePoint const &p,
boost::optional<Geom::Point> const &p_ref,
Geom::Point const &o,
unsigned const snaps) const
{
Inkscape::SnappedPoint sp;
if (snaps > 0) { // 0 means no angular snapping
// p is at an arbitrary angle. Now we should snap this angle to specific increments.
// For this we'll calculate the closest two angles, one at each side of the current angle
Geom::Line y_axis(Geom::Point(0, 0), Geom::Point(0, 1));
Geom::Line p_line(o, p.getPoint());
double angle = Geom::angle_between(y_axis, p_line);
double angle_incr = M_PI / snaps;
double angle_offset = 0;
if (p_ref) {
Geom::Line p_line_ref(o, *p_ref);
angle_offset = Geom::angle_between(y_axis, p_line_ref);
}
double angle_ceil = round_to_upper_multiple_plus(angle, angle_incr, angle_offset);
double angle_floor = round_to_lower_multiple_plus(angle, angle_incr, angle_offset);
// We have two angles now. The constrained snapper will try each of them and return the closest
// Now do the snapping...
std::vector<Inkscape::Snapper::SnapConstraint> constraints;
constraints.push_back(Inkscape::Snapper::SnapConstraint(Geom::Line(o, angle_ceil - M_PI/2)));
constraints.push_back(Inkscape::Snapper::SnapConstraint(Geom::Line(o, angle_floor - M_PI/2)));
sp = multipleConstrainedSnaps(p, constraints); // Constraints will always be applied, even if we didn't snap
if (!sp.getSnapped()) { // If we haven't snapped then we only had the constraint applied;
sp.setTarget(Inkscape::SNAPTARGET_CONSTRAINED_ANGLE);
}
} else {
sp = freeSnap(p);
}
return sp;
}
Inkscape::SnappedPoint SnapManager::findBestSnap(Inkscape::SnapCandidatePoint const &p,
IntermSnapResults const &isr,
bool constrained,
bool allowOffScreen,
bool to_path_only) const
{
g_assert(_desktop != NULL);
/*
std::cout << "Type and number of snapped constraints: " << std::endl;
std::cout << " Points : " << isr.points.size() << std::endl;
std::cout << " Grid lines : " << isr.grid_lines.size()<< std::endl;
std::cout << " Guide lines : " << isr.guide_lines.size()<< std::endl;
std::cout << " Curves : " << isr.curves.size()<< std::endl;
*/
/*
// Display all snap candidates on the canvas
_desktop->snapindicator->remove_debugging_points();
for (std::list<Inkscape::SnappedPoint>::const_iterator i = isr.points.begin(); i != isr.points.end(); i++) {
_desktop->snapindicator->set_new_debugging_point((*i).getPoint());
}
for (std::list<Inkscape::SnappedCurve>::const_iterator i = isr.curves.begin(); i != isr.curves.end(); i++) {
_desktop->snapindicator->set_new_debugging_point((*i).getPoint());
}
for (std::list<Inkscape::SnappedLine>::const_iterator i = isr.grid_lines.begin(); i != isr.grid_lines.end(); i++) {
_desktop->snapindicator->set_new_debugging_point((*i).getPoint());
}
for (std::list<Inkscape::SnappedLine>::const_iterator i = isr.guide_lines.begin(); i != isr.guide_lines.end(); i++) {
_desktop->snapindicator->set_new_debugging_point((*i).getPoint());
}
*/
// Store all snappoints
std::list<Inkscape::SnappedPoint> sp_list;
// search for the closest snapped point
Inkscape::SnappedPoint closestPoint;
if (getClosestSP(isr.points, closestPoint)) {
sp_list.push_back(closestPoint);
}
// search for the closest snapped curve
Inkscape::SnappedCurve closestCurve;
// We might have collected the paths only to snap to their intersection, without the intention to snap to the paths themselves
// Therefore we explicitly check whether the paths should be considered as snap targets themselves
bool exclude_paths = !snapprefs.isTargetSnappable(Inkscape::SNAPTARGET_PATH);
if (getClosestCurve(isr.curves, closestCurve, exclude_paths)) {
sp_list.push_back(Inkscape::SnappedPoint(closestCurve));
}
// search for the closest snapped grid line
Inkscape::SnappedLine closestGridLine;
if (getClosestSL(isr.grid_lines, closestGridLine)) {
sp_list.push_back(Inkscape::SnappedPoint(closestGridLine));
}
// search for the closest snapped guide line
Inkscape::SnappedLine closestGuideLine;
if (getClosestSL(isr.guide_lines, closestGuideLine)) {
sp_list.push_back(Inkscape::SnappedPoint(closestGuideLine));
}
// When freely snapping to a grid/guide/path, only one degree of freedom is eliminated
// Therefore we will try get fully constrained by finding an intersection with another grid/guide/path
// When doing a constrained snap however, we're already at an intersection of the constrained line and
