{{tag>dragonscript behavior}}
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[[:start|Start Page]] >> [[main|DragonScript Scripting Language]] >> [[dragengine:modules:dragonscript:abstractions|Abstraction Layers: How you want to build your Game]] >> [[dragengine:modules:dragonscript:behavior_elements|Behavior Elements]] >> **ECBehaviorVRControlDesktop**
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  * [[behaviors_use_cases|Behaviors Explained: By Use-Case]]
  * [[behaviors_a_to_z|Behaviors Explained: From A to Z]]

====== ECBehaviorVRControlDesktop ======

Behavior adding support to VR hand action to control desktops.

To be used with [[behavior_vrhandaction|BaseVRHandAction]] subclasses. Tracks [[behavior_vrhandpointat|ECBehaviorVRHandPointAt]]. If an element is pointed at that supports [[behavior_controldesktop|ECBehaviorControlDesktop]] moves the mouse pointer and uses trigger pulling to simulate mouse click. Each hand can individually interact with different [[behavior_controldesktop|ECBehaviorControlDesktop]]. Hand action has to call pointAt(), pointAtPull() and pointAtRelease() to interact.

====== Instance Counts ======

This behavior can be used only once on an element.

====== Element Class Properties ======

Element class properties have the prefix ''vrControlDesktop.'' .

====== Events ======

This behavior has no events.

====== Behavior Tree Actions ======

This behavior adds these behavior tree actions if behavior tree is present. If behavior has non-empty identifier replace ''vrControlDesktop'' with ''vrControlDesktop(id)''.

===== vrControlDesktop.set =====

Set one or more control desktop parameters.

^Parameter^Value^Description^
|interact|string|Interact with desktop. If element is absent action fails. Runs interaction with name value. If interaction with name value is absent fails action. If interaction returns false fails action. Otherwise action succeeds.|
|interact.parameters|string|Optional parameters to use with ''interaction''.|
|interactElement.assign|string|Assign desktop to [[behavior_interactelement|ECBehaviorInteractElement]] with identifier matching value string. Action fails if no element is looked at or interact element behavior is absent|

This is an example of using this action:
<code xml>
<action name='vrControlDesktop.set'>
  <parameter name='interactElement.assign'/>
</action>
</code>

===== vrControlDesktop.check =====

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

^Parameter^Value^Description^
|desktop|''true'', ''false''|Desktop is controlled|
|interact.name|string|Name of interaction|
|interact.has|''true'', ''false''|Has desktop and interaction with name ''interaction.name'' is present|
|interact.query|''true'', ''false''|Interact with desktop and test result. Condition is true if desktop is present, interaction with name ''interaction.name'' is present and interaction returns true. It is recommended to use here only interactions without side effects (hence query interactions).|
|interact.parameters|string|Optional parameters to use with ''interaction.query''.|
|wait| |If present action returns BTResult.running instead of BTResult.failed to wait until the checks are all fulfilled|

This is an example of using this action:
<code xml>
<sequence>
  <action name='vrControlDesktop.check'>
    <parameter name='desktop'>true</parameter>
  </action>
  <!-- actions here run only if player is controlling a desktop -->
</sequence>
</code>

====== Behavior Tree Conditions ======

This behavior adds these behavior tree conditions if behavior tree is present. If behavior has non-empty identifier replace ''vrControlDesktop'' with ''vrControlDesktop(id)''.

===== vrControlDesktop.check =====

Check one or more control desktop parameters. Conditions returns true if all parameter value match their respective control desktop parameter. This condition is typically used to run an action or sequence of actions as long as control desktop conditions are true.

^Parameter^Value^Description^
|desktop|''true'', ''false''|Desktop is controlled|
|vrControlDesktop.interact.name|string|Name of interaction|
|vrControlDesktop.interact.has|''true'', ''false''|Has desktop and interaction with name ''interaction.name'' is present|
|vrControlDesktop.interact.query|''true'', ''false''|Interact with desktop and test result. Condition is true if desktop is present, interaction with name ''interaction.name'' is present and interaction returns true. It is recommended to use here only interactions without side effects (hence query interactions).|
|vrControlDesktop.interact.parameters|string|Optional parameters to use with ''interaction.query''.|

This is an example of using this condition:
<code xml>
<action name='myAction' id='doing something'>
  <parameter name='vrControlDesktop.enabled'>true</parameter>
  <condition>vrControlDesktop.check</condition>
</action>
</code>

====== State Machine Actions ======

Same as [[#behavior_tree_actions|Behavior Tree Actions]].

====== State Machine Conditions ======

Same as [[#behavior_tree_conditions|Behavior Tree Conditions]].

====== State Machine Events ======

This behavior sends no state machine events.

====== Required Behaviors ======

  * [[behavior_vrhandpointat|ECBehaviorVRHandPointAt]]

====== Optional Behaviors ======

  * [[behavior_behaviortree|ECBehaviorBehaviorTree]]: Add actions and conditions for behavior trees to use.
  * [[behavior_statemachine|ECBehaviorStateMachine]]: Add actions and conditions for state machine to use and events to send to the state machine.

====== Persistency ======

This behavior does not required element class to be persistable (setPersistable).

====== API Documentation ======

#@LinkApiDocDEDS2_HTML~classDragengine_1_1Scenery_1_1ECBehaviorVRControlDesktop.html,ECBehaviorVRControlDesktop~@#.

Since DragonScript Module Version ''1.12''

====== Use Cases ======

  * Simplifies creating BaseVRHandAction using [[behavior_vrhandpointat|ECBehaviorVRHandPointAt]] pointing at an element supporting [[behavior_controldesktop|ECBehaviorControlDesktop]].

