diff --git a/build.gradle b/build.gradle
index 4aa5cf526..f28ac99dd 100644
--- a/build.gradle
+++ b/build.gradle
@@ -56,8 +56,9 @@ task gamedebug(type: JavaExec) {
     classpath sourceSets.main.runtimeClasspath
     main = 'net.torvald.terrarum.AppLoader'
     group = "Application"
-    description = "Launches the game with debuy key."
+    description = "Launches the game with the debug key."
     args = ["isdev=true"]
+    jvmArgs = ["-ea"]
 }
 
 task spriteassembler(type: JavaExec) {
diff --git a/src/net/torvald/terrarum/worlddrawer/BlocksDrawerNew.kt b/src/net/torvald/terrarum/worlddrawer/BlocksDrawerNew.kt
index e73ed529c..b95693b9e 100644
--- a/src/net/torvald/terrarum/worlddrawer/BlocksDrawerNew.kt
+++ b/src/net/torvald/terrarum/worlddrawer/BlocksDrawerNew.kt
@@ -161,6 +161,10 @@ internal object BlocksDrawer {
     private val connectLut47 = intArrayOf(17,1,17,1,2,3,2,14,17,1,17,1,2,3,2,14,9,7,9,7,4,5,4,35,9,7,9,7,16,37,16,15,17,1,17,1,2,3,2,14,17,1,17,1,2,3,2,14,9,7,9,7,4,5,4,35,9,7,9,7,16,37,16,15,8,10,8,10,0,12,0,43,8,10,8,10,0,12,0,43,11,13,11,13,6,20,6,34,11,13,11,13,36,33,36,46,8,10,8,10,0,12,0,43,8,10,8,10,0,12,0,43,30,42,30,42,38,26,38,18,30,42,30,42,23,45,23,31,17,1,17,1,2,3,2,14,17,1,17,1,2,3,2,14,9,7,9,7,4,5,4,35,9,7,9,7,16,37,16,15,17,1,17,1,2,3,2,14,17,1,17,1,2,3,2,14,9,7,9,7,4,5,4,35,9,7,9,7,16,37,16,15,8,28,8,28,0,41,0,21,8,28,8,28,0,41,0,21,11,44,11,44,6,27,6,40,11,44,11,44,36,19,36,32,8,28,8,28,0,41,0,21,8,28,8,28,0,41,0,21,30,29,30,29,38,39,38,25,30,29,30,29,23,24,23,22)
     private val connectLut16 = intArrayOf(0,2,0,2,4,6,4,6,0,2,0,2,4,6,4,6,8,10,8,10,12,14,12,14,8,10,8,10,12,14,12,14,0,2,0,2,4,6,4,6,0,2,0,2,4,6,4,6,8,10,8,10,12,14,12,14,8,10,8,10,12,14,12,14,1,3,1,3,5,7,5,7,1,3,1,3,5,7,5,7,9,11,9,11,13,15,13,15,9,11,9,11,13,15,13,15,1,3,1,3,5,7,5,7,1,3,1,3,5,7,5,7,9,11,9,11,13,15,13,15,9,11,9,11,13,15,13,15,0,2,0,2,4,6,4,6,0,2,0,2,4,6,4,6,8,10,8,10,12,14,12,14,8,10,8,10,12,14,12,14,0,2,0,2,4,6,4,6,0,2,0,2,4,6,4,6,8,10,8,10,12,14,12,14,8,10,8,10,12,14,12,14,1,3,1,3,5,7,5,7,1,3,1,3,5,7,5,7,9,11,9,11,13,15,13,15,9,11,9,11,13,15,13,15,1,3,1,3,5,7,5,7,1,3,1,3,5,7,5,7,9,11,9,11,13,15,13,15,9,11,9,11,13,15,13,15)
 
