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XRWebGLSubImage: imageIndex property

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

The read-only imageIndex property of the XRWebGLSubImage interface is a number representing the offset into the texture array if the layer was requested with texture-array; null otherwise.

Value

A number or null if the layer wasn't requested with texture-array.

Using imageIndex

The imageIndex property can be passed WebGL2RenderingContext.framebufferTextureLayer() to attach the depth and color textures to a framebuffer with the correct layer index.

js

const xrGlBinding = new XRWebGLBinding(xrSession, gl);
const layer = xrGlBinding.createProjectionLayer({
  textureType: "texture-array",
});
const framebuffer = gl.createFramebuffer();

xrSession.updateRenderState({ layers: [layer] });
xrSession.requestAnimationFrame(onXRFrame);

function onXRFrame(time, xrFrame) {
  xrSession.requestAnimationFrame(onXRFrame);

  gl.bindFramebuffer(gl.FRAMEBUFFER, framebuffer);
  const viewport = xrGlBinding.getSubImage(layer, xrFrame).viewport;
  gl.viewport(viewport.x, viewport.y, viewport.width, viewport.height);

  for (const view in xrViewerPose.views) {
    const subImage = xrGlBinding.getViewSubImage(layer, view);
    gl.framebufferTextureLayer(
      gl.FRAMEBUFFER,
      gl.COLOR_ATTACHMENT0,
      subImage.colorTexture,
      0,
      subImage.imageIndex,
    );
    gl.framebufferTextureLayer(
      gl.FRAMEBUFFER,
      gl.DEPTH_ATTACHMENT,
      subImage.depthStencilTexture,
      0,
      subImage.imageIndex,
    );

    // Render from the viewpoint of xrView
  }
}

Specifications

Browser compatibility

Desktop Mobile
Chrome Edge Firefox Internet Explorer Opera Safari WebView Android Chrome Android Firefox for Android Opera Android Safari on IOS Samsung Internet
imageIndex No No No No No No No No No No No No

See also

© 2005–2023 MDN contributors.
Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.
https://developer.mozilla.org/en-US/docs/Web/API/XRWebGLSubImage/imageIndex