Added comments to tools.py

1 files changed, 22 insertions, 0 deletions

diff --git a/tools.py b/tools.py
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+#==================================================================
+#                           Physics.activity
+#                     Helper classes and functions
+#                           By Alex Levenson
+#==================================================================
+import math
+# distance calculator, pt1 and pt2 are ordred pairs
+def distance(pt1, pt2):
+        return math.sqrt((pt1[0] - pt2[0]) ** 2 + (pt1[1] -pt2[1]) ** 2)
+
+# returns the angle between the line segment from pt1 --> pt2 and the x axis, from -pi to pi
+def getAngle(pt1,pt2):
+    xcomp = pt2[0] - pt1[0]
+    ycomp = pt1[1] - pt2[1]
+    return math.atan2(ycomp,xcomp)
+
+# returns a list of ordered pairs that describe an equilteral triangle around the segment from pt1 --> pt2
+def constructTriangleFromLine(p1,p2):
+    halfHeightVector = (0.57735*(p2[1] - p1[1]), 0.57735*(p2[0] - p1[0]))
+    p3 = (p1[0] + halfHeightVector[0], p1[1] - halfHeightVector[1])
+    p4 = (p1[0] - halfHeightVector[0], p1[1] + halfHeightVector[1])
+    return [p2,p3,p4]