本函数是实验性的。本函数的行为，包括函数名称以及其它任何关于本函数的文档可能会在没有通知的情况下随 PHP 以后的发布而改变。使用本函数风险自担。
swftext->setspacing() sets the current font spacing to spacingspacing. Default is 1.0. 0 is all of the letters written at the same point. This doesn't really work that well because it inflates the advance across the letter, doesn't add the same amount of spacing between the letters. I should try and explain that better, prolly. Or just fix the damn thing to do constant spacing. This was really just a way to figure out how letter advances work, anyway.. So nyah.