video-ad-sdk/dist/adUnit/helpers/vpaid/viewmode.js

VAST/VPAID SDK that allows video ads to be played on top of any player

const FULLSCREEN_LAPSE = 100;
const THUMBNAIL_MAX_WIDTH = 400;
export const viewmode = (width, height) => {
    const { screen } = window;
    const isFullscreen = width + FULLSCREEN_LAPSE > screen.width &&
        height + FULLSCREEN_LAPSE > screen.height;
    if (isFullscreen) {
        return 'fullscreen';
    }
    if (width < THUMBNAIL_MAX_WIDTH) {
        return 'thumbnail';
    }
    return 'normal';
};