Fix snapping during constrained translation, when only snapping the node closest to the mouse pointer

(bzr r7687)

1 files changed, 20 insertions, 15 deletions

diff --git a/src/snapped-point.cpp b/src/snapped-point.cpp
index 7e9a16a66..2d028c6d7 100644
--- a/src/snapped-point.cpp
+++ b/src/snapped-point.cpp
@@ -73,7 +73,7 @@ bool getClosestSP(std::list<Inkscape::SnappedPoint> &list, Inkscape::SnappedPoin
     bool success = false;
 
     for (std::list<Inkscape::SnappedPoint>::const_iterator i = list.begin(); i != list.end(); i++) {
-        if ((i == list.begin()) || (*i).getSnapDistance() < result.getSnapDistance()) {
+    	if ((i == list.begin()) || (*i).getSnapDistance() < result.getSnapDistance()) {
             result = *i;
             success = true;
         }
@@ -92,7 +92,10 @@ bool Inkscape::SnappedPoint::isOtherSnapBetter(Inkscape::SnappedPoint const &oth
     // there's more than one). It is not useful when trying to find the best snapped target point.
     // (both the snap distance and the pointer distance are measured in document pixels, not in screen pixels)
     if (weighted) {
-        // Weight factor: controls which node should be preferred for snapping, which is either
+
+    	Geom::Coord const dist_pointer_other = other_one.getPointerDistance();
+    	Geom::Coord const dist_pointer_this = getPointerDistance();
+    	// Weight factor: controls which node should be preferred for snapping, which is either
         // the node with the closest snap (w = 0), or the node closest to the mousepointer (w = 1)
         Inkscape::Preferences *prefs = Inkscape::Preferences::get();
         double w = prefs->getDoubleLimited("/options/snapweight/value", 0.5, 0, 1);
@@ -100,19 +103,21 @@ bool Inkscape::SnappedPoint::isOtherSnapBetter(Inkscape::SnappedPoint const &oth
             w = 1;
         }
         if (w > 0) {
-            // When accounting for the distance to the mouse pointer, then at least one of the snapped points should
-            // have that distance set. If not, then this is a bug. Either "weighted" must be set to false, or the
-            // mouse pointer distance must be set.
-            g_assert(getPointerDistance() != NR_HUGE || other_one.getPointerDistance() != NR_HUGE);
-            // The snap distance will always be smaller than the tolerance set for the snapper. The pointer distance can
-            // however be very large. To compare these in a fair way, we will have to normalize these metrics first
-            // The closest pointer distance will be normalized to 1.0; the other one will be > 1.0
-            // The snap distance will be normalized to 1.0 if it's equal to the snapper tolerance
-            double const norm_p = std::min(getPointerDistance(), other_one.getPointerDistance());
-            double const norm_t_other = std::min(50.0, other_one.getTolerance());
-            double const norm_t_this = std::min(50.0, getTolerance());
-            dist_other = w * other_one.getPointerDistance() / norm_p + (1-w) * dist_other / norm_t_other;
-            dist_this = w * getPointerDistance() / norm_p + (1-w) * dist_this / norm_t_this;
+        	if (!(w == 1 && dist_pointer_this == dist_pointer_other)) {
+        		// When accounting for the distance to the mouse pointer, then at least one of the snapped points should
+				// have that distance set. If not, then this is a bug. Either "weighted" must be set to false, or the
+				// mouse pointer distance must be set.
+				g_assert(dist_pointer_this != NR_HUGE || dist_pointer_other != NR_HUGE);
+				// The snap distance will always be smaller than the tolerance set for the snapper. The pointer distance can
+				// however be very large. To compare these in a fair way, we will have to normalize these metrics first
+				// The closest pointer distance will be normalized to 1.0; the other one will be > 1.0
+				// The snap distance will be normalized to 1.0 if it's equal to the snapper tolerance
+				double const norm_p = std::min(dist_pointer_this, dist_pointer_other);
+				double const norm_t_other = std::min(50.0, other_one.getTolerance());
+				double const norm_t_this = std::min(50.0, getTolerance());
+				dist_other = w * dist_pointer_other / norm_p + (1-w) * dist_other / norm_t_other;
+				dist_this = w * dist_pointer_this / norm_p + (1-w) * dist_this / norm_t_this;
+	    	}
         }
     }