Function isWithinSubmenu

src/cdk/menu/menu-aim.ts:86–98

* Whether the given mouse trajectory line defined by the slope and y intercept falls within the * submenu as defined by `submenuPoints` * @param submenuPoints the submenu DOMRect points. * @param m the slope of the trajectory line. * @param b the y intercept of the trajectory line. * @return tr

(submenuPoints: DOMRect, m: number, b: number)

 * @return true if any point on the line falls within the submenu.
 */
function isWithinSubmenu(submenuPoints: DOMRect, m: number, b: number) {
  const {left, right, top, bottom} = submenuPoints;

  // Check for intersection with each edge of the submenu (left, right, top, bottom)
  // by fixing one coordinate to that edge's coordinate (either x or y) and checking if the
  // other coordinate is within bounds.
  return (
    (m * left + b >= top && m * left + b <= bottom) ||
    (m * right + b >= top && m * right + b <= bottom) ||
    ((top - b) / m >= left && (top - b) / m <= right) ||
    ((bottom - b) / m >= left && (bottom - b) / m <= right)
  );
}

/**
 * TargetMenuAim predicts if a user is moving into a submenu. It calculates the