GPUQueue: copyExternalImageToTexture() method

source

An object representing the source to write to the destination, and its origin. This can take the following properties:

source

An object providing the source of the snapshot to copy. This can be an ImageBitmap, HTMLVideoElement, HTMLCanvasElement, or OffscreenCanvas. The image source data is captured at the exact moment copyExternalImageToTexture() is invoked.

origin Optional

An object or array specifying the origin of the copy — the top-left corner of the source sub-region to copy from. Together with copySize, this defines the full extent of the source sub-region. The x and y values default to 0 if any of all of origin is omitted.

What follows is a sample array:

js

origin: [0, 0];

The object equivalent would look like this:

js

origin: {
  x: 0,
  y: 0
}

flipY Optional

A boolean. If set to true, the image capture is flipped vertically. If omitted, flipY defaults to false.

destination

An object defining the texture subresource and origin to write the captured image to, plus encoding metadata. This can take the following properties:

aspect Optional

An enumerated value defining which aspects of the texture to write the image to. Possible values are:

"all"

All available aspects of the texture format will be written to, 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 written to.

"stencil-only"

Only the stencil aspect of a depth-or-stencil format will be written to.

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

colorSpace Optional

An enumerated value describing the color space and encoding used to encode data into the destination texture. Possible values are "srgb" and "display-p3". If omitted, colorSpace defaults to "srgb".

Note: The encoding may result in values outside of the range [0, 1] being written to the target texture, if its format can represent them. Otherwise, the results are clamped to the target texture format's range. Conversion may not be necessary if colorSpace matches the source image color space.

mipLevel Optional

A number representing the mip-map level of the texture to write the image to. 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 write the image data to. Together with copySize, this defines the full extent of the region to copy to. The x, y, and z values default to 0 if any of all of origin is omitted.

What follows is a sample array:

js

origin: [0, 0, 0];

The object equivalent would look like this:

js

origin: {
  x: 0,
  y: 0,
  z: 0
}

premultipliedAlpha Optional

A boolean. If set to true, the image data written into the texture will have its RGB channels premultiplied by the alpha channel. If omitted, premultipliedAlpha defaults to false.

Note: If this option is set to true and the source is also premultiplied, the source RGB values must be preserved even if they exceed their corresponding alpha values.

texture

A GPUTexture object representing the texture to write the data to.

copySize

An object or array specifying width, height, and depthOrArrayLayers — of the region to copy from/to.

What follows is a sample array:

js

origin: [16, 1, 1];

The object equivalent would look like this:

js

origin: {
  width: 16,
  height: 1,
  depthOrArrayLayers: 1
}

The width value has to be included. If the height or depthOrArrayLayers values are omitted, they default to 1.

None (Undefined).

OperationError DOMException

The method throws an OperationError if the following criteria are not met:

• source.origin.x + the width of the region to copy to is less than or equal to the width of the source image.
• source.origin.y + the height of the region to copy to is less than or equal to the height of the source image.
• source.origin.z + the depthOrArrayLayers of the region to copy to is less than or equal to 1.
• dataOffset is equal to or smaller than the size of data.
• The size of data (when converted to bytes, in the case of TypedArrays) is a multiple of 4.

SecurityError DOMException

Thrown if the image source data is cross-origin.

The following criteria must be met when calling writeTexture(), otherwise a GPUValidationError is generated and the GPUQueue becomes invalid:

• mipLevel is less than the destination GPUTexture.mipLevelCount.
• origin.x is a multiple of the texel block width of the destination GPUTexture.format.
• origin.y is a multiple of the texel block height of the destination GPUTexture.format.
• If the destination GPUTexture.format is a depth-or-stencil format, the image capture size is equal to size.
• The destination GPUTexture.usage includes the GPUTextureUsage.COPY_DST and GPUTextureUsage.RENDER_ATTACHMENT flags.
• The destination GPUTexture.dimension is "2d".
• The destination GPUTexture.sampleCount is 1.
• The destination GPUTexture.format is one of the following (which support GPUTextureUsage.RENDER_ATTACHMENT usage):
  • "r8unorm"
  • "r16float"
  • "r32float"
  • "rg8unorm"
  • "rg16float"
  • "rg32float"
  • "rgba8unorm"
  • "rgba8unorm-srgb"
  • "bgra8unorm"
  • "bgra8unorm-srgb"
  • "rgb10a2unorm"
  • "rgba16float"
  • "rgba32float"
• destination.origin.x + copySize.width is less than or equal to the destination GPUTexture width.
• destination.origin.y + copySize.height is less than or equal to the destination GPUTexture height.
• destination.origin.z + copySize.depthOrArrayLayers is less than or equal to the destination GPUTexture depthOrArrayLayers.
• The destination GPUTexture.width is a multiple of the texel block width of the destination GPUTexture.format.
• The destination GPUTexture.height is a multiple of the texel block height of the destination GPUTexture.format.

In the WebGPU Samples Textured Cube example, the following snippet is used to fetch an image and upload it into a GPUTexture:

let cubeTexture: GPUTexture; // TypeScript
{
  const img = document.createElement("img");
  img.src = new URL(
    "../../../assets/img/Di-3d.png",
    import.meta.url
  ).toString();
  await img.decode();
  const imageBitmap = await createImageBitmap(img);

  cubeTexture = device.createTexture({
    size: [imageBitmap.width, imageBitmap.height, 1],
    format: "rgba8unorm",
    usage:
      GPUTextureUsage.TEXTURE_BINDING |
      GPUTextureUsage.COPY_DST |
      GPUTextureUsage.RENDER_ATTACHMENT,
  });

  device.queue.copyExternalImageToTexture(
    { source: imageBitmap },
    { texture: cubeTexture },
    [imageBitmap.width, imageBitmap.height]
  );
}

• The WebGPU API