Node Types

There are 3 kinds of nodes: EntryNode, ProcessNode and ValueNode.

Ability starts from an entry node, and move through each FlowNode.
EntryNode and ProcessNode are FlowNode.

EntryNode

EntryNode is the first node for every running abilities. It receives a custom payload object, which should implement IEventContext, and check if the ability can run.

For example, when you play a card, you might need to check whether you have enough mana, and maybe need to match additional conditions. In this case, we can create a PlayCardNode to check if we can pay the resources.

For another example, when the turn end, you want to check and trigger every related abilities. Note that "on turn end" is a game event, so we can create a OnTurnEndNode, and send a payload telling who's turn is end.

Example

[NodeCategory("Card Game Sample")]
public class OnDamagedEventNode : EntryNode
{
    public Outport<Unit> attackerPort;

    public override bool CanExecute(IEventContext payload)
    {
        if (payload is DamageEvent damageEvent)
        {
            // Check if the owner is one of the targets
            for (var i = 0; i < damageEvent.targets.Count; i++)
            {
                if (damageEvent.targets[i] == Actor)
                {
                    return true;
                }
            }
        }

        return false;
    }

    protected override AbilityState DoLogic()
    {
        // Set the outports
        var payload = GetPayload<DamageEvent>();
        attackerPort.SetValue(payload.attacker);
        return AbilityState.RUNNING;
    }
}

ProcessNode

ProcessNode is like an action. The best practice is to make each action small enough.

Example

[NodeCategory("Card Game Sample")]
public class ModifyManaNode : ProcessNode
{
    public Inport<Player> playerPort;
    public Inport<int> amountPort;

    protected override AbilityState DoLogic()
    {
        // Modify the mana from the target
        Player player = playerPort.GetValue();
        int amount = amountPort.GetValue();
        player.ModifyStat(StatId.MANA, amount);

        // Event
        EnqueueEvent(new ManaChangeEvent
        {
            modifyValue = amount,
            newAmount = player.GetStat(StatId.MANA).CurrentValue,
        });

        return AbilityState.RUNNING;
    }
}

ValueNode

ValueNode is not FlowNode. It gives values to other nodes.

To give the values, you need to set the values by overriding EvaluateSelf() method.

Example

[NodeCategory("Card Game Sample")]
public class RandomPickNode : ValueNode
{
    public Inport<IReadOnlyList<Unit>> sourcePort;
    public Outport<Unit> resultPort;

    protected override void EvaluateSelf()
    {
        IReadOnlyList<Unit> source = sourcePort.GetValue();
        var payload = GetPayload<PlayCardNode.Payload>();
        Unit unit = source.RandomPickOne(payload.random);
        resultPort.SetValue(unit);
    }
}