// the grid/guide/path we're snapping to. This snappoint is therefore fully constrained, so there's
// no need to look for additional intersections
if (!constrained) {
if (snapprefs.isTargetSnappable(Inkscape::SNAPTARGET_PATH_INTERSECTION)) {
// search for the closest snapped intersection of curves
Inkscape::SnappedPoint closestCurvesIntersection;
if (getClosestIntersectionCS(isr.curves, p.getPoint(), closestCurvesIntersection, _desktop->dt2doc())) {
closestCurvesIntersection.setSource(p.getSourceType());
sp_list.push_back(closestCurvesIntersection);
}
}
if (snapprefs.isTargetSnappable(Inkscape::SNAPTARGET_PATH_GUIDE_INTERSECTION)) {
// search for the closest snapped intersection of a guide with a curve
Inkscape::SnappedPoint closestCurveGuideIntersection;
if (getClosestIntersectionCL(isr.curves, isr.guide_lines, p.getPoint(), closestCurveGuideIntersection, _desktop->dt2doc())) {
closestCurveGuideIntersection.setSource(p.getSourceType());
sp_list.push_back(closestCurveGuideIntersection);
}
}
// search for the closest snapped intersection of grid lines
Inkscape::SnappedPoint closestGridPoint;
if (getClosestIntersectionSL(isr.grid_lines, closestGridPoint)) {
closestGridPoint.setSource(p.getSourceType());
closestGridPoint.setTarget(Inkscape::SNAPTARGET_GRID_INTERSECTION);
sp_list.push_back(closestGridPoint);
}
// search for the closest snapped intersection of guide lines
Inkscape::SnappedPoint closestGuidePoint;
if (getClosestIntersectionSL(isr.guide_lines, closestGuidePoint)) {
closestGuidePoint.setSource(p.getSourceType());
closestGuidePoint.setTarget(Inkscape::SNAPTARGET_GUIDE_INTERSECTION);
sp_list.push_back(closestGuidePoint);
}
// search for the closest snapped intersection of grid with guide lines
if (snapprefs.isTargetSnappable(Inkscape::SNAPTARGET_GRID_GUIDE_INTERSECTION)) {
Inkscape::SnappedPoint closestGridGuidePoint;
if (getClosestIntersectionSL(isr.grid_lines, isr.guide_lines, closestGridGuidePoint)) {
closestGridGuidePoint.setSource(p.getSourceType());
closestGridGuidePoint.setTarget(Inkscape::SNAPTARGET_GRID_GUIDE_INTERSECTION);
sp_list.push_back(closestGridGuidePoint);
}
}
}
// Filter out all snap targets that do NOT include a path; this is useful when we try to insert
// a node in a path (on doubleclick in the node tool). We don't want to change the shape of the
// path, so the snapped point must be on a path, and not e.g. on a grid intersection
if (to_path_only) {
std::list<Inkscape::SnappedPoint>::iterator i = sp_list.begin();
while (i != sp_list.end()) {
Inkscape::SnapTargetType t = (*i).getTarget();
if (t == Inkscape::SNAPTARGET_LINE_MIDPOINT ||
t == Inkscape::SNAPTARGET_PATH ||
t == Inkscape::SNAPTARGET_PATH_PERPENDICULAR ||
t == Inkscape::SNAPTARGET_PATH_TANGENTIAL ||
t == Inkscape::SNAPTARGET_PATH_INTERSECTION ||
t == Inkscape::SNAPTARGET_PATH_GUIDE_INTERSECTION ||
t == Inkscape::SNAPTARGET_PATH_CLIP ||
t == Inkscape::SNAPTARGET_PATH_MASK ||
t == Inkscape::SNAPTARGET_ELLIPSE_QUADRANT_POINT) {
++i;
} else {
i = sp_list.erase(i);
}
}
}
// now let's see which snapped point gets a thumbs up
Inkscape::SnappedPoint bestSnappedPoint(p.getPoint());
// std::cout << "Finding the best snap..." << std::endl;
for (std::list<Inkscape::SnappedPoint>::const_iterator i = sp_list.begin(); i != sp_list.end(); ++i) {
// std::cout << "sp = " << (*i).getPoint() << " | source = " << (*i).getSource() << " | target = " << (*i).getTarget();
bool onScreen = _desktop->get_display_area().contains((*i).getPoint());
if (onScreen || allowOffScreen) { // Only snap to points which are not off the screen
if ((*i).getSnapDistance() <= (*i).getTolerance()) { // Only snap to points within snapping range
// if it's the first point, or if it is closer than the best snapped point so far
if (i == sp_list.begin() || bestSnappedPoint.isOtherSnapBetter(*i, false)) {
// then prefer this point over the previous one
bestSnappedPoint = *i;
}
}
}
// std::cout << std::endl;
}
// Update the snap indicator, if requested
if (_snapindicator) {
if (bestSnappedPoint.getSnapped()) {
_desktop->snapindicator->set_new_snaptarget(bestSnappedPoint);
} else {
_desktop->snapindicator->remove_snaptarget();
}
}
// std::cout << "findBestSnap = " << bestSnappedPoint.getPoint() << " | dist = " << bestSnappedPoint.getSnapDistance() << std::endl;
return bestSnappedPoint;
}
