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-rw-r--r--src/snap.cpp146
1 files changed, 96 insertions, 50 deletions
diff --git a/src/snap.cpp b/src/snap.cpp
index 452a1e496..ca7efde73 100644
--- a/src/snap.cpp
+++ b/src/snap.cpp
@@ -21,7 +21,7 @@
#include <libnr/nr-scale-ops.h>
#include <libnr/nr-values.h>
-SnapManager::SnapManager(SPNamedView* v) : grid(v, 0), guide(v, 0), object(v, 0)
+SnapManager::SnapManager(SPNamedView const *v) : grid(v, 0), guide(v, 0), object(v, 0)
{
}
@@ -85,7 +85,7 @@ Inkscape::SnappedPoint SnapManager::freeSnap(Inkscape::Snapper::PointType t,
Inkscape::SnappedPoint SnapManager::constrainedSnap(Inkscape::Snapper::PointType t,
NR::Point const &p,
- NR::Point const &c,
+ Inkscape::Snapper::ConstraintLine const &c,
SPItem const *it) const
{
std::list<SPItem const *> lit;
@@ -96,7 +96,7 @@ Inkscape::SnappedPoint SnapManager::constrainedSnap(Inkscape::Snapper::PointType
Inkscape::SnappedPoint SnapManager::constrainedSnap(Inkscape::Snapper::PointType t,
NR::Point const &p,
- NR::Point const &c,
+ Inkscape::Snapper::ConstraintLine const &c,
std::list<SPItem const *> const &it) const
{
Inkscape::SnappedPoint r(p, NR_HUGE);
@@ -113,74 +113,120 @@ Inkscape::SnappedPoint SnapManager::constrainedSnap(Inkscape::Snapper::PointType
}
-std::pair<NR::Point, bool> SnapManager::freeSnapTranslation(Inkscape::Snapper::PointType t,
- std::vector<NR::Point> const &p,
- std::list<SPItem const *> const &it,
- NR::Point const &tr) const
+std::pair<NR::Point, bool> SnapManager::_snapTransformed(Inkscape::Snapper::PointType type,
+ std::vector<NR::Point> const &points,
+ std::list<SPItem const *> const &ignore,
+ bool constrained,
+ Inkscape::Snapper::ConstraintLine const &constraint,
+ Transformation transformation_type,
+ NR::Point const &transformation,
+ NR::Point const &origin) const
{
+ /* We have a list of points, which we are proposing to transform in some way. We need to see
+ ** if any of these points, when transformed, snap to anything. If they do, we return the
+ ** appropriate transformation with `true'; otherwise we return the original scale with `false'.
+ */
+
+ /* Quick check to see if we have any snappers that are enabled */
if (willSnapSomething() == false) {
- return std::make_pair(tr, false);
+ return std::make_pair(transformation, false);
}
- NR::Point best_translation = tr;
- NR::Coord best_distance = NR_HUGE;
-
- for (std::vector<NR::Point>::const_iterator i = p.begin(); i != p.end(); i++) {
- /* Translated version of this point */
- NR::Point const q = *i + tr;
+ /* The current best transformation */
+ NR::Point best_transformation = transformation;
+ /* The current best metric for the best transformation; lower is better, NR_HUGE
+ ** means that we haven't snapped anything.
+ */
+ NR::Coord best_metric = NR_HUGE;
+
+ for (std::vector<NR::Point>::const_iterator i = points.begin(); i != points.end(); i++) {
+
+ /* Work out the transformed version of this point */
+ NR::Point transformed;
+ switch (transformation_type) {
+ case TRANSLATION:
+ transformed = *i + transformation;
+ break;
+ case SCALE:
+ transformed = ((*i - origin) * NR::scale(transformation[NR::X], transformation[NR::Y])) + origin;
+ break;
+ default:
+ g_assert_not_reached();
+ }
+
/* Snap it */
- Inkscape::SnappedPoint s = freeSnap(t, q, it);
- if (s.getDistance() < NR_HUGE) {
- /* Resulting translation */
- NR::Point const r = s.getPoint() - *i;
- NR::Coord const d = NR::L2(r);
- if (d < best_distance) {
- best_distance = d;
- best_translation = r;
+ Inkscape::SnappedPoint const snapped = constrained ?
