API Docs for: 0.7.0

Translate

Extends Transform
Module: transforms
Parent Module: xeogl

A Translate is a Transform that translates associated Entities or Models.

Overview

  • Instances of Transform and its sub-classes may be connected into hierarchies.
  • When an Entity or Model is connected to a leaf Transform within a Transform hierarchy, it will be transformed by each Transform on the path up to the root, in that order.

Examples

Usage

This example has two Entities that are transformed by a hierarchy that contains Rotate, Translate and Scale transforms. The Entities share the same BoxGeometry.

var rotate = new xeogl.Rotate({
   xyz: [0, 1, 0], // Rotate 30 degrees about Y axis
   angle: 30
});

var translate1 = new xeogl.Translate({
   parent: rotate,
   xyz: [-5, 0, 0] // Translate along -X axis
});

var translate2 = new xeogl.Translate({
   parent: rotate,
   xyz: [5, 0, 0] // Translate along +X axis
});

var scale = new xeogl.Scale({
   parent: translate2,
   xyz: [1, 2, 1] // Scale x2 on Y axis
});

var geometry = new xeogl.BoxGeometry();

var entity1 = new xeogl.Entity({
   transform: translate1,
   geometry: geometry
});

var entity2 = new xeogl.Entity({
   transform: scale,
   geometry: geometry
});

Since everything in xeogl is dynamically editable, we can restructure the transform hierarchy at any time.

Let's insert a Scale between the first Translate and the first Entity:

var scale2 = new xeogl.Scale({
   parent: translate1,
   xyz: [1, 1, 2] // Scale x2 on Z axis
});

entity2.transform = scale2;

And just for fun, we'll start updating the second Translate:

// Rotate 0.2 degrees on each frame
scene.on("tick", function(e) {
   var xyz = translate2.xyz;
   xyz[0] += 0.2;
   translate2.xyz = xyz;
});

Constructor

Translate

(
  • [scene]
  • [cfg]
)

Parameters:

  • [scene] Scene optional

    Parent Scene - creates this Translate in the default Scene when omitted.

  • [cfg] optional

    Configs

    • [id] String optional

      Optional ID, unique among all components in the parent scene, generated automatically when omitted.

    • [meta] String:Object optional

      Optional map of user-defined metadata to attach to this Translate.

    • [parent] String | Transform optional

      ID or instance of a parent Transform within the same Scene.

    • [xyz=[0,0,0]] Float32Array optional

      The translation vector

Methods

create

(
  • [cfg]
)

Convenience method for creating a Component within this Component's Scene.

The method is given a component configuration, like so:

var material = myComponent.create({
     type: "xeogl.PhongMaterial",
     diffuse: [1,0,0],
     specular: [1,1,0]
}, "myMaterial");

Parameters:

  • [cfg] optional

    Configuration for the component instance.

Returns:

:

destroy

()

Destroys this component.

Fires a destroyed event on this Component.

Automatically disassociates this component from other components, causing them to fall back on any defaults that this component overrode on them.

TODO: describe effect with respect to #create

error

(
  • message
)

Logs an error for this component to the JavaScript console.

The console message will have this format: [ERROR] [<component type> =<component id>: <message>

Also fires the message as an error event on the parent Scene.

Parameters:

  • message String

    The message to log

fire

(
  • event
  • value
  • [forget=false]
)

Fires an event on this component.

Notifies existing subscribers to the event, optionally retains the event to give to any subsequent notifications on the event as they are made.

Parameters:

  • event String

    The event type name

  • value Object

    The event parameters

  • [forget=false] Boolean optional

    When true, does not retain for subsequent subscribers

hasSubs

(
  • event
)
Boolean

Returns true if there are any subscribers to the given event on this component.

Parameters:

  • event String

    The event

Returns:

Boolean:

True if there are any subscribers to the given event on this component.

isType

(
  • type
)
Boolean

Tests if this component is of the given type, or is a subclass of the given type.

The type may be given as either a string or a component constructor.

This method works by walking up the inheritance type chain, which this component provides in property superTypes, returning true as soon as one of the type strings in the chain matches the given type, of false if none match.

