Struct Group 

pub struct Group {
    pub transform: Transform2D,
    pub opacity: f32,
    pub clip: Option<Path>,
    pub children: Vec<Node>,
    pub cache_key: Option<u64>,
}

A grouping node — applies a transform / opacity / optional clip path to all descendants. Mirrors SVG <g> and PDF q ... Q graphic-state blocks.

Fields

transform: Transform2D

Coordinate transform applied to children. Identity by default.

opacity: f32

Group opacity in 0.0..=1.0. 1.0 is fully opaque.

clip: Option<Path>

Optional clip path. Children are clipped to this path’s interior (using the path’s own fill rule). None means “no clip”.

children: Vec<Node>

cache_key: Option<u64>

Opaque cache key. When Some(k), a downstream rasterizer is free to memoise the rendered bitmap of this group’s content (after transform is applied) under key k, so re-rendering the same group at the same effective resolution returns the cached bitmap.

Producers that emit cacheable content (e.g. scribe shaping a glyph at (face_id, glyph_id, size_q8, subpixel_x)) compute a deterministic hash of their identity tuple and put it here. The rasterizer treats it as a black box — oxideav-core never inspects the value, so each producer’s namespace stays private.

None (the default) means “do not cache; render fresh every time”. Most synthesised vector content (a one-off rectangle, a gradient panel) leaves this None.

Implementations

impl Group

pub fn new() -> Self

An empty group: identity transform, opacity 1.0, no clip, no children, no cache key. Same as Group::default.

pub fn with_transform(self, transform: Transform2D) -> Self

Replace the transform.

pub fn with_opacity(self, opacity: f32) -> Self

Set the group opacity in 0.0..=1.0.

pub fn with_clip(self, clip: Path) -> Self

Set the clip path.

pub fn with_child(self, child: Node) -> Self

Append a child node.

pub fn with_children(self, children: Vec<Node>) -> Self

Replace the children list wholesale.

pub fn with_cache_key(self, key: u64) -> Self

Set the rasterizer cache key. See Group::cache_key.

Trait Implementations

impl Clone for Group

fn clone(&self) -> Group

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for Group

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for Group

fn default() -> Self

Returns the “default value” for a type.