2 Quick Start🔗ℹ

The four functions you’ll likely reach for first are svg-string->bitmap, svg-file->bitmap, svg-string->pict, and svg-file->pict — read an SVG document from a string or a file, and get back either a bitmap% or a pict.

(require svg/svg racket/class)

(define bm

(svg-string->bitmap

#<<SVG

<svg width="160" height="120" xmlns="http://www.w3.org/2000/svg">

<defs>

<linearGradient id="g" x1="0%" y1="0%" x2="100%" y2="0%">

<stop offset="0%" stop-color="gold"/>

<stop offset="100%" stop-color="crimson"/>

</linearGradient>

</defs>

<rect x="10" y="10" width="140" height="60" rx="10" fill="url(#g)"/>

<circle cx="40" cy="95" r="18" fill="steelblue" stroke="black" stroke-width="2"/>

<circle cx="80" cy="95" r="18" fill="seagreen" stroke="black" stroke-width="2"/>

<circle cx="120" cy="95" r="18" fill="orange" stroke="black" stroke-width="2"/>

</svg>

SVG

))

(send bm save-file "out.png" 'png)

Swap svg-string->bitmap for svg-string->pict and you get a pict instead of a bitmap% — one that composes with ordinary picts like disk, text, frame, and hc-append/vc-append, since it’s built on pict’s own dc constructor:

(require svg/svg pict)

(define badge (svg-string->pict "...")) ; same SVG string as above

(hc-append 16 (text "A pict:" '(bold) 16) (frame badge))

svg-file->bitmap and svg-file->pict are the file-path equivalents; use them (rather than reading a file yourself and passing the string to svg-string->bitmap/svg-string->pict) whenever the SVG has relative <image> references, since only the file-path versions know what directory to resolve those against.

Filters, masks, and group opacity all compose the way you’d expect from a browser — a <filter> with feDropShadow, or a <g mask="..."> layered with a semi-transparent group, render correctly rather than as a rough approximation:

If all you need is one of those four top-level functions, you can stop reading here. The rest of this document covers the lower-level pieces (path-data parsing, paint resolution, transform matrices, and so on) that svg/svg also exports, in case you want to reuse a piece of the pipeline directly — say, to parse path data for your own purposes, or to resolve an SVG color string without rendering anything.