Difference between revisions of "Oolite JavaScript Reference: Entity"
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The '''<code>Entity</code>''' class represents an object in the game universe – <code>[[Oolite/Development/Scripting/Class/Vessel|Vessel]]</code>s, <code>[[Oolite/Development/Scripting/Class/Station|Station]]</code>s and <code>[[Oolite/Development/Scripting/Class/CelestialBody|CelestialBody]]</code>s are common types of entity. Note that these more specific types have additional properties and methods. |
The '''<code>Entity</code>''' class represents an object in the game universe – <code>[[Oolite/Development/Scripting/Class/Vessel|Vessel]]</code>s, <code>[[Oolite/Development/Scripting/Class/Station|Station]]</code>s and <code>[[Oolite/Development/Scripting/Class/CelestialBody|CelestialBody]]</code>s are common types of entity. Note that these more specific types have additional properties and methods. |
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| + | === Stale References === |
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| + | When an entity dies or is otherwise removed from the game universe (for instance, because player jumped from the system), existing <code>Entity</code> variables referring to the entity become invalid; all their properties become <code>undefined</code>, and their methods do nothing. In addition to the undefined properties, this can be detected with the <code>[[#valid|valid]]()</code> method. |
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=== Universal IDs === |
=== Universal IDs === |
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void setOrientation([[Oolite/Development/Scripting/Class/Quaternion#Quaternion Expressions|quaternionExpression]]) |
void setOrientation([[Oolite/Development/Scripting/Class/Quaternion#Quaternion Expressions|quaternionExpression]]) |
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Instantaneously rotate the entity to the specified orientation. |
Instantaneously rotate the entity to the specified orientation. |
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| + | === <code>valid</code> === |
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| + | boolean valid() |
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| + | Returns <code>true</code> if the target is a valid entity variable, <code>false</code> if it is [[#Stale References|stale]]. |
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Revision as of 17:17, 6 April 2007
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.
Contents
Stale References
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.
