Package index • vellum

Building & rendering scenes

Build a scene functionally with vl_scene() and a pipeline of push() / draw() / pop(), then render it. render() picks the backend (PNG / SVG / PDF) from the file extension.

vl_scene() push() draw() pop() render(): Build and render a scene
describe(): Set a scene's accessibility name and description
display(): Display a scene in the active graphics device
scene_raster(): Read a rendered scene back as pixels
scene_svg(): Render a scene to an SVG string
as_vellum_scene(): Coerce an object to a vellum scene

Graphical objects (grobs)

The drawable primitives. Most are vectorised and batch internally.

rect_grob() roundrect_grob() lines_grob() polygon_grob() bezier_grob() spline_grob() circle_grob() points_grob() hexagon_grob() sector_grob() loop_grob() segments_grob() path_grob() raster_grob() text_grob(): Graphical objects (grobs)
vl_arrow(): Arrowheads

Units, viewports & layout

Coordinate systems, nested viewports with scales, clipping and rotation, and the row/column layout solver.

vl_unit() is_unit(): Units of measurement
vl_viewport() grid_layout(): Viewports and layouts
grobwidth() grobheight(): Size a unit by a grob's extent
why_size(): Explain why a node has its resolved size

Paint & appearance

The paint model shared across all backends: gradients, tiling patterns, masks, reusable styles, and hand-drawn rendering.

vl_gpar(): Graphical parameters
style(): Reusable style classes
linear_gradient() radial_gradient(): Gradient fills
vl_pattern(): Tiling-pattern fills
as_mask(): Masks
sketch(): Hand-drawn ("sketch") rendering

Text

Device-independent shaping and measurement, plus Markdown-style rich labels.

vl_strwidth() vl_strheight(): Measure text
md(): Rich-text labels (markdown subset)

Big data

Aggregate-then-shade rendering for large point clouds.

datashade(): Aggregate-then-shade a large point cloud (datashader-style)

Inspecting & editing scenes

Because the scene graph is retained, it can be queried, edited by node name, hit-tested, and serialized to a per-element model.

node_names() get_node() edit_node(): Inspect and edit a scene by node name
hit_test(): Hit-test a scene
scene_model(): A serializable, per-element model of a scene

Grid & ggplot2 interop

Render an existing grid grob tree — including ggplot2 and lattice — through the vellum backend.

as_vellum() render_grid(): Render grid graphics (ggplot2 / lattice / grid) through vellum

Caches & diagnostics

vl_clear_render_cache(): Clear the render cache

Package

vellum vellum-package: vellum: A Low-Level Graphics Framework with a Rust Backend