Adds a function to assist with PK damage

* Re-implement battle_calc_pk_damage to help determine when to adjust damage when PK mode is enabled.
* Implement INF2_IGNOREPKREDUCTION skill flag to make skills bypass the damage adjustments.

doc/skill_db.txt

@@ -80,6 +80,7 @@ IsShadowSpell				- Make skill available for SC_AUTOSHADOWSPELL.
 IsChorus					- Chorus skill.
 IgnoreBgReduction			- Ignore Battleground reduction.
 IgnoreGvgReduction			- Ignore GvG reduction.
+IgnorePKReduction			- Ignore PK reduction.
 DisableNearNpc				- Disable self/ground skills near NPC. In tandem with NoNearNpc node.
 TargetTrap					- Damage traps. If TargetType is Trap.
 IgnoreLandProtector			- Ignore SA_LANDPROTECTOR.

src/map/battle.cpp

@@ -1574,8 +1574,8 @@ int64 battle_calc_damage(struct block_list *src,struct block_list *bl,struct Dam
 #endif
 		case SP_SOULEXPLOSION:
 			// Adjust these based on any possible PK damage rates.
-			if (battle_config.pk_mode > 0 && src->type == BL_PC && bl->type == BL_PC && damage > 0 && map_getmapflag(bl->m, MF_PVP))
+			if (battle_config.pk_mode > 0 && map_getmapflag(bl->m, MF_PVP))
-				damage = battle_calc_zone_damage_rate(*bl, damage, flag);
+				damage = battle_calc_pk_damage(*src, *bl, damage, skill_id, flag);
 
 			return damage; //These skills bypass everything else.
 	}
@@ -1584,8 +1584,8 @@ int64 battle_calc_damage(struct block_list *src,struct block_list *bl,struct Dam
 	// So can defense sphere's but what the heck is that??? [Rytech]
 	if (skill_id == SJ_NOVAEXPLOSING && !(tsc && (tsc->getSCE(SC_SAFETYWALL) || tsc->getSCE(SC_MILLENNIUMSHIELD)))) {
 		// Adjust this based on any possible PK damage rates.
-		if (battle_config.pk_mode > 0 && src->type == BL_PC && bl->type == BL_PC && damage > 0 && map_getmapflag(bl->m, MF_PVP))
+		if (battle_config.pk_mode > 0 && map_getmapflag(bl->m, MF_PVP))
-			damage = battle_calc_zone_damage_rate(*bl, damage, flag);
+			damage = battle_calc_pk_damage(*src, *bl, damage, skill_id, flag);
 
 		return damage;
 	}
@@ -1944,8 +1944,8 @@ int64 battle_calc_damage(struct block_list *src,struct block_list *bl,struct Dam
 	} //End of caster SC_ check
 
 	//PK damage rates
-	if (battle_config.pk_mode > 0 && src->type == BL_PC && bl->type == BL_PC && damage > 0 && map_getmapflag(bl->m, MF_PVP))
+	if (battle_config.pk_mode > 0 && map_getmapflag(bl->m, MF_PVP))
-		damage = battle_calc_zone_damage_rate(*bl, damage, flag);
+		damage = battle_calc_pk_damage(*src, *bl, damage, skill_id, flag);
 
 	if(battle_config.skill_min_damage && damage > 0 && damage < div_) {
 		if ((flag&BF_WEAPON && battle_config.skill_min_damage&1)
@@ -2098,6 +2098,31 @@ int64 battle_calc_gvg_damage(struct block_list *src,struct block_list *bl,int64
 	return i64max(battle_calc_zone_damage_rate(*bl, damage, flag), 1);
 }
 
