geometry.py

   1 """Imago geometry module"""
   2
   3 class V(object):
   4     def __init__(self, x, y):
   5         self.x = x
   6         self.y = y
   7
   8     def __add__(self, other):
   9         return V(self.x + other.x, self.y + other.y)
  10
  11     def __sub__(self, other):
  12         return V(self.x - other.x, self.y - other.y)
  13
  14     def __rmul__(self, other):
  15         return V(other * self.x, other * self.y)
  16
  17     def __len__(self):
  18         return 2;
  19
  20     def __getitem__(self, key):
  21         if key == 0:
  22             return self.x
  23         elif key == 1:
  24             return self.y
  25         elif type(key) != int:
  26             raise TypeError("V indices must be integers")
  27         else:
  28             raise KeyError("V index ({}) out of range".format(key))
  29
  30     def __iter__(self):
  31         yield self.x
  32         yield self.y
  33
  34     @property
  35     def normal(self):
  36         return V(-self.y, self.x)
  37
  38 def projection(point, line, vector):
  39     return V(*intersection(g_line(point, point + vector.normal), g_line(*line)))