Fix entity chunk-tracking leaks, add saveCanSave, use chunkindex_t

Entities weren't being detached from their chunk's entities[] slot in
two despawn paths (CUTSCENE_ENTITY_REMOVE, item pickup collection) - the
slot leaked forever until the whole chunk unloaded. Both now call
entitySetChunk(entity, CHUNK_INDEX_INVALID) before nulling the type.

entity_t.chunkIndex and entitySetChunk/mapGetChunk now use chunkindex_t
instead of uint8_t, matching mapGetChunkIndexAt's own -1-is-invalid
convention - added CHUNK_INDEX_INVALID next to the typedef in
worldpos.h rather than reusing the old 0xFF/uint8_t sentinel, which
would silently mean +255 on a signed 16-bit field instead of -1.

mapPositionSet now also recomputes every live entity's cached
chunkIndex after mapRebuildChunkOrder() reshuffles which chunk_t sits
at each chunkOrder slot - done as a direct field recompute rather than
through entitySetChunk, which would've looked up each entity's now-stale
old index, failed to find/clear its real registration, and inserted a
duplicate entry into the correct chunk on every map position change.

Also adds saveCanSave() (false while a cutscene is running) and shows
the player's live chunkIndex in the ui/debug/uiplayerpos overlay.

Co-Authored-By: Claude Sonnet 5 <[email protected]>

src/dusk/rpg/cutscene/item/entity/cutsceneentityremove.c

@@ -14,8 +14,10 @@ void cutsceneEntityRemoveStart(
   const cutsceneitem_t *item,
   cutsceneitemdata_t *data
 ) {
-  cutsceneSystemGetEntity(item->entityRemove.entityIndex)->type = \
-    ENTITY_TYPE_NULL;
+  entity_t *entity =
+    cutsceneSystemGetEntity(item->entityRemove.entityIndex);
+  entitySetChunk(entity, CHUNK_INDEX_INVALID);
+  entity->type = ENTITY_TYPE_NULL;
 }
 
 bool_t cutsceneEntityRemoveUpdate(

src/dusk/rpg/entity/entity.c

@@ -31,7 +31,7 @@ void entityInit(entity_t *entity, const entitytype_t type) {
   entity->id = (uint8_t)(entity - ENTITIES);
   entity->globalId = ENTITY_GLOBAL_ID_NULL;
   entity->type = type;
-  entity->chunkIndex = 0xFF;
+  entity->chunkIndex = -1;
 
   if(ENTITY_CALLBACKS[type].init != NULL) ENTITY_CALLBACKS[type].init(entity);
 }
@@ -288,41 +288,37 @@ void entityPositionSet(entity_t *entity, const worldpos_t pos) {
   entityUpdateChunk(entity);
 }
 
-void entitySetChunk(entity_t *entity, const uint8_t chunkIndex) {
+void entitySetChunk(entity_t *entity, const chunkindex_t chunkIndex) {
   assertNotNull(entity, "Entity pointer cannot be NULL");
 
-  if(entity->chunkIndex != 0xFF) {
-    chunk_t *old = mapGetChunk(entity->chunkIndex);
-    if(old != NULL) {
-      for(uint8_t i = 0; i < CHUNK_ENTITY_COUNT_MAX; i++) {
-        if(old->entities[i] != entity->id) continue;
-        old->entities[i] = 0xFF;
-        break;
-      }
+  chunk_t *old = mapGetChunk(entity->chunkIndex);
+  if(old != NULL) {
+    for(uint8_t i = 0; i < CHUNK_ENTITY_COUNT_MAX; i++) {
+      if(old->entities[i] != entity->id) continue;
+      old->entities[i] = 0xFF;
     }
   }
 
   // Only claim the new chunk once actually inserted into one of its slots -
   // otherwise entity->chunkIndex would point at a chunk that doesn't know
   // about this entity, so it would never be torn down on unload.
-  entity->chunkIndex = 0xFF;
+  entity->chunkIndex = CHUNK_INDEX_INVALID;
 
