WebGLRenderingContext: bufferSubData() method

Syntax

bufferSubData(target, offset)
bufferSubData(target, offset, srcData)

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.

offset

A GLintptr specifying an offset in bytes where the data replacement will start.

srcData Optional

A TypedArray or a DataView that views an ArrayBuffer or SharedArrayBuffer that will be copied into the data store.

Return value

None (undefined).

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

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

Browser compatibility

See also

• WebGL2RenderingContext.bufferSubData()
• WebGLRenderingContext.createBuffer()
• WebGLRenderingContext.bufferData()
• Other buffers: WebGLFramebuffer, WebGLRenderbuffer