From 9b00f12ba0a7d85b4baa613dd7746e151e2141cd Mon Sep 17 00:00:00 2001
From: CitadelStationBot <citadelstationcommunity@gmail.com>
Date: Mon, 4 Sep 2017 01:36:00 -0500
Subject: [PATCH] Makes the shuttle code a little bit more robust by removing a
 snowflake loop (#2559)

---
 code/__DEFINES/shuttles.dm      |   7 +-
 code/modules/shuttle/on_move.dm |  64 +++++++-----
 code/modules/shuttle/shuttle.dm | 175 ++++++++++++++++++++------------
 3 files changed, 152 insertions(+), 94 deletions(-)

diff --git a/code/__DEFINES/shuttles.dm b/code/__DEFINES/shuttles.dm
index bee6508609..f25dddcaf6 100644
--- a/code/__DEFINES/shuttles.dm
+++ b/code/__DEFINES/shuttles.dm
@@ -58,4 +58,9 @@
 #define DOCKING_COMPLETE 1
 #define DOCKING_BLOCKED 2
 #define DOCKING_IMMOBILIZED 4
-#define DOCKING_AREA_EMPTY 8
\ No newline at end of file
+#define DOCKING_AREA_EMPTY 8
+
+//Docking turf movements
+#define MOVE_TURF 1
+#define MOVE_AREA 2
+#define MOVE_CONTENTS 4
\ No newline at end of file
diff --git a/code/modules/shuttle/on_move.dm b/code/modules/shuttle/on_move.dm
index b09c38d714..59a0a46ae8 100644
--- a/code/modules/shuttle/on_move.dm
+++ b/code/modules/shuttle/on_move.dm
@@ -4,15 +4,17 @@ All ShuttleMove procs go here
 
 /************************************Base procs************************************/
 
-// Called on every turf in the shuttle region, return false if it doesn't want to move
-/turf/proc/fromShuttleMove(turf/newT, turf_type, baseturf_type)
-	if(type == turf_type && baseturf == baseturf_type)
-		return FALSE
-	return TRUE
+// Called on every turf in the shuttle region, returns a bitflag for allowed movements of that turf
+// returns the new move_mode (based on the old)
+/turf/proc/fromShuttleMove(turf/newT, turf_type, list/baseturf_cache, move_mode)
+	if(!(move_mode & MOVE_AREA) || (istype(src, turf_type) && baseturf_cache[baseturf]))
+		return move_mode
+	return move_mode | MOVE_TURF | MOVE_CONTENTS
 
 // Called from the new turf before anything has been moved
 // Only gets called if fromShuttleMove returns true first
-/turf/proc/toShuttleMove(turf/oldT, shuttle_dir)
+// returns the new move_mode (based on the old)
+/turf/proc/toShuttleMove(turf/oldT, shuttle_dir, move_mode)
 	for(var/i in contents)
 		var/atom/movable/thing = i
 		if(ismob(thing))
@@ -38,7 +40,7 @@ All ShuttleMove procs go here
 			else
 				qdel(thing)
 
-	return TRUE
+	return move_mode
 
 // Called on the old turf to move the turf data
 /turf/proc/onShuttleMove(turf/newT, turf_type, baseturf_type, rotation, list/movement_force, move_dir)
@@ -73,9 +75,9 @@ All ShuttleMove procs go here
 /////////////////////////////////////////////////////////////////////////////////////
 
 // Called on every atom in shuttle turf contents before anything has been moved
-// Return true if it should be moved regardless of turf being moved
-/atom/movable/proc/beforeShuttleMove(turf/newT, rotation)
-	return FALSE
+// returns the new move_mode (based on the old)
+/atom/movable/proc/beforeShuttleMove(turf/newT, rotation, move_mode)
+	return move_mode
 
 // Called on atoms to move the atom to the new location
 /atom/movable/proc/onShuttleMove(turf/newT, turf/oldT, rotation, list/movement_force, move_dir, old_dock)
@@ -102,13 +104,16 @@ All ShuttleMove procs go here
 /////////////////////////////////////////////////////////////////////////////////////
 
