diff --git a/mods/portal.js b/mods/portal.js
index 36a206e5..aa9caaef 100644
--- a/mods/portal.js
+++ b/mods/portal.js
@@ -1,66 +1,120 @@
-function includesArray(parentArray, testArray) {
-    for (let i = 0; i < parentArray.length; i++) {
-        if (parentArray[i].every(function(value, index) { return value === testArray[index]})) {
-            return true;
-        }
-    }
-    return false;
-}
+var modName = "mods/portal.js";
+var onTryMoveIntoMod = "mods/onTryMoveInto.js";
+var libraryMod = "mods/code_library.js";
 
-elements.portal_in = {
-	color: "#ee7f00",
-	tick: function(pixel) {
-		if(!pixel.portalArray) { pixel.portalArray = [] }
-		if(!Array.isArray(pixel.portalArray)) { pixel.portalArray = [] }
-		for (var i = 1; i < width; i++) {
-			for (var j = 1; j < height; j++) {
-				if (!isEmpty(i,j)) {
-					if(pixelMap[i][j].element == "portal_out") {
-						if(!includesArray(pixel.portalArray,[i,j])) {
-							pixel.portalArray.push([i,j])
-						}
-					}
-				}
-				if (isEmpty(i,j)) {
-					if(includesArray(pixel.portalArray,[i,j])) {
-						pixel.portalArray = pixel.portalArray.filter(dat => !includesArray(pixel.portalArray,[i,j]))
+if(enabledMods.includes(onTryMoveIntoMod) && enabledMods.includes(libraryMod)) {
+	//https://stackoverflow.com/a/60922255
+	if(!enabledMods.includes("mods/mobs.js")) {
+		headBodyObject = {
+			"head": "body",
+		};
+	};
 
