GPUBuffer: mapState property

Limited availability

This feature is not Baseline because it does not work in some of the most widely-used browsers.

Secure context: This feature is available only insecure contexts (HTTPS), in some or allsupporting browsers.

Note: This feature is available inWeb Workers.

ThemapState read-only property of theGPUBuffer interface represents the mapped state of theGPUBuffer.

Value

An enumerated value. Possible values are:

unmapped

The buffer is not mapped.GPUBuffer.getMappedRange() cannot be used to access the contents of theGPUBuffer in JavaScript. This could be because:

GPUBuffer.mapAsync() has not yet been called.
TheGPUBuffer was previously mapped, and then unmapped again withGPUBuffer.unmap().

pending

The buffer is not yet mapped.GPUBuffer.mapAsync() has been called, but itsPromise is currently pending.GPUBuffer.getMappedRange() cannot currently be used to access the contents of theGPUBuffer in JavaScript.

mapped

The buffer is mapped. TheGPUBuffer.mapAsync()Promise has fulfilled, andGPUBuffer.getMappedRange() can now be used to access the contents of theGPUBuffer in JavaScript.

Examples

const stagingBuffer = device.createBuffer({  size: BUFFER_SIZE,  usage: GPUBufferUsage.MAP_READ | GPUBufferUsage.COPY_DST,});console.log(stagingBuffer.mapState); // "unmapped"// …await stagingBuffer.mapAsync(  GPUMapMode.READ,  0, // Offset  BUFFER_SIZE, // Length);console.log(stagingBuffer.mapState); // "mapped"