 // Called on areas before anything has been moved
-/area/proc/beforeShuttleMove()
-	return TRUE
+// returns the new move_mode (based on the old)
+/area/proc/beforeShuttleMove(list/shuttle_areas)
+	if(!shuttle_areas[src])
+		return NONE
+	return MOVE_AREA
 
 // Called on areas to move their turf between areas
 /area/proc/onShuttleMove(turf/oldT, turf/newT, area/underlying_old_area)
 	if(newT == oldT) // In case of in place shuttle rotation shenanigans.
-		return
+		return TRUE
 
 	contents -= oldT
 	underlying_old_area.contents += oldT
@@ -117,7 +122,7 @@ All ShuttleMove procs go here
 
 	var/area/old_dest_area = newT.loc
 	parallax_movedir = old_dest_area.parallax_movedir
-	
+
 	old_dest_area.contents -= newT
 	contents += newT
 	newT.change_area(old_dest_area, src)
@@ -160,9 +165,11 @@ All ShuttleMove procs go here
 	SSair.add_to_active(src, TRUE)
 	SSair.add_to_active(oldT, TRUE)
 
+/************************************Area move procs************************************/
+
 /************************************Machinery move procs************************************/
 
-/obj/machinery/door/airlock/beforeShuttleMove(turf/newT, rotation)
+/obj/machinery/door/airlock/beforeShuttleMove(turf/newT, rotation, move_mode)
 	. = ..()
 	shuttledocked = 0
 	for(var/obj/machinery/door/airlock/A in range(1, src))
@@ -176,11 +183,11 @@ All ShuttleMove procs go here
 	for(var/obj/machinery/door/airlock/A in range(1, src))
 		A.shuttledocked = 1
 
-/obj/machinery/camera/beforeShuttleMove(turf/newT, rotation)
+/obj/machinery/camera/beforeShuttleMove(turf/newT, rotation, move_mode)
 	. = ..()
 	GLOB.cameranet.removeCamera(src)
 	GLOB.cameranet.updateChunk()
-	return TRUE
+	. |= MOVE_CONTENTS
 
 /obj/machinery/camera/afterShuttleMove(list/movement_force, shuttle_dir, shuttle_preferred_direction, move_dir)
 	. = ..()
@@ -207,7 +214,7 @@ All ShuttleMove procs go here
 	if(z == ZLEVEL_MINING) //Avoids double logging and landing on other Z-levels due to badminnery
 		SSblackbox.add_details("colonies_dropped", "[x]|[y]|[z]") //Number of times a base has been dropped!
 
-/obj/machinery/gravity_generator/main/beforeShuttleMove(turf/newT, rotation)
+/obj/machinery/gravity_generator/main/beforeShuttleMove(turf/newT, rotation, move_mode)
 	. = ..()
 	on = FALSE
 	update_list()
@@ -218,9 +225,9 @@ All ShuttleMove procs go here
 		on = TRUE
 	update_list()
 
-/obj/machinery/thruster/beforeShuttleMove(turf/newT, rotation)
+/obj/machinery/thruster/beforeShuttleMove(turf/newT, rotation, move_mode)
 	. = ..()
-	. = TRUE
+	. |= MOVE_CONTENTS
 
 //Properly updates pipes on shuttle movement
 /obj/machinery/atmospherics/shuttleRotate(rotation)
@@ -271,7 +278,7 @@ All ShuttleMove procs go here
 	var/turf/T = loc
 	hide(T.intact)
 
-/obj/machinery/navbeacon/beforeShuttleMove(turf/newT, rotation)
+/obj/machinery/navbeacon/beforeShuttleMove(turf/newT, rotation, move_mode)
 	. = ..()
 	GLOB.navbeacons["[z]"] -= src
 	GLOB.deliverybeacons -= src
@@ -333,13 +340,13 @@ All ShuttleMove procs go here
 
 /************************************Structure move procs************************************/
 
-/obj/structure/grille/beforeShuttleMove(turf/newT, rotation)
+/obj/structure/grille/beforeShuttleMove(turf/newT, rotation, move_mode)
 	. = ..()
-	. = TRUE
+	. |= MOVE_CONTENTS
 
