JavaScript函数：includeScroll() - 应用滚动距离到矩形

function includeScroll(rect, element) {\n var subtract = arguments.length > 2 && arguments[2] !== undefined ? arguments[2] : false;\n\n var scrollTop = getScroll(element, 'top');\n var scrollLeft = getScroll(element, 'left');\n var modifier = subtract ? -1 : 1;\n rect.top += scrollTop * modifier;\n rect.bottom += scrollTop * modifier;\n rect.left += scrollLeft * modifier;\n rect.right += scrollLeft * modifier;\n return rect;\n }