--- deliantra/server/ext/follow.ext	2010/04/29 07:52:01	1.15
+++ deliantra/server/ext/follow.ext	2010/05/02 19:42:15	1.19
@@ -6,7 +6,30 @@
 # implement a 'follow' command
 # don't follow on damned ground
 
-our %follow;
+our $MAX_QUEUE = 5; # the # of positions somebody else can lead
+our %follow; # $followername => [$follower, $target, [$queue]]
+
+sub unfollow($) {
+   my $name = shift;
+
+   if (my $f = delete $follow{$name}) {
+      my ($who, $target, undef) = @$f;
+      $who->contr->detach ("follow_aborter");
+      $target->message ("$name no longer follows you.");
+      $who->message ("You no longer follow " . $target->name . ".");
+   }
+}
+
+cf::player::attachment follow_aborter =>
+   on_move => sub {
+      my ($pl, $dir) = @_;
+      unfollow $pl->ob->name;
+   },
+   on_login => sub {
+      my ($pl, $dir) = @_;
+      $pl->detach ("follow_aborter");
+   },
+;
 
 our $CORO = cf::async {
    $Coro::current->{desc} = "follow handler";
@@ -14,35 +37,37 @@
    while () {
       cf::wait_for_tick;
 
-      while (my ($name, $v) = each %follow) {
-         my ($target, $his, $mine) = @$v;
-         my ($who, $other) = (cf::player::find_active $name, cf::player::find_active $target);
+      for (values %follow) {
+         my ($who, $target, $queue) = @$_;
 
-         if ($who && $other && $other->ob->map) {
-            my ($map, $x, $y) = ($other->ob->map->path, $other->ob->x, $other->ob->y);
+         my ($map, $x, $y) = ($target->map, $target->x, $target->y);
 
-            if (
-               ($map ne $his->[0] || $x != $his->[1] || $y != $his->[2])
-               && $map !~ /^\{/
-            ) {
-               @$mine = @$his;
-               @$his = ($map, $x, $y);
-            }
+         # add new position to queue, if any
+         push @$queue, [$map, $x, $y]
+            if $map != $queue->[-1][0]
+               || $x != $queue->[-1][1]
+               || $y != $queue->[-1][2];
+
+         # try to move to oldest position
+         if (@$queue > $MAX_QUEUE) {
+            $who->message ($target->name . " is too far away - you can't follow anymore!");
+            unfollow $target->name;
+         } else {
+            my ($map, $x, $y) = @{ $queue->[0] };
 
-            my $map;
+            $map->load;
 
-            if ($map = cf::map::find $mine->[0]
-                and $map =~ /^\// # short-gap fix
-                and !grep +($_->flag (cf::FLAG_UNIQUE) || $_->type == cf::SHOP_FLOOR) && $_->flag (cf::FLAG_IS_FLOOR),
-                          $map->at ($mine->[1], $mine->[2])) {
-               $who->ob->goto (@$mine);
-            } else {
-               delete $follow{$name};
-               $who->ob->message ("You can't follow $target anymore!");
+            if (
+               $map->path !~ /^(\{link\}|\/)/
+               or grep $_->flag (cf::FLAG_IS_FLOOR) && ($_->flag (cf::FLAG_UNIQUE) || $_->type == cf::SHOP_FLOOR),
+                  $map->at ($x, $y)
+            ) {
+               $who->message ("You can't follow " . $target->name . " anymore!");
+               unfollow $who->name;
+            } elsif (!$who->blocked ($map, $x, $y)) {
+               shift @$queue;
+               $who->goto ($map, $x, $y);
             }
-         } else {
-            delete $follow{$name};
-            $who->ob->message ("$target is gone...");
          }
       }
 
@@ -57,16 +82,20 @@
 
    if ($args ne "" && $name ne $args) {
       if (my $other = cf::player::find_active $args) {
-         if ($other->ob->map == $who->map
-             && abs ($other->ob->x - $who->x) <= 1
-             && abs ($other->ob->y - $who->y) <= 1) {
+         $other = $other->ob;
+
+         if ($other->map == $who->map
+             && abs ($other->x - $who->x) <= 1
+             && abs ($other->y - $who->y) <= 1
+         ) {
             $who->message ("Following player '$args', to stop, type: 'follow");
-            $other->ob->message ("$name is now following your every step...");
+            $other->message ("$name is now following your every step...");
             $follow{$name} = [
-               $args,
-               [$other->ob->map->path, $other->ob->x, $other->ob->y],
-               [$who->map->path,       $who->x,       $who->y],
+               $who,
+               $other,
+               [[$other->map, $other->x, $other->y]],
             ];
+            $who->contr->attach ("follow_aborter");
             $CORO->ready;
          } else {
             $who->message ("You must stand directly beside '$args' to follow her/him");
@@ -82,20 +111,22 @@
    }
 };
 
-cf::player->attach (
-   on_death => sub {
-      my ($pl) = @_;
+sub unregister {
+   my ($pl) = @_;
 
-      my $name = $pl->ob->name;
+   my $name = $pl->ob->name;
 
-      delete $follow{$name};
+   unfollow $name;
 
-      while (my ($k, $v) = each %follow) {
-         if ($v->[0] eq $name) {
-            delete $follow{$k};
-         }
-      }
-   },
+   while (my ($k, $v) = each %follow) {
+      unfollow $k
+         if $v->[1]->name eq $name;
+   }
+}
+
+cf::player->attach (
+   on_death  => \&unregister,
+   on_logout => \&unregister,
 );