WebGLRenderingContext: bufferSubData() method
Baseline
Widely available
This feature is well established and works across many devices and browser versions. It’s been available across browsers since July 2015.
Note: This feature is available in Web Workers.
The WebGLRenderingContext.bufferSubData() method of the WebGL API updates a subset of a buffer object's data store.
Syntax
js
bufferSubData(target, offset)
bufferSubData(target, offset, srcData)
Parameters
target-
A
GLenumspecifying 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.
offset-
A
GLintptrspecifying an offset in bytes where the data replacement will start. srcDataOptional-
A
TypedArrayor aDataViewthat views anArrayBufferorSharedArrayBufferthat will be copied into the data store.
Return value
None (undefined).
Exceptions
- A
gl.INVALID_VALUEerror is thrown if the data would be written past the end of the buffer or ifdataisnull. - A
gl.INVALID_ENUMerror is thrown iftargetis not one of the allowed enums.
Examples
Using bufferSubData
js
const canvas = document.getElementById("canvas");
const gl = canvas.getContext("webgl");
const buffer = gl.createBuffer();
const data = new Float32Array([1, 2, 3, 4]);
gl.bindBuffer(gl.ARRAY_BUFFER, buffer);
gl.bufferData(gl.ARRAY_BUFFER, 1024, gl.STATIC_DRAW);
gl.bufferSubData(gl.ARRAY_BUFFER, 512, data);
Specifications
| Specification |
|---|
| WebGL Specification # 5.14.5 |