SVG Shapes

Golang library to define and encode shapes as SVG.

Examples

Use the NewDocument function to create a document with the given view box. Shapes can be created and attached to this document with the document's methods Circle, Polygon etc.

doc := svgshapes.NewDocument("-50,-50,100,100")
doc.Circle(10.5, 25, 15)
doc.Polygon(
	svgshapes.Point{ 10, 20 },
	svgshapes.Point{ 4.5, 4.5 },
	svgshapes.Point{ 20, 8 },
)

To generate an SVG file from the document, use the Write method:

err := doc.Write(file)
if err != nil {
	log.Fatal(err)
}

You can also define individual shapes without a document:

circle := svgshapes.Circle{
	CenterX: 10.5,
	CenterY: 25,
	Radius:  15,
}
polygon := svgshapes.Polygon{
	Points: []svgshapes.Point{
		svgshapes.Point{ 10, 20 },
		svgshapes.Point{ 4.5, 4.5 },
		svgshapes.Point{ 20, 8 },
	},
}

Add these shapes to a document by directly modifying the Shapes property:

doc := svgshapes.NewDocument("-50,-50,100,100")
doc.Shapes = append(doc.Shapes, circle)
doc.Shapes = append(doc.Shapes, polygon)

Limitations

This SVG library is kept very simple. Some things might not work as expected:

• SVG shapes without child elements (e.g. circle, polygon, path etc.) are normally written as self-closing tags (tags in the form <circle ... />, <polygon ... />, <path ... /> etc.). Golang's XML encoding library does not support creating self-closing tags (see the corresponding issue for details).
• The SVG specification recommends "that SVG generators split long path data strings across multiple lines, with each line not exceeding 255 characters". Golang's XML encoding library replaces all newline characters within attributes with the entity 
. As this does not help with viewing or editing such path data, no line-breaks will be inserted into the path data.
• Only the most basic SVG elements and their attributes are supported.
• All numeric values are encoded as unit-less numbers. This means that lengths and coordinates will be interpreted in the current user coordinate system. Units, such as px, pt, em and %, are not supported at the moment.