refactor blade stop effect check

it is now in a new function with each of its conditions documented.

this will make easier to read and to include rebalance-related checks.

src/map/battle.c

@@ -6637,6 +6637,39 @@ static bool battle_check_arrows(struct map_session_data *sd)
 	return true;
 }
 
+/**
+ * Check whether an attack from src to target should cause Blade Stop to start.
+ * @param src attacker
+ * @param target unit being attacked
+ * @returns true if Blade Stop should start, false otherwise
+ */
+static bool battle_should_bladestop_attacker(struct block_list *src, struct block_list *target)
+{
+	nullpo_retr(false, src);
+	nullpo_retr(false, target);
+
+	struct status_change *tsc = status->get_sc(target);
+	if (tsc == NULL || tsc->data[SC_BLADESTOP_WAIT] == NULL)
+		return false; // Target is not in BladeStop wait mode
+
+	if (is_boss(src))
+		return false; // Boss monsters are not affected
+
+	// CHECKME: Is that right?
+	if (src->type == BL_PC)
+		return true; // Player gets into BladeStop regardless of distance
+
+	struct map_session_data *tsd = BL_CAST(BL_PC, target);
+	if (tsd != NULL) {
+		int max_distance = tsd->weapontype == W_FIST ? 1 : 2;
+		return distance_bl(src, target) <= max_distance;
+	}
+
+	// CHECKME: Is that right?
+	// Target is not a player. BladeStop starts regardless of distance
+	return true;
+}
+
 /*==========================================
  * Do a basic physical attack (call trough unit_attack_timer)
  *------------------------------------------*/
@@ -6702,8 +6735,7 @@ static enum damage_lv battle_weapon_attack(struct block_list *src, struct block_
 			return ATK_BLOCK;
 		}
 	}
-	if( tsc && tsc->data[SC_BLADESTOP_WAIT] && !is_boss(src) && (src->type == BL_PC || tsd == NULL || distance_bl(src, target) <= (tsd->weapontype == W_FIST ? 1 : 2)) )
-	{
+	if (battle->should_bladestop_attacker(src, target)) {
 		uint16 skill_lv = tsc->data[SC_BLADESTOP_WAIT]->val1;
 		int duration = skill->get_time2(MO_BLADESTOP,skill_lv);
 		status_change_end(target, SC_BLADESTOP_WAIT, INVALID_TIMER);
@@ -8300,6 +8332,7 @@ void battle_defaults(void)
 	battle->calc_gvg_damage = battle_calc_gvg_damage;
 	battle->calc_bg_damage = battle_calc_bg_damage;
 	battle->weapon_attack = battle_weapon_attack;
+	battle->should_bladestop_attacker = battle_should_bladestop_attacker;
 	battle->check_arrows = battle_check_arrows;
 	battle->calc_weapon_attack = battle_calc_weapon_attack;
 	battle->delay_damage = battle_delay_damage;

src/map/battle.h

@@ -705,6 +705,8 @@ struct battle_interface {
 	int64 (*calc_bg_damage) (struct block_list *src, struct block_list *bl, int64 damage, int div_, uint16 skill_id, uint16 skill_lv, int flag);
 	/* normal weapon attack */
 	enum damage_lv (*weapon_attack) (struct block_list *bl, struct block_list *target, int64 tick, int flag);
+	/* returns whether bladestop should start for attacker/target */
+	bool (*should_bladestop_attacker) (struct block_list *src, struct block_list *target);
 	/* check is equipped ammo and this ammo allowed */
 	bool (*check_arrows) (struct map_session_data *sd);
 	/* calculate weapon attack */

src/plugins/HPMHooking/HPMHooking.Defs.inc

@@ -460,6 +460,8 @@ typedef int64 (*HPMHOOK_pre_battle_calc_bg_damage) (struct block_list **src, str
 typedef int64 (*HPMHOOK_post_battle_calc_bg_damage) (int64 retVal___, struct block_list *src, struct block_list *bl, int64 damage, int div_, uint16 skill_id, uint16 skill_lv, int flag);
 typedef enum damage_lv (*HPMHOOK_pre_battle_weapon_attack) (struct block_list **bl, struct block_list **target, int64 *tick, int *flag);
 typedef enum damage_lv (*HPMHOOK_post_battle_weapon_attack) (enum damage_lv retVal___, struct block_list *bl, struct block_list *target, int64 tick, int flag);
+typedef bool (*HPMHOOK_pre_battle_should_bladestop_attacker) (struct block_list **src, struct block_list **target);
+typedef bool (*HPMHOOK_post_battle_should_bladestop_attacker) (bool retVal___, struct block_list *src, struct block_list *target);
 typedef bool (*HPMHOOK_pre_battle_check_arrows) (struct map_session_data **sd);
 typedef bool (*HPMHOOK_post_battle_check_arrows) (bool retVal___, struct map_session_data *sd);
 typedef struct Damage (*HPMHOOK_pre_battle_calc_weapon_attack) (struct block_list **src, struct block_list **target, uint16 *skill_id, uint16 *skill_lv, int *wflag);

