Buffer

Methods

staticCesium.Buffer.createIndexBuffer(options) → IndexBuffer

Creates an index buffer, which contains typed indices in GPU-controlled memory.

An index buffer can be attached to a vertex array to select vertices for rendering. Context.draw can render using the entire index buffer or a subset of the index buffer defined by an offset and count.

Name	Type	Description
options	Object	An object containing the following properties: Name Type Description context Context The context in which to create the buffer typedArray ArrayBufferView optional A typed array containing the data to copy to the buffer. sizeInBytes Number optional A Number defining the size of the buffer in bytes. Required if options.typedArray is not given. usage BufferUsage Specifies the expected usage pattern of the buffer. On some GL implementations, this can significantly affect performance. See BufferUsage. indexDatatype IndexDatatype The datatype of indices in the buffer.

Returns:

The index buffer, ready to be attached to a vertex array.

Throws:

• DeveloperError : Must specify either or , but not both.
• DeveloperError : IndexDatatype.UNSIGNED_INT requires OES_element_index_uint, which is not supported on this system. Check context.elementIndexUint.
• DeveloperError : The size in bytes must be greater than zero.
• DeveloperError : Invalid usage.
• DeveloperError : Invalid indexDatatype.

Examples:

// Example 1. Create a stream index buffer of unsigned shorts that is
// 16 bytes in size.
var buffer = Buffer.createIndexBuffer({
    context : context,
    sizeInBytes : 16,
    usage : BufferUsage.STREAM_DRAW,
    indexDatatype : IndexDatatype.UNSIGNED_SHORT
});

// Example 2. Create a static index buffer containing three unsigned shorts.
var buffer = Buffer.createIndexBuffer({
    context : context,
    typedArray : new Uint16Array([0, 1, 2]),
    usage : BufferUsage.STATIC_DRAW,
    indexDatatype : IndexDatatype.UNSIGNED_SHORT
});

See:

• glGenBuffer
• glBindBuffer with ELEMENT_ARRAY_BUFFER
• glBufferData with ELEMENT_ARRAY_BUFFER

staticCesium.Buffer.createVertexBuffer(options) → VertexBuffer

Creates a vertex buffer, which contains untyped vertex data in GPU-controlled memory.

A vertex array defines the actual makeup of a vertex, e.g., positions, normals, texture coordinates, etc., by interpreting the raw data in one or more vertex buffers.

Name	Type	Description
options	Object	An object containing the following properties: Name Type Description context Context The context in which to create the buffer typedArray ArrayBufferView optional A typed array containing the data to copy to the buffer. sizeInBytes Number optional A Number defining the size of the buffer in bytes. Required if options.typedArray is not given. usage BufferUsage Specifies the expected usage pattern of the buffer. On some GL implementations, this can significantly affect performance. See BufferUsage.

Returns:

The vertex buffer, ready to be attached to a vertex array.

Throws:

• DeveloperError : Must specify either or , but not both.
• DeveloperError : The buffer size must be greater than zero.
• DeveloperError : Invalid usage.

Examples:

// Example 1. Create a dynamic vertex buffer 16 bytes in size.
var buffer = Buffer.createVertexBuffer({
    context : context,
    sizeInBytes : 16,
    usage : BufferUsage.DYNAMIC_DRAW
});

// Example 2. Create a dynamic vertex buffer from three floating-point values.
// The data copied to the vertex buffer is considered raw bytes until it is
// interpreted as vertices using a vertex array.
var positionBuffer = buffer.createVertexBuffer({
    context : context,
    typedArray : new Float32Array([0, 0, 0]),
    usage : BufferUsage.STATIC_DRAW
});

See:

• glGenBuffer
• glBindBuffer with ARRAY_BUFFER
• glBufferData with ARRAY_BUFFER