DtCustomProjectile Class Reference

Detailed Description

PATTERN: Extending VR-Forces Projectile Classes To create custom munition types in VR-Forces:

1. Derive from makVre::DtProjectile (or DtBallistic, DtGuided for specific types)
2. Add any additional state needed for your behavior (for example, accumulated time in flight)
3. Override update() to implement custom physics or behavior
4. Implement clone(), operator==, type(), and static creator() methods
5. Register with projectile factory in plugin initialization

This Example: Adds a time-in-flight value that accumulates the total flight time at runtime. The value is not configurable in data files and is not serialized; it exists only while the projectile is active in the simulation. This simple example can be extended with:

• Custom guidance algorithms (target tracking, waypoint following)
• Environmental effects (wind, gravity variations)
• Special detonation logic (proximity fuze, timed fuze)
• Visual effects (smoke trails, exhaust plumes)
• Performance characteristics (fuel consumption, thrust curves)

REUSABLE: This class structure is directly reusable for any custom projectile type. Replace myTimeInFlight with your custom parameters and update() logic with your custom behavior.

#include <customProjectile.h>

Inheritance diagram for DtCustomProjectile:

Public Member Functions
	DtCustomProjectile (const DtString &name, DtReaderWriterRegistry *const parentRegistry=nullptr)
	DtCustomProjectile (const DtSymbolString &name, DtReaderWriterRegistry *const parentRegistry=nullptr)
	DtCustomProjectile (const DtCustomProjectile &orig, DtReaderWriterRegistry *const parentRegistry=nullptr)
virtual	~DtCustomProjectile () override
DtCustomProjectile &	operator= (const DtCustomProjectile &orig)
virtual makVre::DtProjectile *	clone () const override
bool	operator== (const DtCustomProjectile &) const
bool	operator!= (const DtCustomProjectile &rhs) const
virtual DtString	type () const override
virtual makVre::DtProjectileDetonationResult	update (double deltaTime) override
Public Member Functions inherited from makVre::DtProjectile
	DtProjectile (const DtString &name, DtReaderWriterRegistry *const parentRegistry=NULL)
	DtProjectile (const DtSymbolString &name, DtReaderWriterRegistry *const parentRegistry=NULL)
	DtProjectile (const DtProjectile &orig, DtReaderWriterRegistry *const parentRegistry=NULL)
virtual	~DtProjectile () override
DtProjectile &	operator= (const DtProjectile &orig)
bool	operator== (const DtProjectile &) const
bool	operator!= (const DtProjectile &rhs)
virtual void	setMunitionType (const DtEntityType &munitionType)
virtual void	setCrossSection (double crossSection)
virtual void	setDragCoefficient (double dragCoefficient)
virtual void	setMass (double mass)
virtual void	setMaxRange (double maxRange)
virtual void	setPosition (DtVector position)
virtual void	setVelocity (DtVector velocity)
virtual void	setDistanceTraveled (double distanceTraveled)
virtual void	setFiringEntity (DtSimObject *firingEntity)
virtual void	setPhysicalWorld (DtPhysicalWorld *physicalWorld)
virtual const DtEntityType &	munitionType ()
virtual DtVector	velocity ()
virtual void	putData (std::string &fp, int indentLevel=0) override
virtual DtlObjPtr	getData (DtlObjPtr args, const DtReaderWriter::SearchPaths &searchPaths, const DtVariableBindingsList &variableBindings) override

Static Public Member Functions
static makVre::DtProjectile *	creator (const DtString &name, DtReaderWriterRegistry *const parentRegistry=nullptr)
Static Public Member Functions inherited from makVre::DtProjectile
static void	addProjectileCreatorFcn (const std::string &type, makVre::DtProjectileCreatorFcn fcn)
static DtProjectile *	createProjectile (DtlObjPtr mtlStream)
static DtProjectile *	createProjectile (const char *type, const char *pName, DtReaderWriterRegistry *const parentRegistry=NULL)
static DtProjectile *	creator (const DtString &name, DtReaderWriterRegistry *const parentRegistry=NULL)
static DtProjectileFactory *	factory ()
static void	setFactory (DtProjectileFactory *factory)

Protected Member Functions
	DtCustomProjectile ()
Protected Member Functions inherited from makVre::DtProjectile
	DtProjectile ()
virtual ProjectileUpdateResult	updateProjectilePosition (double deltaTime)
virtual DtProjectileDetonationResult	checkForProjectileCollision (const ProjectileUpdateResult &projectUpdateResult)

Protected Attributes
double	myTimeInFlight
Protected Attributes inherited from makVre::DtProjectile
DtRwEntityType	myMunitionType
DtRwReal	myCrossSection
DtRwReal	myDragCoefficient
DtRwReal	myMass
DtRwReal	myMaxRange
DtRwVector	myPosition
DtRwVector	myVelocity
DtRwReal	myDistanceTraveled
DtSimObject *	myFiringEntity
DtPhysicalWorld *	myPhysicalWorld

Additional Inherited Members
Static Protected Attributes inherited from makVre::DtProjectile
static DtProjectileFactory *	theFactory

Constructor & Destructor Documentation

DtCustomProjectile() [1/4]

DtCustomProjectile::DtCustomProjectile	(	const DtString &	name,
		DtReaderWriterRegistry *const	parentRegistry = nullptr )

Construct projectile with string name.

