Awesome

minisvg <img src="man/figures/logo.png" align="right" height=230>

minisvg is a package for building SVG documents in R.

Overview

Quick Examples

Vignettes

• Animating SVG with SMIL
• Animating SVG with CSS
• Styling SVG with CSS both as an inline style chunk and as an external CSS document.
• Transformations example
• Some pretty (?) animated geometry
• Creating and Animating the carpet from The Overlook Hotel in The Shining
• Creating and Animating a 70s wallpaper pattern
• Some examples of filter usage
• Adding javascript to an SVG
• Specifying coordinates for polygons and polylines
• Inserting literal HTML into an SVG: MathML in an SVG
• Editing an SVG

Installation

You can install minisvg from GitHub with:

# install.packages("devtools")
devtools::install_github("coolbutuseless/minisvg")

stag helper (autocomplete SVG element creation)

The stag helper is similar to shiny::tag and minihtml::htag

svg_prop helper (autocomplete SVG attribute creation)

The svg_prop helper uses autocomplete to help remember the property attributes of many SVG elements, along with their possible values.

Interface

• Individual elements can be created in a number of ways. E.g. creating a defs block
  • As a stand-alone element
    • new_elem <- SVGElement$new('defs', style = 'color: black;')
    • new_elem <- svg_elem('defs', style = 'color: black;')
    • new_elem <- stag$defs(style = 'color: black;')
  • As a sub-element of an existing document or element - the element is created, added to the parent document (or element) and returned.
    • doc <- SVGDocument$new(); new_elem <- doc$add('defs', style = 'color: black;')
    • doc <- SVGDocument$new(); new_elem <- doc$defs(style = 'color: black;')
    • elem <- SVGElement$new('xxx'); new_elem <- elem$add('defs', style = 'color: black;')
    • elem <- SVGElement$new('xxx'); new_elem <- elem$defs(style = 'color: black;')
• $add() creates an element and adds it to the parent (and returns it)
  • new_elem <- doc$add('defs')
• $append() appends the given elements as children
  • new_elem <- stag$defs(); doc$append(new_elem, ...)
• $new(name, ...), $update(...) and $add(name, ...) all accept ... where
  • named arguments are added as attributes of this node
  • unnamed argument are added as children of this node

Hello World SVG Example

This first example demonstrates:

• initialising a document of a certain size
• using methods on the SVGDocument object to create a circle
• using the $append() method to add the border rectangle
• creating the border rectangle using the stag$rect helper
• using the svg_prop helper (and autocomplete) to assist in remembering what the stroke width parameter is called
• adding text
• adding a rotation transformation to the text

#~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
# Create a document, add a border and a circle
#~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
doc <- SVGDocument$new(width = 400, height = 400)
doc$circle(cx=200, cy=200, r=100, fill = 'yellow')
doc$append(
  stag$rect(
    x = 0, y = 0, width = 400, height = 400, fill = 'none', 
    stroke = 'black', svg_prop$`stroke-width`$set(12)
  )
)

#~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
# Add some text to the document
#~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
mytext <- doc$text("Hello world", x= 160, y = 210, size = 30)

#~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
# Manipulate the text object to add some animation to it
#~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
mytext$animateTransform(
  attributeName = 'transform',
  type          = 'rotate',
  from          = "0 200 200",
  to            = "360 200 200",
  dur           = 5,
  repeatCount   = 'indefinite'
)

# doc$show()
doc$save("man/figures/README-helloworld.svg")

Parsing SVG text into a minisvg document

minisvg uses xml2 to parse SVGL text (or file) into a minisvg document.

my_svg <- "<svg><circle cx='10' cy='10' r='5'/></svg>"
doc <- minisvg::parse_svg_doc(my_svg)
doc$update(fill = "none")$
  add(name = 'rect')

print(doc)

   <?xml version="1.0" encoding="UTF-8"?>
   <svg width="400" height="400" viewBox="0 0 400 400" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" fill="none">
     <circle cx="10" cy="10" r="5" />
     <rect />
   </svg>

Example: 70s wallpaper is my jam!