-  if(chunkIndex != 0xFF) {
-    chunk_t *next = mapGetChunk(chunkIndex);
-    if(next != NULL) {
-      for(uint8_t i = 0; i < CHUNK_ENTITY_COUNT_MAX; i++) {
-        if(next->entities[i] != 0xFF) continue;
-        next->entities[i] = entity->id;
-        entity->chunkIndex = chunkIndex;
-        break;
-      }
-      if(entity->chunkIndex != chunkIndex) {
-        consolePrint(
-          "entitySetChunk: chunk %u has no free entity slots, entity %u "
-          "left untracked",
-          chunkIndex, entity->id
-        );
-      }
+  chunk_t *next = mapGetChunk(chunkIndex);
+  if(next != NULL) {
+    for(uint8_t i = 0; i < CHUNK_ENTITY_COUNT_MAX; i++) {
+      if(next->entities[i] != 0xFF) continue;
+      next->entities[i] = entity->id;
+      entity->chunkIndex = chunkIndex;
+      break;
+    }
+
+    if(entity->chunkIndex != chunkIndex) {
+      consolePrint(
+        "entitySetChunk: chunk %d has no free entity slots, entity %u "
+        "left untracked",
+        chunkIndex, entity->id
+      );
     }
   }
 }
@@ -333,5 +329,5 @@ void entityUpdateChunk(entity_t *entity) {
   chunkpos_t cp;
   worldPosToChunkPos(&entity->position, &cp);
   chunkindex_t ci = mapGetChunkIndexAt(cp);
-  if(ci != -1) entitySetChunk(entity, (uint8_t)ci);
+  entitySetChunk(entity, ci);
 }

src/dusk/rpg/entity/entity.h

@@ -39,7 +39,7 @@ typedef struct entity_s {
 
   entityinteract_t interact;
 
-  uint8_t chunkIndex;
+  chunkindex_t chunkIndex;
 } entity_t;
 
 extern entity_t ENTITIES[ENTITY_COUNT];
@@ -185,15 +185,17 @@ uint8_t entityGetAvailable();
 
 /**
  * Assigns an entity to a chunk, removing it from its current chunk first.
- * Pass 0xFF as chunkIndex to detach the entity from any chunk. If the
- * target chunk has no free entity slots, the entity is left detached
- * (chunkIndex 0xFF) rather than assigned to a chunk that isn't actually
- * tracking it - entityUpdateChunk will keep retrying on subsequent moves.
+ * Pass CHUNK_INDEX_INVALID as chunkIndex to detach the entity from any
+ * chunk. If the target chunk has no free entity slots, the entity is
+ * left detached (chunkIndex CHUNK_INDEX_INVALID) rather than assigned to
+ * a chunk that isn't actually tracking it - entityUpdateChunk will keep
+ * retrying on subsequent moves.
  *
  * @param entity Pointer to the entity.
- * @param chunkIndex Index of the chunk to assign to, or 0xFF for none.
+ * @param chunkIndex Index of the chunk to assign to, or
+ * CHUNK_INDEX_INVALID for none.
  */
-void entitySetChunk(entity_t *entity, const uint8_t chunkIndex);
+void entitySetChunk(entity_t *entity, const chunkindex_t chunkIndex);
 
 /**
  * Resolves the chunk that an entity's current position falls into and

src/dusk/rpg/entity/item/entityitem.c

@@ -40,5 +40,6 @@ void entityItemMovement(entity_t *entity) {
   if(!entity->data.item.collected) return;
   if(uiTextboxMainIsActive()) return;
 
