OverlapResolver.bb

Function CheckRoomOverlap(r1.Rooms, r2.Rooms)
	Return (CalcOverlapArea(r1, r2) > 0)
End Function

Function CalcOverlapArea#(r1.Rooms, r2.Rooms)
	If (r1\MaxX	<= r2\MinX Or r1\MaxY <= r2\MinY Or r1\MaxZ <= r2\MinZ) Then Return 0
	If (r1\MinX	>= r2\MaxX Or r1\MinY >= r2\MaxY Or r1\MinZ >= r2\MaxZ) Then Return 0
	Return (Min(r1\MaxX, r2\MaxX) - Max(r1\MinX, r2\MinX)) * (Min(r1\MaxZ, r2\MaxZ) - Max(r1\MinZ, r2\MinZ))
End Function

Function CalcAllRoomOverlaps#(r.Rooms)
	Local overlapArea# = 0
	Local r2.Rooms
	For r2 = Each Rooms
		If Not r2\RoomTemplate\DisableOverlapCheck Then
			If r2<>r Then
				overlapArea = overlapArea + CalcOverlapArea(r, r2)
			EndIf
		EndIf
	Next
	Return overlapArea
End Function

Function ReportOverlaps()
	Local r1.Rooms,r2.Rooms
	For r1 = Each Rooms
		For r2 = Each Rooms
			If r2<>r1 Then
				If CheckRoomOverlap(r1, r2) Then
					DebugLog "Overlapping rooms: " + r1\RoomTemplate\Name + " / " + r2\RoomTemplate\Name
				EndIf
			EndIf
		Next
	Next
End Function

Function RotateRoom(r.Rooms)
	RotateEntity r\obj,0,r\angle,0
	CalculateRoomExtents(r)
End Function

Function MoveRoom(r.Rooms)
	PositionEntity r\obj,r\x,r\y,r\z
	RotateEntity r\obj,0,r\angle,0
	CalculateRoomExtents(r)
End Function

Function ShouldSkipOverlapCandidate(r.Rooms)
	Local rt.RoomTemplates = r\RoomTemplate
	Return rt\DisableOverlapCheck Lor rt\Name = "checkpoint1" Lor rt\Name = "checkpoint2" Lor rt\Name = "start"
End Function

Function PreventRoomOverlap(r.Rooms)
	If r\RoomTemplate\DisableOverlapCheck Then Return
	
	; Just skip it when it would try to check for the checkpoints
	If ShouldSkipOverlapCandidate(r) Then Return
	
	Local r2.Rooms,r3.Rooms
	Local overlapAreaBefore1#,overlapAreaAfter1#
	Local overlapAreaBefore2#,overlapAreaAfter2#
	
	DebugLog "PreventRoomOverlap: " + r\RoomTemplate\Name
	
	; First, check if the room is actually intersecting at all
	overlapAreaBefore1 = CalcAllRoomOverlaps(r)
	If overlapAreaBefore1 = 0 Then Return
	
	DebugLog "Room is intersecting, overlapping area = " + overlapAreaBefore1
	
	; Room is intersecting: First, check if the given room is a ROOM2, so we could potentially just turn it by 180 degrees
	If r\RoomTemplate\Shape = ROOM2 Then
		;Room is a ROOM2, let's check if turning it 180 degrees fixes the overlapping issue
		r\angle = r\angle + 180
		RotateRoom(r)
		
		overlapAreaAfter1 = CalcAllRoomOverlaps(r)
		
		; room is ROOM2 and was able to be turned by 180 degrees
		If overlapAreaAfter1 = 0
			DebugLog "ROOM2 turning succesful! " + r\RoomTemplate\Name
			Return
		EndIf
		
		; room still overlaps after rotate. Check if new position any better
		If overlapAreaBefore1 > overlapAreaAfter1 Then
			DebugLog "Better position after ROOM2 rotate: " + overlapAreaBefore1 + " -> " + overlapAreaAfter1
			overlapAreaBefore1 = overlapAreaAfter1;
		Else
			; didn't work -> rotate the room back and move to the next step
			DebugLog "rollback ROOM2 rotate"
			r\angle = r\angle - 180
			RotateRoom(r)
		EndIf
	EndIf
	
	;Room is either not a ROOM2 or the ROOM2 is still intersecting, now trying to swap the room with another of the same type
	Local oldX1#,oldZ1#,oldAngle1%
	Local oldX2#,oldZ2#,oldAngle2%
	
	For r2 = Each Rooms
		If r\RoomTemplate\Shape = r2\RoomTemplate\Shape And r\zone = r2\zone And r <> r2 And (Not ShouldSkipOverlapCandidate(r2)) Then
			overlapAreaBefore2 = CalcAllRoomOverlaps(r2)
			Local candidatesOverlapAreaBefore# = CalcOverlapArea(r, r2)
			DebugLog "Swap overlap area: " + overlapAreaBefore2

			; remember original position before swap
			oldX1 = r\x
			oldZ1 = r\z
			oldAngle1 = r\angle

			oldX2 = r2\x
			oldZ2 = r2\z
			oldAngle2 = r2\angle

			; swap itself
			r\x = oldX2
			r\z = oldZ2
			r\angle = oldAngle2
			MoveRoom(r)

			r2\x = oldX1
			r2\z = oldZ1
			r2\angle = oldAngle1
			MoveRoom(r2)

			;make sure neither room overlaps with anything after the swap
			overlapAreaAfter1 = 0
			overlapAreaAfter2 = 0
			Local candidatesOverlapAreaAfter# = CalcOverlapArea(r, r2)
			For r3 = Each Rooms
				If Not r3\RoomTemplate\DisableOverlapCheck Then
					If r3 <> r Then 
						overlapAreaAfter1 = overlapAreaAfter1 + CalcOverlapArea(r, r3);
					EndIf
					If r3 <> r2 Then 
						overlapAreaAfter2 = overlapAreaAfter2 + CalcOverlapArea(r2, r3);
					EndIf
				EndIf
			Next
			DebugLog "Overlaps after swap: MAIN " + overlapAreaBefore1 + " -> " + overlapAreaAfter1 + ", SWAP " + overlapAreaBefore2 + " -> " + overlapAreaAfter2

			; Check if no overlaps after swap - then problem solved, return
			If overlapAreaAfter1 = 0 And overlapAreaAfter2 = 0 Then
				DebugLog "Successful rooms swap: " + r\RoomTemplate\Name + " / " + r2\RoomTemplate\Name
				Return
			EndIf

			; If we still have overlap - check if overlapping area is smaller than before and continue search
			; We subtract the overlap area between the candidates as it is otherwise counted twice, once as part of each sum.
			If (overlapAreaAfter1 + overlapAreaAfter2 - candidatesOverlapAreaAfter) < (overlapAreaBefore1 + overlapAreaBefore2 - candidatesOverlapAreaBefore) Then
				DebugLog "Partial overlap fix, rooms swap: " + r\RoomTemplate\Name + " / " + r2\RoomTemplate\Name
				overlapAreaBefore1 = overlapAreaAfter1
			Else
				; overlap area is bigger than before - then rollback this change and continue search
				DebugLog "Cancel this swap"
				r\x = oldX1
				r\z = oldZ1
				r\angle = oldAngle1
				MoveRoom(r)

				r2\x = oldX2
				r2\z = oldZ2
				r2\angle = oldAngle2
				MoveRoom(r2)
			EndIf
		EndIf
	Next
	
	DebugLog "Couldn't fix overlap issue for room " + r\RoomTemplate\Name
End Function