2Geom fix: derivative of order 1 bezier, and an out of range bug affecting intersection computation.

(bzr r5000)

3 files changed, 6 insertions, 7 deletions

diff --git a/src/2geom/bezier.h b/src/2geom/bezier.h
index bdc672a57..af6df0840 100644
--- a/src/2geom/bezier.h
+++ b/src/2geom/bezier.h
@@ -173,7 +173,8 @@ public:
         Coord d_[order()+1];
         unsigned nn = n_derivs;
         if(nn > order())
-            nn = order();
+            //nn = order();
+            nn = order()+1;
         for(unsigned i = 0; i < size(); i++)
             d_[i] = c_[i];
         for(unsigned di = 0; di < nn; di++) {
@@ -262,7 +263,8 @@ inline std::vector<Point> bezier_points(const D2<Bezier > & a) {
 }
 
 inline Bezier derivative(const Bezier & a) {
-    if(a.order() == 1) return Bezier(0.0);
+    //if(a.order() == 1) return Bezier(0.0);
+    if(a.order() == 1) return Bezier(a.c_[1]-a.c_[0]);
     Bezier der(Bezier::Order(a.order()-1));
     
     for(unsigned i = 0; i < a.order(); i++) {
diff --git a/src/2geom/path.h b/src/2geom/path.h
index 72c5d50fa..f314e6efa 100644
--- a/src/2geom/path.h
+++ b/src/2geom/path.h
@@ -236,11 +236,7 @@ public:
         return new BezierCurve<order-1>(Geom::derivative(inner[X]), Geom::derivative(inner[Y]));
      else if (order == 1) {
         double dx = inner[X][1] - inner[X][0], dy = inner[Y][1] - inner[Y][0];
-        if(dx == 0) return new BezierCurve<1>(Point(0,0), Point(0,0));
-        double slope = dy / dx;
-        Geom::Point pnt;
-        if(slope == 0) pnt = Geom::Point(0, 0); else pnt = Geom::Point(slope, 1./slope);
-        return new BezierCurve<1>(pnt, pnt);
+        return new BezierCurve<1>(Point(dx,dy),Point(dx,dy));
      }
   }
 
diff --git a/src/2geom/sweep.cpp b/src/2geom/sweep.cpp
index 08674ab2f..b9ef71b5c 100644
--- a/src/2geom/sweep.cpp
+++ b/src/2geom/sweep.cpp
@@ -82,6 +82,7 @@ std::vector<std::vector<unsigned> > sweep_bounds(std::vector<Rect> a, std::vecto
             open[n].push_back(ix);
         }
         i[n]++;
+	if(i[n]>=events[n].size()) {break;}
         n = (events[!n][i[!n]] < events[n][i[n]]) ? !n : n;
     }
     return pairs;