-/obj/structure/lattice/beforeShuttleMove(turf/newT, rotation)
+/obj/structure/lattice/beforeShuttleMove(turf/newT, rotation, move_mode)
 	. = ..()
-	. = TRUE
+	. |= MOVE_CONTENTS
 
 /obj/structure/disposalpipe/afterShuttleMove(list/movement_force, shuttle_dir, shuttle_preferred_direction, move_dir)
 	. = ..()
@@ -350,6 +357,11 @@ All ShuttleMove procs go here
 	var/turf/T = loc
 	if(level==1)
 		hide(T.intact)
+		
+/obj/structure/shuttle/beforeShuttleMove(turf/newT, rotation, move_mode)
+	. = ..()
+	. |= MOVE_CONTENTS
+
 
 /************************************Misc move procs************************************/
 
@@ -371,4 +383,4 @@ All ShuttleMove procs go here
 
 /obj/effect/abstract/proximity_checker/onShuttleMove(turf/newT, turf/oldT, rotation, list/movement_force, move_dir, old_dock)
 	//timer so it only happens once
-	addtimer(CALLBACK(monitor, /datum/proximity_monitor/proc/SetRange, monitor.current_range, TRUE), 0, TIMER_UNIQUE)
+	addtimer(CALLBACK(monitor, /datum/proximity_monitor/proc/SetRange, monitor.current_range, TRUE), 0, TIMER_UNIQUE)
\ No newline at end of file
diff --git a/code/modules/shuttle/shuttle.dm b/code/modules/shuttle/shuttle.dm
index d0d5952a0c..6ae0d98dfe 100644
--- a/code/modules/shuttle/shuttle.dm
+++ b/code/modules/shuttle/shuttle.dm
@@ -21,6 +21,10 @@
 	var/dwidth = 0	//position relative to covered area, perpendicular to dir
 	var/dheight = 0	//position relative to covered area, parallel to dir
 
+	var/area_type
+	var/turf_type
+	var/baseturf_type
+
 	//these objects are indestructible
 /obj/docking_port/Destroy(force)
 	// unless you assert that you know what you're doing. Horrible things
@@ -119,6 +123,39 @@
 			else
 				. += T
 
+/obj/docking_port/proc/return_ordered_assoc_turfs(_x, _y, _z, _dir)
+	if(!_dir)
+		_dir = dir
+	if(!_x)
+		_x = x
+	if(!_y)
+		_y = y
+	if(!_z)
+		_z = z
+	var/cos = 1
+	var/sin = 0
+	switch(_dir)
+		if(WEST)
+			cos = 0
+			sin = 1
+		if(SOUTH)
+			cos = -1
+			sin = 0
+		if(EAST)
+			cos = 0
+			sin = -1
+
+	. = list()
+
+	var/xi
+	var/yi
+	for(var/dx=0, dx<width, ++dx)
+		for(var/dy=0, dy<height, ++dy)
+			xi = _x + (dx-dwidth)*cos - (dy-dheight)*sin
+			yi = _y + (dy-dheight)*cos + (dx-dwidth)*sin
+			var/turf/T = locate(xi, yi, _z)
+			.[T] = NONE
+
 #ifdef DOCKING_PORT_HIGHLIGHT
 //Debug proc used to highlight bounding area
 /obj/docking_port/proc/highlight(_color)
@@ -147,9 +184,12 @@
 /obj/docking_port/stationary
 	name = "dock"
 
-	var/turf_type = /turf/open/space
-	var/baseturf_type = /turf/open/space
-	var/area_type = /area/space
+	turf_type = /turf/open/space
+	baseturf_type = /turf/open/space
+	area_type = /area/space
+
+	var/list/baseturf_cache
+
 	var/last_dock_time
 
 /obj/docking_port/stationary/Initialize()
@@ -159,6 +199,7 @@
 		id = "[SSshuttle.stationary.len]"
 	if(name == "dock")
 		name = "dock[SSshuttle.stationary.len]"
+	baseturf_cache = typecacheof(baseturf_type)
 
 	#ifdef DOCKING_PORT_HIGHLIGHT
 	highlight("#f00")
@@ -204,7 +245,8 @@
 	name = "shuttle"
 	icon_state = "pinonclose"
 
