Merge pull request #30940 from kevingranade/reset-seen-cache-fully

Invalidate seen cache properly in many-z-level mode

src/lightmap.cpp

@@ -1180,12 +1180,12 @@ void map::build_seen_cache( const tripoint &origin, const int target_z )
 
     constexpr float light_transparency_solid = LIGHT_TRANSPARENCY_SOLID;
     constexpr int map_dimensions = MAPSIZE_X * MAPSIZE_Y;
-    std::uninitialized_fill_n(
-        &seen_cache[0][0], map_dimensions, light_transparency_solid );
     std::uninitialized_fill_n(
         &camera_cache[0][0], map_dimensions, light_transparency_solid );
 
     if( !fov_3d ) {
+        std::uninitialized_fill_n(
+            &seen_cache[0][0], map_dimensions, light_transparency_solid );
         seen_cache[origin.x][origin.y] = LIGHT_TRANSPARENCY_CLEAR;
 
         castLightAll<float, float, sight_calc, sight_check, update_light, accumulate_transparency>(
@@ -1204,6 +1204,8 @@ void map::build_seen_cache( const tripoint &origin, const int target_z )
             transparency_caches[z + OVERMAP_DEPTH] = &cur_cache.transparency_cache;
             seen_caches[z + OVERMAP_DEPTH] = &cur_cache.seen_cache;
             floor_caches[z + OVERMAP_DEPTH] = &cur_cache.floor_cache;
+            std::uninitialized_fill_n(
+                &cur_cache.seen_cache[0][0], map_dimensions, light_transparency_solid );
         }
         cast_zlight<float, sight_calc, sight_check, accumulate_transparency>(
             seen_caches, transparency_caches, floor_caches, origin, 0, 1.0 );