WebGLRenderingContext.bufferSubData()

The WebGLRenderingContext.bufferSubData() method of the WebGL API updates a subset of a buffer object's data store.

Syntax

// WebGL1: 
void gl.bufferSubData(target, offset, ArrayBuffer srcData); 
void gl.bufferSubData(target, offset, ArrayBufferView srcData); 

// WebGL2: 
void gl.bufferSubData(target, dstByteOffset, ArrayBufferView srcData, srcOffset, length);

Parameters

target
A GLenum specifying the binding point (target). 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.
  • When using a WebGL 2 context, the following values are available additionally:
    • gl.COPY_READ_BUFFER: Buffer for copying from one buffer object to another.
    • gl.COPY_WRITE_BUFFER: Buffer for copying from one buffer object to another.
    • 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.
dstByteOffset
A GLintptr specifying an offset in bytes where the data replacement will start.
srcData Optional
An ArrayBufferSharedArrayBuffer or one of the ArrayBufferView typed array types that will be copied into the data store.
srcOffset
A GLuint specifying the element index offset where to start reading the buffer.
length Optional
A GLuint defaulting to 0.

Return value

None.

Exceptions

  • A gl.INVALID_VALUE error is thrown if the data would be written past the end of the buffer or if data is null.
  • A gl.INVALID_ENUM error is thrown if target is not one of the allowed enums.

Examples

Using bufferSubData

var canvas = document.getElementById('canvas');
var gl = canvas.getContext('webgl');
var buffer = gl.createBuffer();
gl.bindBuffer(gl.ARRAY_BUFFER, buffer);
gl.bufferData(gl.ARRAY_BUFFER, 1024, gl.STATIC_DRAW);
gl.bufferSubData(gl.ARRAY_BUFFER, 512, data);

Specifications

Specification Status Comment
WebGL 1.0
The definition of 'bufferSubData' in that specification.
Recommendation Initial definition for WebGL.
OpenGL ES 2.0
The definition of 'glBufferSubData' in that specification.
Standard Man page of the OpenGL ES 2 API.
OpenGL ES 3.0
The definition of 'glBufferSubData' in that specification.
Standard Man page of the (similar) OpenGL ES 3 API.

Adds new target buffers:
gl.COPY_READ_BUFFER,
gl.COPY_WRITE_BUFFER,
gl.TRANSFORM_FEEDBACK_BUFFER,
gl.UNIFORM_BUFFER,
gl.PIXEL_PACK_BUFFER,
gl.PIXEL_UNPACK_BUFFER.

Browser compatibility

Update compatibility data on GitHub
DesktopMobile
ChromeEdgeFirefoxInternet ExplorerOperaSafariAndroid webviewChrome for AndroidEdge MobileFirefox for AndroidOpera for AndroidiOS SafariSamsung Internet
Basic supportChrome Full support 9Edge Full support 12Firefox Full support 4IE Full support 11Opera Full support 12Safari Full support 5.1WebView Android Full support YesChrome Android Full support 25Edge Mobile Full support YesFirefox Android Full support YesOpera Android Full support 12Safari iOS Full support 8.1Samsung Internet Android Full support Yes
WebGL2Chrome Full support 56Edge No support NoFirefox Full support 51IE No support NoOpera Full support 43Safari No support NoWebView Android Full support 58Chrome Android Full support 58Edge Mobile No support NoFirefox Android Full support 51Opera Android Full support 43Safari iOS No support NoSamsung Internet Android Full support 7.0

Legend

Full support  
Full support
No support  
No support

See also

Document Tags and Contributors

Contributors to this page: Jedipedia, fscholz, tcsc, nmve, teoli
Last updated by: Jedipedia,