using kotlin's newfangled 'x in xs.indices' instead of 'x in 0 until xs.size'

src/net/torvald/terrarum/modulebasegame/TerrarumIngame.kt

@@ -407,7 +407,7 @@ open class TerrarumIngame(batch: SpriteBatch) : IngameInstance(batch) {
         }
         // scan for the one with non-null UI.
         // what if there's multiple of such fixtures? whatever, you are supposed to DISALLOW such situation.
-        for (kk in 0 until actorsUnderMouse.size) {
+        for (kk in actorsUnderMouse.indices) {
             actorsUnderMouse[kk].mainUI?.let {
                 uiOpened = true
 

src/net/torvald/terrarum/modulebasegame/gameworld/WorldSimulator.kt

@@ -378,8 +378,8 @@ object WorldSimulator {
     private val FALLABLE_MAX_FALL_SPEED = 2
 
     private fun monitorIllegalFluidSetup() {
-        for (y in 0 until fluidMap.size) {
-            for (x in 0 until fluidMap[0].size) {
+        for (y in fluidMap.indices) {
+            for (x in fluidMap[0].indices) {
                 val fluidData = world.getFluid(x + updateXFrom, y + updateYFrom)
                 if (fluidData.amount < 0f) {
                     throw InternalError("Negative amount of fluid at (${x + updateXFrom},${y + updateYFrom}): $fluidData")
@@ -391,8 +391,8 @@ object WorldSimulator {
     private fun makeFluidMapFromWorld() {
         //printdbg(this, "Scan area: ($updateXFrom,$updateYFrom)..(${updateXFrom + fluidMap[0].size},${updateYFrom + fluidMap.size})")
 
-        for (y in 0 until fluidMap.size) {
-            for (x in 0 until fluidMap[0].size) {
+        for (y in fluidMap.indices) {
+            for (x in fluidMap[0].indices) {
                 val fluidData = world.getFluid(x + updateXFrom, y + updateYFrom)
                 fluidMap[y][x] = fluidData.amount
                 fluidTypeMap[y][x] = fluidData.type
@@ -407,8 +407,8 @@ object WorldSimulator {
     }
 
     private fun fluidmapToWorld() {
-        for (y in 0 until fluidMap.size) {
-            for (x in 0 until fluidMap[0].size) {
+        for (y in fluidMap.indices) {
+            for (x in fluidMap[0].indices) {
                 world.setFluid(x + updateXFrom, y + updateYFrom, fluidNewTypeMap[y][x], fluidNewMap[y][x])
             }
         }

src/net/torvald/terrarum/modulebasegame/ui/UIInventory.kt

@@ -307,7 +307,7 @@ package net.torvald.terrarum.modulebasegame.ui
             inventorySortList.sortBy { it.item.name }
 
             // map sortList to item list
-            for (k in 0 until items.size) {
+            for (k in items.indices) {
                 // we have an item
                 try {
                     val sortListItem = inventorySortList[k + itemPage * items.size]

src/net/torvald/terrarum/modulebasegame/ui/UIItemInventoryDynamicList.kt

@@ -353,7 +353,7 @@ class UIItemInventoryDynamicList(
         inventorySortList.sortBy { ItemCodex[it.item]!!.name }
 
         // map sortList to item list
-        for (k in 0 until items.size) {
+        for (k in items.indices) {
             // we have an item
             try {
                 val sortListItem = inventorySortList[k + itemPage * items.size]
@@ -372,7 +372,7 @@ class UIItemInventoryDynamicList(
                 }
 
                 // set equippedslot number
-                for (eq in 0 until inventory.itemEquipped.size) {
+                for (eq in inventory.itemEquipped.indices) {
                     if (eq < inventory.itemEquipped.size) {
                         if (inventory.itemEquipped[eq] == items[k].item?.dynamicID) {
                             items[k].equippedSlot = eq

src/net/torvald/terrarum/modulebasegame/ui/UIItemInventoryEquippedView.kt

@@ -118,7 +118,7 @@ class UIItemInventoryEquippedView(
         // sort by equip position
 
         // fill the grid from fastest index, make no gap in-between of slots
-        for (k in 0 until itemGrid.size) {
+        for (k in itemGrid.indices) {
             val item = inventory.itemEquipped[k]
 
             if (item == null) {