Difference between revisions of "Oolite JavaScript Reference: SystemInfo"
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<small>'''Prototype:''' <code>Object</code></small><br /> |
<small>'''Prototype:''' <code>Object</code></small><br /> |
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− | '''<code>SystemInfo</code>''' objects provide information about a specific system. <code>SystemInfo</code>s can be retrieved for any system in |
+ | '''<code>SystemInfo</code>''' objects provide information about a specific system. <code>SystemInfo</code>s can be retrieved for any system in any galaxy as of version 1.82. In previous versions, only systems for the current galaxy could be read. |
In interstellar space, <code>system.info</code> refers to a temporary <code>SystemInfo</code> object whose properties cannot be written to. Attempting to read properties of such a temporary <code>SystemInfo</code> after leaving interstellar space will raise an exception. |
In interstellar space, <code>system.info</code> refers to a temporary <code>SystemInfo</code> object whose properties cannot be written to. Attempting to read properties of such a temporary <code>SystemInfo</code> after leaving interstellar space will raise an exception. |
Revision as of 20:36, 4 July 2015
Prototype: Object
SystemInfo
objects provide information about a specific system. SystemInfo
s can be retrieved for any system in any galaxy as of version 1.82. In previous versions, only systems for the current galaxy could be read.
In interstellar space, system.info
refers to a temporary SystemInfo
object whose properties cannot be written to. Attempting to read properties of such a temporary SystemInfo
after leaving interstellar space will raise an exception.
Contents
Properties
coordinates
coordinates : Vector3D
(read-only)
The coordinates of the system in light years. e.g. for Lave: (8, 34.6, 0)
. The z component is always zero.
The upper left corner has the coordinate (0, 0, 0)
. Going right increases the x value while going down on the map increases the y value.
Example:
System.infoForSystem(galaxyNumber, 7).coordinates
returns the coordinates of the system with an ID number of 7 in the current galaxy. In the first galaxy that would be the coordinates for Lave: (8, 34.6, 0)
.
galaxyID
galaxyID : Number (read-only nonnegative integer)
The ID number of the galaxy.
internalCoordinates
internalCoordinates : Vector3D
(read-only)
Discouraged in favour of coordinates
.
The coordinate of the system in the internal coordinate system.
systemID
systemID : Number (read-only nonnegative integer)
The ID number of the system.
More properties
In addition to the properties above, you can access many other system properties, using the same keys as planetinfo.plist.
Example:
system.info.description = "This is a dull planet."
sets the description of the current planet to “This is a dull planet.”
Modified properties are permanent and are stored in saved game. Changes made by scripts override those in planetinfo.plist. Set a property to null
to restore the planetinfo.plist value, or the default.
Methods
distanceToSystem
function distanceToSystem(system : SystemInfo) : Number
Returns the distance in light years to another SystemInfo
.
Example:
System.infoForSystem(galaxyNumber, 7).distanceToSystem(System.infoForSystem(galaxyNumber, 8))
If galaxyNumber is 0, this returns 92.8.
routeToSystem
function routeToSystem(system : SystemInfo [, "OPTIMIZED_BY_JUMPS" | "OPTIMIZED_BY_TIME"] ) : Object
Returns a dictionary containing the route information to another SystemInfo
. The dictionary contains the array of system IDs that belong to the route
found, the distance
and the time
corresponding to said route. Takes the optional parameter "OPTIMIZED_BY_JUMPS"
(default) or "OPTIMIZED_BY_TIME"
to calculate least number of jumps or fastest transit time routes respectively.
Example:
var myRoute = System.infoForSystem(galaxyNumber, 7).routeToSystem(System.infoForSystem(galaxyNumber, 8)) myRoute.route myRoute.distance myRoute.time
returns:
7,129,227,73,89,222,29,42,131,62,150,36,28,16,185,86,138,51,8 (the route) 96.40 (distance of added jumps) 530.40 (travelled time)
Warning: in version 1.76 or earlier there is a bug in this method which may cause a crash if either the start or end of the route is in interstellar space (i.e. system ID -1). In later versions this simply returns null.
samplePrice
This method was added in Oolite test release 1.81.
function samplePrice(commodity : String) : Array
Return a sample main market price in decicredits for the commodity with that key in this system. As this requires reading system information, it will only work for systems in the current galaxy. There is of course no guarantee that the price returned by this function will be anywhere near the actual price when the system is next entered.
setProperty
This method was added in Oolite test release 1.81.
function setProperty(key : String, value: String, layer: Number [, manifest: String])
This lets you set properties with more control than provided by writing directly to systemInfo.property
. layer
is the layer from 0 to 3 that the change should be applied at, as in planetinfo.plist. Layer 2 is the default layer for Javascript-initiated changes, but 3 may be used for changes absolutely crucial for OXP functionality.
It is also possible to make changes on behalf of a different OXP by passing the manifest ID of that OXP as the fourth parameter. Otherwise the OXP responsible for the current script execution context will be used.
systemsInRange
function systemsInRange([range : Number]) : Array
Returns an array of SystemInfo
s in range (default: 7) from the given system.
Note: will not produce correct results if used in interstellar space.
Example:
system.info.systemsInRange(5);
Static methods
filteredSystems
function filteredSystems(this : Object, predicate : Function) : Array of SystemInfo
A list of the SystemInfo
s for which predicate
returns true
.
Example:
// This is the actual implementation of systemsInRange()
.
SystemInfo.prototype.systemsInRange = function systemsInRange(range)
{
if (range === undefined)
{
range = 7;
}
return SystemInfo.filteredSystems(this, function(other)
{
return (other.systemID !== this.systemID) && (this.distanceToSystem(other) <= range);
});
}
setInterstellarProperty
This method was added in Oolite test release 1.81.
function setInterstellarProperty(galaxy : Number, fromsystem : Number, tosystem : Number, layer: Number, key : String, value: String, [, manifest: String])
This is similar to setProperty but for setting properties of interstellar space regions. Changes made to the current interstellar space region will only take effect if the player leaves and returns.
Note that the order of fromsystem (the last real system visited) and tosystem (the target of the latest jump) is significant - 0,7,55 is Lave to Leesti; 0,55,7 is Leesti to Lave. In many cases setting the same change for both directions may be necessary.