Web/API/WebGL2RenderingContext/copyBufferSubData

This is an experimental technologyCheck the Browser compatibility table carefully before using this in production.

The WebGL2RenderingContext.copyBufferSubData() method of the WebGL 2 API copies part of the data of a buffer to another buffer.

Syntax

void gl.copyBufferSubData(readTarget, writeTarget, readOffset, writeOffset, size);

Parameters

readTarget writeTarget: A GLenum specifying the binding point (target) from whose data store should be read or written. Possible values:

gl.ARRAY_BUFFER

Buffer containing vertex attributes, such as vertex coordinates, texture coordinate data, or vertex color data.
gl.ELEMENT_ARRAY_BUFFER: Buffer used for element indices.
gl.COPY_READ_BUFFER: Buffer for copying from one buffer object to another (provided specifically for copy operations).
gl.COPY_WRITE_BUFFER: Buffer for copying from one buffer object to another (provided specifically for copy operations).
gl.TRANSFORM_FEEDBACK_BUFFER: Buffer for transform feedback operations.
gl.UNIFORM_BUFFER: Buffer used for storing uniform blocks.
gl.PIXEL_PACK_BUFFER: Buffer used for pixel transfer operations.
gl.PIXEL_UNPACK_BUFFER: Buffer used for pixel transfer operations.

readOffset writeOffset: A GLintptr specifying the byte offset from which to start reading from or writing to the buffer.
size: A GLsizei in bytes specifying the size of the data to be copied from readTarget to writeTarget.

Return value

None.

Examples

var srcBuffer = gl.createBuffer();
var dstBuffer = gl.createBuffer();

var data = new Float32Array(vertices);
var length = vertices.length * 4;

gl.bindBuffer(gl.ARRAY_BUFFER, srcBuffer);
gl.bufferData(gl.ARRAY_BUFFER, data, gl.STATIC_DRAW);
gl.bindBuffer(gl.COPY_READ_BUFFER, srcBuffer);

gl.bindBuffer(gl.ARRAY_BUFFER, dstBuffer);
gl.bufferData(gl.ARRAY_BUFFER, new Float32Array(length), gl.STATIC_DRAW);

gl.copyBufferSubData(gl.COPY_READ_BUFFER, gl.ARRAY_BUFFER, 0, 0, length);

Specifications

Specification	Status	Comment
WebGL 2.0The definition of 'copyBufferSubData' in that specification.	Editor's Draft	Initial definition for WebGL.
OpenGL ES 3.0The definition of 'glCopyBufferSubData' in that specification.	Standard	Man page of the (similar) OpenGL API.

Browser compatibility

The compatibility table in this page is generated from structured data. If you'd like to contribute to the data, please check out https://github.com/mdn/browser-compat-data and send us a pull request.

Update compatibility data on GitHub

	Desktop						Mobile
	Chrome	Edge	Firefox	Internet Explorer	Opera	Safari	Android webview	Chrome for Android	Firefox for Android	Opera for Android	Safari on iOS	Samsung Internet
`copyBufferSubData`	Chrome Full support 56	Edge Full support 79	Firefox Full support 51	IE No support No	Opera Full support 43	Safari No support No	WebView Android Full support 58	Chrome Android Full support 58	Firefox Android Full support 51	Opera Android Full support 43	Safari iOS No support No	Samsung Internet Android Full support 7.0

Legend

Full support: Full support
No support: No support