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

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, a DataView, or a TypedArray 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.

None (undefined).

• 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.

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