+ constrainedSnap(type, transformed, constraint, ignore) : freeSnap(type, transformed, ignore);
+
+ if (snapped.getDistance() < NR_HUGE) {
+ /* We snapped. Find the transformation that describes where the snapped point has
+ ** ended up, and also the metric for this transformation.
+ */
+ NR::Point result;
+ NR::Coord metric;
+ switch (transformation_type) {
+ case TRANSLATION:
+ result = snapped.getPoint() - *i;
+ metric = NR::L2(result);
+ break;
+ case SCALE:
+ NR::Point const a = (snapped.getPoint() - origin);
+ NR::Point const b = (*i - origin);
+ result = NR::Point(a[NR::X] / b[NR::X], a[NR::Y] / b[NR::Y]);
+ metric = std::abs(NR::L2(result) - NR::L2(transformation));
+ break;
+ }
+
+ /* Note it if it's the best so far */
+ if (metric < best_metric && metric != 0) {
+ best_transformation = result;
+ best_metric = metric;
}
}
}
+
+ return std::make_pair(best_transformation, best_metric < NR_HUGE);
+}
+
- return std::make_pair(best_translation, best_distance < NR_HUGE);
+std::pair<NR::Point, bool> SnapManager::freeSnapTranslation(Inkscape::Snapper::PointType t,
+ std::vector<NR::Point> const &p,
+ std::list<SPItem const *> const &it,
+ NR::Point const &tr) const
+{
+ return _snapTransformed(t, p, it, false, NR::Point(), TRANSLATION, tr, NR::Point(0, 0));
}
std::pair<NR::Point, bool> SnapManager::constrainedSnapTranslation(Inkscape::Snapper::PointType t,
std::vector<NR::Point> const &p,
- NR::Point const &c,
std::list<SPItem const *> const &it,
+ Inkscape::Snapper::ConstraintLine const &c,
NR::Point const &tr) const
{
- if (willSnapSomething() == false) {
- return std::make_pair(tr, false);
- }
-
- NR::Point best_translation = tr;
- NR::Coord best_distance = NR_HUGE;
-
- for (std::vector<NR::Point>::const_iterator i = p.begin(); i != p.end(); i++) {
- /* Translated version of this point */
- NR::Point const q = *i + tr;
- /* Snap it */
- Inkscape::SnappedPoint s = constrainedSnap(t, q, c, it);
- if (s.getDistance() < NR_HUGE) {
- /* Resulting translation */
- NR::Point const r = s.getPoint() - *i;
- NR::Coord const d = NR::L2(r);
- if (d < best_distance) {
- best_distance = d;
- best_translation = r;
- }
- }
- }
-
- return std::make_pair(best_translation, best_distance < NR_HUGE);
+ return _snapTransformed(t, p, it, true, c, TRANSLATION, tr, NR::Point(0, 0));
}
+std::pair<NR::scale, bool> SnapManager::freeSnapScale(Inkscape::Snapper::PointType t,
+ std::vector<NR::Point> const &p,
+ std::list<SPItem const *> const &it,
+ NR::scale const &s,
+ NR::Point const &o) const
+{
+ return _snapTransformed(t, p, it, false, NR::Point(0, 0), SCALE, NR::Point(s[NR::X], s[NR::Y]), o);
+}
-
+std::pair<NR::scale, bool> SnapManager::constrainedSnapScale(Inkscape::Snapper::PointType t,
+ std::vector<NR::Point> const &p,
+ std::list<SPItem const *> const &it,
+ Inkscape::Snapper::ConstraintLine const &c,
+ NR::scale const &s,
+ NR::Point const &o) const
+{
+ return _snapTransformed(t, p, it, true, c, SCALE, NR::Point(s[NR::X], s[NR::Y]), o);
+}
/// Minimal distance to norm before point is considered for snap.
@@ -292,7 +338,7 @@ std::pair<double, bool> namedview_vector_snap_list(SPNamedView const *nv, Inksca
return std::make_pair(ratio, dist < NR_HUGE);
}
-
+
/**
* Try to snap points in \a p after they have been scaled by \a sx with respect to
generated by cgit v1.2.3 (git 2.25.1) at 2026-05-19 06:18:39 +0000