Oolite JavaScript Reference: Entity

This page documents a planned future Oolite scripting feature. It is presented as a basis for discussion or to help developers organize their thoughts. The functionality presented may end up taking a radically different form, or may not become available at all.

The Entity class represents an object in the game universe – Vessels, Stations and CelestialBodys are common types of entity. Note that these more specific types have additional properties and methods.

When an entity dies or is otherwise removed from the game universe (for instance, because player jumped from the system), existing Entity variables referring to the entity become invalid; all their properties become undefined, and their methods do nothing. In addition to the undefined properties, this can be detected with the valid() method.

Universal IDs

Every Entity has an unique universal ID. All Oolite-provided functions which take an Entity as an argument may also be passed an integer representing the Entity’s ID.

Properties

`ID`

ID [read-only integer]

The universal ID of the entity.

`position`

position [read-only Vector]

The position of the entity in system co-ordinates.

See Also: setPosition()

`velocity`

velocity [read-only Vector]

The velocity of the entity in system units (nominal metres) per second.

`speed`

speed [read-only double]

The speed of the entity in system units (nominal metres) per second.

entity.speed() is equivalent to entity.velocity().magnitude().

`orientation`

orientation [read-only Quaternion]

The spacial orientation of the entity.

See Also: setOrientation()

`heading`

heading [read-only Vector]

The heading of the entity. This is equivalent to orientation, but ignoring the axial twist component (roll in the case of a ship).

entity.heading() is equivalent to entity.orientation.forwardVector().

`status`

status [read-only string]

The current status of the entity (such as “STATUS_IN_FLIGHT” and “STATUS_BEING_SCOOPED”).

`scanClass`

scanClass [read-only string]

The current scan class of the entity (such as “CLASS_NEUTRAL” and “CLASS_CARGO”).

`mass`

mass [read-only double]

The mass of the entity. Currently, this is directly proportional to the volume.

`owner`

owner [read-only Entity]

The entity which owns this one. In the case of a subentity, the entity to which it is attached. In the case of a defense ship, the station it belongs to. In the case of a missile, the ship that launched it. There may be other uses.

`energy`

energy [read-write double]

The entity’s total energy; ranges from 0 to maxEnergy.

`maxEnergy`

maxEnergy [read-only double]

The highest permissible value of energy.

Methods

`setPosition`

void setPosition(vectorExpression)

Instantaneously move the entity to the specified position.

`setOrientation`

void setOrientation(quaternionExpression)

Instantaneously rotate the entity to the specified orientation.

`valid`

boolean valid()

Returns true if the target is a valid entity variable, false if it is stale.