Fix bug:7454

* Official Icewall implementation and other fixes
- Reverted all the icewall-related changes done in SVN r15777 and following as testing shows they aren't official and are actually pretty exploitable (bugreport:7412)
- Instead implemented the official icewall characteristic that monsters can only leave an icewall cell to the west or south, the changes include:
  * The "sight" path check no longer checks for the current cell so standing on an icewall allows you to see/attack into any direction
  * The path finding will still ignore the current cell as before but the walk routine will not allow to walk east or north while standing on an icewall cell
  * This leads monsters in the situation where they go through an AI loop not allowing them to escape the icewall (if their target is north or east of them)
  * Monster in this situation will use idle skills and if they get attacked will use their rudeattacked skills if available, similar to traps like Spiderweb
  * Added a configuration icewall_walk_block that allows to configure how long a monster should go through the AI loop before the server allows it any movement, this "safety" system is official and seems to equal about 75 AI loops; if you want to disable the whole icewall system so that monsters don't get stuck in icewall at all, just set this to 0
  * Here are videos from jRO showing how this system works: http://ragdo.blog56.fc2.com/blog-entry-763.html
- Implemented the official calculation for "direction"; now you will be considered horizontal/vertical/diagonally aligned with a target cell in the exact same way as on official servers, this is for example used to determine whether an icewall or a firewall should be horizontal, vertical or diagonal; the only thing that is still unofficial is the default direction (officially always "west"); effectively now there are more situations considered diagonal than before
- Further cleanups on the idle skill use code for immobile monsters and monsters near a player but without a target (now skill using will always go via mob_unlocktarget)
  * This also fixes that monsters switched to idle mode and start to use idle skills one second too late

Mega thanks to Playtester (rathena 5540d89cb0e)

1 files changed, 13 insertions, 4 deletions

diff --git a/conf/battle/skill.conf b/conf/battle/skill.conf
index 10cca4af7..1bb58211a 100644
--- a/conf/battle/skill.conf
+++ b/conf/battle/skill.conf
@@ -69,9 +69,9 @@ skill_out_range_consume: no
 skillrange_by_distance: 14
 
 // Should the equipped weapon's range override the skill's range defined in the skill_db for most weapon-based skills? (Note 3)
-// NOTE: Skills affected by this option are those whose range in the skill_db are negative. Note that unless monster_ai&0x400 is
-// set, the range of all skills is 9 for monsters.
-skillrange_from_weapon: 30
+// NOTE: Skills affected by this option are those whose range in the skill_db are negative. By default always the skill range is used.
+// Note that if you want all monster skills to have a range of 9 you need to set monster_ai&0x400.
+skillrange_from_weapon: 0
 
 // Should a check on the caster's status be performed in all skill attacks?
 // When set to yes, meteors, storm gust and any other ground skills will have 
@@ -293,4 +293,13 @@ mob_max_skilllvl: 100
 // 1: Gutter line system without demi gutter bug
 // 2-20: Area around caster (2 = 5x5, 3 = 7x7, 4 = 9x9, ..., 20 = 41x41)
 // Note: If you knock the target out of the area it will only be hit once and won't do splash damage
-bowling_bash_area: 0
\ No newline at end of file
+bowling_bash_area: 0
+
+// How many attempts should a monster need until it can escape from an icewall casted directly on it?
+// On official servers, monsters can only leave an icewall to the west and south. If their target is north or east of them
+// they will continously try to chase it but fail doing so. This brings them into a loop during which they will cast idle
+// and rudeattacked skills (if attacked). Official servers have a safety system that eventually allows monsters to escape
+// when their walk routine failed many times in row so they won't stay on the loop endlessly. The time for this seems to be
+// around 15 seconds for fast monsters and 35 seconds for slow monsters, this equals about 75 attempts.
+// Set this to 0 if you don't want monsters to be stuck in icewalls at all.
+icewall_walk_block: 75
\ No newline at end of file