Function pathops_tight_bounds 

pub fn pathops_tight_bounds(path: &Path) -> Option<Rect>

计算路径的紧密包围盒（pathops 实现）。Computes tight bounds using pathops algorithm.

对含曲线路径可能比 Path::tight_bounds 更精确，但在解析失败时返回 None。 More accurate for curved paths than Path::tight_bounds, but returns None on parse failure.