@woosh/meep-engine/src/engine/input/devices/touch/getTouchCenter.js

Pure JavaScript game engine. Fully featured and production ready.

/**
 *
 * @param {TouchList} touchList
 * @param {Vector2} result
 */
export function getTouchCenter(touchList, result) {
    const length = touchList.length;

    let x = 0, y = 0;

    if (length > 0) {

        for (let i = 0; i < length; i++) {
            const touch = touchList.item(i);

            if (touch === null) {
                continue;
            }

            x += touch.clientX;
            y += touch.clientY;
        }

        // average to get center
        x /= length;
        y /= length;

    }

    result.set(x, y);

}