Class: RubyVor::Visualizer

Inherits:
Object
  • Object
show all
Includes:
LibXML
Defined in:
lib/ruby_vor/visualizer.rb

Constant Summary collapse

COLORS =
%w{black red blue lime gray yellow purple orange pink}

Class Method Summary collapse

Class Method Details

.make_svg(computation, opts = {}) ⇒ Object



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# File 'lib/ruby_vor/visualizer.rb', line 10

def self.make_svg(computation, opts={})
  @opts = opts = {
    :name            => 'vddt.svg',
    :triangulation   => true,
    :voronoi_diagram => false,
    :mst             => false,
    :cbd             => false,
  }.merge(opts)

  line_colors = COLORS.clone
  
  doc = XML::Document.new()
  
  doc.root = XML::Node.new('svg')
  doc.root['xmlns'] = 'http://www.w3.org/2000/svg'
  doc.root['xml:space'] = 'preserve'

  max_x = 0
  min_x = Float::MAX
  max_y = 0
  min_y = Float::MAX
  pmax_x = 0
  pmin_x = Float::MAX
  pmax_y = 0
  pmin_y = Float::MAX

  computation.points.each do |point|
    max_x = point.x if point.x > max_x
    min_x = point.x if point.x < min_x
    max_y = point.y if point.y > max_y
    min_y = point.y if point.y < min_y
    pmax_x = point.x if point.x > pmax_x
    pmin_x = point.x if point.x < pmin_x
    pmax_y = point.y if point.y > pmax_y
    pmin_y = point.y if point.y < pmin_y
  end

  if opts[:voronoi_diagram]
    computation.voronoi_diagram_raw.each do |item|
      if item.first == :v
        max_x = item[1] if item[1] > max_x
        min_x = item[1] if item[1] < min_x
        max_y = item[2] if item[2] > max_y
        min_y = item[2] if item[2] < min_y
      end
    end
  end
  
  opts[:offset_x] = -1.0 * min_x + 20
  opts[:offset_y] = -1.0 * min_y + 20

  if opts[:triangulation]
    # Draw in the triangulation
    color = line_colors.shift
    computation.delaunay_triangulation_raw.each do |triplet|
      for i in 0..2
        line = line_from_points(computation.points[triplet[i % 2 + 1]], computation.points[triplet[i & 6]])
        line['style'] = "stroke:#{color};stroke-width:1;"            
        doc.root << line
      end
    end
  end

  if opts[:mst]
    color = line_colors.shift
    computation.minimum_spanning_tree.each do |edge, weight|
      line = line_from_points(computation.points[edge[0]], computation.points[edge[1]])
      line['style'] = "stroke:#{color};stroke-width:1;"
      doc.root << line
    end
  end

  if opts[:cbd]
    mst = computation.minimum_spanning_tree
    
    computation.cluster_by_distance(opts[:cbd]).each do |cluster|
      
      color = new_color
      min_dist = Float::MAX
      set_min  = false
      cluster.each do |a|
        cluster.each do |b|
          next if a == b
          k = a < b ? [a,b] : [b,a]
          next unless mst.has_key?(k)

          if mst[k] < min_dist
            min_dist = mst[k]
            set_min = true
          end
        end
      end

      min_dist = 10 unless set_min


      cluster.each do |v|
        node = circle_from_point(computation.points[v])
        node['r'] = (min_dist + 10).to_s
        node['style'] = "fill:#{color};stroke:#{color};"
        node['opacity'] = '0.4'

        doc.root << node
      end

    end
  end

  if opts[:voronoi_diagram]
    voronoi_vertices = []
    draw_lines = []
    draw_points = []
    line_functions = []
    
    xcut = (pmax_x + pmin_x) / 2.0
    ycut = (pmax_y + pmin_y) / 2.0

    color = line_colors.shift

    computation.voronoi_diagram_raw.each do |item|
      case item.first
      when :v
        # Draw a voronoi vertex
        v = RubyVor::Point.new(item[1], item[2])
        voronoi_vertices.push(v)
        node = circle_from_point(v)
        node['fill'] = 'red'
        node['r'] = '2'
        node['stroke'] = 'black'
        node['stroke-width'] = '1'

        draw_points << node
      when :l
        # :l a b c  --> ax + by = c
        a = item[1]
        b = item[2]
        c = item[3]
        line_functions.push({ :y => lambda{|x| (c - a * x) / b},
                              :x => lambda{|y| (c - b * y) / a} })
      when :e
        if item[2] == -1 || item[3] == -1
          from_vertex = voronoi_vertices[item[2] == -1 ? item[3] : item[2]]
          
          next if from_vertex < RubyVor::Point.new(0,0)              

          if item[2] == -1
            inf_vertex = RubyVor::Point.new(0, line_functions[item[1]][:y][0])
          else
            inf_vertex = RubyVor::Point.new(max_x, line_functions[item[1]][:y][max_x])
          end

          line = line_from_points(from_vertex, inf_vertex)
        else
          line = line_from_points(voronoi_vertices[item[2]], voronoi_vertices[item[3]])
        end

        line['style'] = "stroke:#{color};stroke-width:1;"
        draw_lines << line

      end
    end

    draw_lines.each {|l| doc.root << l}
    draw_points.each {|p| doc.root << p}
  end
  
  # Now draw in nodes
  computation.points.each do |point|
    node = circle_from_point(point)
    node['fill'] = 'lime'

    doc.root << node
  end

  doc.root['width']  = (max_x + opts[:offset_x] + 50).to_s
  doc.root['height'] = (max_y + opts[:offset_y] + 50).to_s
  
  doc.save(opts[:name] || 'vddt.svg')
end