Behavior element behavior adding flags support to behavior trees and state machines.

Adds actions, conditions and events allowing behavior trees and state machines to set, clear and check named flags. Flags are stored per element instance. Flags that are not set are considered cleared. Flags are persisted together with the element.

This behavior can be added only once to an element class.

This behavior has no element class properties.

This behavior adds these behavior tree actions if behavior tree is present.

Update flags. Action always succeeds.

This is an example of setting a flag:

<action name='flags.update'>
  <parameter name='set'>arrived at target</parameter>
</action>

This is an example of setting and clearing a flag in the same action:

<action name='flags.update'>
  <parameter name='set'>arrived at target</parameter>
  <parameter name='clear'>stay seated</parameter>
</action>

Check one or more flag parameters. Action succeeds if all parameter values match their respective flag state otherwise action fails. This action is typically used as first action in a sequence to run the sequence only if a flag matches (or not).

This is an example of checking if a flag is set right now:

<action name='flags.check'>
  <parameter name='flag'>arrived at target</parameter>
  <parameter name='set'>true</parameter>
</action>

This is an example of waiting until a flag is set:

<action name='flags.check' id='waiting'>
  <parameter name='flag'>arrived at target</parameter>
  <parameter name='set'>true</parameter>
  <parameter name='wait'/>
</action>

This is an example of waiting until a flag is set and then clearing it:

<action name='flags.check' id='waiting'>
  <parameter name='flag'>arrived at target</parameter>
  <parameter name='set'>true</parameter>
  <parameter name='wait'/>
  <parameter name='reset'/>
</action>

This behavior adds these behavior tree conditions if behavior tree is present.

Check flag parameters. Condition returns true if all parameter values match their respective flag state. This condition is typically used to run an action or sequence of actions as long as flag conditions are true.

This is an example of using this condition:

<action name='myAction' id='doing something'>
  <condition>flags.check</condition>
  <parameter name='flags.flag'>arrived at target</parameter>
  <parameter name='flags.set'>true</parameter>
</action>

Same as Behavior Tree Actions.

Same as Behavior Tree Conditions.

This behavior sends these state machine events.

Flag named name changed from cleared to set. The name of the flag is appended to the event name.

This is an example of a transition that runs if the flag “arrived at target” has been set:

<transition event='flags.set:arrived at target' state='nextState'>
</transition>

Flag named name changed from set to cleared. The name of the flag is appended to the event name.

This is an example of a transition that runs if the flag “arrived at target” has been cleared:

<transition event='flags.cleared:arrived at target' state='nextState'>
</transition>

This behavior requires no other behaviors.

• ECBehaviorBehaviorTree: Add actions and conditions for behavior trees to use.
• ECBehaviorStateMachine: Add actions and conditions for state machine to use and events to send to the state machine.

This behavior does support element class to be persistable (setPersistable). Set flags are persisted.

ECBehaviorBTSMFlags.

Since DragonScript Module Version 1.35

• Remember that an event has happened, for example that a character arrived at a target.
• Share a yes/no state between behavior trees and state machines of the same element.
• Wait until another part of the element sets a flag before continuing.

This example defines an element which contains flags.

class MyElement extends BehaviorElementClass
  public var ECBehaviorBTSMFlags flags
  func new()
    flags = ECBehaviorBTSMFlags.new(this)
  end
end

Using element class supporting adding behaviors the behavior can be added like this:

<?xml version='1.0' encoding='UTF-8'?>
<elementClass name='MyClass' class='GenericBehaviorElement'>
  <behavior type='ECBehaviorBTSMFlags'>
    <!-- optional: add behavior trees. default adds all behavior trees. -->
    <list name='behaviorTrees'>
      <string/> <!-- add behavior with empty identifier -->
      <string>default</string> <!-- add behavior with 'default' identifier -->
    </list>
 
    <!-- optional: add state machines. default adds all state machines. -->
    <list name='stateMachines'>
      <string/> <!-- add behavior with empty identifier -->
      <string>default</string> <!-- add behavior with 'default' identifier -->
    </list>
  </behavior>
</elementClass>

• DEExamples Repository