+  entitySetChunk(entity, CHUNK_INDEX_INVALID);
   entity->type = ENTITY_TYPE_NULL;
 }

src/dusk/rpg/overworld/map.c

@@ -98,6 +98,29 @@ errorret_t mapPositionSet(const chunkpos_t newPos) {
 
   MAP.chunkPosition = newPos;
   mapRebuildChunkOrder();
+
+  // chunkOrder was just reshuffled, so entity->chunkIndex (an index into
+  // chunkOrder, not a direct chunk_t pointer) may now resolve to a
+  // completely different chunk than the one that actually still tracks
+  // this entity in its entities[] slot - a chunk that stays loaded keeps
+  // its entities[] contents untouched by the reorder, only its slot
+  // number within chunkOrder moves. Recompute the cached index directly
+  // from each entity's (unmoved) position rather than going through
+  // entitySetChunk, which would look up the stale old index, fail to
+  // find/clear the entity's real registration, and insert a duplicate
+  // entry alongside it. Entities already handled by mapChunkUnload above
+  // (detached to CHUNK_INDEX_INVALID, or despawned to ENTITY_TYPE_NULL)
+  // are skipped.
+  for(uint8_t i = 0; i < ENTITY_COUNT; i++) {
+    entity_t *entity = &ENTITIES[i];
+    if(entity->type == ENTITY_TYPE_NULL) continue;
+    if(entity->chunkIndex == CHUNK_INDEX_INVALID) continue;
+
+    chunkpos_t cp;
+    worldPosToChunkPos(&entity->position, &cp);
+    entity->chunkIndex = mapGetChunkIndexAt(cp);
+  }
+
   errorOk();
 }
 
@@ -120,7 +143,7 @@ void mapChunkUnload(chunk_t *chunk) {
     if(chunk->entities[i] == 0xFF) continue;
     entity_t *entity = &ENTITIES[chunk->entities[i]];
     if(!entityCanUnload(entity)) {
-      entitySetChunk(entity, 0xFF);
+      entitySetChunk(entity, CHUNK_INDEX_INVALID);
     } else {
       entity->type = ENTITY_TYPE_NULL;
     }
@@ -268,7 +291,7 @@ void mapChunkLoadQueueRemove(chunk_t *chunk) {
 
 
 chunkindex_t mapGetChunkIndexAt(const chunkpos_t position) {
-  if(!mapIsLoaded()) return -1;
+  if(!mapIsLoaded()) return CHUNK_INDEX_INVALID;
 
   chunkpos_t relPos = {
     position.x - MAP.chunkPosition.x,
@@ -282,14 +305,14 @@ chunkindex_t mapGetChunkIndexAt(const chunkpos_t position) {
     relPos.y >= MAP_CHUNK_HEIGHT ||
     relPos.z >= MAP_CHUNK_DEPTH
   ) {
-    return -1;
+    return CHUNK_INDEX_INVALID;
   }
 
   return chunkPosToIndex(&relPos);
 }
 
-chunk_t *mapGetChunk(const uint8_t index) {
-  if(index >= MAP_CHUNK_COUNT) return NULL;
+chunk_t *mapGetChunk(const chunkindex_t index) {
+  if(index == CHUNK_INDEX_INVALID || index >= MAP_CHUNK_COUNT) return NULL;
   if(!mapIsLoaded()) return NULL;
   return MAP.chunkOrder[index];
 }
@@ -300,7 +323,7 @@ tile_t mapGetTile(const worldpos_t position) {
   chunkpos_t chunkPos;
   worldPosToChunkPos(&position, &chunkPos);
   chunkindex_t chunkIndex = mapGetChunkIndexAt(chunkPos);
-  if(chunkIndex == -1) return TILE_NULL;
+  if(chunkIndex == CHUNK_INDEX_INVALID) return TILE_NULL;
 
   chunk_t *chunk = mapGetChunk(chunkIndex);
   assertNotNull(chunk, "Chunk pointer cannot be NULL");

src/dusk/rpg/overworld/map.h

@@ -132,17 +132,19 @@ void mapRebuildChunkOrder();
  * Gets the index of a chunk, within the world, at the given position.
  *
  * @param position The chunk position.
- * @return The index of the chunk, or -1 if out of bounds.
+ * @return The index of the chunk, or CHUNK_INDEX_INVALID if out of
+ * bounds.
  */
 chunkindex_t mapGetChunkIndexAt(const chunkpos_t position);
 