Examples:

var myRotate = new xeogl.Rotate({ ... });

myRotate.isType(xeogl.Component); // Returns true for all xeogl components
myRotate.isType("xeogl.Component"); // Returns true for all xeogl components
myRotate.isType(xeogl.Rotate); // Returns true
myRotate.isType(xeogl.Transform); // Returns true
myRotate.isType("xeogl.Transform"); // Returns true
myRotate.isType(xeogl.Entity); // Returns false, because xeogl.Rotate does not (even indirectly) extend xeogl.Entity

Parameters:

  • type String | Function

    Component type to compare with, eg "xeogl.PhongMaterial", or a xeogl component constructor.

Returns:

Boolean:

True if this component is of given type or is subclass of the given type.

log

(
  • message
)

Logs a console debugging message for this component.

The console message will have this format: [LOG] [<component type> <component id>: <message>

Also fires the message as a log event on the parent Scene.

Parameters:

  • message String

    The message to log

off

(
  • handle
)

Cancels an event subscription that was previously made with on or once.

Parameters:

  • handle String

    Publication handle

on

(
  • event
  • callback
  • [scope=this]
)
String

Subscribes to an event on this component.

The callback is be called with this component as scope.

Parameters:

  • event String

    The event

  • callback Function

    Called fired on the event

  • [scope=this] Object optional

    Scope for the callback

Returns:

String:

Handle to the subscription, which may be used to unsubscribe with {@link #off}.

once

(
  • event
  • callback
  • [scope=this]
)

Subscribes to the next occurrence of the given event, then un-subscribes as soon as the event is handled.

This is equivalent to calling on, and then calling off inside the callback function.

Parameters:

  • event String

    Data event to listen to

  • callback Function(data)

    Called when fresh data is available at the event

  • [scope=this] Object optional

    Scope for the callback

warn

(
  • message
)

Logs a warning for this component to the JavaScript console.

The console message will have this format: [WARN] [<component type> =<component id>: <message>

Also fires the message as a warn event on the parent Scene.

Parameters:

  • message String

    The message to log

Properties

destroyed

Boolean

True as soon as this Component has been destroyed

id

String final

Unique ID for this Component within its parent Scene.

isDefault

Boolean

Indicates whether this is one of the Scene's built-in Components.

leafMatrix

Float32Array

Returns the product of all matrix's on Transforms on the path via parent up to the root.

The value of this property will have a fresh value after each Transform/updated:property event, which is fired whenever any Transform on the path receives an update for its matrix or matrix property.

Default: [1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1]

leafNormalMatrix

Float32Array

Returns the product of all Transform/normalMatrix:property's on Transforms on the path via parent up to the root.

The value of this property will have a fresh value after each Transform/updated:property event, which is fired whenever any Transform on the path receives an update for its matrix or matrix property.

Default: [1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1]

matrix

Float32Array

The Transform's local matrix.

Fires a matrix event on change.

Default: [1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1]

metadata

Object

Arbitrary, user-defined metadata on this component.

parent

Transform

The parent Transform.

postMultiply

Boolean

Flag that indicates whether this Transform is post-multiplied (default) or pre-multiplied by its parent Transform.

Default: true

scene

Scene final

The parent Scene that contains this Component.

superTypes

Array of String final

An array of strings that indicates the chain of super-types within this component's inheritance hierarchy.

For example, if this component is a Rotate, which extends Transform, which in turn extends Component, then this property will have the value:

["xeogl.Component", "xeogl.Transform"]
                    

Note that the chain is ordered downwards in the hierarchy, ie. from super-class down towards sub-class.

type

String final

JavaScript class name for this Component.

For example: "xeogl.AmbientLight", "xeogl.ColorTarget", "xeogl.Lights" etc.

xyz

Float32Array

Vector indicating a translation amount for each axis.

Default: [0,0,0]

Events

destroyed

Fired when this Component is destroyed.

matrix

Fired whenever this Transform's matrix property changes.

Event Payload:

  • value Object

    The property's new value

updated

Fired whenever this Transform's leafMatrix property changes.

This event does not carry the updated property value. Instead, subscribers will need to read that property again to get its updated value (which may be lazy-computed then).