fixes to LPEKnot, now usable again.

knotholder: if knot coords are non-finite, hide knot. used for hiding the lpeknot switcher knot if there are no crossings

Fixed bugs:
  - https://launchpad.net/bugs/781893

(bzr r13428)

3 files changed, 23 insertions, 18 deletions

diff --git a/src/knot-holder-entity.cpp b/src/knot-holder-entity.cpp
index 6471124ec..6af5c6a56 100644
--- a/src/knot-holder-entity.cpp
+++ b/src/knot-holder-entity.cpp
@@ -80,13 +80,17 @@ KnotHolderEntity::~KnotHolderEntity()
 void
 KnotHolderEntity::update_knot()
 {
-    Geom::Affine const i2dt(item->i2dt_affine());
+    Geom::Point knot_pos(knot_get());
+    if (knot_pos.isFinite()) {
+        Geom::Point dp(knot_pos * item->i2dt_affine());
 
-    Geom::Point dp(knot_get() * i2dt);
-
-    _moved_connection.block();
-    knot->setPosition(dp, SP_KNOT_STATE_NORMAL);
-    _moved_connection.unblock();
+        _moved_connection.block();
+        knot->setPosition(dp, SP_KNOT_STATE_NORMAL);
+        _moved_connection.unblock();
+    } else {
+        // knot coords are non-finite, hide knot
+        knot->hide();
+    }
 }
 
 Geom::Point
diff --git a/src/live_effects/lpe-knot.cpp b/src/live_effects/lpe-knot.cpp
index 581c632f5..cac3a9347 100644
--- a/src/live_effects/lpe-knot.cpp
+++ b/src/live_effects/lpe-knot.cpp
@@ -353,7 +353,11 @@ LPEKnot::LPEKnot(LivePathEffectObject *lpeobject) :
     add_other_stroke_width(_("_Crossing path stroke width"), _("Add crossed stroke width to the interruption size"), "add_other_stroke_width", &wr, this, true),
     switcher_size(_("S_witcher size:"), _("Orientation indicator/switcher size"), "switcher_size", &wr, this, 15),
     crossing_points_vector(_("Crossing Signs"), _("Crossings signs"), "crossing_points_vector", &wr, this),
-    gpaths(),gstroke_widths()
+    crossing_points(),
+    gpaths(),
+    gstroke_widths(),
+    selectedCrossing(0),
+    switcher(0.,0.)
 {
     // register all your parameters here, so Inkscape knows which parameters this effect has:
     registerParameter( dynamic_cast<Parameter *>(&interruption_width) );
@@ -363,10 +367,6 @@ LPEKnot::LPEKnot(LivePathEffectObject *lpeobject) :
     registerParameter( dynamic_cast<Parameter *>(&switcher_size) );
     registerParameter( dynamic_cast<Parameter *>(&crossing_points_vector) );
 
-    crossing_points = LPEKnotNS::CrossingPoints();
-    selectedCrossing = 0;
-    switcher = Geom::Point(0,0);
-
     _provides_knotholder_entities = true;
 }
 
@@ -386,9 +386,7 @@ LPEKnot::updateSwitcher(){
         //std::cout<<"placing switcher at "<<switcher<<" \n";
     }else{
         //std::cout<<"hiding switcher!\n";
-        //TODO: is there a way to properly hide the helper.
-        //switcher = Geom::Point(Geom::infinity(),Geom::infinity());
-        switcher = Geom::Point(1e10,1e10);
+        switcher = Geom::Point(Geom::infinity(),Geom::infinity());
     }
 }
 
@@ -539,8 +537,9 @@ LPEKnot::doBeforeEffect (SPLPEItem const* lpeitem)
     using namespace Geom;
     original_bbox(lpeitem);
 
-    gpaths = std::vector<Geom::Path>();
-    gstroke_widths = std::vector<double>();
+    gpaths.clear();
+    gstroke_widths.clear();
+
     collectPathsAndWidths(lpeitem, gpaths, gstroke_widths);
 
 //     std::cout<<"\nPaths on input:\n";
@@ -586,7 +585,10 @@ LPEKnot::doBeforeEffect (SPLPEItem const* lpeitem)
 //         std::cout<<crossing_points[toto].sign<<"),";
 //     }
     crossing_points.inherit_signs(old_crdata);
-    crossing_points_vector.param_set_and_write_new_value(crossing_points.to_vector());
+
+    // Don't write to XML here, only store it in the param itself. Will be written to SVG later
+    crossing_points_vector.param_setValue(crossing_points.to_vector());
+
     updateSwitcher();
 }
 
diff --git a/src/live_effects/lpe-knot.h b/src/live_effects/lpe-knot.h
index b937f9021..f926bf085 100644
--- a/src/live_effects/lpe-knot.h
+++ b/src/live_effects/lpe-knot.h
@@ -74,7 +74,6 @@ private:
   BoolParam  add_stroke_width;
   BoolParam  add_other_stroke_width;
   ScalarParam switcher_size;
-  double stroke_width;
   ArrayParam<double> crossing_points_vector;//svg storage of crossing_points
   
   LPEKnotNS::CrossingPoints crossing_points;//topology representation of the knot.