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
ArrayBuffer
,SharedArrayBuffer
or one of theArrayBufferView
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 ifdata
isnull
. - A
gl.INVALID_ENUM
error is thrown iftarget
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
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.
Feature | Chrome | Edge | Firefox | Internet Explorer | Opera | Safari |
---|---|---|---|---|---|---|
Basic support | 9 | 12 | 4 | 11 | 12 | 5.1 |
WebGL2 | 56 | No | 51 | No | 43 | No |
Feature | Android webview | Chrome for Android | Edge mobile | Firefox for Android | IE mobile | Opera Android | iOS Safari |
---|---|---|---|---|---|---|---|
Basic support | Yes | 25 | Yes | Yes | 11 | 12 | 8.1 |
WebGL2 | 58 | 58 | No | 51 | No | 43 | No |