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, 12 insertions, 13 deletions

diff --git a/src/map/map.c b/src/map/map.c
index 14af392b7..5fa8779eb 100644
--- a/src/map/map.c
+++ b/src/map/map.c
@@ -2420,28 +2420,27 @@ uint8 map_calc_dir(struct block_list* src, int16 x, int16 y)
 	}
 	else if( dx >= 0 && dy >=0 )
 	{	// upper-right
-		if( dx*2 <= dy )      dir = 0;	// up
-		else if( dx > dy*2 )  dir = 6;	// right
-		else                  dir = 7;	// up-right
+		if( dx*2 < dy || dx == 0 )         dir = 0;	// up
+		else if( dx > dy*2+1 || dy == 0 )  dir = 6;	// right
+		else                               dir = 7;	// up-right
 	}
 	else if( dx >= 0 && dy <= 0 )
 	{	// lower-right
-		if( dx*2 <= -dy )     dir = 4;	// down
-		else if( dx > -dy*2 ) dir = 6;	// right
-		else                  dir = 5;	// down-right
+		if( dx*2 < -dy || dx == 0 )        dir = 4;	// down
+		else if( dx > -dy*2+1 || dy == 0 ) dir = 6;	// right
+		else                               dir = 5;	// down-right
 	}
 	else if( dx <= 0 && dy <= 0 )
 	{	// lower-left
-		if( dx*2 >= dy )      dir = 4;	// down
-		else if( dx < dy*2 )  dir = 2;	// left
-		else                  dir = 3;	// down-left
+		if( dx*2 > dy || dx == 0 )         dir = 4;	// down
+		else if( dx < dy*2-1 || dy == 0 )  dir = 2;	// left
+		else                               dir = 3;	// down-left
 	}
 	else
 	{	// upper-left
-		if( -dx*2 <= dy )     dir = 0;	// up
-		else if( -dx > dy*2 ) dir = 2;	// left
-		else                  dir = 1;	// up-left
-
+		if( -dx*2 < dy || dx == 0 )        dir = 0;	// up
+		else if( -dx > dy*2+1 || dy == 0)  dir = 2;	// left
+		else                               dir = 1;	// up-left
 	}
 	return dir;
 }