Problem with chain spells

[Regeton5306]

Priority

Medium

Area

• Datapack
• Source
• Map
• Other

What happened?

When you apply chain spell to a creature, the spell activates for other creatures, including NPCs, Although it doesn't damage them, it just activates the chaining and the effect on them.

What OS are you seeing the problem on?

Windows

Code of Conduct

• I agree to follow this project's Code of Conduct

[lBaah]

Chain spells have a function called canChain where you can select who is going to be part of the chain:

Example to select only players:

function canChain(creature, target)
	if target:isPlayer() then
		return true
	end
	return false
end

Remember to set the callback:
combat:setCallback(CALLBACK_PARAM_CHAINPICKER, "canChain")

[Regeton5306]

Chain spells have a function called canChain where you can select who is going to be part of the chain:

Example to select only players:

function canChain(creature, target)
	if target:isPlayer() then
		return true
	end
	return false
end

Remember to set the callback: combat:setCallback(CALLBACK_PARAM_CHAINPICKER, "canChain")

Does that also apply to player summons and that the chain spell effect does not come out within the safe zone?

[lBaah]

The script is going to do what you tell it to do. In my example it will pick only players to chain: if target:isPlayer() then.

[Mortera-world]

below this line in combat.cpp

for (const auto &spectator : spectators) {
            if (!spectator || visited.contains(spectator->getID())) {
                continue;
            } 

ADD

            if (spectator->getZoneType() == ZONE_PROTECTION) {
                visited.insert(spectator->getID());
                continue;
            }
            if (spectator->getNpc()) {
                visited.insert(spectator->getID());
                continue;
            }
            if (spectator == caster) {
                visited.insert(spectator->getID());
                continue;
            }
            const auto& casterPlayer = caster->getPlayer();
            const auto& casterMonster = caster->getMonster();
            const auto& spectatorPlayer = spectator->getPlayer();
			const auto& spectatorSummon = spectator->isSummon();

            if (casterPlayer) {
                if (casterPlayer->hasSecureMode()) {
                    if (spectatorPlayer) {
                        visited.insert(spectator->getID());
                        continue;
                    }
                    if (spectatorSummon && spectator->getMaster() && spectator->getMaster()->getPlayer()) {
                        visited.insert(spectator->getID());
                        continue;
                    }
                }
            } else if (casterMonster) {
                if (spectatorSummon) {
                    const auto& master = spectator->getMaster();
                    if (!master || !master->getPlayer()) {
                        visited.insert(spectator->getID());
                        continue;
                    }
                } else if (!spectator->getPlayer()) {
                    visited.insert(spectator->getID());
                    continue;
                }
            } 

This worked for me, already tested in chain attack, amp res, weapons with chain, everything seems to be fine

[Regeton5306]

below this line in combat.cpp

for (const auto &spectator : spectators) {
            if (!spectator || visited.contains(spectator->getID())) {
                continue;
            } 

ADD

            if (spectator->getZoneType() == ZONE_PROTECTION) {
                visited.insert(spectator->getID());
                continue;
            }
            if (spectator->getNpc()) {
                visited.insert(spectator->getID());
                continue;
            }
            if (spectator == caster) {
                visited.insert(spectator->getID());
                continue;
            }
            const auto& casterPlayer = caster->getPlayer();
            const auto& casterMonster = caster->getMonster();
            const auto& spectatorPlayer = spectator->getPlayer();
			const auto& spectatorSummon = spectator->isSummon();

            if (casterPlayer) {
                if (casterPlayer->hasSecureMode()) {
                    if (spectatorPlayer) {
                        visited.insert(spectator->getID());
                        continue;
                    }
                    if (spectatorSummon && spectator->getMaster() && spectator->getMaster()->getPlayer()) {
                        visited.insert(spectator->getID());
                        continue;
                    }
                }
            } else if (casterMonster) {
                if (spectatorSummon) {
                    const auto& master = spectator->getMaster();
                    if (!master || !master->getPlayer()) {
                        visited.insert(spectator->getID());
                        continue;
                    }
                } else if (!spectator->getPlayer()) {
                    visited.insert(spectator->getID());
                    continue;
                }
            } 

This worked for me, already tested in chain attack, amp res, weapons with chain, everything seems to be fine

That worked, thanks

[murilo09]

@Mortera-world can you open a PR?

[lBaah]

@Mortera-world can you open a PR?

The reason why CALLBACK_PARAM_CHAINPICKER exists is to resolve this. No PR needed. This is not an issue, as the spell is misconfigured.

[Mortera-world]

@Mortera-world can you open a PR?

The reason why CALLBACK_PARAM_CHAINPICKER exists is to resolve this. No PR needed. This is not an issue, as the spell is misconfigured.

Sorry, I tried many ways to correct this from the spell but I had no results

I tried this and it crashed, I tried in several ways and it crashed, from the spell you can't make the chain magic not enter safe zones

function canChain(creature, target)
    if not creature or not target then
        return false
    end

    if target:isPlayer() then
        return true
    elseif target:isSummon() then
        local master = target:getMaster()
        if master and master:isPlayer() and master == creature then
            return true
        end
    end

    return false
end

combat:setCallback(CALLBACK_PARAM_CHAINPICKER, "canChain")

sorry I don't know how I can correct this from the spell because many ways I tried gave me a crash on the server

[lBaah]

The chain enters protection zone because you don't check if the target is in protection zone.

if target:getPosition():isProtectionZoneTile() then
        return false -- false means it will not chain this target
end

When you do

if target:isPlayer() then
        return true
end

it will chain the player, because you are telling it is TRUE to chain this target regardless of it's position.

[Mortera-world]

-- false means it will not chain this target

I repeat, I tried it in many ways including safe zone checks, if the caster has pz or skull, the fact is that being a target it only works with the target, what follows after is the chain and that does not apply that target order, I imagine why it always hit in a safe zone even having verification that it does not

In fact, I had that problem for a long time and no matter how much I asked for help, I didn't find a solution or no one wanted to share it. That was the solution for me and it worked for me. So far, it hasn't given me any problems.
I tested the script with many canChain and onChain checks, I even tried to test some things from the Chivalrous Challenge magic and the result for the chain magic of the creatures was always the same, I couldn't make it not cast the chain at NPCs, at other creatures, at the summons, that it didn't enter the safe zone.

If later there is someone who shares the spell correctly I will use them, as long as that works well for me