 /**
  * Gets a chunk by its index.
- * 
+ *
  * @param chunkIndex The index of the chunk.
- * @return A pointer to the chunk.
+ * @return A pointer to the chunk, or NULL if chunkIndex is
+ * CHUNK_INDEX_INVALID, out of range, or no map is currently loaded.
  */
-chunk_t * mapGetChunk(const uint8_t chunkIndex);
+chunk_t * mapGetChunk(const chunkindex_t chunkIndex);
 
 /**
  * Gets the tile at the given world position.

src/dusk/rpg/overworld/worldpos.h

@@ -37,6 +37,11 @@ typedef int16_t chunkunit_t;
 typedef int16_t chunkindex_t;
 typedef uint32_t chunktileindex_t;
 
+// Sentinel chunkindex_t value meaning "no chunk" - returned by
+// mapGetChunkIndexAt when a position falls outside every loaded chunk,
+// and used throughout as the "not assigned to any chunk" state.
+#define CHUNK_INDEX_INVALID ((chunkindex_t)-1)
+
 typedef int32_t worldunits_t;
 typedef int32_t chunkunits_t;
 

src/dusk/save/save.c

@@ -8,6 +8,7 @@
 #include "save.h"
 #include "util/memory.h"
 #include "assert/assert.h"
+#include "rpg/cutscene/cutscenesystem.h"
 
 save_t SAVE;
 
@@ -164,6 +165,10 @@ void saveOnDeviceAvailabilityChecked(savedevice_t *device, void *user) {
   SAVE.deviceCurrent = (uint8_t)(device - &SAVE.devices[0]);
 }
 
+bool_t saveCanSave() {
+  return CUTSCENE_SYSTEM.scene == NULL;
+}
+
 errorret_t saveSaveSettings() {
   assertTrue(SAVE.deviceCurrent != 0xFF, "No current device");
 

src/dusk/save/save.h

@@ -67,6 +67,14 @@ void saveFindAvailableDevice(
  */
 void saveOnDeviceAvailabilityChecked(savedevice_t *device, void *user);
 
+/**
+ * Whether the game is in a state where saving is currently allowed.
+ * Currently just checks that no cutscene is running.
+ *
+ * @return True if saving is currently allowed, false otherwise.
+ */
+bool_t saveCanSave();
+
 /**
  * Saves the current settings to the current device.
  *

src/dusk/ui/debug/uiplayerpos.c

@@ -46,13 +46,14 @@ errorret_t uiPlayerPosDraw() {
   stringFormat(
     UIPLAYERPOS.text,
     UI_PLAYERPOS_TEXT_MAX - 1,
-    "%d,%d,%d[%d,%d,%d]",
+    "%d,%d,%d[%d,%d,%d]#%d",
     (int_t)player->position.x,
     (int_t)player->position.y,
     (int_t)player->position.z,
     (int_t)chunkPos.x,
     (int_t)chunkPos.y,
-    (int_t)chunkPos.z
+    (int_t)chunkPos.z,
+    (int_t)player->chunkIndex
   );
   UIPLAYERPOS.label.dirty = true;
 

src/dusk/ui/debug/uiplayerpos.h

@@ -28,9 +28,9 @@ extern uiplayerpos_t UIPLAYERPOS;
 errorret_t uiPlayerPosInit();
 
 /**
- * Draws the player world and chunk position on screen.
- * Searches for the first ENTITY_TYPE_PLAYER and renders:
- * WORLDX,WORLDY,WORLDZ[chunkx,chunky,chunkz]
+ * Draws the player world position, chunk position, and chunk index on
+ * screen. Searches for the first ENTITY_TYPE_PLAYER and renders:
+ * WORLDX,WORLDY,WORLDZ[chunkx,chunky,chunkz]#chunkIndex
  *
  * @return Any error that occurs.
  */