src/plugins/HPMHooking/HPMHooking_map.HPMHooksCore.inc

@@ -228,6 +228,8 @@ struct {
 	struct HPMHookPoint *HP_battle_calc_bg_damage_post;
 	struct HPMHookPoint *HP_battle_weapon_attack_pre;
 	struct HPMHookPoint *HP_battle_weapon_attack_post;
+	struct HPMHookPoint *HP_battle_should_bladestop_attacker_pre;
+	struct HPMHookPoint *HP_battle_should_bladestop_attacker_post;
 	struct HPMHookPoint *HP_battle_check_arrows_pre;
 	struct HPMHookPoint *HP_battle_check_arrows_post;
 	struct HPMHookPoint *HP_battle_calc_weapon_attack_pre;
@@ -7767,6 +7769,8 @@ struct {
 	int HP_battle_calc_bg_damage_post;
 	int HP_battle_weapon_attack_pre;
 	int HP_battle_weapon_attack_post;
+	int HP_battle_should_bladestop_attacker_pre;
+	int HP_battle_should_bladestop_attacker_post;
 	int HP_battle_check_arrows_pre;
 	int HP_battle_check_arrows_post;
 	int HP_battle_calc_weapon_attack_pre;

src/plugins/HPMHooking/HPMHooking_map.HookingPoints.inc

@@ -131,6 +131,7 @@ struct HookingPointData HookingPoints[] = {
 	{ HP_POP(battle->calc_gvg_damage, HP_battle_calc_gvg_damage) },
 	{ HP_POP(battle->calc_bg_damage, HP_battle_calc_bg_damage) },
 	{ HP_POP(battle->weapon_attack, HP_battle_weapon_attack) },
+	{ HP_POP(battle->should_bladestop_attacker, HP_battle_should_bladestop_attacker) },
 	{ HP_POP(battle->check_arrows, HP_battle_check_arrows) },
 	{ HP_POP(battle->calc_weapon_attack, HP_battle_calc_weapon_attack) },
 	{ HP_POP(battle->delay_damage, HP_battle_delay_damage) },

src/plugins/HPMHooking/HPMHooking_map.Hooks.inc

@@ -2752,6 +2752,33 @@ enum damage_lv HP_battle_weapon_attack(struct block_list *bl, struct block_list
 	}
 	return retVal___;
 }
+bool HP_battle_should_bladestop_attacker(struct block_list *src, struct block_list *target) {
+	int hIndex = 0;
+	bool retVal___ = false;
+	if (HPMHooks.count.HP_battle_should_bladestop_attacker_pre > 0) {
+		bool (*preHookFunc) (struct block_list **src, struct block_list **target);
+		*HPMforce_return = false;
+		for (hIndex = 0; hIndex < HPMHooks.count.HP_battle_should_bladestop_attacker_pre; hIndex++) {
+			preHookFunc = HPMHooks.list.HP_battle_should_bladestop_attacker_pre[hIndex].func;
+			retVal___ = preHookFunc(&src, &target);
+		}
+		if (*HPMforce_return) {
+			*HPMforce_return = false;
+			return retVal___;
+		}
+	}
+	{
+		retVal___ = HPMHooks.source.battle.should_bladestop_attacker(src, target);
+	}
+	if (HPMHooks.count.HP_battle_should_bladestop_attacker_post > 0) {
+		bool (*postHookFunc) (bool retVal___, struct block_list *src, struct block_list *target);
+		for (hIndex = 0; hIndex < HPMHooks.count.HP_battle_should_bladestop_attacker_post; hIndex++) {
+			postHookFunc = HPMHooks.list.HP_battle_should_bladestop_attacker_post[hIndex].func;
+			retVal___ = postHookFunc(retVal___, src, target);
+		}
+	}
+	return retVal___;
+}
 bool HP_battle_check_arrows(struct map_session_data *sd) {
 	int hIndex = 0;
 	bool retVal___ = false;