From 5b312b0634211515bca34d9a4e2c203ef376cf48 Mon Sep 17 00:00:00 2001
From: Marko Lindqvist <cazfi74@gmail.com>
Date: Wed, 12 Apr 2023 00:13:08 +0300
Subject: [PATCH 41/41] Add unit_class cache of hiding extras

See osdn #47838

Signed-off-by: Marko Lindqvist <cazfi74@gmail.com>
---
 common/player.c   | 25 +++++++++++++++----------
 common/unittype.c |  9 +++++++++
 common/unittype.h |  1 +
 3 files changed, 25 insertions(+), 10 deletions(-)

diff --git a/common/player.c b/common/player.c
index 90da00acef..c4f68f4b9e 100644
--- a/common/player.c
+++ b/common/player.c
@@ -1019,6 +1019,7 @@ bool can_player_see_unit_at(const struct player *pplayer,
 {
   struct city *pcity;
   bool allied;
+  struct unit_class *pclass;
 
   /* If the player can't even see the tile... */
   if (TILE_KNOWN_SEEN != tile_get_known(ptile, pplayer)) {
@@ -1039,20 +1040,24 @@ bool can_player_see_unit_at(const struct player *pplayer,
     return FALSE;
   }
 
+  /* Allied units are always seen.
+   * See also stealth unit hiding part in map_change_seen() */
+  if (allied) {
+    return TRUE;
+  }
+
   /* Units within some extras may be hidden. */
-  if (!allied) {
-    const struct unit_type *ptype = unit_type_get(punit);
+  pclass = unit_class_get(punit);
 
-    extra_type_list_iterate(extra_type_list_of_unit_hiders(), pextra) {
-      if (tile_has_extra(ptile, pextra) && is_native_extra_to_utype(pextra, ptype)) {
-        return FALSE;
-      }
-    } extra_type_list_iterate_end;
-  }
+  extra_type_list_iterate(pclass->cache.hiding_extras, pextra) {
+    if (tile_has_extra(ptile, pextra)) {
+      return FALSE;
+    }
+  } extra_type_list_iterate_end;
 
-  /* Allied or non-hiding units are always seen.
+  /* Non-hiding units are always seen.
    * See also stealth unit hiding part in map_change_seen() */
-  if (allied || !is_hiding_unit(punit)) {
+  if (!is_hiding_unit(punit)) {
     return TRUE;
   }
 
diff --git a/common/unittype.c b/common/unittype.c
index 474e7059a5..d50aab9be0 100644
--- a/common/unittype.c
+++ b/common/unittype.c
@@ -2514,6 +2514,7 @@ void unit_classes_init(void)
     unit_classes[i].cache.native_tile_extras = NULL;
     unit_classes[i].cache.native_bases = NULL;
     unit_classes[i].cache.bonus_roads = NULL;
+    unit_classes[i].cache.hiding_extras = NULL;
     unit_classes[i].cache.subset_movers = NULL;
     unit_classes[i].helptext = NULL;
     unit_classes[i].ruledit_disabled = FALSE;
@@ -2544,6 +2545,10 @@ void unit_classes_free(void)
       extra_type_list_destroy(unit_classes[i].cache.bonus_roads);
       unit_classes[i].cache.bonus_roads = NULL;
     }
+    if (unit_classes[i].cache.hiding_extras != NULL) {
+      extra_type_list_destroy(unit_classes[i].cache.hiding_extras);
+      unit_classes[i].cache.hiding_extras = NULL;
+    }
     if (unit_classes[i].cache.subset_movers != NULL) {
       unit_class_list_destroy(unit_classes[i].cache.subset_movers);
     }
@@ -2739,6 +2744,7 @@ void set_unit_class_caches(struct unit_class *pclass)
   pclass->cache.native_tile_extras = extra_type_list_new();
   pclass->cache.native_bases = extra_type_list_new();
   pclass->cache.bonus_roads = extra_type_list_new();
+  pclass->cache.hiding_extras = extra_type_list_new();
   pclass->cache.subset_movers = unit_class_list_new();
 
   extra_type_iterate(pextra) {
@@ -2757,6 +2763,9 @@ void set_unit_class_caches(struct unit_class *pclass)
       if (proad != NULL && road_provides_move_bonus(proad)) {
         extra_type_list_append(pclass->cache.bonus_roads, pextra);
       }
+      if (pextra->eus == EUS_HIDDEN) {
+        extra_type_list_append(pclass->cache.hiding_extras, pextra);
+      }
     }
   } extra_type_iterate_end;
 
diff --git a/common/unittype.h b/common/unittype.h
index 0ee9cebcc7..eba74cb90f 100644
--- a/common/unittype.h
+++ b/common/unittype.h
@@ -168,6 +168,7 @@ struct unit_class {
     struct extra_type_list *native_tile_extras;
     struct extra_type_list *native_bases;
     struct extra_type_list *bonus_roads;
+    struct extra_type_list *hiding_extras;
     struct unit_class_list *subset_movers;
   } cache;
 };
-- 
2.39.2