Data commit

Task/Sutherland-Hodgman-polygon-clipping/Python/sutherland-hodgman-polygon-clipping.py

@@ -0,0 +1,32 @@
+def clip(subjectPolygon, clipPolygon):
+   def inside(p):
+      return(cp2[0]-cp1[0])*(p[1]-cp1[1]) > (cp2[1]-cp1[1])*(p[0]-cp1[0])
+
+   def computeIntersection():
+      dc = [ cp1[0] - cp2[0], cp1[1] - cp2[1] ]
+      dp = [ s[0] - e[0], s[1] - e[1] ]
+      n1 = cp1[0] * cp2[1] - cp1[1] * cp2[0]
+      n2 = s[0] * e[1] - s[1] * e[0]
+      n3 = 1.0 / (dc[0] * dp[1] - dc[1] * dp[0])
+      return [(n1*dp[0] - n2*dc[0]) * n3, (n1*dp[1] - n2*dc[1]) * n3]
+
+   outputList = subjectPolygon
+   cp1 = clipPolygon[-1]
+
+   for clipVertex in clipPolygon:
+      cp2 = clipVertex
+      inputList = outputList
+      outputList = []
+      s = inputList[-1]
+
+      for subjectVertex in inputList:
+         e = subjectVertex
+         if inside(e):
+            if not inside(s):
+               outputList.append(computeIntersection())
+            outputList.append(e)
+         elif inside(s):
+            outputList.append(computeIntersection())
+         s = e
+      cp1 = cp2
+   return(outputList)