1 files changed, 52 insertions, 0 deletions
diff --git a/src/cython/utils.py b/src/cython/utils.py
new file mode 100644
index 0000000..1115d32
--- /dev/null
+++ b/src/cython/utils.py
@@ -0,0 +1,52 @@
+from Tkinter import *
+
+import math
+
+import cy2geom
+from cy2geom import Point, Path
+
+
+def Nagon(N):
+    """Return N-agon with side of length 1."""
+    side = cy2geom.LineSegment(Point(-0.5, 0), Point(0.5, 0))
+    angle = 2*math.pi/N
+    distance_to_center = 0.5 / math.tan(math.pi/N)
+    return Path.fromList(
+        [ side.transformed( 
+            cy2geom.Translate(Point(0, -distance_to_center))*
+            cy2geom.Rotate(angle*i)) 
+            for i in range(N)
+        ], 
+        stitching = Path.STITCH_DISCONTINUOUS, 
+        closed = True )
+
+def draw(c, dt=0.001, batch=10, scale=20, x_offset = 400, y_offset = 300):
+    """Draw curve or path."""
+    master = Tk()
+    w = Canvas(master, width=800, height=600)
+    w.pack()
+    n = 0
+    t = 0
+    points = []
+    
+    if isinstance(c, Path):
+        maxt = c.size_default()
+    else:
+        maxt = 1
+    
+    while (t < maxt):
+        t = n*dt
+        n+=1
+        p = c(t)
+        points.extend( [ p.x * scale + x_offset, p.y * scale + y_offset] )
+        
+    while points:
+        draw_points = tuple(points[:batch*2])
+        if len(points) == 2:
+            break
+        del points[:batch*2]
+        
+        l = w.create_line(*draw_points)
+        w.grid()
+
+    master.mainloop()