(PECL haru >= 0.0.1)
HaruPage::arc — Append an arc to the current path
Appends an arc to the current path.
Horizontal coordinate of the center.
Vertical coordinate of the center.
The ray of the arc.
The angle of the beginning.
The angle of the end. Must be greater than ang1.
Returns TRUE on success.
发生错误时抛出 HaruException 异常。