The getMappedRange() method of the GPUBuffer interface returns an ArrayBuffer containing the mapped contents of the GPUBuffer in the specified range.

This can only happen once the GPUBuffer has been successfully mapped with GPUBuffer.mapAsync() (this can be checked via GPUBuffer.mapState). While the GPUBuffer is mapped it cannot be used in any GPU commands.

When you have finished working with the GPUBuffer values, call GPUBuffer.unmap() to unmap it, making it accessible to the GPU again.

offset Optional

A number representing the offset, in bytes, from the start of the GPUBuffer's mapped range to the start of the range to be returned in the ArrayBuffer. If offset is omitted, it defaults to 0.

size Optional

A number representing the size, in bytes, of the ArrayBuffer to return. If size is omitted, the range extends to the end of the GPUBuffer's mapped range.

An ArrayBuffer.

The following criteria must be met when calling getMappedRange(), otherwise an OperationError DOMException is thrown:

• offset is a multiple of 8.
• The total range to be mapped (size if specified, or mapped range length - offset if not) is a multiple of 4.
• The total range is inside the bounds of the mapped range and does not overlap with the ArrayBuffer ranges specified by any other active getMappedRange() calls.

TypeError DOMException

Thrown if an attempt is made to detach the ArrayBuffer in any way other than via GPUBuffer.unmap().

See the main GPUBuffer page for an example.

• The WebGPU API