--- deliantra/server/ext/follow.ext	2006/12/17 00:44:59	1.2
+++ deliantra/server/ext/follow.ext	2010/05/18 21:30:16	1.21
@@ -6,57 +6,75 @@
 # implement a 'follow' command
 # don't follow on damned ground
 
-sub teleport {
-   my ($pl, $map, $x, $y) = @_;
+our $MAX_QUEUE = 5; # the # of positions somebody else can lead
+our %follow; # $followername => [$follower, $target, [$queue]]
 
-   return if $pl->ob->map->path eq $map
-          && abs ($pl->ob->x - $x) <= 1
-          && abs ($pl->ob->y - $y) <= 1;
+sub unfollow($) {
+   my $name = shift;
 
-   my $portal = cf::object::new "exit";
+   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 . ".");
+   }
+}
 
-   $portal->slaying   ($map);
-   $portal->stats->hp ($x);
-   $portal->stats->sp ($y);
+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");
+   },
+;
 
-   $portal->apply ($pl->ob);
+our $CORO = cf::async {
+   $Coro::current->{desc} = "follow handler";
 
-   $portal->destroy;
-}
+   while () {
+      cf::wait_for_tick;
 
-my %follow;
+      for (values %follow) {
+         my ($who, $target, $queue) = @$_;
 
-my $timer = Event->timer (interval => 0.2, parked => 1, data => cf::WF_AUTOCANCEL, cb => sub {
-   while (my ($name, $v) = each %follow) {
-      my ($target, $his, $mine) = @$v;
-      my ($who, $other) = (cf::player::find $name, cf::player::find $target);
-
-      if ($who && $other && $other->ob->map) {
-         my ($map, $x, $y) = ($other->ob->map->path, $other->ob->x, $other->ob->y);
-
-         if ($map ne $his->[0] || $x != $his->[1] || $y != $his->[2]) {
-            @$mine = @$his;
-            @$his = ($map, $x, $y);
-         }
+         my ($map, $x, $y) = ($target->map, $target->x, $target->y);
+
+         # add new position to queue, if any
+         push @$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 !grep $_->flag (cf::FLAG_UNIQUE) && $_->flag (cf::FLAG_IS_FLOOR),
-                       $map->at ($mine->[1], $mine->[2])) {
-            teleport $who, @$mine;
-         } else {
-            delete $follow{$name};
-            $who->ob->message ("You can't follow $target anymore!");
+            if (
+               !$map->valid
+               or $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...");
       }
-   }
 
-   $_[0]->w->stop unless keys %follow;
-});
+      Coro::schedule unless keys %follow;
+   }
+};
 
 cf::register_command follow => sub {
    my ($who, $args) = @_;
@@ -64,18 +82,22 @@
    my $name = $who->name;
 
    if ($args ne "" && $name ne $args) {
-      if (my $other = cf::player::find $args) {
-         if ($other->ob->map->path eq $who->map->path
-             && abs ($other->ob->x - $who->x) <= 1
-             && abs ($other->ob->y - $who->y) <= 1) {
+      if (my $other = cf::player::find_active $args) {
+         $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]],
             ];
-            $timer->start;
+            $who->contr->attach ("follow_aborter");
+            $CORO->ready;
          } else {
             $who->message ("You must stand directly beside '$args' to follow her/him");
             delete $follow{$name};
@@ -90,22 +112,21 @@
    }
 };
 
-cf::attach_to_players
-   on_death => sub {
-      my ($pl) = @_;
-
-      my $name = $pl->ob->name;
-
-      delete $follow{$name};
+sub unregister {
+   my ($pl) = @_;
 
-      while (my ($k, $v) = each %follow) {
-         if ($v->[0] eq $name) {
-            delete $follow{$k};
-         }
-      }
-   },
-;
+   my $name = $pl->ob->name;
 
+   unfollow $name;
 
+   while (my ($k, $v) = each %follow) {
+      unfollow $k
+         if $v->[1]->name eq $name;
+   }
+}
 
+cf::player->attach (
+   on_death  => \&unregister,
+   on_logout => \&unregister,
+);