Tightened clamping.

src/engine/InterestManagement/HeightMap.java

@@ -331,9 +331,9 @@ public class HeightMap {
         if (gridY < 0)
             gridY = 0;
 
-        if (gridX > maxX)
+        if (gridX >= maxX)
             gridX = maxX - 1;
-        if (gridY > maxY)
+        if (gridY >= maxY)
             gridY = maxY - 1;
 
         float offsetX = (gridSquare.x - gridX);