This is a reproduction of a 70s wallpaper pattern.

This example demonstrates:

• Using svg_doc() as an alternative to SVGDocument$new()
• Creating a <defs><pattern> object and applying it to a rectangle

doc <- svg_doc(width = 800, height = 800) 
doc$rect(x=0, y=0, width="100%", height="100%", fill='#9B8A54')

pat  <- stag$defs()$pattern(id = 'motif', width=400, height=400, patternUnits = 'userSpaceOnUse')
patg <- pat$g()

patg$circle(cx=  0, cy=  0, r=138, fill= 'white')
patg$circle(cx=  0, cy=400, r=138, fill= 'white')
patg$circle(cx=400, cy=  0, r=138, fill= 'white')
patg$circle(cx=400, cy=400, r=138, fill= 'white')
patg$circle(cx=200, cy=200, r=138, fill= 'white')

patg$circle(cx=  0, cy=  0, r=90, fill= 'none', stroke = '#4a3322', stroke_width=35)
patg$circle(cx=  0, cy=400, r=90, fill= 'none', stroke = '#4a3322', stroke_width=35)
patg$circle(cx=400, cy=  0, r=90, fill= 'none', stroke = '#4a3322', stroke_width=35)
patg$circle(cx=400, cy=400, r=90, fill= 'none', stroke = '#4a3322', stroke_width=35)
patg$circle(cx=200, cy=200, r=90, fill= 'none', stroke = '#4a3322', stroke_width=35)

patg$circle(cx=200, cy=  0, r=90, fill= 'none', stroke = '#4a3322', stroke_width=10)
patg$circle(cx=  0, cy=200, r=90, fill= 'none', stroke = '#4a3322', stroke_width=10)
patg$circle(cx=400, cy=200, r=90, fill= 'none', stroke = '#4a3322', stroke_width=10)
patg$circle(cx=200, cy=400, r=90, fill= 'none', stroke = '#4a3322', stroke_width=10)

doc$append(pat)

doc$rect(x=0, y=0, width="100%", height="100%", fill=pat) 
# doc$show()
doc$save("man/figures/README-wallpaper.svg")

Creating the logo for this package

Note: Because github sanitizes SVG files it makes the SVG produced in this section unviewable. Instead, the SVG was first saved, and then rendered to PNG

#~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
# Building an SVG logo with an animated stripe
#~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
logo <- svg_doc(width = 200, height = 200)$
  update(width=NULL, height=NULL)

#~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
# Background White Rect
#~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
logo$rect(x=0, y=0, width="100%", height="100%", fill='white')

#~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
# Include an image of a Mini Cooper S
#~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
image <- stag$image(
  href = "https://coolbutuseless.github.io/2020/mini-cooper-s.gif",
  width = 130,
  x = 25, 
  y = 30
)

logo$append(image)

#~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
# Create a hexagon filled, and add it to the document
#~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
len     <- 95
angles  <- (seq(0, 360, 60) + 90) * pi/180
xs      <- round(len * cos(angles) + 100, 2)
ys      <- round(len * sin(angles) + 100, 2)
hex     <- stag$polygon(id = 'hex', xs = xs, ys = ys)
hex$update(stroke = '#223344', fill_opacity=0, stroke_width = 3)
logo$append(hex)


#~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
# Text label
#~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
text <- stag$text(
  "svg",
  class = "mainfont",
  x = 72, y = 160
)

logo$append(text)


#~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
# Load CSS for google font and specify styling for 'mainfont'
#~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
logo$add_css_url("https://fonts.googleapis.com/css?family=Abril%20Fatface")
logo$add_css("
.mainfont {
  font-size: 40px;
  font-family: 'Abril Fatface', sans-serif;
  fill: #223344;
}
")

#~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
# output
#~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
# logo$show()
logo$save("man/figures/logo.svg")

References

• The minisvg R6 interface is inspired by some of the javascript SVG builders
  • SVG.js
  • Snap SVG
• Mozilla Developer Network SVG docs