====== Element Class Example ======

<code>
class MyElement extends BehaviorElementClass
  public var ECBehaviorVRPlayspace vrPlayspace
  public var ECBehaviorVRHand vrHandRight
  public var ECBehaviorVRHand vrHandLeft
  public var ECBehaviorVRHandPointAt vrRightHandPointAt
  public var ECBehaviorVRHandPointAt vrLeftHandPointAt
  public var ECBehaviorVRControlDesktop vrControlDesktopRight
  public var ECBehaviorVRControlDesktop vrControlDesktopLeft
  func new()
      vrPlayspace = ECBehaviorVRPlayspace.new(this)
      vrHandRight = ECBehaviorVRHand.new(this, vrPlayspace, InputDeviceType.vrRightHand, BaseVRActorClass.idVRRightHand)
      vrHandLeft = ECBehaviorVRHand.new(this, vrPlayspace, InputDeviceType.vrLeftHand, BaseVRActorClass.idVRLeftHand)
      vrRightHandPointAt = ECBehaviorVRHandPointAt.new(this, vrRightHand, BaseVRActorClass.idVRRightHand)
      vrLeftHandPointAt = ECBehaviorVRHandPointAt.new(this, vrLeftHand, BaseVRActorClass.idVRLeftHand)
      vrControlDesktopRight = ECBehaviorVRControlDesktop.new(this, vrHandRight, BaseVRActorClass.idVRRightHand)
      vrControlDesktopLeft = ECBehaviorVRControlDesktop.new(this, vrHandLeft, BaseVRActorClass.idVRLeftHand)
  end
end
</code>

Example of VR-Hand action using this behavior.

<code>
class MyHandAction extends BaseVRHandAction implements BAAVRTriggerInput
  protected var ECBehaviorVRControlDesktop.Instance controlDesktop
  
  // Create action.
  func new()
  end
  
  // Init behaviors. This stores aside the behavior matching the VR hand this action belongs to.
  protected func void initBehaviors()
    super.initBehaviors()
    
    if vrHand.getECBehavior().getID().equals(BaseVRActorClass.idVRRightHand)
      controlDesktop = ECBehaviorVRControlDesktop.getInstanceIn(actor, BaseVRActorClass.idVRRightHand)
    else
      controlDesktop = ECBehaviorVRControlDesktop.getInstanceIn(actor, BaseVRActorClass.idVRLeftHand)
    end
  end
  
  // Activate hand behavior. Enable hand point at to enable controlling desktops.
  func void activate(BehaviorElement actor, ECBehaviorVRHand.Instance vrHand)
    super.activate(actor, vrHand)
    
    handPointAt.setEnabled(true)
  end
  
  // Deactivate hand behavior. Disable hand point at and stop interacting with desktop.
  // Do not stop interacting here if you want to switch to another action that should
  // keep on using the desktop.
  func void deactivate()
    controlDesktop.pointAtRelease()
    handPointAt.setEnabled(false)
    
    super.deactivate()
  end
  
  // Frame update. Interact with control desktop if pointed at. The if check allows
  // to test various possible interactions stopping at the first one that works.
  // Make sure super.think(elapsed) is alway called even if exiting early
  func void think(float elapsed)
    if controlDesktop.pointAt()
      super.think(elapsed)
      return
    end
    
    // Here you could test for other possible interactions
    
    super.think(elapsed)
  end
  
  // Events by BAAVRTriggerInput we do not use for this example but have to be declared.
  func void triggerTouch()
  end
  
  func void triggerUntouch()
  end
  
  func void triggerAnalog(float value)
  end
  
  // Trigger is pulled. Sends left mouse press to desktop if one is controlled.
  // The if check allows to test various possible interactions stopping at the
  // first one that works.
  func void triggerPull()
    if controlDesktop.pointAtPull()
      return
    end
    
    // Here you could test for other possible interactions
  end
  
  // Trigger has been released. Sends left mouse release to desktop if one is
  // controlled. // The if check allows to test various possible interactions
  // stopping at the first one that works.
  func void triggerRelease()
    if controlDesktop.pointAtRelease()
      return
    end
  end
end
</code>

====== Behavior Factory ======

Using element class supporting adding behaviors the behavior can be added like this:
<code xml>
<?xml version='1.0' encoding='UTF-8'?>
<elementClass name='MyClass' class='GenericBehaviorElement'>
  <behavior type='ECBehaviorVRPlayspace'/>
  <behavior type='ECBehaviorVRHand' id='right'/>
  <behavior type='ECBehaviorVRHand' id='left'/>
  <behavior type='ECBehaviorVRHandPointAt' id='right'>
    <string name='vrHand'>right</string>
  </behavior>
  <behavior type='ECBehaviorVRHandPointAt' id='left'>
    <string name='vrHand'>left</string>
  </behavior>
  
  <behavior type='ECBehaviorVRControlDesktop' id='right'>
    <!-- required: use vr hand point at with id -->
    <string name='vrHandPointAt'>right</string>
    
    <!-- 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>
    
    <!-- set element properties. omit property prefix if used inside behavior tag -->
    <string name='.name'>value</string>
  </behavior>
  
  <behavior type='ECBehaviorVRControlDesktop' id='left'>
    <string name='vrHandPointAt'>left</string>
  </behavior>
</elementClass>
</code>

====== Live Examples ======

  * [[https://github.com/LordOfDragons/deexamples|DEExamples Repository]]