Synchronize Damage Feature

- Added a new config synchronize_damage, when set to "yes", the client will display the damage of normal monster attacks at the exact time it is applied on the server, removing position lag (fixes #259)

conf/battle/client.conf

@@ -169,3 +169,9 @@ macro_detection_punishment: 0
 // Amount of time in minutes that the punishment type is active for. Use 0 for infinite.
 // Official: 0
 macro_detection_punishment_time: 0
+
+// Should the damage timing be synchronized between the client and server?
+// This is not official behavior, but it removes the position lag after being hit.
+// Right now it only works for being hit by normal monster attacks.
+// Tired of Dark Illusion hitting you 5 seconds too late? Then turn this on. (Note 1)
+synchronize_damage: no

src/map/battle.cpp

@@ -411,7 +411,14 @@ int battle_delay_damage(t_tick tick, int amotion, struct block_list *src, struct
  dat->additional_effects = additional_effects;
  dat->src_type = src->type;
  dat->isspdamage = isspdamage;
- if (src->type != BL_PC && amotion > 1000)
+ if (skill_id == 0 && src->type == BL_MOB && battle_config.synchronize_damage) {
+ mob_data* md = BL_CAST(BL_MOB, src);
+ // The client refuses to display animations slower than 1x speed
+ // So we need to shorten AttackMotion to be in-sync with the client in this case
+ if (amotion > md->status.clientamotion)
+ amotion = md->status.clientamotion;
+ }
+ else if (src->type != BL_PC && amotion > 1000)
  amotion = 1000; //Aegis places a damage-delay cap of 1 sec to non player attacks. [Skotlex]
 
  if( src->type == BL_PC )
@@ -11461,6 +11468,7 @@ static const struct _battle_data {
 #else
  { "feature.instance_allow_reconnect", &battle_config.instance_allow_reconnect, 0, 0, 1, },
 #endif
+ { "synchronize_damage", &battle_config.synchronize_damage, 0, 0, 1, },
 
 #include <custom/battle_config_init.inc>
 };

src/map/battle.hpp

@@ -755,6 +755,7 @@ struct Battle_Config
  int feature_stylist;
  int feature_banking_state_enforce;
  int instance_allow_reconnect;
+ int synchronize_damage;
 
 #include <custom/battle_config_struct.inc>
 };

src/map/clif.cpp

@@ -5242,6 +5242,13 @@ int clif_damage(struct block_list* src, struct block_list* dst, t_tick tick, int
  }
  }
 
+ // Calculate what sdelay to send to the client so it applies damage at the same time as the server
+ if (src->type == BL_MOB && battle_config.synchronize_damage) {
+ mob_data* md = BL_CAST(BL_MOB, src);
+ // The client only accepts values between 0 and 432; 432 stands for 1x animation speed
+ sdelay = sdelay * 432 / md->status.clientamotion;
+ }
+
  WBUFW(buf,0) = cmd;
  WBUFL(buf,2) = src->id;
  WBUFL(buf,6) = dst->id;