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
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 |
---|
WebGL Specification # 5.14.5 |
Browser compatibility
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