PATTERN: Projectile Construction Projectiles are constructed with a name (used for identification and debugging) and an optional parent registry (for hierarchical parameter organization used by the base class).

The constructor must:

1. Initialize the base class (DtProjectile)
2. Initialize any custom state

Parameters

name	Unique identifier for this projectile instance
parentRegistry	Optional parent registry for hierarchical organization

Referenced by DtCustomProjectile(), operator!=(), operator=(), and operator==().

DtCustomProjectile() [2/4]

DtCustomProjectile::DtCustomProjectile	(	const DtSymbolString &	name,
		DtReaderWriterRegistry *const	parentRegistry = nullptr )

Construct projectile with symbol string name.

Parameters

name	Symbol string identifier for this projectile instance
parentRegistry	Optional parent registry for hierarchical organization

DtCustomProjectile() [3/4]

DtCustomProjectile::DtCustomProjectile	(	const DtCustomProjectile &	orig,
		DtReaderWriterRegistry *const	parentRegistry = nullptr )

Copy constructor for projectile cloning.

PATTERN: Projectile Copying Projectiles must be copyable for cloning (for example, when creating multiple rounds from a template). The copy constructor must:

1. Copy base class state
2. Copy all custom state

Parameters

orig	Source projectile to copy
parentRegistry	Optional parent registry for the copy

References DtCustomProjectile().

~DtCustomProjectile()

virtual DtCustomProjectile::~DtCustomProjectile ( )

inlineoverridevirtual

Destructor - base class handles cleanup.

DtCustomProjectile() [4/4]

DtCustomProjectile::DtCustomProjectile ( )

protected

Default constructor - not implemented (projectiles require names)

Member Function Documentation

operator=()

DtCustomProjectile & DtCustomProjectile::operator=

(

const DtCustomProjectile &

orig

)

Assignment operator for projectile state copying.

Must copy both base class state and all custom parameters.

Parameters

orig	Source projectile to copy from

Returns

Reference to this projectile for assignment chaining

References DtCustomProjectile().

clone()

virtual makVre::DtProjectile * DtCustomProjectile::clone ( ) const

overridevirtual

Create a deep copy of this projectile.

Required by VR-Forces framework for projectile instantiation from templates. When multiple rounds of the same munition type are fired, the framework clones a template projectile rather than re-reading configuration files.

Returns

New projectile instance with copied state

Reimplemented from makVre::DtProjectile.

operator==()

bool DtCustomProjectile::operator==

(

const DtCustomProjectile &

)

const

Equality comparison for projectile state.

Parameters

rhs	Projectile to compare against

Returns

true if all parameters match, false otherwise

References DtCustomProjectile().

operator!=()

bool DtCustomProjectile::operator!= ( const DtCustomProjectile & rhs ) const

inline

Inequality comparison for projectile state.

Parameters

rhs	Projectile to compare against

Returns

true if any parameters differ, false if all match

References DtCustomProjectile().

type()

virtual DtString DtCustomProjectile::type ( ) const

overridevirtual

Return the class type identifier string.

PATTERN: Projectile Type Identification The type() method returns a unique string identifying this projectile class. This string is used by:

• Factory system to create correct class instances
• MTL file serialization to identify projectile class on load
• Runtime type identification (alternative to dynamic_cast)

The type string must match the string used in factory registration.

Returns

Type identifier string (DtCustomProjectileType constant)

Reimplemented from makVre::DtProjectile.

update()

virtual makVre::DtProjectileDetonationResult DtCustomProjectile::update ( double deltaTime )

overridevirtual

Update projectile state for one simulation frame.

PATTERN: Custom Projectile Update Logic The update() method is called once per simulation frame to advance projectile physics and behavior. Custom projectiles override this to implement:

• Custom guidance algorithms (updating velocity/orientation)
• Time-based effects (fuel depletion, stage separation)
• Environmental interactions (wind drift, drag calculations)
• Custom detonation conditions (proximity detection, time fuzes)

This Example: Increments the time-in-flight parameter by deltaTime, then calls the base class update() to perform standard projectile physics (position integration, collision detection, detonation logic).

REUSABLE: This override pattern applies to any custom update logic. Always call the base class update() unless completely replacing default physics.

Parameters

deltaTime

Time elapsed since last update in seconds

Returns

Detonation result indicating if projectile should be removed

Reimplemented from makVre::DtProjectile.

creator()

static makVre::DtProjectile * DtCustomProjectile::creator ( const DtString & name, DtReaderWriterRegistry *const parentRegistry = nullptr )

static

Static factory creator method.

PATTERN: Projectile Factory Pattern VR-Forces uses factory methods to instantiate projectiles by type name. The creator() method must be static and return a new instance of this class.

This method is registered with the projectile factory during plugin initialization: DtProjectileFactory::instance().registerProjectile( DtCustomProjectileType, &DtCustomProjectile::creator);

When MTL files reference this projectile type, the factory uses this creator to instantiate objects.

REUSABLE: This exact signature is required for all custom projectiles.

Parameters

name	Name for the new projectile instance
parentRegistry	Optional parent registry for the new instance

Returns

Newly created projectile instance

Member Data Documentation

myTimeInFlight

double DtCustomProjectile::myTimeInFlight

protected

Custom time-in-flight parameter.

The time-in-flight value is internal simulation state. It is not configured from data files and is not serialized; it is reset to zero when the projectile is constructed and accumulates while the projectile is active.

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The documentation for this class was generated from the following file:

• examples/customProjectile/customProjectile.h