Unit/GeometryTest.py

   1 import unittest
   2
   3 from Geometry import *
   4
   5
   6 class TwoVectorTest(unittest.TestCase):
   7
   8     def testAdd(self):
   9         """
  10         Add a couple of test vectors and check that they sum
  11         correctly.
  12         """
  13         v1 = TwoVector(0,0)
  14         v2 = TwoVector(100, -19)
  15         self.assertTrue(v2 == (v1+v2))
  16
  17         v1 = TwoVector(23, -10)
  18         v2 = TwoVector(-23, 10)
  19         zero = TwoVector(0, 0)
  20         self.assertTrue((v1+v2) == zero)
  21
  22
  23     def testDotProduct(self):
  24         """
  25         The dot product of a vector v with a vector to which it's
  26         perpendicular, v_perp, should always be zero.
  27
  28         The dot product of any vector with the zero vector should be
  29         zero.
  30         """
  31         v1 = TwoVector(235, -2352)
  32         v2 = TwoVector(9382335.024, -235235.1242)
  33         self.assertEqual(0, v1.dot_product(v1.perpendicular()))
  34         self.assertEqual(0, v2.dot_product(v2.perpendicular()))
  35
  36         zero = TwoVector(0, 0)
  37         self.assertEqual(0, v1.dot_product(zero))
  38
  39
  40
  41 class PolygonTest(unittest.TestCase):
  42
  43     def testEquals(self):
  44         """
  45         We defined our own __eq__ method; make sure it works.
  46         """
  47         unit_square1 = Polygon([ (0,0), (1,0), (1,1), (0,1) ])
  48         unit_square2 = Polygon([ (0,0), (1,0), (1,1), (0,1) ])
  49         self.assertTrue(unit_square1 == unit_square2)
  50
  51         hexagon = Polygon([ (1,0),
  52                             (0.5, sqrt(3)/2.0),
  53                             (-0.5, sqrt(3)/2.0),
  54                             (-1, 0),
  55                             (-0.5, -sqrt(3)/2.0),
  56                             (0.5, -sqrt(3)/2.0) ])
  57
  58         self.assertFalse(unit_square1 == hexagon)
  59
  60
  61     def testDrag(self):
  62         """
  63         Drag the unit square 5 units to the right.
  64         """
  65         unit_square = Polygon([ (0,0), (1,0), (1,1), (0,1) ])
  66         v = TwoVector(5,0)
  67         result = unit_square.drag(v)
  68         expected_result = Polygon([ (0,0), (6,0), (6,1), (0,1) ])
  69         self.assertTrue(result == expected_result)
  70
  71
  72
  73     def testDragVertices(self):
  74         """
  75         A diamond shape has nice drag vertices which we can calculate
  76         by hand.
  77         """
  78         diamond = Polygon([ (0,1), (-1,0), (0,-1), (1,0) ])
  79
  80         # First, we drag it to the right along the x-axis.
  81         drag_vector = TwoVector(5,0)
  82         dvs = set(diamond.drag_vertices(drag_vector))
  83         expected_dvs = set([(0,1), (0,-1)])
  84         self.assertTrue(dvs == expected_dvs)
  85
  86         # Now, drag it up.
  87         drag_vector = TwoVector(0,5)
  88         dvs = set(diamond.drag_vertices(drag_vector))
  89         expected_dvs = set([(1,0), (-1,0)])
  90         self.assertTrue(dvs == expected_dvs)
  91
  92
  93 def suite():
  94     suite = unittest.TestSuite()
  95     suite.addTest(unittest.makeSuite(TwoVectorTest))
  96     suite.addTest(unittest.makeSuite(PolygonTest))
  97     return suite