Snap to intersections of line segments

[inkscape.git] / src / conn-avoid-ref.cpp

diff --git a/src/conn-avoid-ref.cpp b/src/conn-avoid-ref.cpp
index 0532a76687b29dca413d3efd0cad77b486ec1a17..0bbefa3c015d194af8f777d7ad72c255e037f0c1 100644 (file)
--- a/src/conn-avoid-ref.cpp
+++ b/src/conn-avoid-ref.cpp
@@ -94,11 +94,11 @@ void SPAvoidRef::handleSettingChange(void)
     
     _transformed_connection.disconnect();
     if (new_setting) {
-        _transformed_connection = item->connectTransformed(
-                sigc::ptr_fun(&avoid_item_move));
-
         Avoid::Polygn poly = avoid_item_poly(item);
         if (poly.pn > 0) {
+            _transformed_connection = item->connectTransformed(
+                    sigc::ptr_fun(&avoid_item_move));
+
             const char *id = SP_OBJECT_REPR(item)->attribute("id");
             g_assert(id != NULL);
             
@@ -186,42 +186,24 @@ static Avoid::Polygn avoid_item_poly(SPItem const *item)
     //       some convex hull code, though not NR::ConvexHull as this
     //       only keeps the bounding box of the convex hull currently.
 
-    // TODO: SPItem::invokeBbox gives the wrong result for some objects
+    // TODO: SPItem::getBounds gives the wrong result for some objects
     //       that have internal representations that are updated later
     //       by the sp_*_update functions, e.g., text.
     sp_document_ensure_up_to_date(item->document);
     
-    NR::Rect rHull = item->invokeBbox(sp_item_i2doc_affine(item));
-
+    NR::Maybe<NR::Rect> rHull = item->getBounds(sp_item_i2doc_affine(item));
+    if (!rHull) {
+        return Avoid::newPoly(0);
+    }
 
     double spacing = desktop->namedview->connector_spacing;
 
     // Add a little buffer around the edge of each object.
-    NR::Rect rExpandedHull = NR::expand(rHull, -spacing); 
+    NR::Rect rExpandedHull = NR::expand(*rHull, -spacing); 
     poly = Avoid::newPoly(4);
 
     for (unsigned n = 0; n < 4; ++n) {
-        // TODO: I think the winding order in libavoid or inkscape might
-        //       be backwards, probably due to the inverse y co-ordinates
-        //       used for the screen.  The '3 - n' reverses the order.
-        /* On "correct" winding order: Winding order of NR::Rect::corner is in a positive
-         * direction, like libart.  "Positive direction" means the same as in most of Inkscape and
-         * SVG: if you visualize y as increasing upwards, as is the convention in mathematics, then
-         * positive angle is visualized as anticlockwise, as in mathematics; so if you visualize y
-         * as increasing downwards, as is common outside of mathematics, then positive angle
-         * direction is visualized as clockwise, as is common outside of mathematics.  This
-         * convention makes it easier mix pure mathematics code with graphics code: the important
-         * thing when mixing code is that the number values stored in variables (representing y
-         * coordinate, angle) match up; variables store numbers, not visualized positions, and the
-         * programmer is free to switch between visualizations when thinking about a given piece of
-         * code.
-         *
-         * MathWorld, libart and NR::Rect::corner all seem to take positive winding (i.e. winding
-         * that yields +1 winding number inside a simple closed shape) to mean winding in a
-         * positive angle.  This, together with the observation that variables store numbers rather
-         * than positions, suggests that NR::Rect::corner uses the right direction.
-         */
-        NR::Point hullPoint = rExpandedHull.corner(3 - n);
+        NR::Point hullPoint = rExpandedHull.corner(n);
         poly.ps[n].x = hullPoint[NR::X];
         poly.ps[n].y = hullPoint[NR::Y];
     }
@@ -254,7 +236,7 @@ GSList *get_avoided_items(GSList *list, SPObject *from, SPDesktop *desktop,
 }
 
 
-void avoid_item_move(NR::Matrix const *mp, SPItem *moved_item)
+void avoid_item_move(NR::Matrix const */*mp*/, SPItem *moved_item)
 {
     Avoid::ShapeRef *shapeRef = moved_item->avoidRef->shapeRef;
     g_assert(shapeRef);
@@ -274,7 +256,7 @@ void init_avoided_shape_geometry(SPDesktop *desktop)
     // it is basically just llate initialisation.
     SPDocument *document = sp_desktop_document(desktop);
     bool saved = sp_document_get_undo_sensitive(document);
-    sp_document_set_undo_sensitive(document, FALSE);
+    sp_document_set_undo_sensitive(document, false);
     
     bool initialised = false;
     GSList *items = get_avoided_items(NULL, desktop->currentRoot(), desktop,