fixes map rendering by sorting planes correctly (#17679)

![](https://images-na.ssl-images-amazon.com/images/I/61CTVBlRL4L._SL1000_.jpg)

__DEFINES/planes+layers.dm

@@ -250,3 +250,17 @@ var/obj/abstract/screen/plane_master/clickmaster/clickmaster = new()
 	plane = BASE_PLANE
 
 var/obj/abstract/screen/plane_master/clickmaster_dummy/clickmaster_dummy = new()
+
+// returns a list with the objects sorted depending on their layer, with the lowest objects being the first in the list and the highest objects being last
+/proc/plane_layer_sort(var/list/to_sort)
+	var/list/sorted = list()
+	for(var/current_atom in to_sort)
+		var/compare_index
+		for(compare_index = sorted.len, compare_index > 0, --compare_index) // count down from the length of the list to zero.
+			var/atom/compare_atom = sorted[compare_index] // compare to the next object down the list.
+			if(compare_atom.plane < current_atom:plane) // is this object below our current atom?
+				break
+			else if((compare_atom.plane == current_atom:plane) && (compare_atom.layer <= current_atom:layer))	// is this object below our current atom?
+				break
+		sorted.Insert(compare_index+1, current_atom) // insert it just above the atom it was higher than - or at the bottom if it was higher than nothing.
+	return sorted // return the sorted list.

code/libs/Get Flat Icon/Get Flat Icon.dm

@@ -56,7 +56,6 @@ var/list/exception = list(
 proc/getFlatIcon(atom/A, dir, cache=1, exact=0) // 1 = use cache, 2 = override cache, 0 = ignore cache	//exact = 1 means the atom won't be rotated if it's a lying mob/living/carbon
 
 
-	var/list/layers = list() // Associative list of [overlay = layer]
 	var/hash = "" // Hash of overlay combination
 
 	if(is_type_in_list(A, directional)&&!is_type_in_list(A, exception))
@@ -82,65 +81,9 @@ proc/getFlatIcon(atom/A, dir, cache=1, exact=0) // 1 = use cache, 2 = override c
 		var/image/copy = image(icon=A.icon,icon_state=A.icon_state,layer=A.layer,dir=dir)
 		initialimage[copy] = A.layer
 
-
-	// Loop through the underlays, then overlays, sorting them into the layers list
-	var/list/process = A.underlays // Current list being processed
-	var/processSubset=0 // Which list is being processed: 0 = underlays, 1 = overlays
-
-	var/currentIndex=1 // index of 'current' in list being processed
-	var/currentOverlay // Current overlay being sorted
-	var/currentLayer // Calculated layer that overlay appears on (special case for FLOAT_LAYER)
-
-	var/compareOverlay // The overlay that the current overlay is being compared against
-	var/compareIndex // The index in the layers list of 'compare'
-
-	var/list/underlaysort = list()
-	var/list/overlaysort = list()
-	var/list/sorting = underlaysort
-
-	while(TRUE)
-		if(currentIndex<=process.len)
-			//All this does is find the appropriate layer and image
-			currentOverlay = process[currentIndex]
-			currentLayer = currentOverlay:layer
-			if(currentLayer<0) // Special case for FLY_LAYER
-				ASSERT(currentLayer > -1000)
-				if(processSubset == 0) // Underlay
-					currentLayer = A.layer+currentLayer/1000
-				else // Overlay
-					currentLayer = A.layer+(1000+currentLayer)/1000
-
-			//Next is a simple sort algorithm to place the overlay by layer
-			if(!sorting.len)
-				sorting[currentOverlay] = currentLayer
-				currentIndex++
-				continue
-
-			for(compareIndex=1,compareIndex<=sorting.len,compareIndex++)
-				compareOverlay = sorting[compareIndex]
-				if(currentLayer < sorting[compareOverlay]) // Associated value is the calculated layer
-					sorting.Insert(compareIndex,currentOverlay)
-					sorting[currentOverlay] = currentLayer
-					break
-			if(compareIndex>sorting.len) // Reached end of list without inserting
-				sorting[currentOverlay]=currentLayer // Place at end
-
-			currentIndex++
-
-		if(currentIndex>process.len)
-			if(processSubset == 0) // Switch to overlays
-				currentIndex = 1
-				processSubset = 1
-				process = A.overlays
-				sorting = overlaysort
-			else // All done
-				break
-
-	//Get flat icon previously understood layers as interspersing
-	//and could render overlays above the atom's icon before this following modification
-	layers = underlaysort
+	var/list/layers = plane_layer_sort(A.underlays)
 	layers += initialimage
-	layers += overlaysort
+	layers += plane_layer_sort(A.overlays)
 
 	if(cache!=0) // If cache is NOT disabled
 		// Create a hash value to represent this specific flattened icon

code/modules/paperwork/photography.dm

@@ -259,21 +259,9 @@
 				continue
 			atoms.Add(A)
 
