Package {rpic}

Title:	The 'pic' Graphics Language Rendered to SVG, PNG and PDF
Version:	0.12.1
Description:	Renders diagrams written in the 'pic' picture-drawing language (Kernighan, 1984) to SVG, PNG and PDF, using 'rpic' https://github.com/milkway/rpic-lang, a reimplementation of 'pic' in 'Rust' with no system dependencies. Includes a native circuit-element library in the spirit of 'circuit_macros', TeX math labels typeset natively, structured compile diagnostics, and a 'knitr' language engine for inline diagrams in 'R Markdown' and 'Quarto' documents.
License:	BSD_2_clause + file LICENSE
Encoding:	UTF-8
SystemRequirements:	Cargo (Rust's package manager), rustc (>= 1.88.0)
Suggests:	jsonlite, knitr, rmarkdown
VignetteBuilder:	knitr
URL:	https://milkway.github.io/rpic-r/, https://github.com/milkway/rpic-r, https://github.com/milkway/rpic-lang
BugReports:	https://github.com/milkway/rpic-r/issues
Config/rextendr/version:	0.5.0
Depends:	R (≥ 4.2)
Config/roxygen2/version:	8.0.0
NeedsCompilation:	yes
Packaged:	2026-11-02 16:53:31 UTC; leite
Author:	André Leite [aut, cre, cph], The authors of the dependency Rust crates [cph] (see inst/AUTHORS for details)
Maintainer:	André Leite <leite@castlab.org>
Repository:	CRAN
Date/Publication:	2026-11-02 20:30:02 UTC

rpic: The 'pic' Graphics Language Rendered to SVG, PNG and PDF

Description

Renders diagrams written in the 'pic' picture-drawing language (Kernighan, 1984) to SVG, PNG and PDF, using 'rpic' https://github.com/milkway/rpic-lang, a reimplementation of 'pic' in 'Rust' with no system dependencies. Includes a native circuit-element library in the spirit of 'circuit_macros', TeX math labels typeset natively, structured compile diagnostics, and a 'knitr' language engine for inline diagrams in 'R Markdown' and 'Quarto' documents.

Author(s)

Maintainer: André Leite leite@castlab.org (ORCID) [copyright holder]

Authors:

• André Leite leite@castlab.org (ORCID) [copyright holder]

Other contributors:

• The authors of the dependency Rust crates (see inst/AUTHORS for details) [copyright holder]

See Also

Useful links:

• https://milkway.github.io/rpic-r/

• https://github.com/milkway/rpic-r

• https://github.com/milkway/rpic-lang

• Report bugs at https://github.com/milkway/rpic-r/issues

knitr engine for {rpic} chunks

Description

Register with rpic_register_knitr(), then write pic code in a chunk:

```{rpic, circuits=TRUE}
A:(0,0); B:(2,0)
resistor(A,B)
```

Chunk options: circuits, texlabels, scale.

Usage

rpic_knitr_engine(options)

Arguments

Value

The chunk output produced by knitr::engine_output() (the rendered diagram as an included figure).

Compile to a JSON bundle (as a string)

Description

Returns ⁠{svg, animations, diagnostics, warnings, objects}⁠ — warnings carries structured compiler warnings for accepted-but-ignored input (unknown attribute words, unknown animate effects), each with the same fields as the rpic_error diagnostic. objects lists every drawn object: its SVG id ("s0", "s1", ...), kind, bounding box in viewBox units and source position. An interactions array is added when the source marks objects draggable. On a pic error the JSON is ⁠{error, error_info}⁠ instead (no condition is raised — the error travels in-band).

Usage

rpic_manifest(src, circuits = FALSE, texlabels = FALSE)

Arguments

Value

a JSON string; parse with e.g. jsonlite::fromJSON().

Examples

rpic_manifest('box; animate last box with "pop"')

Render pic source to a PDF file

Description

Render pic source to a PDF file

Usage

rpic_pdf(src, file, circuits = FALSE, texlabels = FALSE)

Arguments

Value

the file path, invisibly.

Render pic source to a PNG file

Description

Render pic source to a PNG file

Usage

rpic_png(src, file, scale = 2, circuits = FALSE, texlabels = FALSE)

Arguments

Value

the file path, invisibly.

Register the rpic knitr engine

Description

Register the rpic knitr engine

Usage

rpic_register_knitr()

Value

No return value; called for its side effect of registering the rpic engine with knitr::knit_engines.

Compile to the scene JSON (the resolved draw list)

Description

The scene is the engine's device-independent output (format 1, see docs/scene.md in the engine repository): the fully resolved draw list — final geometry in inches (y-up), curves as cubic Béziers, style as descriptors with colors resolved to hex, text as text with baseline anchor points, every variable's final value under vars, and items in draw order carrying the same stable ⁠s<N>⁠ ids as the SVG. Use it to build your own backend (maps, TikZ, editors) on top of rpic's layout.

Usage

rpic_scene(
  src,
  flatten = NULL,
  outline = FALSE,
  circuits = FALSE,
  texlabels = FALSE
)

Arguments

Details

Anything the SVG paints that the scene cannot represent is reported as an R warning() (engine kind scene_unsupported) — never silently dropped.

Value

a JSON string; parse with e.g. jsonlite::fromJSON().

Errors

Compile errors raise the same classed rpic_error condition as rpic_svg().

Examples

scene <- rpic_scene('geo_lon = -34.88
B: box "hub"
arrow right from B.e')
if (requireNamespace("jsonlite", quietly = TRUE)) {
  s <- jsonlite::fromJSON(scene, simplifyVector = FALSE)
  s$vars$geo_lon      # -34.88
  s$items[[2]]$kind   # "arrow"
}

Render pic source to an SVG string

Description

Render pic source to an SVG string

Usage

rpic_svg(src, circuits = FALSE, texlabels = FALSE)

Arguments

Value

an SVG string.

Errors

Compile errors are raised as a classed rpic_error condition whose info field holds the structured diagnostic (message, line, col, end_col, file, kind, found, expected, hint; absent values are NA, and file names a copy include — NA means your own input). Positions are relative to your own source, even with circuits = TRUE:

tryCatch(
  rpic_svg("bxo", circuits = TRUE),
  rpic_error = function(e) e$info$hint  # "did you mean `box`?"
)

Examples

rpic_svg('box "hi"; arrow; circle "x"')
tryCatch(rpic_svg("bxo"), rpic_error = function(e) e$info$line)