-					}
-				}
-			}
-		}
-		if(pixel.portalArray.length > 0) {
-			randomDestination = pixel.portalArray[Math.floor((Math.random() * pixel.portalArray.length))]
-			if(!isEmpty(pixel.x-1,pixel.y) && !outOfBounds(pixel.x-1,pixel.y)) {
-				if(pixelMap[pixel.x-1][pixel.y].element != pixel.element) {
-					tryMove(pixelMap[pixel.x-1][pixel.y],(randomDestination[0] + 1),(randomDestination[1]))
-				}
-			}
-			if(!isEmpty(pixel.x+1,pixel.y) && !outOfBounds(pixel.x+1,pixel.y)) {
-				if(pixelMap[pixel.x+1][pixel.y].element != pixel.element) {
-					tryMove(pixelMap[pixel.x+1][pixel.y],(randomDestination[0] - 1),(randomDestination[1]))
-				}
-			}
-			if(!isEmpty(pixel.x,pixel.y-1) && !outOfBounds(pixel.x,pixel.y-1)) {
-				if(pixelMap[pixel.x][pixel.y-1].element != pixel.element) {
-					tryMove(pixelMap[pixel.x][pixel.y-1],(randomDestination[0]),(randomDestination[1] + 1))
-				}
-			}
-			if(!isEmpty(pixel.x,pixel.y+1) && !outOfBounds(pixel.x,pixel.y+1)) {
-				if(pixelMap[pixel.x][pixel.y+1].element != pixel.element) {
-					tryMove(pixelMap[pixel.x][pixel.y+1],(randomDestination[0]),(randomDestination[1] - 1))
-				}
-			}
-		}
+	elements.portal_in = {
+		color: "#ee7f00",
+		properties: {
+			_channel: 0,
+			_correspondingPortals: null,
+		},
+		insulate: true,
+		onTryMoveInto: function(pixel,otherPixel) {
+			if(pixel._correspondingPortals == null) {
+				return;
+			};
+			if(pixel._correspondingPortals.length <= 0) {
+				return;
+			};
+			
+			var portal = randomChoice(pixel._correspondingPortals);
+			
+			var offset = {x: pixel.x - otherPixel.x, y: pixel.y - otherPixel.y}; //teleport destination's offset, inverted by subtraction
+			
+			var destination = {x: portal.x + offset.x, y: portal.y + offset.y};
+
+			var otherElement = otherPixel.element;
+			var isHead = (typeof(headBodyObject[otherElement]) !== "undefined");
+			var isBody = (typeof(getKeyByValue(headBodyObject,otherElement)) !== "undefined");
+			var isBipartite = xor(isHead,isBody); //a head being its own body will break the code	
+			
+			if(isBipartite) {
+				if(isHead) {
+					var dead = otherPixel.dead;
+					var body = pixelMap[otherPixel.x][otherPixel.y+1];
+					if(body == undefined) { body = null };
+					if(!dead && (body !== null)) {
+						if(offset.y == -1) {
+							offset.y--;
+							destination.y--;
+						};
+						var headSpotIsEmpty = isEmpty(destination.x,destination.y,false);
+						var bodySpotIsEmpty = isEmpty(destination.x,destination.y+1,false);
+						if(headSpotIsEmpty && bodySpotIsEmpty) {
+							tryMove(otherPixel,destination.x,destination.y);
+							tryMove(body,destination.x,destination.y+1);
+						};
+					} else {
+						tryMove(otherPixel,destination.x,destination.y);
+					};
+				} else if(isBody) {
+					var dead = otherPixel.dead;
+					var head = pixelMap[otherPixel.x][otherPixel.y-1];
+					if(head == undefined) { head = null };
+					if(!dead && (head !== null)) {
+						if(offset.y == 1) {
+							offset.y++;
+							destination.y++;
+						};
+						var headSpotIsEmpty = isEmpty(destination.x,destination.y-1,false);
+						var bodySpotIsEmpty = isEmpty(destination.x,destination.y,false);
+						if(headSpotIsEmpty && bodySpotIsEmpty) {
+							tryMove(head,destination.x,destination.y-1);
+							tryMove(otherPixel,destination.x,destination.y);
+						};
+					} else {
+						tryMove(otherPixel,destination.x,destination.y);
+					};
+				};
+			} else {
+				tryMove(otherPixel,destination.x,destination.y);
+			};
+		},
+		tick: function(pixel) {
+			pixel._channel = Math.floor(pixel.temp / 100);
+
+			pixel._correspondingPortals = currentPixels.filter(function(pixelToCheck) {
+				return (
+					pixelToCheck.element == "portal_out" &&
+					pixelToCheck._channel == pixelChannel
+				);
+			},pixelChannel=pixel._channel);
+			
+			for(i = 0; i < pixel._correspondingPortals.length; i++) {
+				pixel._correspondingPortals[i] = {x: pixel._correspondingPortals[i].x, y: pixel._correspondingPortals[i].y};
+			};
+			
+			//pixel.tempdebug = JSON.stringify(pixel._correspondingPortals);
+		},
+		category: "machines",
+		state: "solid",
 	},
-	category: "machines",
-	state: "solid",
-	portalArray: [],
-},
 
-elements.portal_out = {
-	color: "#2222ee",
-	behavior: behaviors.WALL,
-	category: "machines",
-	state: "solid",
-}
+	elements.portal_out = {
+		color: "#2222ee",
+		properties: {
+			channel: 0
+		},
+		insulate: true,
+		tick: function(pixel) {
+			pixel._channel = Math.floor(pixel.temp / 100);
+		},
+		behavior: behaviors.WALL,
+		category: "machines",
+		state: "solid",
+		insulate: true,
+	}
+} else {
+	if(!enabledMods.includes(libraryMod))		{ enabledMods.splice(enabledMods.indexOf(modName),0,libraryMod) };
+	if(!enabledMods.includes(onTryMoveIntoMod))	{ enabledMods.splice(enabledMods.indexOf(modName),0,onTryMoveIntoMod) };
+	localStorage.setItem("enabledMods", JSON.stringify(enabledMods));
+	alert(`The "${libraryMod}" and "${onTryMoveIntoMod}" mods are all required; any missing mods in this list have been automatically inserted (reload for this to take effect).`)
+};