librsvg provides Scala Native bindings for librsvg, the GNOME SVG rendering library. It renders SVG documents directly into a Cairo context, so a scalable vector graphic composites into a larger Cairo scene with full clip, transform and opacity support — no intermediate raster step.

librsvg's internals were rewritten in Rust, but the library still ships a stable C API/ABI (librsvg-2), so it binds like any other C library. This project pairs it with libcairo: you load an SVG into a Handle, then render it onto a libcairo Context.

The programmer-friendly facade lives in the io.github.edadma.librsvg package — that is the only package you need to import. The io.github.edadma.librsvg.extern package holds the raw C interop using Scala Native's unsafe types; nothing in the public facade exposes those types, so you never deal with manual memory management or pointer conversions.

This library is published for Scala Native to Maven Central. The librsvg C library (and Cairo) must be installed on your system:

brew install librsvg              # macOS (Homebrew) — pulls in cairo + glib
sudo apt install librsvg2-dev     # Debian / Ubuntu

Enable Scala Native in project/plugins.sbt:

addSbtPlugin("org.scala-native" % "sbt-scala-native" % "0.5.12")

Add the dependency in build.sbt (it brings libcairo transitively):

libraryDependencies += "io.github.edadma" %%% "librsvg" % "0.0.4"

Then import the facade:

import io.github.edadma.librsvg._
import io.github.edadma.libcairo._

Load an SVG from a string, render it into a Cairo image surface, and write a PNG:

import io.github.edadma.librsvg._
import io.github.edadma.libcairo._

@main def run(): Unit =
  val svg =
    """<svg xmlns="http://www.w3.org/2000/svg" width="64" height="64" viewBox="0 0 64 64">
      |  <rect x="4" y="4" width="56" height="56" rx="12" fill="#4dabf7"/>
      |  <circle cx="32" cy="32" r="16" fill="#ffffff"/>
      |  <path d="M24 32 l6 6 l12 -14" stroke="#4dabf7" stroke-width="4" fill="none"
      |        stroke-linecap="round" stroke-linejoin="round"/>
      |</svg>""".stripMargin

  val handle = handleNewFromString(svg)

  handle.intrinsicSize.foreach { case (w, h) => println(s"intrinsic size: ${w}x$h") }

  val surface = imageSurfaceCreate(Format.ARGB32, 64, 64)
  val cr      = surface.create

  handle.renderDocument(cr, 0, 0, 64, 64)   // draws into the 64x64 viewport

  surface.writeToPNG("rsvg-demo.png")

  cr.destroy()
  surface.destroy()
  handle.destroy()

Loading (each throws RsvgException on a parse error):

• handleNewFromFile(filename: String): Handle
• handleNewFromData(data: Array[Byte]): Handle — plain .svg or gzip-compressed .svgz
• handleNewFromString(svg: String): Handle

On a Handle:

• renderDocument(cr: Context, x, y, width, height): Boolean — render into a viewport rectangle on a libcairo Context
• intrinsicSize: Option[(Double, Double)] — the document's pixel size when it declares one
• setDpi(dpi: Double): Unit — resolution for physical units (pt, cm, …)
• destroy(): Unit — release the handle

API documentation is forthcoming; documentation for the C library is found here.

ISC