Index: binaries/data/mods/public/gui/credits/texts/programming.json
===================================================================
--- binaries/data/mods/public/gui/credits/texts/programming.json
+++ binaries/data/mods/public/gui/credits/texts/programming.json
@@ -36,6 +36,7 @@
 				{ "nick": "ArnH", "name": "Arno Hemelhof" },
 				{ "nick": "Aurium", "name": "Aurélio Heckert" },
 				{ "nick": "badmadblacksad", "name": "Martin F" },
+				{ "nick": "badosu", "name": "Amadeus Folego" },
 				{ "nick": "bb", "name": "Bouke Jansen" },
 				{ "nick": "Ben", "name": "Ben Vinegar" },
 				{ "nick": "Bird" },
Index: binaries/data/mods/public/maps/random/rmgen/placer/centered/DiskPlacer.js
===================================================================
--- binaries/data/mods/public/maps/random/rmgen/placer/centered/DiskPlacer.js
+++ binaries/data/mods/public/maps/random/rmgen/placer/centered/DiskPlacer.js
@@ -4,6 +4,7 @@
 function DiskPlacer(radius, centerPosition = undefined)
 {
 	this.radiusSquared = Math.square(radius);
+	this.radius = radius;
 	this.centerPosition = undefined;
 
 	if (centerPosition)
@@ -19,12 +20,17 @@
 {
 	let points = [];
 
-	for (let x = 0; x < g_Map.getSize(); ++x)
-		for (let y = 0; y < g_Map.getSize(); ++y)
+	const xMin = Math.max(0, this.centerPosition.x - this.radius);
+	const yMin = Math.max(0, this.centerPosition.y - this.radius);
+	const xMax = Math.min(g_Map.getSize(), this.centerPosition.x + this.radius);
+	const yMax = Math.min(g_Map.getSize(), this.centerPosition.y + this.radius);
+
+	let it = new Vector2D();
+	for (it.x = xMin; it.x <= xMax; ++it.x)
+		for (it.y = yMin; it.y <= yMax; ++it.y)
 		{
-			let point = new Vector2D(x, y);
-			if (this.centerPosition.distanceToSquared(point) <= this.radiusSquared && constraint.allows(point))
-				points.push(point);
+			if (g_Map.validTile(it) && this.centerPosition.distanceToSquared(it) <= this.radiusSquared && constraint.allows(it))
+				points.push(it.clone());
 		}
 
 	return points;
Index: binaries/data/mods/public/maps/random/tests/test_DiskPlacer.js
===================================================================
--- /dev/null
+++ binaries/data/mods/public/maps/random/tests/test_DiskPlacer.js
@@ -0,0 +1,36 @@
+Engine.LoadLibrary("rmgen");
+
+var g_MapSettings = { "Size": 512 };
+var g_Map = new RandomMap(0, 0, "blackness");
+
+{
+	let center = new Vector2D(10, 10);
+	let area = createArea(new DiskPlacer(3, center));
+
+	// contains center
+	TS_ASSERT(area.contains(new Vector2D(10, 10)));
+
+	// contains disk boundaries
+	TS_ASSERT(area.contains(new Vector2D(10, 13)));
+	TS_ASSERT(area.contains(new Vector2D(10, 7)));
+	TS_ASSERT(area.contains(new Vector2D(7, 10)));
+	TS_ASSERT(area.contains(new Vector2D(13, 10)));
+
+	// does not contain rectangle vertices
+	TS_ASSERT(!area.contains(new Vector2D(13, 13)));
+	TS_ASSERT(!area.contains(new Vector2D(7, 7)));
+	TS_ASSERT(!area.contains(new Vector2D(13, 7)));
+	TS_ASSERT(!area.contains(new Vector2D(7, 13)));
+
+
+	// does not contain points outside disk range
+	TS_ASSERT(!area.contains(new Vector2D(10, 14)));
+	TS_ASSERT(!area.contains(new Vector2D(10, 6)));
+	TS_ASSERT(!area.contains(new Vector2D(6, 10)));
+	TS_ASSERT(!area.contains(new Vector2D(14, 10)));
+
+	area = createArea(new DiskPlacer(3, new Vector2D(0, 0)));
+
+	TS_ASSERT(!area.contains(new Vector2D(-1, 0))); // does not allow points out of map boundaries
+	TS_ASSERT(area.contains(new Vector2D(0, 0)));   // contains center on map edge
+}