-	var/area_type = /area/shuttle
+	area_type = /area/shuttle
+
 	var/list/area/shuttle/shuttle_areas
 
 	var/timer						//used as a timer (if you want time left to complete move, use timeLeft proc)
@@ -465,25 +507,36 @@
 			return DOCKING_IMMOBILIZED
 
 	var/obj/docking_port/stationary/old_dock = get_docked()
-	var/turf_type = /turf/open/space //The turf that gets placed under where the shuttle moved from
-	var/baseturf_type = /turf/open/space //The baseturf that the gets assigned to the turf_type above
-	var/area_type = /area/space //The area that gets placed under where the shuttle moved from
+	var/underlying_turf_type = /turf/open/space //The turf that gets placed under where the shuttle moved from
+	var/underlying_baseturf_type = /turf/open/space //The baseturf that the gets assigned to the turf_type above
+	var/underlying_area_type = /area/space //The area that gets placed under where the shuttle moved from
+	var/list/baseturf_cache
 	if(old_dock) //Dock overwrites
 		if(old_dock.turf_type)
-			turf_type = old_dock.turf_type
+			underlying_turf_type = old_dock.turf_type
 		if(old_dock.baseturf_type)
-			baseturf_type = old_dock.baseturf_type
+			underlying_baseturf_type = old_dock.baseturf_type
 		if(old_dock.area_type)
-			area_type = old_dock.area_type
+			underlying_area_type = old_dock.area_type
+		if(old_dock.baseturf_cache)
+			baseturf_cache = old_dock.baseturf_cache
+	if(!baseturf_cache)
+		//Don't want to call this needlessly
+		baseturf_cache = typecacheof(underlying_baseturf_type)
 
-	var/list/old_turfs = return_ordered_turfs(x, y, z, dir)
+	/**************************************************************************************************************
+		old_turfs is an associative list with a turf:bitflag structure
+		new_turfs is a standard list composed of turf instances
+		The bitflag contains the data for what inhabitants of that coordinate should be moved to the new location
+		The bitflags can be found in __DEFINES/shuttles.dm
+	*/
+	var/list/old_turfs = return_ordered_assoc_turfs(x, y, z, dir)
 	var/list/new_turfs = return_ordered_turfs(new_dock.x, new_dock.y, new_dock.z, new_dock.dir)
-	var/list/old_contents = list() //Lists of turfs to only move contents and area but not move the turf
-	var/list/new_contents = list() //For structures etc that act attached to the ship
+	/**************************************************************************************************************/
 
-	var/area/underlying_old_area = locate("[area_type]")
+	var/area/underlying_old_area = locate("[underlying_area_type]")
 	if(!underlying_old_area)
-		underlying_old_area = new area_type(null)
+		underlying_old_area = new underlying_area_type(null)
 
 	var/rotation = 0
 	if(new_dock.dir != dir) //Even when the dirs are the same rotation is coming out as not 0 for some reason
@@ -501,67 +554,55 @@
 	var/list/areas_to_move = list() //unique assoc list of areas on turfs being moved
 
 	/****************************************All beforeShuttleMove procs*****************************************/
-	var/index = 1
-	while(index <= old_turfs.len)
-		var/turf/oldT = old_turfs[index]
-		var/turf/newT = new_turfs[index]
-		var/area/old_area = oldT.loc
-		var/move_turf = TRUE //Should this turf be moved, if false remove from the turf list
-		if(!(shuttle_areas[old_area]))
-			move_turf = FALSE
-		if(move_turf)
-			move_turf = oldT.fromShuttleMove(newT, turf_type, baseturf_type)								//turf
-			if(move_turf) //Only call toShuttleMove if the source turf is willing to move
-				move_turf = newT.toShuttleMove(oldT, dir)													//turf
-		for(var/ii in 1 to oldT.contents.len)
-			var/atom/movable/moving_atom = oldT.contents[ii]
-			if(moving_atom.beforeShuttleMove(newT, rotation) && !move_turf) 								//atoms
-				old_contents += oldT
-				new_contents += newT
-		if(!move_turf)
-			old_turfs.Cut(index,index+1)
-			new_turfs.Cut(index,index+1)
-			continue
-		areas_to_move[old_area] = TRUE
+	var/index = 0
+	for(var/place in old_turfs)
 		index++
+		var/turf/oldT = place
+		var/turf/newT = new_turfs[index]
+		if(!newT || !oldT)
+			continue
 
