Add skill_get_item_index() function

2 files changed, 37 insertions, 0 deletions

diff --git a/src/map/skill.c b/src/map/skill.c
index 24fbe7892..26f4cf0c0 100644
--- a/src/map/skill.c
+++ b/src/map/skill.c
@@ -370,6 +370,41 @@ static int skill_get_spiritball(int skill_id, int skill_lv)
 }
 
 /**
+ * Gets the index of the first required item for a skill at given level.
+ *
+ * @param skill_id The skill's ID.
+ * @param skill_lv The skill's level.
+ * @return The required item's index. Defaults to INDEX_NOT_FOUND (-1) in case of error or if no appropriate index was found.
+ *
+ **/
+static int skill_get_item_index(int skill_id, int skill_lv)
+{
+	if (skill_id == 0)
+		return INDEX_NOT_FOUND;
+
+	Assert_retr(INDEX_NOT_FOUND, skill_lv > 0);
+
+	int idx = skill->get_index(skill_id);
+
+	Assert_retr(INDEX_NOT_FOUND, idx != 0);
+
+	int item_index = INDEX_NOT_FOUND;
+	int level_index = skill_get_lvl_idx(skill_lv);
+
+	for (int i = 0; i < MAX_SKILL_ITEM_REQUIRE; i++) {
+		if (skill->dbs->db[idx].req_items.item[i].id == 0)
+			continue;
+
+		if (skill->dbs->db[idx].req_items.item[i].amount[level_index] != -1) {
+			item_index = i;
+			break;
+		}
+	}
+
+	return item_index;
+}
+
+/**
  * Gets a skill's required item's ID by the skill's ID and the item's index.
  *
  * @param skill_id The skill's ID.
@@ -23937,6 +23972,7 @@ void skill_defaults(void)
 	skill->get_sp_rate = skill_get_sp_rate;
 	skill->get_state = skill_get_state;
 	skill->get_spiritball = skill_get_spiritball;
+	skill->get_item_index = skill_get_item_index;
 	skill->get_itemid = skill_get_itemid;
 	skill->get_itemqty = skill_get_itemqty;
 	skill->get_item_any_flag = skill_get_item_any_flag;
diff --git a/src/map/skill.h b/src/map/skill.h
index b505412b6..fdeaefe01 100644
--- a/src/map/skill.h
+++ b/src/map/skill.h
@@ -2007,6 +2007,7 @@ struct skill_interface {
 	int (*get_sp_rate) (int skill_id, int skill_lv);
 	int (*get_state) (int skill_id, int skill_lv);
 	int (*get_spiritball) (int skill_id, int skill_lv);
+	int (*get_item_index) (int skill_id, int skill_lv);
 	int (*get_itemid) (int skill_id, int item_idx);
 	int (*get_itemqty) (int skill_id, int item_idx, int skill_lv);
 	bool (*get_item_any_flag) (int skill_id, int skill_lv);