fixed-foveation.js

import {Component, Type} from '@wonderlandengine/api';

/**
 * Applies [fixed foveation](https://www.w3.org/TR/webxrlayers-1/#dom-xrcompositionlayer-fixedfoveation)
 * once a WebXR session is started
 *
 * Fixed foveation reduces shading cost at the periphery by rendering at lower resolutions at the
 * edges of the users vision.
 */
export class FixedFoveation extends Component {
    static TypeName = 'fixed-foveation';
    static Properties = {
        /** Amount to apply from 0 (none) to 1 (full) */
        fixedFoveation: {type: Type.Float, default: 0.5},
    };

    start() {
        this.onSessionStartCallback = this.setFixedFoveation.bind(this);
    }

    onActivate() {
        this.engine.onXRSessionStart.add(this.onSessionStartCallback);
    }

    onDeactivate() {
        this.engine.onXRSessionStart.remove(this.onSessionStartCallback);
    }

    setFixedFoveation() {
        this.engine.xr.baseLayer.fixedFoveation = this.fixedFoveation;
    }
}