9.10. The IndexBuffer Object

An IndexBuffer object is an optimal read-only container for index data.

9.10.1. Constructor

IndexBuffers are created using GraphicsDevice.createIndexBuffer.

9.10.2. Methods

9.10.2.1. setData

Summary

Set the data by passing in an array of numbers.

Create the IndexBuffer as dynamic if you are planning to update the index data at runtime.

Syntax

var indexData = [0, 1, 2];
var offset = 0;
var count = indexData.length;
indexBuffer.setData(indexData, offset, count);

indexData

An array of numbers.

offset (Optional)

Offset in indicies from the beginning of the buffer. Optional, assumed to be 0 if omitted.

count (Optional)

The number of elements to write, normally indexData.length. Optional, assumed to be IndexBuffer.numIndices if omitted.

9.10.2.2. map

Summary

Requests write access to an IndexBuffer.

Create the IndexBuffer as dynamic if you are planning to update the index data at runtime.

Syntax

var writer = indexBuffer.map(offset, count);
if (writer)
{
    for (var n = 0; n < (numIndices / 3); n += 1)
    {
        writer(n, (n + 1), (n + 2));
    }

    indexBuffer.unmap(writer);
}

Returns an index writer.

offset (Optional)

Offset in indicies from the beginning of the buffer. Optional, assumed to be 0 if omitted.

count (Optional)

The number of elements to be written. Optional, assumed to be IndexBuffer.numIndices if omitted.

The writer can be called once for each mapped index. It can also be called with multiple values in order to write multiple indices with just one call, this is more optimal than a call per index but be careful not to write more indices than the ones the IndexBuffer was created with or the writer will fail.

The entire contents of the buffer must be updated.

9.10.2.3. unmap

Summary

Communicate to the IndexBuffer that write access is no longer required.

Syntax

var writer = indexBuffer.map();
if (writer)
{
    // Do something with the writer here

    indexBuffer.unmap(writer);
}

writer

The index writer returned by a previous call to map.

This method must be called if map returns a valid writer.

9.10.3. Properties

9.10.3.1. numIndices

Summary

Number of indices stored on the IndexBuffer.

Syntax

var numIndices = indexBuffer.numIndices;

Note

Read Only

9.10.3.2. format

Summary

String with the format name of the index data.

Syntax

var indexFormat = indexBuffer.format;

Note

Read Only

9.10.3.3. dynamic

Summary

True if the IndexBuffer was created as dynamic and hence can be modified at runtime, false otherwise.

Syntax

var isDynamic = indexBuffer.dynamic;

Note

Read Only