-	for(var/thing in areas_to_move)
-		var/area/internal_area = thing
-		internal_area.beforeShuttleMove() 																	//areas
+		var/area/old_area = oldT.loc
+		var/move_mode = old_area.beforeShuttleMove(shuttle_areas)											//areas
 
-	if(!old_turfs.len && !old_contents.len) //This should only happen if no shuttle area has been specified
-		return DOCKING_AREA_EMPTY
+		for(var/i in 1 to oldT.contents.len)
+			var/atom/movable/moving_atom = oldT.contents[i]
+			move_mode = moving_atom.beforeShuttleMove(newT, rotation, move_mode)							//atoms
+
+		move_mode = oldT.fromShuttleMove(newT, underlying_turf_type, baseturf_cache, move_mode)	//turfs
+		move_mode = newT.toShuttleMove(oldT, dir, move_mode)												//turfs
+
+		if(move_mode & MOVE_AREA)
+			areas_to_move[old_area] = TRUE
+		
+		old_turfs[place] = move_mode
 
 	/*******************************************All onShuttleMove procs******************************************/
 
-	for(var/i in 1 to old_turfs.len)
-		var/turf/oldT = old_turfs[i]
-		var/turf/newT = new_turfs[i]
-		if(!oldT || !newT) //This really shouldn't happen
-			continue
-		for(var/thing in oldT) //Needs to be this kind of loop in case, because of shuttle rotation shenanigans, the destination turf is the same as the source turf
-			var/atom/movable/moving_atom = thing
-			moving_atom.onShuttleMove(newT, oldT, rotation, movement_force, movement_direction, old_dock)	//atoms
-			moved_atoms += moving_atom
-		oldT.onShuttleMove(newT, turf_type, baseturf_type, rotation, movement_force, movement_direction) 	//turfs
-		var/area/shuttle_area = oldT.loc
-		shuttle_area.onShuttleMove(oldT, newT, underlying_old_area) 										//areas
-
-	for(var/i in 1 to old_contents.len) //This is for moving atoms that need to move without their turf
-		var/turf/oldT = old_contents[i] //I'll figure out a way of merging these loops eventualy, probably
-		var/turf/newT = new_contents[i]
-		if(!oldT || !newT)
-			continue
-		for(var/thing in oldT)
-			var/atom/movable/moving_atom = thing
-			moving_atom.onShuttleMove(newT, oldT, rotation, movement_force, movement_direction)				//atoms
-			moved_atoms += moving_atom
+	index = 0
+	for(var/place in old_turfs)
+		index++
+		var/turf/oldT = place
+		var/turf/newT = new_turfs[index]
+		var/move_mode = old_turfs[place]
+		if(move_mode & MOVE_CONTENTS)
+			for(var/thing in oldT)
+				var/atom/movable/moving_atom = thing
+				moving_atom.onShuttleMove(newT, oldT, rotation, movement_force, movement_direction, old_dock)//atoms
+				moved_atoms += moving_atom
+		if(move_mode & MOVE_TURF)
+			oldT.onShuttleMove(newT, underlying_turf_type, underlying_baseturf_type, rotation, movement_force, movement_direction)//turfs
+		if(move_mode & MOVE_AREA)
+			var/area/shuttle_area = oldT.loc
+			shuttle_area.onShuttleMove(oldT, newT, underlying_old_area)										//areas
 
 	/******************************************All afterShuttleMove procs****************************************/
 
-	for(var/i in 1 to new_turfs.len)
-		var/turf/oldT = old_turfs[i]
-		var/turf/newT = new_turfs[i]
+	index = 0
+	for(var/thing in old_turfs)
+		index++
+		var/turf/oldT = thing
+		var/turf/newT = new_turfs[index]
 		newT.afterShuttleMove(oldT)																			//turfs
 
 	for(var/i in 1 to moved_atoms.len)