The WebGLRenderingContext.bufferData()
method of the WebGL API initializes and creates the
buffer object's data store.
Syntax
// WebGL1:
void gl.bufferData(target, size, usage);
void gl.bufferData(target, ArrayBuffer? srcData, usage);
void gl.bufferData(target, ArrayBufferView srcData, usage);
// WebGL2:
void gl.bufferData(target, ArrayBufferView srcData, usage, 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.
size
- A
GLsizeiptr
setting the size in bytes of the buffer object's data store. srcData
Optional- An
ArrayBuffer
,SharedArrayBuffer
or one of theArrayBufferView
typed array types that will be copied into the data store. Ifnull
, a data store is still created, but the content is uninitialized and undefined. usage
- A
GLenum
specifying the intended usage pattern of the data store for optimization purposes. Possible values:gl.STATIC_DRAW
: The contents are intended to be specified once by the application, and used many times as the source for WebGL drawing and image specification commands.gl.DYNAMIC_DRAW
: The contents are intended to be respecified repeatedly by the application, and used many times as the source for WebGL drawing and image specification commands.gl.STREAM_DRAW
: The contents are intended to be specified once by the application, and used at most a few times as the source for WebGL drawing and image specification commands.- When using a WebGL 2 context, the following values are available additionally:
gl.STATIC_READ
: The contents are intended to be specified once by reading data from WebGL, and queried many times by the application.gl.DYNAMIC_READ
: The contents are intended to be respecified repeatedly by reading data from WebGL, and queried many times by the application.gl.STREAM_READ
: The contents are intended to be specified once by reading data from WebGL, and queried at most a few times by the applicationgl.STATIC_COPY
: The contents are intended to be specified once by reading data from WebGL, and used many times as the source for WebGL drawing and image specification commands.gl.DYNAMIC_COPY
: The contents are intended to be respecified repeatedly by reading data from WebGL, and used many times as the source for WebGL drawing and image specification commands.gl.STREAM_COPY
: The contents are intended to be specified once by reading data from WebGL, and used at most a few times as the source for WebGL drawing and image specification commands.
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.OUT_OF_MEMORY
error is thrown if the context is unable to create a data store with the givensize
. - A
gl.INVALID_VALUE
error is thrown ifsize
is negative. - A
gl.INVALID_ENUM
error is thrown iftarget
orusage
are not one of the allowed enums.
Examples
Using bufferData
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);
Getting buffer information
To check the current buffer usage and buffer size, use the
WebGLRenderingContext.getBufferParameter()
method.
gl.getBufferParameter(gl.ARRAY_BUFFER, gl.BUFFER_SIZE);
gl.getBufferParameter(gl.ARRAY_BUFFER, gl.BUFFER_USAGE);
Getting size of a typed array
To calculate size parameter for a typed array.
var dataArray = new Float32Array([1, 2, 3, 4]);
var sizeInBytes = dataArray.length * dataArray.BYTES_PER_ELEMENT;
Specifications
Specification | Status | Comment |
---|---|---|
WebGL 1.0 The definition of 'bufferData' in that specification. |
Recommendation | Initial definition. |
OpenGL ES 2.0 The definition of 'glBufferData' in that specification. |
Standard | Man page of the OpenGL API. |
OpenGL ES 3.0 The definition of 'glBufferData' 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 Adds new usage hints:gl.STATIC_READ ,gl.DYNAMIC_READ ,gl.STREAM_READ ,gl.STATIC_COPY ,gl.DYNAMIC_COPY ,gl.STREAM_COPY .
|
Browser compatibility
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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.