finished ex3

Author: geooo109

gitignore

@@ -0,0 +1 @@
+/part1/src/ex*/*.pyc

part1/src/ex3_ex4/main.py

@@ -3,7 +3,7 @@
 import numpy as np
 import matplotlib.pyplot as plt
 import time
-RANGE_XY = 10000
+RANGE_XY = 1000000
 def parse_input():
     points = []
     ch = raw_input("To autogenerate write ->AUTO<- else just type something: ")
@@ -31,10 +31,10 @@ def main():
     if plane.check_points() == True:
         print("***Found 2 Points with same x, Algorithm ends***")
         return
-    choice = raw_input("Type (1) for Incremental / Type (2) for Gift Wrap")
+    choice = raw_input("Type (1) for Incremental / Type (2) for Gift Wrap: ")
     while True:
         if choice == "1":
-            print(plane.incremental_convex_hull())
+            plane.incremental_convex_hull()
             break
         elif choice == "2":
             plane.gift_wrap_convex_hull()

part1/src/ex3_ex4/plane.py

@@ -36,7 +36,8 @@ def check_points(self):
             curr += 1
         return False
 
-    def ort(self, pt1 , pt2, r):
+    #if we start from left to right
+    def ort_min_max(self, pt1 , pt2, r):
         v = ((pt2.get_y()-pt1.get_y())*(r.get_x()-pt2.get_x())
             -(pt2.get_x()-pt1.get_x())*(r.get_y()-pt2.get_y()))
         if v == 0:
@@ -46,10 +47,13 @@ def ort(self, pt1 , pt2, r):
         else:
             return CCW
 
-    def cross(self, pt1 , pt2, r):
+    #if we start from right to left
+    def ort_max_min(self, pt1 , pt2, r):
         v = ((pt2.get_x()-pt1.get_x())*(r.get_y()-pt2.get_y())
             -(pt2.get_y()-pt1.get_y())*(r.get_x()-pt2.get_x()))
-        if v <= 0:
+        if v == 0:
+            return COLINEAR
+        elif v < 0:
             return CW
         else:
             return CCW
@@ -86,41 +90,52 @@ def sort_function(self,point):
         return point.get_x()
 
     def incremental_convex_hull(self):
-        lowerHull = []
-        upperHull = []
+        lower_hull = []
+        upper_hull = []
 
-        if len(self.points) == 0:
+        if len(self.points) <= 1:
             return self.points
 
-        #sorting list based on x coord
-        #self.print_plane()
-        self.points = sorted(self.points,key=self.sort_function)
-        #self.print_plane()
+        #sorting list based on x coord {max -> min}
+        self.points = sorted(self.points,key = self.sort_function, reverse = True)
         N = len(self.points)
 
         # culculating lower hull #
         for idx in range(N):
-            #print idx
-            while len(lowerHull) >= 2 and self.cross(lowerHull[-2], lowerHull[-1], self.points[idx]) == CW:
-                lowerHull.pop()
-            lowerHull.append(self.points[idx])
+            while True:
+                curr_len = len(lower_hull)
+                if (curr_len >= 2):
+                    ort = self.ort_max_min(lower_hull[-2], lower_hull[-1], self.points[idx])
+                    if ort == CW:
+                        lower_hull.pop()
+                    elif ort == CCW:
+                        break
+                    else:
+                        print ("COLINEAR points in the lower_hull")
+                else:
+                    break
+            lower_hull.append(self.points[idx])
 
         # culculating upper hull #
+        self.points.reverse()
         for idx in range(N):
-            self.points.reverse()
-            #self.print_plane()
-            while len(upperHull) >= 2 and \
-                    (self.ort(lowerHull[-2], lowerHull[-1], self.points[idx]) == CCW or \
-                    self.ort(lowerHull[-2], lowerHull[-1], self.points[idx]) == COLINEAR):
-                upperHull.pop()
-            upperHull.append(self.points[idx])
-
-        #pop common point
-        lowerHull.pop()
-        hull = lowerHull + upperHull
-        #self.display_hull(lowerHull)
-        #self.display_hull(upperHull)
+            while True:
+                curr_len = len(upper_hull)
+                if (curr_len >= 2):
+                    ort = self.ort_max_min(upper_hull[-2], upper_hull[-1], self.points[idx])
+                    if ort == CW:
+                        upper_hull.pop()
+                    elif ort == CCW:
+                        break
+                    else:
+                        print ("COLINEAR points in the lower_hull")
+                else:
+                    break
+            upper_hull.append(self.points[idx])
+
+        hull = lower_hull + upper_hull
         self.display_hull(hull)
+        return
 
 
     def gift_wrap_convex_hull(self):
@@ -134,7 +149,7 @@ def gift_wrap_convex_hull(self):
             curr_pt = (cr_pt+1)%total_points
             #check for orientation of all other Points
             for i in range(0, total_points):
-                ort = self.ort(self.points[cr_pt], self.points[i], self.points[curr_pt])
+                ort = self.ort_min_max(self.points[cr_pt], self.points[i], self.points[curr_pt])
                 if ort == CCW:
                     curr_pt = i
             cr_pt = curr_pt