IndexBuffer

An index buffer stores index values into a VertexBuffer. Indexed graphical primitives can normally utilize less memory that unindexed primitives (if vertices are shared).

Typically, index buffers are set on Mesh objects.

// Create an index buffer holding 3 16-bit indices. The buffer is marked as
// static, hinting that the buffer will never be modified.
const indices = new UInt16Array([0, 1, 2]);
const indexBuffer = new pc.IndexBuffer(graphicsDevice,
                                       pc.INDEXFORMAT_UINT16,
                                       3,
                                       pc.BUFFER_STATIC,
                                       indices);

Summary

Methods

destroy	Frees resources associated with this index buffer.
getFormat	Returns the data format of the specified index buffer.
getNumIndices	Returns the number of indices stored in the specified index buffer.
lock	Gives access to the block of memory that stores the buffer's indices.
unlock	Signals that the block of memory returned by a call to the lock function is ready to be given to the graphics hardware.

Details

Constructor

IndexBuffer(graphicsDevice, format, numIndices, [usage], [initialData]) 

Create a new IndexBuffer instance.

// Create an index buffer holding 3 16-bit indices. The buffer is marked as
// static, hinting that the buffer will never be modified.
const indices = new UInt16Array([0, 1, 2]);
const indexBuffer = new pc.IndexBuffer(graphicsDevice,
                                       pc.INDEXFORMAT_UINT16,
                                       3,
                                       pc.BUFFER_STATIC,
                                       indices);

Parameters

graphicsDevice	GraphicsDevice	The graphics device used to manage this index buffer.
format	number	The type of each index to be stored in the index buffer. Can be: INDEXFORMAT_UINT8 INDEXFORMAT_UINT16 INDEXFORMAT_UINT32
numIndices	number	The number of indices to be stored in the index buffer.
usage	number	The usage type of the vertex buffer. Can be: BUFFER_DYNAMIC BUFFER_STATIC BUFFER_STREAM Defaults to BUFFER_STATIC.
initialData	ArrayBuffer	Initial data. If left unspecified, the index buffer will be initialized to zeros.

Methods

destroy() 

Frees resources associated with this index buffer.

getFormat() 

Returns the data format of the specified index buffer.

Returns

number

The data format of the specified index buffer. Can be:

getNumIndices() 

Returns the number of indices stored in the specified index buffer.

Returns

number

The number of indices stored in the specified index buffer.

lock() 

Gives access to the block of memory that stores the buffer's indices.

Returns

ArrayBuffer

A contiguous block of memory where index data can be written to.

unlock() 

Signals that the block of memory returned by a call to the lock function is ready to be given to the graphics hardware. Only unlocked index buffers can be set on the currently active device.