-	var/list/sorted = list()
-	var/j
-	for(var/i = 1 to atoms.len)
-		var/atom/c = atoms[i]
-		for(j = sorted.len, j > 0, --j)
-			var/atom/c2 = sorted[j]
-			if(c2.plane < c.plane)
-				break
-			else if((c2.plane == c.plane) && (c2.layer <= c.layer))
-				break
-		sorted.Insert(j+1, c)
-
 	var/icon/res = get_base_photo_icon()
 
-	for(var/atom/A in sorted)
+	for(var/atom/A in plane_layer_sort(atoms))
 		var/icon/img = getFlatIcon(A,A.dir,0)
 		if(istype(A, /mob/living) && A:lying)
 			img.Turn(A:lying)
@@ -310,21 +298,9 @@
 			else
 				atoms.Add(A)
 
-	var/list/sorted = list()
-	var/j
-	for(var/i = 1 to atoms.len)
-		var/atom/c = atoms[i]
-		for(j = sorted.len, j > 0, --j)
-			var/atom/c2 = sorted[j]
-			if(c2.plane < c.plane)
-				break
-			else if((c2.plane == c.plane) && (c2.layer <= c.layer))
-				break
-		sorted.Insert(j+1, c)
-
 	var/icon/res = get_base_photo_icon()
 
-	for(var/atom/A in sorted)
+	for(var/atom/A in plane_layer_sort(atoms))
 		var/icon/img = getFlatIcon(A,A.dir,0)
 		if(istype(A, /mob/living) && A:lying)
 			img.Turn(A:lying)

maprendering/maprendering.dm

@@ -69,41 +69,16 @@
 						if(!allturfcontents.len)
 							continue
 
-						//Initializing our layer sorting variables
-						var/list/sorting = list()
-						var/atom/currentAtom = allturfcontents[1]
-						var/currentLayer
-						sorting[allturfcontents[1]] = currentAtom.layer
-						allturfcontents -= currentAtom
-						var/currentIndex = 1
-						var/compareIndex = 1
-
-						if(allturfcontents.len)
-							//Simple insertion sort, simple variant of the form in getflaticon
-							while(currentIndex <= allturfcontents.len)
-								currentAtom = allturfcontents[currentIndex]
-								currentLayer = currentAtom.layer
-
-								for(compareIndex=1,compareIndex<=sorting.len,compareIndex++)
-									if(currentLayer < sorting[sorting[compareIndex]])
-										sorting.Insert(compareIndex,currentAtom)
-										sorting[currentAtom] = currentLayer
-										break
-								if(compareIndex>sorting.len)
-									sorting[currentAtom]=currentLayer
-
-								currentIndex++
-
 						//Preparing to blend get flat icon of
-						for(var/atom/A in sorting)
-							var/icon/icontoblend = getFlatIcon(A = A, dir = A.dir, cache = 0)
+						for(var/A in plane_layer_sort(allturfcontents))
+							var/icon/icontoblend = getFlatIcon(A,A:dir, cache = 0)
 							map_icon.Blend(icontoblend, ICON_OVERLAY, ((a-1)*WORLD_ICON_SIZE)+1, ((b-1)*WORLD_ICON_SIZE)+1)
 						sleep(-1)
 
-				for(var/atom/A in pixel_shift_objects)
-					var/icon/icontoblend = getFlatIcon(A = A, dir = A.dir, cache = 0)
+				for(var/A in pixel_shift_objects)
+					var/icon/icontoblend = getFlatIcon(A, A:dir, cache = 0)
 					//This part is tricky since we've skipped a and b, since these are map objects they have valid x,y. a and b should be the modulo'd value of x,y with icon_size
-					map_icon.Blend(icontoblend, ICON_OVERLAY, (((A.x % icon_size)-1)*WORLD_ICON_SIZE)+1+A.pixel_x, (((A.y % icon_size)-1)*WORLD_ICON_SIZE)+1+A.pixel_y)
+					map_icon.Blend(icontoblend, ICON_OVERLAY, (((A:x % icon_size)-1)*WORLD_ICON_SIZE)+1+A:pixel_x, (((A:y % icon_size)-1)*WORLD_ICON_SIZE)+1+A:pixel_y)
 
 				if(y >= world.maxy)
 					map_icon.DrawBox(rgb(255,255,255,255), x1 = 1, y1 = 1, x2 = WORLD_ICON_SIZE*icon_size, y2 = WORLD_ICON_SIZE*(icon_size-world.maxy % icon_size))
@@ -119,3 +94,5 @@
 				if(fexists(resultpath))
 					fdel(resultpath)
 				fcopy(result_icon, resultpath)
+	to_chat(world, "<b>The map has been rendered successfully<b>")
+	src << sound('sound/effects/maprendercomplete.ogg')