Struct SceneGraph 

pub struct SceneGraph { /* private fields */ }

Arena of nodes for one scene run. Node 0 is the view (root).

Implementations

impl SceneGraph

pub const ROOT: NodeId

The root node (the scene’s view).

pub fn new(width: u32, height: u32) -> Rc<SceneGraph>

An empty scene of the given size in pixels, with only the root.

pub fn size(&self) -> (u32, u32)

Scene size in pixels.

pub fn set_time(&self, seconds: f64)

Time, in seconds, that the next draw_list paints. The engine sets this after each frame.

pub fn time(&self) -> f64

Time the last set_time stored.

pub fn len(&self) -> usize

Number of nodes, including the root.

pub fn is_empty(&self) -> bool

Never true: the root always exists.

pub fn node(&self, id: NodeId) -> Ref<'_, NodeData>

Borrows a node’s stored state.

Panics

If id is not a node of this graph.

pub fn measure(&self, id: NodeId) -> (f64, f64)

Size of a node’s box in its own (unscaled) coordinates.

pub fn has_post(&self) -> bool

Some node reads or changes drawn pixels (an effect, or a shader that reads the frame). When false, the draw list has no markers and a renderer can draw it in one go.

pub fn draw_list(&self) -> Vec<DrawItem>

Flattened, paint-ordered list of everything to draw.

pub fn shader_diags(&self) -> Vec<ShaderDiag>

WGSL problems from the last draw_list.

pub fn draw_drift(&self) -> Option<(String, Option<String>)>

Some when painting this frame twice does not produce the same primitives. The string is the node’s name, or its add call site.

pub fn pick(&self, p: Point) -> Option<NodeId>

Topmost node under p (scene coordinates), excluding the view.

pub fn world_transform(&self, id: NodeId) -> Option<Affine>

World transform of a node (including layout offsets).

pub fn box_in(&self, id: NodeId, frame: NodeId) -> Option<Rect>

The box of id (its size around its origin) in the coordinate frame of frame’s children: for a camera, where the node sits in the world the camera looks at. Axis-aligned.

pub fn frame_size(&self) -> (f64, f64)

Frame size in pixels.

pub fn tree( &self, ) -> Vec<(NodeId, Option<NodeId>, &'static str, Option<String>)>

(id, parent, kind, name) of every attached node, depth-first.

pub fn describe(&self, id: NodeId) -> Vec<(String, String)>

Current signal values of a node, for the inspector.

pub fn inspect_nodes(&self) -> Vec<InspectNode>

One record per attached node, in tree order, with scene-space bounds.

order is paint order (0 is the back). Nodes that are not drawn (fully transparent) get u32::MAX.

impl SceneGraph

pub fn enter<R>(self: &Rc<SceneGraph>, f: impl FnOnce() -> R) -> R

Makes this graph the target of node handles for the duration of f.