GPUDevice: createBuffer() method

{{APIRef("WebGPU API")}}{{SecureContext_Header}}{{AvailableInWorkers}}

The createBuffer() method of the {{domxref("GPUDevice")}} interface creates a {{domxref("GPUBuffer")}} in which to store raw data to use in GPU operations.

Syntax

createBuffer(descriptor)

Parameters

• descriptor
  • : An object containing the following properties:

    • label {{optional_inline}}

      • : A string providing a label that can be used to identify the object, for example in {{domxref("GPUError")}} messages or console warnings.

    • mappedAtCreation {{optional_inline}}

      • : A boolean. If set to true, the buffer will be mapped upon creation, meaning that you can set the values inside the buffer immediately by calling {{domxref("GPUBuffer.getMappedRange()")}}. The default value is false.

        Note that it is valid to set mappedAtCreation: true so you can set the buffer's initial data, even if the GPUBufferUsage.MAP_READ or GPUBufferUsage.MAP_WRITE usage flags are not set.

    • size

      • : A number representing the size of the buffer, in bytes. If mappedAtCreation is set to true, this must be a multiple of 4.

    • usage

      • : The {{glossary("Bitwise flags", "bitwise flags")}} representing the allowed usages for the GPUBuffer. The possible values are in the GPUBuffer.usage value table.

        Note that multiple possible usages can be specified by separating values with bitwise OR, for example: GPUBufferUsage.COPY_SRC | GPUBufferUsage.MAP_WRITE.

Return value

A {{domxref("GPUBuffer")}} object instance.

Exceptions

• RangeError {{domxref("DOMException")}}
  • : Thrown if mappedAtCreation is set to true, and the specified size is not a multiple of 4.

Validation

The following criteria must be met when calling createBuffer(), otherwise a {{domxref("GPUValidationError")}} is generated and an invalid {{domxref("GPUBuffer")}} object is returned:

• A valid usage is specified.
• GPUBufferUsage.MAP_READ is specified, and no additional flags are specified other than GPUBufferUsage.COPY_DST.
• GPUBufferUsage.MAP_WRITE is specified, and no additional flags are specified other than GPUBufferUsage.COPY_SRC.

[!NOTE] If the buffer allocation fails without any specific side-effects, a {{domxref("GPUOutOfMemoryError")}} object is generated.

Examples

In our basic compute demo, we create an output buffer to read GPU calculations to, and a staging buffer to be mapped for JavaScript access.

const output = device.createBuffer({
  size: BUFFER_SIZE,
  usage: GPUBufferUsage.STORAGE | GPUBufferUsage.COPY_SRC,
});

const stagingBuffer = device.createBuffer({
  size: BUFFER_SIZE,
  usage: GPUBufferUsage.MAP_READ | GPUBufferUsage.COPY_DST,
});

Specifications

{{Specifications}}

Browser compatibility

{{Compat}}

See also

• The WebGPU API