FindPairs.ms

		function FindPairs EPolyObj  = 
		(
			local N = polyop.getNumVerts EPolyObj 
			local Result = #{} -- Result is a bitArray, will tell non paired (=true) vertices at the end 
            local t1 = 0
			Result.count = N	  --with N elements			
			Result = - Result  -- inverting makes all elements true.
			
			local UnPairedTag = N+99
            
            local positiveVerts = #()
            local negativeVerts = #()
			
			VertsInfo.count = N
			
			--initializing vertInfo
            t1 = timeStamp()
			for i=1 to N do in coordsys local
			(
				local v1 = polyop.getVert EPolyObj i
				VertsInfo[i] = TVertInfo undefined undefined undefined v1				
                VertsInfo[i].RightSide = ( v1.x >= 0 )  -- RightSide = positive
                if VertsInfo[i].RightSide then (  append PositiveVerts i )  else ( append negativeVerts i )
				
				--Vertices on the "center" Symmetry AXE paired with themselves. 
				If 	abs(v1.x) <= Tolerance then 
				(	
					VertsInfo[i].PairedWith = i	
					Result[i]=false
				)
				
				--Links
				--Find the list of vertices connected via edge, store in LinkedTo bitarray
				local MyEdges = polyop.getEdgesUsingVert EPolyObj  i
				VertsInfo[i].Linkedto = #{}	
				for k in MyEdges do
				(
					VertsInfo[i].Linkedto  = VertsInfo[i].Linkedto  + (polyop.getVertsUsingEdge EPolyObj k )			
				)		
				--remove self
				VertsInfo[i].Linkedto =  VertsInfo[i].Linkedto - #{i}
			)
         
            print ("Initializing Verts Info. delay: "+(timeStamp()-t1) as string)
			
			
			--Finding Pairs by position------------------------------- The standard easy way				
			print "Finding symmetrical pairs..."
            t1 = timeStamp()
			proBar.color = [0,255,255]
			for i=1 to positiveVerts.count do in coordsys local
			(
				local v1 = VertsInfo[ positiveVerts[i] ].vPos
				
				for j=1 to negativeVerts.count do
				(			
					local v2 = copy VertsInfo[ negativeVerts[j] ].vPos
					v2.x = -v2.x
					local d = (distance v1 v2)
					
					if d<=Tolerance then
					(
						VertsInfo[ positiveVerts[i] ].PairedWith = negativeVerts[j]
						VertsInfo[ negativeVerts[j] ].PairedWith = positiveVerts[i] 
						Result[ positiveVerts[i] ]=false
						Result[ negativeVerts[j] ]=false
					)	
				)
				proBar.value = (i * 100) / N
			)
			print ("Done. delay: "+(timeStamp()-t1) as string )
            
			
			-- Find pairs by links -------------------------- the cool start here -------------- Edge Connections Analysis            
            local ResultList = result as array
            -- ResultList cointatins the vertices that has not pairs yet.
			print ("Finding pairs by edge connections. Verts count: "+(ResultList.count as string))
            t1 = timeStamp()
			--proBar.value = 0
			proBar.color = [255, 255, 0]
			local NewLinksCount = 0            
			local UnlinkedPairs = (ResultList.count / 2) +1            
            
			if (chkEdgeAnalysis.checked==true) and (ResultList.count != 0) then 
			do
			(
				Local FoundNewPairs=0
				
				for r=1 to ResultList.count do in coordsys local                    
				(		
					local i = ResultList[r]
					
						if VertsInfo[i].PairedWith==undefined then
						(
							Result[i] = true
							local MyCandidate = 0
							local MyCandidateNum = 0
							
							for rr=1 to ResultList.count do
							(                                
                                local j = ResultList[rr]  -- to avoid rename all J vars O.o
								if i!=j then 
								(							
									local RSymLinks = #{}
									local RUnpairedLinks = 0
									local LSymLinks = #{}
									local LUnpairedLinks = 0
									--Remap the links using paired Vertice Numbers. 
									--Side 1
									for k in VertsInfo[i].LinkedTo do
									(
										if VertsInfo[k].PairedWith==undefined then
										(
											RUnpairedLinks +=  1
										) else 
										(
                                            -- collect just the links indices for this side
											RSymLinks = RSymLinks + #{ k }											
										)					
									)
									--Side 2
									for k in VertsInfo[j].LinkedTo do
									(
										if VertsInfo[k].PairedWith==undefined then
										(
											LUnpairedLinks += 1
										) else 
										(
                                            -- for this side The pairs of the links
											LSymLinks = LSymLinks + #{ VertsInfo[k].PairedWith } 											
										)					
									)
									
									-- And now the moment of "almost" truth!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
									-- The left vert qualify for pairing???
									
									--Empty links sets, cant prove nothing 
									if (not RSymLInks.isEmpty) and (not RSymLinks.isEmpty )then 
									(
										-- Testing if two SETS are EQUAL:
										if (RSymLinks-LSymLinks).isEmpty and (LSymLinks-RSymLinks).IsEmpty  then
										(
											--but wat about the Unpaired links?
											if RUnpairedLinks == LUnpairedLinks then
											(
												--this is a good candidate!
												--lets see if  there not already one before...
												if MyCandidate==0 then 
												(
													--Nice this is the first (hope only)
													MyCandidate=j 
													MyCandidateNum+= 1
													--print ("Candidate! " + (MyCandidate as string) )
												) else
												(
													--no need for more searching there are duplicated "ideal" conditions
													--but instead of exiting the loops, lets just count the candidates
													MyCandidateNum += 1
												)
											)
										)
									)
								
								)
							)--For J end
							
							--if One and only One then yeah
							if MyCandidateNum == 1 then
							(
								--We can pair vert I with vert MyCandidate
								VertsInfo[i].PairedWith = MyCandidate
								VertsInfo[MyCandidate].PairedWith = i
                                -- Revise the Side of the vertices.
                                
								FoundNewPairs += 1 
								Result[i]=false
								Result[MyCandidate]=false                                
								NewLinksCount += 1
								--updating progressbar
								proBar.value = (100 * NewLinkscount) / UnlinkedPairs	
									
							)--if MyCandidateNum == 1
							
						)--if VertsInfo[i].PairedWith==undefined
					
				)--For I end
                
                
				--print ("Found New Pairs: " + (FoundNewPairs	as string))
			)	while FoundNewPairs!=0
				
			print ("Done. delay: " +(timeStamp()-t1) as string)
			print ( "New found: " + (NewLinkscount as string))
			print ("Unpaired: " + (UnlinkedPairs as string))
			proBar.value = 100;
			proBar.color = [0,255,0]
			
			EPolyObj.selectedVerts = Result
			Result
		) -- FindPairs funciton END