Any way to ensure teleport success?

[Enjay]

I have a situation where I am teleporting a couple of boss enemies into an arena, I am doing this via TeleportOther.

It works fine but I worry that the teleport might fail. I have done my best to ensure that can't happen (it's highly unlikely - perhaps even impossible that it will fail with the way that I have set up the map), but I was wondering if there was any way to check whether the teleport has been successful or not and, if not keep trying until it is?

Thanks.

[MartinHowe]

Is this from a monster closet (Vanilla/Limit-Removing) or is ZScript available? And do these monsters already have context or could they be spawned?

[Enjay]

They already exist on the map, and the player may have interacted with them (and damaged them a bit) before the teleport happens. They appear, the player does stuff, they go away, and then they come back at a later point in a different area of the map.

ZScript is a possibility.

[MartinHowe]

Well, you know you can spawn an item and check if it was spawned? I'm thinking something like this:

• Define an actor the same size as the one to be teleported.
• Make it invisible but solid
• Use SpawnItemEx to spawn it, checking if it was spawned, until it is
• Make the monster non-solid and invisible
• Teleport it to the desired area using the co-ordinates of the other actor
• Make the original monster solid again
• Destroy() the other actor
• Spawn a teleport flash at the same location (these are not solid so should be OK)
• Make the monster visible again

It's a bit hacky but should work. Or you could have several of these fake actors already in the arena marked +NOINTERACTION and shortly before the teleport, remove the nointeraction flag and make it solid on one that has nothing else in the same place; for a short time, there will appear to be a part of the map that monsters are avoiding, but hopefully the player won't notice in the confusion.

This is what I use for repeated attempted spawns:

Code: Select all

    const SPAWNCATS_Y_SPREAD = 256;

    void SpawnCats(actor player, array<BlackCatToken> catsToSpawn)
    {
        uint count = catsToSpawn.Size();

        if (!count)
        {
            return;
        }

        int yofs = -(SPAWNCATS_Y_SPREAD / 2);
        int ystep = SPAWNCATS_Y_SPREAD / count;

        double a = player.angle;
        double s = sin(a);
        double c = cos(a);
        double z = player.pos.z;

        // Offset code adapted from that in A_SpawnItemEx

        for (int cat = 0 ; cat < count ; cat++)
        {
            BlackCatToken catToken = catsToSpawn[cat];

            for (int attempt = 0; attempt < 32; attempt++)
            {
                int xofs = 32 * attempt;

    			vector3 newpos = player.Vec2OffsetZ(xofs * c + yofs * s, xofs * s - yofs * c, z);
                if (Level.IsPointInLevel(newpos))
                {
                    bool wasSpawned;
                    actor whatWasSpawned;
                    [wasSpawned, whatWasSpawned] = player.A_SpawnItemEx(catToken.catClass, xofs, yofs, 0);
                    if (wasSpawned && whatWasSpawned)
                    {
                        BlackCat aCat = BlackCat(whatWasSpawned);
                        aCat.StartHealth = catToken.startHealth;
                        aCat.Health = catToken.currentHealth;
                        aCat.FriendPlayer = catToken.FriendPlayer;
                        aCat.bSpawnWithTeleportFog = true;
                        aCat.bFollowPlayerToMap = catToken.followToMap;
                        aCat.bFollowPlayerInHub = catToken.followInHub;
                        aCat.bFollowPlayerToHub = catToken.followToHub;
                        break;
                    }
                }
            }

            yofs = yofs + ystep;
        }
    }

[Enjay]

OK, yes, thanks. I can work with and adapt that to my needs.

[Blue Shadow]

There's an easier and simpler way.

Code: Select all

script 1 (void)
{
	while (!TeleportOther(...))
	{
		Delay(35);
	}
}

The script will attempt to teleport the monster. If the teleportation fails, it'll try again every second until it succeeds.

[Enjay]

Oh, I didn't realise that you could effectively check for TeleportOther success like that (and presumably other teleports). That is simpler. Thanks.

[MartinHowe]

Oh, I didn't realise that you could effectively check for TeleportOther success like that (and presumably other teleports).

Nor did I; the Wiki is out of date; it reports the special as void rather than bool.

[Enjay]

Yep, same for me. I checked the Wiki and when I didn't see any way of checking success listed, I started this thread.