Merging in svg back end work. All but save_doc is done.

samples/backend-config.yml

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+# To configure for using SVG as our backend, we need to set this option
+# This will create a series of SVG files that get updated with Squib command
+backend: svg
+# They are auto-saved with this background
+prefix: backend_

samples/backend.rb

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+require 'squib'
+
+# Our SVGs are auto-saved after each step using the configuration parameters
+Squib::Deck.new(config: 'backend-config.yml') do
+
+  # These are all supported by the SVG backend
+  background color: :white
+  text       str: "Hello, world!", y: 500, width: 825, font: 'Sans bold 72', align: :center
+  rect       x: 10, y: 10, width: 20, height: 20
+  circle     x: 40, y: 40, radius: 25
+  triangle   x1: 50, y1: 15, x2: 60, y2: 25, x3: 75, y3: 25
+  line       x1: 100, y1: 620, x2: 720, y2: 620, stroke_width: 15.0
+  svg        file: 'spanner.svg', x: 100, y: 20
+  svg        file: 'glass-heart.svg', x: 100, y: 200, width: 100, height: 100, mask: :sangria
+  png        file: 'shiny-purse.png', x: 250, y: 20
+  png        file: 'shiny-purse.png', x: 250, y: 200, mask: :red
+
+  # We can still rasterize whenever we want
+  save_png prefix: 'backend_'
+
+  # And our PDFs will be vectorized.
+  save_pdf file: 'backend_vectorized.pdf'
+
+  # This one is, unfortunately, not possible with svg back ends
+  #   Cairo lacks a perspective transform (currently), so we have to
+  #   use a striping method, which assumes raster. Fortunately, Cairo
+  #   has perspective transforms on its roadmap,
+  #   so perhaps this can be done someday with all vectors.
+  #
+  # showcase file: 'showcase.png', fill_color: 'white'
+
+end

samples/cairopdfsvg.rb

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+require 'cairo'
+require 'pango'
+require 'rsvg2'
+
+svg = RSVG::Handle.new_from_file('spanner.svg')
+pdf = Cairo::PDFSurface.new("_output/blahblah2.pdf",8.5*300, 11*300)
+cxt = Cairo::Context.new(pdf)
+cxt.translate(1900,500)
+cxt.render_rsvg_handle(svg, nil)
+cxt.translate(-500,0)
+cxt.render_rsvg_handle(svg, nil)