diff --git a/main.py b/main.py
index e53204d..ec86a30 100644
--- a/main.py
+++ b/main.py
@@ -42,7 +42,7 @@ class Cross_painter(Widget):
         # create new cross
         if touch.button=="right":
             if self.check_add((touch.x,touch.y)):
-                new=Cross((touch.x,touch.y))
+                new=Cross(touch.x,touch.y)
                 with self.canvas:
                     new.draw()
                 # add to list
@@ -66,7 +66,7 @@ class Cross_painter(Widget):
         # only move on left click
         if touch.button=="left" and self.selected!=None:
             #self.selected.pos=self.check_move((touch.x,touch.y),self.selected)
-            self.selected.pos=(touch.x,touch.y)
+            self.selected.setpos(touch.x,touch.y)
             # redraw
             self.canvas.clear()
             self.draw()
@@ -95,17 +95,13 @@ class Cross_painter(Widget):
                 return False
         return True
 
-    # check whether a cross at pos interacts with cross
-    def check_interaction(self,pos,cross):
-        return int((pos[0]-cross.pos[0])/cross.size)**2+int((pos[1]-cross.pos[1])/cross.size)**2>=5
-
 # cross
 class Cross():
     # size of central square
     size=50
 
-    def __init__(self,pos,**kwargs):
-        self.pos=pos
+    def __init__(self,x,y,**kwargs):
+        self.pos=Point(x,y)
         self.color=kwargs.get("color",(0,0,1))
         self.selected=False
 
@@ -116,33 +112,55 @@ class Cross():
         #else:
         #    Color(1,0,0)
         Color(*(self.color))
-        Rectangle(pos=(self.pos[0]-self.size*1.5,self.pos[1]-self.size*0.5),size=(3*self.size,self.size))
-        Rectangle(pos=(self.pos[0]-self.size*0.5,self.pos[1]-self.size*1.5),size=(self.size,3*self.size))
+        Rectangle(pos=(self.pos.x-self.size*1.5,self.pos.y-self.size*0.5),size=(3*self.size,self.size))
+        Rectangle(pos=(self.pos.x-self.size*0.5,self.pos.y-self.size*1.5),size=(self.size,3*self.size))
 
         # stroke
         Color(1,1,1)
         Line(points=(
-        *(self.pos[0]-self.size*0.5,self.pos[1]-self.size*0.5),
-        *(self.pos[0]-self.size*0.5,self.pos[1]-self.size*1.5),
-        *(self.pos[0]+self.size*0.5,self.pos[1]-self.size*1.5),
-        *(self.pos[0]+self.size*0.5,self.pos[1]-self.size*0.5),
-        *(self.pos[0]+self.size*1.5,self.pos[1]-self.size*0.5),
-        *(self.pos[0]+self.size*1.5,self.pos[1]+self.size*0.5),
-        *(self.pos[0]+self.size*0.5,self.pos[1]+self.size*0.5),
-        *(self.pos[0]+self.size*0.5,self.pos[1]+self.size*1.5),
-        *(self.pos[0]-self.size*0.5,self.pos[1]+self.size*1.5),
-        *(self.pos[0]-self.size*0.5,self.pos[1]+self.size*0.5),
-        *(self.pos[0]-self.size*1.5,self.pos[1]+self.size*0.5),
-        *(self.pos[0]-self.size*1.5,self.pos[1]-self.size*0.5),
-        *(self.pos[0]-self.size*0.5,self.pos[1]-self.size*0.5),
+        *(self.pos.x-self.size*0.5,self.pos.y-self.size*0.5),
+        *(self.pos.x-self.size*0.5,self.pos.y-self.size*1.5),
+        *(self.pos.x+self.size*0.5,self.pos.y-self.size*1.5),
+        *(self.pos.x+self.size*0.5,self.pos.y-self.size*0.5),
+        *(self.pos.x+self.size*1.5,self.pos.y-self.size*0.5),
+        *(self.pos.x+self.size*1.5,self.pos.y+self.size*0.5),
+        *(self.pos.x+self.size*0.5,self.pos.y+self.size*0.5),
+        *(self.pos.x+self.size*0.5,self.pos.y+self.size*1.5),
+        *(self.pos.x-self.size*0.5,self.pos.y+self.size*1.5),
+        *(self.pos.x-self.size*0.5,self.pos.y+self.size*0.5),
+        *(self.pos.x-self.size*1.5,self.pos.y+self.size*0.5),
+        *(self.pos.x-self.size*1.5,self.pos.y-self.size*0.5),
+        *(self.pos.x-self.size*0.5,self.pos.y-self.size*0.5),
         ))
 
+    # check whether a cross at pos interacts with cross
+    def check_interaction(self,pos):
+        return int((pos.x-self.pos.x)/self.size)**2+int((pos.y-self.pos.y)/self.size)**2>=5
+
+    # find position along a line that comes in contact with the line
+    #def move_on_line_to_stick(self,x,v):
+
+class Point:
+    def __init__(self,x,y):
+        self.x=x
+        self.y=y
+
+    def __add__(self,point):
+        return Point(self.x+point.x,self.y+point.y)
+
+    def __neg__(self):
+        return Point(-self.x,self.y)
+
+    def setpos(self,x,y):
+        self.x=x
+        self.y=y
+
 # L_infinity distance rescalled by 3 in the x direction
 def cross_distx(x,y):
-    return max(abs(x[0]-y[0])/3,abs(x[1]-y[1]))
+    return max(abs(x.x-y.x)/3,abs(x.y-y.y))
 # L_infinity distance rescalled by 3 in the y direction
 def cross_disty(x,y):
-    return max(abs(x[0]-y[0]),abs(x[1]-y[1])/3)
+    return max(abs(x.x-y.x),abs(x.y-y.y)/3)
 
 # polar description of touching cross
 def cross_polar(t):