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//! 虚线路径效果。Dash path effect.
use crate::bridge::ffi;
use crate::path::Path;
use crate::stroke_rec::StrokeRec;
use cxx::UniquePtr;
/// 虚线路径效果，将路径描边转为虚线。
/// Dash path effect for stroked paths (on/off intervals).
pub struct DashPathEffect {
inner: UniquePtr<ffi::PathEffectHolder>,
}
impl DashPathEffect {
/// 创建虚线效果。Creates a dash effect.
///
/// `intervals`: 交替的 on/off 长度，如 [10.0, 20.0] 表示 10 像素 on、20 像素 off
/// `intervals`: on/off lengths, e.g. [10.0, 20.0] = 10px on, 20px off
/// `phase`: 相位偏移
/// `phase`: phase offset into the pattern
pub fn new(intervals: &[f32], phase: f32) -> Option<Self> {
if intervals.is_empty() || !intervals.len().is_multiple_of(2) {
return None;
}
let inner = ffi::dash_effect_make(intervals, phase);
if inner.is_null() {
return None;
}
Some(Self { inner })
}
/// 应用到路径。Applies effect to path (requires stroke width).
///
/// `path`: 输入路径
/// `stroke_width`: 描边宽度（虚线仅对描边路径有效）
/// `path`: input path
/// `stroke_width`: stroke width (dash only affects stroked paths)
///
/// 失败时返回 `None`。Returns `None` on failure.
pub fn filter_path(&self, path: &Path, stroke_width: f32) -> Option<Path> {
let mut dst = Path::new();
let mut rec = StrokeRec::new_stroke(stroke_width, false);
let bounds = path.tight_bounds();
let cull: ffi::Rect = bounds.into();
let ok = ffi::path_effect_filter(
self.inner.as_ref().expect("PathEffect"),
dst.as_raw_pin_mut(),
path.as_raw(),
rec.pin_holder_mut(),
&cull,
);
if ok {
Some(dst)
} else {
None
}
}
}