diff --git a/biome-ui.js b/biome-ui.js
index 9f4d702..4290635 100644
--- a/biome-ui.js
+++ b/biome-ui.js
@@ -8,10 +8,12 @@ const DRAW_MIN = LIMIT_MIN - 10
 const DRAW_MAX = LIMIT_MAX + 10
 const GRID_STEP = 10
 
+let lastBiomeID = 0;
 
 let biomePoints = [
-	{name: generateBiomeName(50, 50), heat:50, humidity:50, min_y: MIN_Y_DEFAULT, max_y: MAX_Y_DEFAULT},
+	{id: 0, name: generateBiomeName(50, 50), heat:50, humidity:50, min_y: MIN_Y_DEFAULT, max_y: MAX_Y_DEFAULT},
 ];
+lastBiomeID++;
 
 // FOREST-16 palette, plus black
 const pointColor = "#913636";
@@ -36,17 +38,21 @@ const cellColors = [
 	"#ecddba",
 ];
 
-// define an array and randomize it
-function shuffleArray(values) {
-	let index = values.length, randomIndex;
-	// While there remain elements to shuffle
-	while (index != 0) {
-		// Pick a remaining element.
-		randomIndex = Math.floor(Math.random() * index);
-		index--; // And swap it with the current element.
-		[values[index], values[randomIndex]] = [values[randomIndex], values[index]];
+// returns the biome point by its given ID
+// or null if it couldn't be found
+function getBiomeByID(id) {
+	for(let b=0; b<biomePoints.length; b++) {
+		let biome = biomePoints[b];
+		if (biome.id === id) {
+			return biome;
+		}
 	}
-	return values;
+	return null;
+}
+
+// Returns a biome name for displaying it, based on heat and humidity values.
+function generateBiomeName(heat, humidity) {
+	return "("+heat+","+humidity+")";
 }
 
 function biomePointToVoronoiPoint(point) {
@@ -207,7 +213,7 @@ function getVoronoiDiagram(recalculate) {
 function getDrawContext() {
 	let canvas = document.getElementById("voronoiCanvas");
 	// TODO: Check for getContext support of browser
-	return  canvas.getContext("2d");
+	return canvas.getContext("2d");
 }
 function drawInit() {
 	let context = getDrawContext();
@@ -216,10 +222,13 @@ function drawInit() {
 }
 function draw(recalculate) {
 	let context = getDrawContext();
+	// Clear draw area
 	context.fillStyle = "#FFFFFF";
 	context.fillRect(DRAW_MIN, DRAW_MIN, DRAW_MAX-DRAW_MIN, DRAW_MAX-DRAW_MIN);
+
 	let diagram = getVoronoiDiagram(recalculate);
-	//let colors = shuffleArray(cellColors);
+
+	// Render cell colors
 	let colors = cellColors;
 	for (let c=0; c<diagram.cells.length; c++) {
 		let cell = diagram.cells[c]
@@ -240,7 +249,10 @@ function draw(recalculate) {
 		context.closePath();
 		context.fill();
 	}
+	// If there's only 1 cell, we have to manually colorize it because
+	// the Voronoi script doesn't return that area in this special case.
 	if (biomePoints.length === 1 && diagram.cells.length === 1) {
+		// 1 cell means the whole area is filled
 		context.fillStyle = colors[0];
 		context.fillRect(DRAW_MIN, DRAW_MIN, DRAW_MAX-DRAW_MIN, DRAW_MAX-DRAW_MIN);
 	}
@@ -248,6 +260,7 @@ function draw(recalculate) {
 	//putAxes(context);
 	putGrid(context);
 
+	// Render Voronoi cell edges
 	context.lineWidth = 2;
 	for (let e=0; e<diagram.edges.length; e++) {
 		let edge = diagram.edges[e];
@@ -263,6 +276,7 @@ function draw(recalculate) {
 		context.stroke();
 	}
 
+	// Render biome points
 	for (let p=0; p<biomePoints.length; p++) {
 		if (p === biomeSelector.selectedIndex) {
 			context.fillStyle = pointColorSelected;
@@ -272,6 +286,7 @@ function draw(recalculate) {
 		putPoint(context, biomePoints[p]);
 	}
 
+	// Render a special message if there are no biomes
 	if (biomePoints.length === 0) {
 		context.textAlign = "center";
 		context.fillStyle = "black";
@@ -280,10 +295,6 @@ function draw(recalculate) {
 	}
 
 }
-window.addEventListener("load", drawInit);
-window.addEventListener("load", draw);
-window.addEventListener("load", rewriteBiomeSelector);
-window.addEventListener("load", updateWidgetStates);
 
 function rewriteBiomeSelector() {
 	biomeSelector.innerHTML = "";
@@ -321,10 +332,6 @@ function updateWidgetStates() {
 	}
 }
 
-function generateBiomeName(heat, humidity) {
-	return "("+heat+","+humidity+")";
-}
-
 biomeSelector.onchange = function() {
 	draw(false);
 	if (biomeSelector.selectedIndex !== -1) {
@@ -376,6 +383,7 @@ addBiomeButton.onclick = function() {
 	let he = Math.round(Math.random()*100);
 	let hu = Math.round(Math.random()*100);
 	let newPoint = {
+		id: lastBiomeID,
 		name: generateBiomeName(he, hu),
 		heat: he,
 		min_y: MIN_Y_DEFAULT,
@@ -386,7 +394,9 @@ addBiomeButton.onclick = function() {
 	let num = biomePoints.length
 
 	let newElem = document.createElement("option");
+	newElem.id = "_biome_id_" + lastBiomeID;
 	newElem.value = "" + num;
+
 	let newElemText = document.createTextNode(newPoint.name);
 	newElem.append(newElemText);
 	biomeSelector.append(newElem);
@@ -394,6 +404,8 @@ addBiomeButton.onclick = function() {
 
 	draw(true);
 	updateWidgetStates();
+
+	lastBiomeID++;
 }
 removeBiomeButton.onclick = function() {
 	if (biomeSelector.selectedOptions.length === 0) {
@@ -420,3 +432,9 @@ removeBiomeButton.onclick = function() {
 	draw(true);
 	updateWidgetStates();
 }
+
+
+window.addEventListener("load", drawInit);
+window.addEventListener("load", draw);
+window.addEventListener("load", rewriteBiomeSelector);
+window.addEventListener("load", updateWidgetStates);