From bbb8693298714fcf773726de8e2a8c810e9418e5 Mon Sep 17 00:00:00 2001
From: Charles Jekel <cjekel@gmail.com>
Date: Sat, 21 Dec 2019 13:02:24 -0800
Subject: [PATCH] A simple quadrilateral will have at least three of the same
 sign cross products

---
 similaritymeasures/VERSION               |  2 +-
 similaritymeasures/similaritymeasures.py |  4 +---
 tests/tests.py                           | 22 +++++++++++++++++-----
 3 files changed, 19 insertions(+), 9 deletions(-)

diff --git a/similaritymeasures/VERSION b/similaritymeasures/VERSION
index 267577d..2b7c5ae 100644
--- a/similaritymeasures/VERSION
+++ b/similaritymeasures/VERSION
@@ -1 +1 @@
-0.4.1
+0.4.2
diff --git a/similaritymeasures/similaritymeasures.py b/similaritymeasures/similaritymeasures.py
index 2781113..44a6412 100644
--- a/similaritymeasures/similaritymeasures.py
+++ b/similaritymeasures/similaritymeasures.py
@@ -97,9 +97,7 @@ def is_simple_quad(ab, bc, cd, da):
     #   Because they don't necessarily need to lie in the same 'Z' direction
     if sum(crossTF) <= 1:
         crossTF = cross <= 0
-    if sum(crossTF) == 2:
-        return True
-    elif sum(crossTF) == 4:
+    if sum(crossTF) > 2:
         return True
     else:
         return False
diff --git a/tests/tests.py b/tests/tests.py
index 452762f..ffd0f87 100644
--- a/tests/tests.py
+++ b/tests/tests.py
@@ -135,13 +135,25 @@ def test_P_Q_dtw_minkowski_p3(self):
         self.assertTrue(r, 3.0)
 
     def test_complex_quad(self):
-        a = [0., 0.]
-        b = [1., 1.]
-        c = [1., 0.]
-        d = [0., 1.]
-        quad = similaritymeasures.is_simple_quad(a, b, d, c)
+        x = [0, 1, 1, 0]
+        y = [0, 1, 0, 1]
+        AB = [x[1]-x[0], y[1]-y[0]]
+        BC = [x[2]-x[1], y[2]-y[1]]
+        CD = [x[3]-x[2], y[3]-y[2]]
+        DA = [x[0]-x[3], y[0]-y[3]]
+        quad = similaritymeasures.is_simple_quad(AB, BC, CD, DA)
         self.assertFalse(quad)
 
+    def test_simple_quad(self):
+        x = [0, 0, 1, 1]
+        y = [0, 1, 1, 0]
+        AB = [x[1]-x[0], y[1]-y[0]]
+        BC = [x[2]-x[1], y[2]-y[1]]
+        CD = [x[3]-x[2], y[3]-y[2]]
+        DA = [x[0]-x[3], y[0]-y[3]]
+        quad = similaritymeasures.is_simple_quad(AB, BC, CD, DA)
+        self.assertTrue(quad)
+
     def test_random_dtw(self):
         r, d = similaritymeasures.dtw(curve_a_rand, curve_b_rand)
         path = similaritymeasures.dtw_path(d)