Improve snapper performance (mainly in by editting WillSnapSomething())

(bzr r2917)

7 files changed, 52 insertions, 33 deletions

diff --git a/src/guide-snapper.cpp b/src/guide-snapper.cpp
index a05ecd3e6..9fd13705c 100644
--- a/src/guide-snapper.cpp
+++ b/src/guide-snapper.cpp
@@ -26,7 +26,7 @@ Inkscape::GuideSnapper::LineList Inkscape::GuideSnapper::_getSnapLines(NR::Point
 {
     LineList s;
 
-    if ( NULL == _named_view ) {
+    if ( NULL == _named_view || willSnapSomething() == false) {
         return s;
     }
 
@@ -44,6 +44,14 @@ Inkscape::GuideSnapper::LineList Inkscape::GuideSnapper::_getSnapLines(NR::Point
     return s;
 }
 
+/**
+ *  \return true if this Snapper will snap at least one kind of point.
+ */
+bool Inkscape::GuideSnapper::willSnapSomething() const
+{
+    return _named_view == NULL ? false : (_enabled && _snap_to != 0 && _named_view->showguides);
+}
+
 /*
   Local Variables:
   mode:c++
diff --git a/src/guide-snapper.h b/src/guide-snapper.h
index 37e3e3006..37ea08701 100644
--- a/src/guide-snapper.h
+++ b/src/guide-snapper.h
@@ -29,6 +29,8 @@ class GuideSnapper : public LineSnapper
 {
 public:
     GuideSnapper(SPNamedView const *nv, NR::Coord const d);
+    
+    bool willSnapSomething() const;
 
 private:
     LineList _getSnapLines(NR::Point const &p) const;
diff --git a/src/object-snapper.cpp b/src/object-snapper.cpp
index 5492fc439..e39d398b1 100644
--- a/src/object-snapper.cpp
+++ b/src/object-snapper.cpp
@@ -38,28 +38,30 @@ void Inkscape::ObjectSnapper::_findCandidates(std::list<SPItem*>& c,
                                               std::list<SPItem const *> const &it,
                                               NR::Point const &p) const
 {
-    SPDesktop const *desktop = SP_ACTIVE_DESKTOP;
-    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(c, o, it, p);
-                } else {
-                    NR::Maybe<NR::Rect> b = sp_item_bbox_desktop(SP_ITEM(o));
-                    if ( b && NR::expand(*b, -getDistance()).contains(p) ) {
-                        c.push_back(SP_ITEM(o));
+    if (willSnapSomething()) {    
+        SPDesktop const *desktop = SP_ACTIVE_DESKTOP;
+        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(c, o, it, p);
+                    } else {
+                        NR::Maybe<NR::Rect> b = sp_item_bbox_desktop(SP_ITEM(o));
+                        if ( b && NR::expand(*b, -getDistance()).contains(p) ) {
+                            c.push_back(SP_ITEM(o));
+                        }
                     }
                 }
+    
             }
-
         }
     }
 }
@@ -181,6 +183,15 @@ Inkscape::SnappedPoint Inkscape::ObjectSnapper::_doConstrainedSnap(NR::Point con
     return _doFreeSnap(p, it);
 }
 
+/**
+ *  \return true if this Snapper will snap at least one kind of point.
+ */
+bool Inkscape::ObjectSnapper::willSnapSomething() const
+{
+    return (_enabled && _snap_to != 0 && (_snap_to_paths || _snap_to_nodes));
+}
+
+
 /*
   Local Variables:
   mode:c++
diff --git a/src/object-snapper.h b/src/object-snapper.h
index 4e74b2f74..f9c7a9817 100644
--- a/src/object-snapper.h
+++ b/src/object-snapper.h
@@ -43,6 +43,8 @@ public:
     return _snap_to_paths;
   }
   
+  bool willSnapSomething() const;
+  
 private:
   SnappedPoint _doFreeSnap(NR::Point const &p,
 			   std::list<SPItem const *> const &it) const;
diff --git a/src/snap.cpp b/src/snap.cpp
index 1714b6b67..b03b3f89d 100644
--- a/src/snap.cpp
+++ b/src/snap.cpp
@@ -89,6 +89,7 @@ bool SnapManager::willSnapSomething() const
         i++;
     }
 
+    
     return (i != s.end());
 }
 
diff --git a/src/snapper.cpp b/src/snapper.cpp
index 105ec4631..390e0957e 100644
--- a/src/snapper.cpp
+++ b/src/snapper.cpp
@@ -21,7 +21,7 @@ Inkscape::Snapper::PointType const Inkscape::Snapper::SNAP_POINT = 0x2;
  *  \param nv Named view.
  *  \param d Snap distance.
  */
-Inkscape::Snapper::Snapper(SPNamedView const *nv, NR::Coord const d) : _named_view(nv), _distance(d), _enabled(true)
+Inkscape::Snapper::Snapper(SPNamedView const *nv, NR::Coord const d) : _named_view(nv), _enabled(true), _distance(d)
 {
     g_assert(_named_view != NULL);
     g_assert(SP_IS_NAMEDVIEW(_named_view));
@@ -70,15 +70,6 @@ bool Inkscape::Snapper::getSnapTo(PointType t) const
 }
 
 /**
- *  \return true if this Snapper will snap at least one kind of point.
- */
-bool Inkscape::Snapper::willSnapSomething() const
-{
-    return (_enabled && _snap_to != 0);
-}
-
-
-/**
  *  \param s true to enable this snapper, otherwise false.
  */
 
diff --git a/src/snapper.h b/src/snapper.h
index 89e4f9d72..21e96b019 100644
--- a/src/snapper.h
+++ b/src/snapper.h
@@ -44,7 +44,11 @@ public:
     bool getSnapTo(PointType t) const;
     ::NR::Coord getDistance() const;
 
-    bool willSnapSomething() const;
+    /**
+    *  \return true if this Snapper will snap at least one kind of point.
+    */
+    virtual bool willSnapSomething() const {return (_enabled && _snap_to != 0);} // will likely be overridden by derived classes
+
 
     void setEnabled(bool s);
 
@@ -92,6 +96,8 @@ public:
                                  std::list<SPItem const *> const &it) const;
 protected:
     SPNamedView const *_named_view;
+    int _snap_to; ///< bitmap of point types that we will snap to
+    bool _enabled; ///< true if this snapper is enabled, otherwise false
     
 private:
 
@@ -122,8 +128,6 @@ private:
                                             std::list<SPItem const *> const &it) const = 0;
     
     ::NR::Coord _distance; ///< snap distance (desktop coordinates)
-    int _snap_to; ///< bitmap of point types that we will snap to
-    bool _enabled; ///< true if this snapper is enabled, otherwise false
 };
 
 }