Function computeInputData

docs/tests/v2/es6/js/sanddance.js:51879–51921

* extend the data with some usable properties like scale, rotate, velocity etc * @param {Object} manager * @param {Object} input

(manager, input)

  function computeInputData(manager, input) {
    var session = manager.session;
    var pointers = input.pointers;
    var pointersLength = pointers.length; // store the first input to calculate the distance and direction

    if (!session.firstInput) {
      session.firstInput = simpleCloneInputData(input);
    } // to compute scale and rotation we need to store the multiple touches


    if (pointersLength > 1 && !session.firstMultiple) {
      session.firstMultiple = simpleCloneInputData(input);
    } else if (pointersLength === 1) {
      session.firstMultiple = false;
    }

    var firstInput = session.firstInput;
    var firstMultiple = session.firstMultiple;
    var offsetCenter = firstMultiple ? firstMultiple.center : firstInput.center;
    var center = input.center = getCenter(pointers);
    input.timeStamp = now();
    input.deltaTime = input.timeStamp - firstInput.timeStamp;
    input.angle = getAngle(offsetCenter, center);
    input.distance = getDistance(offsetCenter, center);
    computeDeltaXY(session, input);
    input.offsetDirection = getDirection(input.deltaX, input.deltaY);
    var overallVelocity = getVelocity(input.deltaTime, input.deltaX, input.deltaY);
    input.overallVelocityX = overallVelocity.x;
    input.overallVelocityY = overallVelocity.y;
    input.overallVelocity = abs(overallVelocity.x) > abs(overallVelocity.y) ? overallVelocity.x : overallVelocity.y;
    input.scale = firstMultiple ? getScale(firstMultiple.pointers, pointers) : 1;
    input.rotation = firstMultiple ? getRotation(firstMultiple.pointers, pointers) : 0;
    input.maxPointers = !session.prevInput ? input.pointers.length : input.pointers.length > session.prevInput.maxPointers ? input.pointers.length : session.prevInput.maxPointers;
    computeIntervalInputData(session, input); // find the correct target

    var target = manager.element;

    if (hasParent(input.srcEvent.target, target)) {
      target = input.srcEvent.target;
    }

    input.target = target;
  }

  function computeDeltaXY(session, input) {
    var center = input.center;