[name]
This class stores data for an attribute (such as vertex positions, face indices, normals,
colors, UVs, and any custom attributes ) associated with a [page:BufferGeometry], which allows
for more efficient passing of data to the GPU. See that page for details and a usage example.
Data is stored as vectors of any length (defined by [page:BufferAttribute.itemSize itemSize]),
and in general in the methods outlined below if passing in an index, this is automatically
multiplied by the vector length.
Constructor
[name]( [param:TypedArray array], [param:Integer itemSize], [param:Boolean normalized] )
[page:TypedArray array] -- Must be a [link:https://developer.mozilla.org/en/docs/Web/JavaScript/Reference/Global_Objects/TypedArray TypedArray].
Used to instantiate the buffer.
This array should have
itemSize * numVertices
elements, where numVertices is the number of vertices in the associated [page:BufferGeometry BufferGeometry].
[page:Integer itemSize] -- the number of values of the array that should be associated with
a particular vertex. For instance, if this
attribute is storing a 3-component vector (such as a position, normal, or color), then itemSize should be 3.
[page:Boolean normalized] -- (optional) Indicates how the underlying data in the buffer maps
to the values in the GLSL code. For instance, if [page:TypedArray array] is an instance of
UInt16Array, and [page:Boolean normalized] is true, the values 0 - +65535 in the array
data will be mapped to 0.0f - +1.0f in the GLSL attribute. An Int16Array (signed) would map
from -32767 - +32767 to -1.0f - +1.0f. If [page:Boolean normalized] is false, the values
will be converted to floats which contain the exact value, i.e. 32767 becomes 32767.0f.
Properties
[property:TypedArray array]
The [page:TypedArray array] holding data stored in the buffer.
[property:Integer count]
Stores the [page:BufferAttribute.array array]'s length divided by the [page:BufferAttribute.itemSize itemSize].
If the buffer is storing a 3-component vector (such as a position, normal, or color),
then this will count the number of such vectors stored.
[property:Boolean dynamic]
Whether the buffer is dynamic or not. Default is *false*.
If false, the GPU is informed that contents of the buffer are likely to be used often and not change often.
This corresponds to the [link:https://developer.mozilla.org/en-US/docs/Web/API/WebGLRenderingContext/bufferData gl.STATIC_DRAW] flag.
if true, the GPU is informed that contents of the buffer are likely to be used often and change often.
This corresponds to the [link:https://developer.mozilla.org/en-US/docs/Web/API/WebGLRenderingContext/bufferData gl.DYNAMIC_DRAW] flag.
[property:Boolean isBufferAttribute]
Used to check whether this or derived classes are BufferAttributes. Default is *true*.
You should not change this, as it used internally for optimisation.
[property:Integer itemSize]
The length of vectors that are being stored in the [page:BufferAttribute.array array].
[property:String name]
Optional name for this attribute instance. Default is an empty string.
[property:Boolean needsUpdate]
Flag to indicate that this attribute has changed and should be re-sent to the GPU.
Set this to true when you modify the value of the array.
Setting this to true also increments the [page:BufferAttribute.version version].
[property:Boolean normalized]
Indicates how the underlying data in the buffer maps to the values in the GLSL shader code.
See the constructor above for details.
[property:Function onUploadCallback]
A callback function that is executed after the Renderer has transfered the attribute array data to the GPU.
[property:Object updateRange]
Object containing:
[page:Integer offset]: Default is *0*. Position at whcih to start update.
[page:Integer count]: Default is *-1*, which means don't use update ranges.
This can be used to only update some components of stored vectors (for example, just the component
related to color).
[property:String uuid]
[link:http://en.wikipedia.org/wiki/Universally_unique_identifier UUID] of this object instance.
This gets automatically assigned and this shouldn't be edited.
[property:Integer version]
A version number, incremented every time the [page:BufferAttribute.needsUpdate needsUpdate] property is set to true.
Methods
[method:BufferAttribute clone]()
Return a copy of this bufferAttribute.
[method:BufferAttribute copyArray]( array )
Copy the array given here (which can be a normal array or TypedArray) into
[page:BufferAttribute.array array].
See [link:https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/TypedArray/set TypedArray.set]
for notes on requirements if copying a TypedArray.
[method:null copyAt] ( [param:Integer index1], [param:BufferAttribute bufferAttribute], [param:Integer index2] )
Copy a vector from bufferAttribute[index2] to [page:BufferAttribute.array array][index1].
[method:BufferAttribute copyColorsArray]( colors )
Copy an array representing RGB color values into [page:BufferAttribute.array array].
[method:BufferAttribute copyVector2sArray]( vectors )
Copy an array representing [page:Vector2]s into [page:BufferAttribute.array array].
[method:BufferAttribute copyVector3sArray]( vectors )
Copy an array representing [page:Vector3]s into [page:BufferAttribute.array array].
[method:BufferAttribute copyVector4sArray]( vectors )
Copy an array representing [page:Vector4]s into [page:BufferAttribute.array array].
[method:Number getX]( index )
Returns the x component of the vector at the given index.
[method:Number getY]( index )
Returns the y component of the vector at the given index.
[method:Number getZ]( index )
Returns the z component of the vector at the given index.
[method:Number getW]( index )
Returns the w component of the vector at the given index.
[method:null onUpload]( [param:Function callback] )
Sets the value of the onUploadCallback property.
In the [example:webgl_buffergeometry WebGL / Buffergeometry] this is used to free memory
after the buffer has been transfered to the GPU.
[method:null set] ( [param:Array value], [param:Integer offset] )
value -- an [page:Array] or [page:TypedArray] from which to copy values.
offset -- (optional) index of the [page:BufferAttribute.array array] at which to start copying.
Calls [link:https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/TypedArray/set TypedArray.set]( [page:Array value], [page:Integer offset] )
on the [page:BufferAttribute.array array].
In particular, see that page for requirements on [page:Array value]
being a [page:TypedArray].
[method:null setArray] ( [param:TypedArray array] )
[page:BufferAttribute.array array] to the TypedArray passed in here.
After setting the array, [page:BufferAttribute.needsUpdate needsUpdate] should be set to true.
[method:BufferAttribute setDynamic] ( [param:Boolean value] )
Set [page:BufferAttribute.dynamic dynamic] to value.
[method:null setX]( index, x )
Sets the x component of the vector at the given index.
[method:null setY]( index, y )
Sets the y component of the vector at the given index.
[method:null setZ]( index, z )
Sets the z component of the vector at the given index.
[method:null setW]( index, w )
Sets the w component of the vector at the given index.
[method:null setXY]( index, x, y )
Sets the x and y components of the vector at the given index.
[method:null setXYZ]( index, x, y, z )
Sets the x, y and z components of the vector at the given index.
[method:null setXYZW]( index, x, y, z, w )
Sets the x, y, z and w components of the vector at the given index.
Source
[link:https://github.com/mrdoob/three.js/blob/master/src/[path].js src/[path].js]