Klayout svg export

svgexport.rb

class SVGWriter

  # Based off https://www.klayout.de/forum/discussion/873/working-with-dxfs
  def initialize(file)
    @file = File.open(file, "w")
    @shift = 0
  end

  def start(w, h)
    @file.puts(<<"END")
<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<svg
   xmlns:svg="http://www.w3.org/2000/svg"
   xmlns="http://www.w3.org/2000/svg"
   xmlns:xlink="http://www.w3.org/1999/xlink"
   width="#{'%.12g'%w}mm"
   height="#{'%.12g'%h}mm"
   viewBox="0 0 #{'%.12g'%w} #{'%.12g'%h}"
   version="1.1">
END
end

  def layerPattern(idx, color, stipple, name)
    @shift= @shift+0.1 # TODO: make this better by only shifting the same
    if @shift > 0.6
      @shift = 0
      end
    color = '%06x' % (color & 0xffffff)
    linePattern = '<line x1="0" y1="0" x2="0" y2="10" style="stroke-width:0.1" />'
    angle = 0
    scale = 2
    pwidth=0.5
    pheight=0.5
    case stipple
      when 0 # Full
        pattern = '<rect x="0" y="0" width="0.5" height="0.5" style="fill:#'"#{color}"';stroke:none" />'
      when 1 # empty
        pattern = ''
      when 2 # tiny squares close one to another
        pwidth = 0.25
        pheight = 0.25
        pattern = '<rect x="0" y="0" width="0.125" height="0.125" style="fill:#'"#{color}"';stroke:none" />\n<rect x="0.125" y="0.125" width="0.125" height="0.125" style="fill:#'"#{color}"';stroke:none" />\n'
      when 3 # tiny square, but spaced out
        pattern = '<rect x="0.125" y="0" width="0.125" height="0.125" style="fill:#'"#{color}"';stroke:none" />'
      when 5 # dash 1
        angle = 135
        scale = 2
        pattern = linePattern
      when 9 # dash 2
        angle = 45
        scale = 2
        pattern = linePattern
      when 13
        pattern = '<line x1="0" y1="0" x2="0" y2="10" style="stroke-width:0.1" />\n<line x1="10" y1="0" x2="0" y2="0" style="stroke-width:0.1" />'
        angle = 45
      else
        print("dither pattern #{stipple} not found\n")
        pattern = ''
      end
    @file.puts(<<"END")
       <!-- #{idx} / #{name} -->
    <pattern
       id="pattern-layer-#{idx}"
       width="#{pwidth}"
       height="#{pheight}"
       stroke="##{color}"
       stroke-linecap="square"
       patternTransform="rotate(#{angle}) scale(#{scale}) translate(#{@shift})"
       patternUnits="userSpaceOnUse">
            #{pattern}
    </pattern>
END
  end
  
  def prepareLayers(layers)
    @file.puts("<defs>\n")
    layers.each do |lp|
      idx = lp.layer_index
      col = lp.fill_color
      stip = lp.dither_pattern
      layerPattern(idx, col, stip, lp.name)
    end
    @file.puts("</defs>\n")
  end

  def finish
    @file.puts("</svg>")
    @file.close
  end

  def begin_layer(lp)
    @stroke_color = lp.frame_color
    @fill_color = lp.fill_color
    # see https://www.klayout.de/doc-qt5/code/class_LayerProperties.html#method24
    @stipple = lp.eff_dither_pattern
    @index = lp.layer_index
    @name = lp.name
    @file.puts("<g>")
  end

  def end_layer(lp)
    @file.puts("</g>")
  end

  def polygon(p, dbu)

    pts = []
    p.each_point_hull { |pt| pts << ("%.12g %.12g" % [pt.x * dbu, pt.y * dbu]) }
    ctrs = [ "M " + pts.join(" L ") + " z" ]
    p.holes.times do |h|
      pts = []
      p.each_point_hole(h) { |pt| pts << ("%.12g %.12g" % [pt.x * dbu, pt.y * dbu]) }
      ctrs << [ "M " + pts.join(" L ") + " z" ]
    end
    d = ctrs.join(" ")

    @file.puts("  <path style=\"fill:url(#pattern-layer-#{@index});stroke-width:0.2;stroke:##{'%06x' % (@stroke_color & 0xffffff)}\"")
    @file.puts("   d=\"#{d}\"/>")

  end

end

lv = RBA::LayoutView::current 
lv || raise("No view opened")

cv = RBA::CellView::active 
cv || raise("No layout loaded")
ly = cv.layout 
cell = cv.cell

out = RBA::FileDialog::ask_save_file_name("Chose SVG file to write", ".", "SVG files (*.svg);;All files (*)")
if out

  layers = []

  li = lv.begin_layers
  while !li.at_end?
    if li.current.visible? && !li.current.has_children? && li.current.layer_index >= 0
      layers << li.current
    end
    li.next
  end

  bbox = cell.bbox
  dbu = ly.dbu*10

  writer = SVGWriter::new(out)
  writer.start(bbox.width * dbu, bbox.height * dbu)

  canvas_tr = RBA::CplxTrans::new(1.0, 0.0, true, RBA::DPoint::new(-bbox.left, bbox.top))

  writer.prepareLayers(layers)

  layers.each do |lp|
    writer.begin_layer(lp)
    si = cell.begin_shapes_rec(lp.layer_index)
    while !si.at_end?
      s = si.shape   
      if s.is_path? || s.is_box? || s.is_polygon?
        writer.polygon(s.polygon.transformed(canvas_tr * si.trans), dbu)
      end
      si.next
    end
    writer.end_layer(lp)
  end

  writer.finish

end

I'll create an actual repo or plugin a bit latter. I still have a lot of stipples to match, border patterns, etc. The code is quite hackish, lacks testing, and the layer shift is very hacky too. I need to make sure it works at different zoom levels.

Bear with me, it's my first time writing ruby :)