Description

Package svg generates SVG as defined by the Scalable Vector Graphics 1.1 Specification (<http://www.w3.org/TR/SVG11/>). Output goes to the specified io.Writer.

Supported SVG elements and functions

Shapes, lines, text

circle, ellipse, polygon, polyline, rect (including roundrects), line, text

Paths

general, arc, cubic and quadratic bezier paths,

Image and Gradients

image, linearGradient, radialGradient,

Transforms

translate, rotate, scale, skewX, skewY

Filter Effects

filter, feBlend, feColorMatrix, feColorMatrix, feComponentTransfer, feComposite, feConvolveMatrix, feDiffuseLighting,
feDisplacementMap, feDistantLight, feFlood, feGaussianBlur, feImage, feMerge, feMorphology, feOffset, fePointLight,
feSpecularLighting, feSpotLight,feTile, feTurbulence

Metadata elements

desc, defs, g (style, transform, id), mask, marker, pattern, title, (a)ddress, link, script, use

Usage: (assuming GOPATH is set)

go get github.com/ajstarks/svgo/float

You can use godoc to browse the documentation from the command line:

$ go doc github.com/ajstarks/svgo/float

a minimal program, to generate SVG to standard output.

package main

import (
	"github.com/ajstarks/svgo/float"
	"os"
)

func main() {
	width := 500.0
	height := 500.0
	canvas := svg.New(os.Stdout)
	canvas.Start(width, height)
	canvas.Circle(width/2, height/2, 100)
	canvas.Text(width/2, height/2, "Hello, SVG", "text-anchor:middle;font-size:30px;fill:white")
	canvas.End()
}

Drawing in a web server: (http://localhost:2003/circle)

package main

import (
	"log"
	"github.com/ajstarks/svgo"
	"net/http"
)

func main() {
	http.Handle("/circle", http.HandlerFunc(circle))
	err := http.ListenAndServe(":2003", nil)
	if err != nil {
		log.Fatal("ListenAndServe:", err)
	}
}

func circle(w http.ResponseWriter, req *http.Request) {
  w.Header().Set("Content-Type", "image/svg+xml")
  s := svg.New(w)
  s.Start(500, 500)
  s.Circle(250, 250, 125, "fill:none;stroke:black")
  s.End()
}

Functions and types

Many functions use x, y to specify an object's location, and w, h to specify the object's width and height. Where applicable, a final optional argument specifies the style to be applied to the object. The style strings follow the SVG standard; name:value pairs delimited by semicolons, or a series of name="value" pairs. For example: `"fill:none; opacity:0.3"` or `fill="none" opacity="0.3"` (see: <http://www.w3.org/TR/SVG11/styling.html>)

The SVG type:

	type SVG struct {
        Writer   io.Writer
	}

Most operations are methods on this type, specifying the destination io.Writer.

The Offcolor type:

type Offcolor struct {
	Offset  uint8
	Color   string
	Opacity float64
}

is used to specify the offset, color, and opacity of stop colors in linear and radial gradients

The Filterspec type:

type Filterspec struct {
	In string
	In2 string
	Result string
}

is used to specify inputs and results for filter effects

Package svg provides an API for generating Scalable Vector Graphics (SVG), using floating point units

svg is referenced in 3 repositories

github.com/ajstarks/svgo github.com/frankbraun/asciiart github.com/luxengine/glm