VRLayerInit.leftBounds - Web APIs 编辑

Experimental

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

The leftBounds property of the VRLayerInit interface (dictionary) defines the left texture bounds of the canvas whose contents will be presented by the VRDisplay.

Syntax

var myVRLayerInit = { };
myVRLayerInit.leftBounds = [0.0, 0.0, 0.5, 1.0];

Value

An array of four floating point values, which can take values from 0.0–1.0:

• The left offset of the bounds.
• The top offset of the bounds.
• The width of the bounds.
• The height of the bounds.

If leftBounds is not specified in the dictionary, the default value used is [0.0, 0.0, 0.5, 1.0].

Examples

// currently returns an empty array
var layers = vrDisplay.getLayers();

if(navigator.getVRDisplays) {
  console.log('WebVR 1.1 supported');
  // Then get the displays attached to the computer
  navigator.getVRDisplays().then(function(displays) {
    // If a display is available, use it to present the scene
    if(displays.length > 0) {
      vrDisplay = displays[0];
      console.log('Display found');
      // Starting the presentation when the button is clicked: It can only be called in response to a user gesture
      btn.addEventListener('click', function() {
        vrDisplay.requestPresent([{ source: canvas }]).then(function() {
          console.log('Presenting to WebVR display');

          // Here it returns an array of VRLayerInit objects
          var layers = vrDisplay.getLayers();

          ...
        });
      });
    }
  });
}

VRLayerInit objects look something like this:

{
  leftBounds : [ ... ],
  rightBounds: [ ... ],
  source: canvasReference
}

Note: The canvasReference refers to the <canvas> element itself, not the WebGL context associated with the canvas. The other two members are arrays

Specifications

Browser compatibility

BCD tables only load in the browser

See also

• WebVR API homepage
• MozVr.com — demos, downloads, and other resources from the Mozilla VR team.