User-Created State Properties

Table of Contents

• Accessing User-Created State Properties from the Simulation Engine
• Accessing User-Created State Properties from the GUI
• Accessing User-Created State Properties from Remote Applications
• Supported Data Types for User-Created State Properties

VR-Forces users can add new state properties and parameter properties without using the VR-Forces Toolkit.

They do this by adding code to OPE files. (For details, please see State Properties and Parameter Properties, in VR-Forces Users Guide.) You can access these properties using the API, as described in this section.

• Getting and Setting User-Created State Property Values
• Publishing User-Created State Properties

Accessing User-Created State Properties from the Simulation Engine

State properties are stored in the DtStatePropertiesStateComponent of all VR-Forces simulation objects. Please see the example plug-in to see some sample code for how state properties can be looked up and set.

Parameter properties are also stored separately in the DtStatePropertiesStateComponent and can be accessed in a similar way.

Accessing User-Created State Properties from the GUI

State properties can be found by accessing the state of reflected objects through the DtVrfStateViewCollectionManager. Please see the example plug-in to see some sample code for accessing the values of state properties for an entity.

Accessing User-Created State Properties from Remote Applications

Other applications can access state properties by instantiating special reflected lists that support them. These are DtReflectedVrfExtEntityList, DtReflectedVrfExtAggregateList, and DtReflectedVrfControlObjectList. The VRF Message Dump (vrfMsgDump) tool has a DtVrfStatePropertyPrinter that serves as an example of how to use these classes in your own remote application.

Supported Data Types for User-Created State Properties

The following table identifies the data types supported for state properties. The Data Type column indicates the name of the data type used in the C++ code. (The data types used in OPE files are slightly different.) The Description column describes the format of this type. The HLA Representation/Encoding column indicates what type should be used in an HLA 1516 FOM to match the specification in the OPE.

Data Types Supported for State Properties and Parameter Properties
Data Type	Description	HLA Representation/Encoding
DtRwInt, DtRwInt32	A 32-bit integer	RPRunsignedInteger32BE, HLAinteger32BE
DtRwInt16	A 16-bit integer	RPRunsignedInteger16BE, HLAinteger16BE
DtRwInt8	An 8-bit integer	RPRunsignedInteger8BE, HLAoctet
DtRwReal, DtRwReal64	A 64-bit float	HLAfloat64BE
DtRwReal32	A 32-bit float	HLAfloat32BE
DtRwBoolean	A Boolean	RPRboolean
DtRwString	An ASCII string	RPRnullTerminatedArray of HLAASCIIchar
DtRwVector	A location in geocentric coordinates	WorldLocationStruct, from the RPR FOM
C++: DtRwPropertiesFixedArray OPE:DtRwFixedArray	A fixed size list of items	HLAFixedArray
C++: DtRwPropertySizedString OPE: DtRwSizedString	An ASCII string (alternate encoding for DtRwString)	HLAASCIIstring
C++: DtRwPropertiesStructure OPE: DtRwStructure	A fixed structure with multiple named fields	HLAfixedRecord with matching fields
C++: DtRwPropertiesList OPE: DtRwList	A variable sized list of items	HLAvariableArray
C++: DtRwPropertiesMap OPE: DtRwMap	A variable sized map of items	HLAvariableArray of HLAfixedRecords, where the first field in each record is the key