GPUCommandEncoder: copyTextureToBuffer() method

Limited availability

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

Experimental: This is an experimental technology
Check the Browser compatibility table carefully before using this in production.

Secure context: This feature is available only in secure contexts (HTTPS), in some or all supporting browsers.

The copyTextureToBuffer() method of the GPUCommandEncoder interface encodes a command that copies data from a GPUTexture to a GPUBuffer.

Syntax

js
copyTextureToBuffer(source, destination, copySize)

Parameters

source

An object defining the texture to copy the data from. Combined with copySize, defines the region of the source texture subresource. source can take the following properties:

aspect Optional

An enumerated value defining which aspects of the texture to copy the data from. Possible values are:

"all"

All available aspects of the texture format will be copied from, which can mean all or any of color, depth, and stencil, depending on what kind of format you are dealing with.

"depth-only"

Only the depth aspect of a depth-or-stencil format will be copied from.

"stencil-only"

Only the stencil aspect of a depth-or-stencil format will be copied from.

If omitted, aspect takes a value of "all".

mipLevel Optional

A number representing the mip-map level of the texture to copy the data from. If omitted, mipLevel defaults to 0.

origin Optional

An object or array specifying the origin of the copy — the minimum corner of the texture region to copy the data from. Together with size, this defines the full extent of the region to copy from. The x, y, and z values default to 0 if any of all of origin is omitted.

What follows is a sample array:

js
[0, 0, 0];

The object equivalent would look like this:

js
{
  x: 0,
  y: 0,
  z: 0
}
texture

A GPUTexture object representing the texture to copy the data from.

destination

An object that defines the buffer to write to, plus the layout of the data to write to the buffer. Combined with copySize, it defines the region of the destination buffer. source can take the following properties:

buffer

The GPUBuffer to write to.

offset Optional

The offset, in bytes, from the beginning of data to the start position to write the copied data to. If omitted, offset defaults to 0.

bytesPerRow Optional

A number representing the stride, in bytes, between the start of each block row (i.e. a row of complete texel blocks) and the subsequent block row. This is required if there are multiple block rows (i.e. the copy height or depth is more than one block).

rowsPerImage Optional

The number of block rows per single image inside the data. bytesPerRow × rowsPerImage will give you the stride, in bytes, between the start of each complete image. This is required if there are multiple images to copy.

copySize

An object or array specifying the width, height, and depth/array layer count of the copied data. The width value must always be specified, while the height and depth/array layer count values are optional and will default to 1 if omitted.

What follows is a sample copySize array:

js
[16, 16, 2];

The object equivalent would look like this:

js
{
  width: 16,
  height: 16,
  depthOrArrayLayers: 2
}

Return value

None (Undefined).

Validation

The following criteria must be met when calling copyTextureToBuffer(), otherwise a GPUValidationError is generated and the GPUCommandEncoder becomes invalid.

For the source:

For the destination:

  • destination.bytesPerRow is a multiple of 256.
  • The destination.buffer's GPUBuffer.usage includes the GPUBufferUsage.COPY_DST flag.

Examples

js
commandEncoder.copyTextureToBuffer(
  {
    texture: sourceTexture,
  },
  {
    buffer: destinationBuffer,
  },
  {
    width: 16,
    height: 16,
    depthOrArrayLayers: 2,
  },
);

Specifications

Specification
WebGPU
# dom-gpucommandencoder-copytexturetobuffer

Browser compatibility

BCD tables only load in the browser

See also