Function flyToViewport

docs/app/js/sanddance-app.js:80664–80688

(startProps, endProps, t, options)

    speed: 1.2
};
function flyToViewport(startProps, endProps, t, options) {
    const { startZoom , startCenterXY , uDelta , w0 , u1 , S , rho , rho2 , r0  } = getFlyToTransitionParams(startProps, endProps, options);
    if (u1 < EPSILON) {
        const viewport = {};
        for (const key of VIEWPORT_TRANSITION_PROPS){
            const startValue = startProps[key];
            const endValue = endProps[key];
            viewport[key] = (0, _mathUtils.lerp)(startValue, endValue, t);
        }
        return viewport;
    }
    const s = t * S;
    const w = Math.cosh(r0) / Math.cosh(r0 + rho * s);
    const u = w0 * ((Math.cosh(r0) * Math.tanh(r0 + rho * s) - Math.sinh(r0)) / rho2) / u1;
    const scaleIncrement = 1 / w;
    const newZoom = startZoom + (0, _webMercatorUtils.scaleToZoom)(scaleIncrement);
    const newCenterWorld = _vec2.scale([], uDelta, u);
    _vec2.add(newCenterWorld, newCenterWorld, startCenterXY);
    const newCenter = (0, _webMercatorUtils.worldToLngLat)(newCenterWorld);
    return {
        longitude: newCenter[0],
        latitude: newCenter[1],
        zoom: newZoom
    };
}
exports.default = flyToViewport;
function getFlyToDuration(startProps, endProps, options) {
    const opts = {