+/**
+ * Calculates PK related damage adjustments (between players only).
+ * @param src: Source object
+ * @param bl: Target object
+ * @param damage: Damage being done
+ * @param skill_id: Skill used
+ * @param flag: Battle flag type
+ * @return Modified damage
+ */
+int64 battle_calc_pk_damage(block_list &src, block_list &bl, int64 damage, uint16 skill_id, int flag) {
+	if (damage == 0) // No reductions to make.
+		return 0;
+
+	if (battle_config.pk_mode == 0) // PK mode is disabled.
+		return damage;
+
+	if (skill_get_inf2(skill_id, INF2_IGNOREPKREDUCTION)) //Skills with no pk damage reduction.
+		return damage;
+
+	if (src.type == BL_PC && bl.type == BL_PC)
+		return i64max(battle_calc_zone_damage_rate(bl, damage, flag), 1);
+	else
+		return damage;
+}
+
 /**
  * HP/SP drain calculation
  * @param damage Damage inflicted to the enemy
@@ -8878,8 +8903,8 @@ int64 battle_calc_return_damage(struct block_list* tbl, struct block_list *src,
 		rdamage = battle_calc_gvg_damage(src, tbl, rdamage, skill_id, flag);
 	else if (mapdata->getMapFlag(MF_BATTLEGROUND))
 		rdamage = battle_calc_bg_damage(src, tbl, rdamage, skill_id, flag);
-	else if (battle_config.pk_mode > 0 && src->type == BL_PC && tbl->type == BL_PC && damage > 0 && mapdata->getMapFlag(MF_PVP))
+	else if (battle_config.pk_mode > 0 && mapdata->getMapFlag(MF_PVP))
-		rdamage = battle_calc_zone_damage_rate(*tbl, damage, flag);
+			damage = battle_calc_pk_damage(*src, *tbl, damage, skill_id, flag);
 
 	// Skill damage adjustment
 	int skill_damage = battle_skill_damage(src, tbl, skill_id);

src/map/battle.hpp

@@ -102,6 +102,7 @@ int battle_calc_cardfix(int attack_type, struct block_list *src, struct block_li
 int64 battle_calc_damage(struct block_list *src,struct block_list *bl,struct Damage *d,int64 damage,uint16 skill_id,uint16 skill_lv);
 int64 battle_calc_gvg_damage(struct block_list *src,struct block_list *bl,int64 damage,uint16 skill_id,int flag);
 int64 battle_calc_bg_damage(struct block_list *src,struct block_list *bl,int64 damage,uint16 skill_id,int flag);
+int64 battle_calc_pk_damage(block_list &src, block_list &bl, int64 damage, uint16 skill_id, int flag);
 
 void battle_damage(struct block_list *src, struct block_list *target, int64 damage, t_tick delay, uint16 skill_lv, uint16 skill_id, enum damage_lv dmg_lv, unsigned short attack_type, bool additional_effects, t_tick tick, bool spdamage);
 int battle_delay_damage (t_tick tick, int amotion, struct block_list *src, struct block_list *target, int attack_type, uint16 skill_id, uint16 skill_lv, int64 damage, enum damage_lv dmg_lv, t_tick ddelay, bool additional_effects, bool spdamage);

src/map/script_constants.hpp

@@ -9837,6 +9837,7 @@
 	export_constant(INF2_SHOWSCALE);
 	export_constant(INF2_IGNOREGTB);
 	export_constant(INF2_TOGGLEABLE);
+	export_constant(INF2_IGNOREPKREDUCTION);
 
 	/* skill no near npc flags */
 	export_constant(SKILL_NONEAR_WARPPORTAL);

src/map/skill.hpp

@@ -110,6 +110,7 @@ enum e_skill_inf2 : uint8 {
 	INF2_SHOWSCALE, // Skill shows AoE area while casting
 	INF2_IGNOREGTB, // Skill ignores effect of GTB
 	INF2_TOGGLEABLE, // Skill can be toggled on and off (won't consume HP/SP when toggled off)
+	INF2_IGNOREPKREDUCTION, // Skill that ignore pk reduction
 	INF2_MAX,
 };