Enemies should not be able to teleport or summon with targets out of sight

[DominusExult]

Especially with Liches, they shouldn't be able to teleport to or summon something at the Avatar without a line of sight. See Gotcha's forum post http://exult.info/forum/viewtopic.php?f=1&t=1791278&sid=cfc074524d41ae44dde03f0466733d9c.
A check for line of sight prevents this. Please let me know if I do this correctly and whether you can think of a place where this could break the game:

diff --git a/combat.cc b/combat.cc
index 75f9e87d..fbd3268c 100644
--- a/combat.cc
+++ b/combat.cc
@@ -234,6 +234,10 @@ bool Combat_schedule::teleport(
 	eman->add_effect(std::make_unique<Fire_field_effect>(src));
 	int sfx = Audio::game_sfx(43);
 	Audio::get_ptr()->play_sound_effect(sfx, npc);  // The weird noise.
+	// check line of sight now to give it the appaearnace of the spell 
+	// failing as in the original
+	if (!Fast_pathfinder_client::is_straight_path(npc, trg))
+		return false;
 	npc->move(dest.tx, dest.ty, dest.tz);
 	// Show the stars.
 	eman->add_effect(std::make_unique<Sprites_effect>(7, npc, 0, 0, 0, 0));
@@ -246,6 +250,9 @@ bool Combat_schedule::teleport(
 
 bool Combat_schedule::summon(
 ) {
+	Game_object *trg = npc->get_target();
+	if (!Fast_pathfinder_client::is_straight_path(npc, trg))
+		return false;
 	ucmachine->call_usecode(SummonSpellUsecode,
 	                        npc, Usecode_machine::double_click);
 	npc->start_std();       // Back into queue.

[drcode1]

Send reasonable.

…

On Sun, Feb 13, 2022, 5:19 PM Dominik Reichardt ***@***.***> wrote: Especially with Liches, they shouldn't be able to teleport to or summon something at the Avatar without a line of sight. See Gotcha's forum post http://exult.info/forum/viewtopic.php?f=1&t=1791278&sid=cfc074524d41ae44dde03f0466733d9c . A check for line of sight prevents this. Please let me know if I do this correctly and whether you can think of a place where this could break the game: diff --git a/combat.cc b/combat.cc index 75f9e87d..fbd3268c 100644 --- a/combat.cc +++ b/combat.cc @@ -234,6 +234,10 @@ bool Combat_schedule::teleport( eman->add_effect(std::make_unique<Fire_field_effect>(src)); int sfx = Audio::game_sfx(43); Audio::get_ptr()->play_sound_effect(sfx, npc); // The weird noise. + // check line of sight now to give it the appaearnace of the spell + // failing as in the original + if (!Fast_pathfinder_client::is_straight_path(npc, trg)) + return false; npc->move(dest.tx, dest.ty, dest.tz); // Show the stars. eman->add_effect(std::make_unique<Sprites_effect>(7, npc, 0, 0, 0, 0)); @@ -246,6 +250,9 @@ bool Combat_schedule::teleport( bool Combat_schedule::summon( ) { + Game_object *trg = npc->get_target(); + if (!Fast_pathfinder_client::is_straight_path(npc, trg)) + return false; ucmachine->call_usecode(SummonSpellUsecode, npc, Usecode_machine::double_click); npc->start_std(); // Back into queue. — Reply to this email directly, view it on GitHub <#148>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AAE2RJK3P3OJSTHGKLJJSJDU3A36PANCNFSM5OJ3QECA> . Triage notifications on the go with GitHub Mobile for iOS <https://apps.apple.com/app/apple-store/id1477376905?ct=notification-email&mt=8&pt=524675> or Android <https://play.google.com/store/apps/details?id=com.github.android&referrer=utm_campaign%3Dnotification-email%26utm_medium%3Demail%26utm_source%3Dgithub>. You are receiving this because you are subscribed to this thread.Message ID: ***@***.***>

[DominusExult]

Thanks! Added in e0a5530

[Dragon-Baroque]

Should you move the Line of Sight check up in Combat_schedule::teleport ? I mean before it creates the Fire Field at the point of departure, and along with the other test for letting the Avatar escape ?

I would assume a Lich, a Supra-Genius evil creature, be able to predict that the Teleport will fail by lack of Line of Sight and not even attempt it, much less create a Fire Field where it is standing.

[DominusExult]

In the original the fire fields get created as well, so I thought mimicking this would be the best way to handle it. Without those fire fields it might look too boring, perhaps?

Something else I was thinking about there in regard to the combat difficulty setting. Maybe it would be a nice touch to allow monsters without line of sight to summon at harder and to teleport at hardest. So far the combat difficulty only handles hit points differently AFAIK

[Dragon-Baroque]

In the original the fire fields get created as well.

If so then OK. Looks to me as a defect in the combat IA, but OK.

In that case, please replace the return false of the Line of Sight check in Combat_schedule::teleport, possibly also the one in Combat_schedule::summon, by a return true.

Because, as they are called, summon() and teleport() returning false do not mean the action has failed, but the action has not taken place, since only a true result adjusts the dexterity points and terminates the current action. The false result instead leaves the possibility for another action : strike instead of summon or walk instead of teleport.
As it stands your patch creates a Fire Field but does not inflict its cost in dexterity points or in time to the Lich.
Not that this changes much to a jailed Lich, but in an open area with sight obstructing walls, it might...

[DominusExult]

Thanks for the explanation! Changed the teleport() function accordingly but left the summon() as I have no indication if the original did execute it.
And yes, it might be a defect in the original teleport() but no idea if we should leave it in or not.