+    init {
+        assert(256 == connectLut47.size && 256 == connectLut16.size)
+    }
+
     /**
      * Tiles that half-transparent and has hue
      * will blend colour using colour multiplication
diff --git a/src/net/torvald/terrarum/worlddrawer/LightmapRendererNew.kt b/src/net/torvald/terrarum/worlddrawer/LightmapRendererNew.kt
index 8fcf3b594..91f1ced87 100644
--- a/src/net/torvald/terrarum/worlddrawer/LightmapRendererNew.kt
+++ b/src/net/torvald/terrarum/worlddrawer/LightmapRendererNew.kt
@@ -72,8 +72,8 @@ object LightmapRenderer {
 
     // TODO resize(int, int) -aware
 
-    val LIGHTMAP_WIDTH = (Terrarum.ingame?.ZOOM_MINIMUM ?: 1f).inv().times(Terrarum.WIDTH).div(TILE_SIZE).ceil() + overscan_open * 2 + 3
-    val LIGHTMAP_HEIGHT = (Terrarum.ingame?.ZOOM_MINIMUM ?: 1f).inv().times(Terrarum.HEIGHT).div(TILE_SIZE).ceil() + overscan_open * 2 + 3
+    var LIGHTMAP_WIDTH = (Terrarum.ingame?.ZOOM_MINIMUM ?: 1f).inv().times(Terrarum.WIDTH).div(TILE_SIZE).ceil() + overscan_open * 2 + 3
+    var LIGHTMAP_HEIGHT = (Terrarum.ingame?.ZOOM_MINIMUM ?: 1f).inv().times(Terrarum.HEIGHT).div(TILE_SIZE).ceil() + overscan_open * 2 + 3
 
     val noopMask = HashSet<Point2i>((LIGHTMAP_WIDTH + LIGHTMAP_HEIGHT) * 2)
 
@@ -82,7 +82,7 @@ object LightmapRenderer {
      */
     // it utilises alpha channel to determine brightness of "glow" sprites (so that alpha channel works like UV light)
     //private val lightmap: Array<Array<Color>> = Array(LIGHTMAP_HEIGHT) { Array(LIGHTMAP_WIDTH, { Color(0f,0f,0f,0f) }) } // Can't use framebuffer/pixmap -- this is a fvec4 array, whereas they are ivec4.
-    private val lightmap: Array<Color> = Array(LIGHTMAP_WIDTH * LIGHTMAP_HEIGHT) { Color(0f,0f,0f,0f) } // Can't use framebuffer/pixmap -- this is a fvec4 array, whereas they are ivec4.
+    private var lightmap: Array<Color> = Array(LIGHTMAP_WIDTH * LIGHTMAP_HEIGHT) { Color(0) } // Can't use framebuffer/pixmap -- this is a fvec4 array, whereas they are ivec4.
     private val lanternMap = HashMap<BlockAddress, Color>((Terrarum.ingame?.ACTORCONTAINER_INITIAL_SIZE ?: 2) * 4)
 
     init {
@@ -713,6 +713,9 @@ object LightmapRenderer {
         val tilesInHorizontal = (screenW.toFloat() / TILE_SIZE).ceilInt() + 1
         val tilesInVertical = (screenH.toFloat() / TILE_SIZE).ceilInt() + 1
 
+        LIGHTMAP_WIDTH = (Terrarum.ingame?.ZOOM_MINIMUM ?: 1f).inv().times(Terrarum.WIDTH).div(TILE_SIZE).ceil() + overscan_open * 2 + 3
+        LIGHTMAP_HEIGHT = (Terrarum.ingame?.ZOOM_MINIMUM ?: 1f).inv().times(Terrarum.HEIGHT).div(TILE_SIZE).ceil() + overscan_open * 2 + 3
+
         if (_init) {
             lightBuffer.dispose()
         }
@@ -720,6 +723,7 @@ object LightmapRenderer {
             _init = true
         }
         lightBuffer = Pixmap(tilesInHorizontal, tilesInVertical, Pixmap.Format.RGBA8888)
+        lightmap = Array<Color>(LIGHTMAP_WIDTH * LIGHTMAP_HEIGHT) { Color(0) }
 
 
         printdbg(this, "Resize event")