1 files changed, 12 insertions, 2 deletions
diff --git a/AutoVisual/IGPFamily.pde b/AutoVisual/IGPFamily.pde
index 78e3f2f..7b97c6f 100644
--- a/AutoVisual/IGPFamily.pde
+++ b/AutoVisual/IGPFamily.pde
@@ -241,10 +241,20 @@ class IGPFamily {
 
   PVector getVectorOnExtendedLine(PVector startPoint, PVector endPoint, float boundary, boolean vertical){
     float m,n;
-    m = (endPoint.y-startPoint.y)/(endPoint.x-startPoint.x);
+    boolean dirac = false;
+    if (endPoint.x-startPoint.x == 0){
+      dirac = true;
+      m = 0;
+    } else {
+      m = (endPoint.y-startPoint.y)/(endPoint.x-startPoint.x);
+    }
     n = endPoint.y-m*endPoint.x;
     if (vertical){
-      return new PVector((boundary-n)/m, boundary);
+      if (dirac){
+        return new PVector(startPoint.x, boundary);
+      }else{
+        return new PVector((boundary-n)/m, boundary);
+      }
     } else {
       return new PVector(boundary, (m*boundary)+n);
     }