Changeset 1831:75ab76fc4bf2 in lemon-0.x for gui/gdc-broken_edge.cc

Timestamp:

11/23/05 17:24:59 (18 years ago)

Author:

Hegyi Péter

Branch:

default

Phase:

public

Convert:

svn:c9d7d8f5-90d6-0310-b91f-818b3a526b0e/lemon/trunk@2381

Message:

No segmentation fault caused by zero long edges.

File:

• gui/gdc-broken_edge.cc (modified) (3 diffs)

gui/gdc-broken_edge.cc

@@ -74 +74 @@
           double absb=sqrt(b_v.normSquare());
 
-          //old vector from one node to the breakpoint - c
-          xy<double> c_v(my_points[1].get_x()-my_points[0].get_x(),my_points[1].get_y()-my_points[0].get_y());
-
-          //unit vector with the same direction to a_v
-          xy<double> a_v_u(a_v.x/absa,a_v.y/absa);
-
-          //normal vector of unit vector with the same direction to a_v
-          xy<double> a_v_u_n(((-1)*a_v_u.y),a_v_u.x);
-
-          //unit vector with the same direction to b_v
-          xy<double> b_v_u(b_v.x/absb,b_v.y/absb);
-
-          //normal vector of unit vector with the same direction to b_v
-          xy<double> b_v_u_n(((-1)*b_v_u.y),b_v_u.x);
-
-          //vector c in a_v_u and a_v_u_n co-ordinate system
-          xy<double> c_a(c_v*a_v_u,c_v*a_v_u_n);
-
-          //new vector from one node to the breakpoint - d - we have to calculate this one
-          xy<double> d_v=absb/absa*(c_a.x*b_v_u+c_a.y*b_v_u_n);
-
-          my_points[1]=Gnome::Art::Point(d_v.x+p[0].get_x(),d_v.y+p[0].get_y());
-
-          my_points[0]=p[0];
-          my_points[2]=p[1];
-
-          Gnome::Canvas::Points points;
-          for(int i=0;i<3;i++)
+          if((absa!=0)&&(absb!=0))
             {
-              points.push_back(my_points[i]);
+              //old vector from one node to the breakpoint - c
+              xy<double> c_v(my_points[1].get_x()-my_points[0].get_x(),my_points[1].get_y()-my_points[0].get_y());
+
+              //unit vector with the same direction to a_v
+              xy<double> a_v_u(a_v.x/absa,a_v.y/absa);
+
+              //normal vector of unit vector with the same direction to a_v
+              xy<double> a_v_u_n(((-1)*a_v_u.y),a_v_u.x);
+
+              //unit vector with the same direction to b_v
+              xy<double> b_v_u(b_v.x/absb,b_v.y/absb);
+
+              //normal vector of unit vector with the same direction to b_v
+              xy<double> b_v_u_n(((-1)*b_v_u.y),b_v_u.x);
+
+              //vector c in a_v_u and a_v_u_n co-ordinate system
+              xy<double> c_a(c_v*a_v_u,c_v*a_v_u_n);
+
+              //new vector from one node to the breakpoint - d - we have to calculate this one
+              xy<double> d_v=absb/absa*(c_a.x*b_v_u+c_a.y*b_v_u_n);
+
+              my_points[1]=Gnome::Art::Point(d_v.x+p[0].get_x(),d_v.y+p[0].get_y());
+
+              my_points[0]=p[0];
+              my_points[2]=p[1];
+          
+              Gnome::Canvas::Points points;
+              for(int i=0;i<3;i++)
+                {
+                  points.push_back(my_points[i]);
+                }
+              property_points().set_value(points);
             }
-          property_points().set_value(points);
+          else
+            {
+              //if distance is 0, segmentation would be occured
+              //in calculations, because of division by zero
+              //But we have luck: the edge cannot be seen in
+              //this case, so no update needed
+              set_arrow=false;
+            }
         }
     }
@@ -116 +127 @@
 
       xy<gdouble> unit_vector_in_dir(target-center);
+      double length=sqrt( unit_vector_in_dir.normSquare() );
+
       //       std::cout << target << " - " << center << " = " << unit_vector_in_dir << "    / " <<unit_vector_in_dir.normSquare() ;
-      unit_vector_in_dir/=sqrt( unit_vector_in_dir.normSquare() );
+      unit_vector_in_dir/=length;
       //       std::cout << " = " << unit_vector_in_dir << std::endl;
 
@@ -141 +154 @@
       xy<gdouble> top(center + unit_vector_in_dir * 3 * size);
          
-      //       std::cout << bl << " " << br << " " << ccl << " "  << ccr << " " << cl << " " << cr << " " << top << std::endl;
+      //std::cout << bl << " " << br << " " << ccl << " "  << ccr << " " << cl << " " << cr << " " << top << std::endl;
 
       Gnome::Canvas::Points arrow_points;