Initial commit

geometry/drawing.py

@@ -0,0 +1,34 @@
+from turtle import *
+from superturtle.movement import fly
+
+def centered_circle(radius):
+    """Draws a circle, centered on the turtle's current position.
+    The built-in circle function annoyingly draws a circle whose center
+    is one radius left of the turtle.
+    """
+    right(90)
+    penup()
+    forward(radius)
+    pendown()
+    left(90)
+    circle(radius)
+    left(90)
+    penup()
+    forward(radius)
+    pendown()
+    right(90)
+
+def write_label(point, label, align=None, font=None):
+    fly(point.x, point.y)
+    write(label, align=align, font=font)
+
+def line_end_arrow():
+    "Draws an arrow"
+    left(20)
+    back(20)
+    forward(20)
+    right(40)
+    back(20)
+    forward(20)
+    left(20)
+