#!/usr/bin/ruby

# Draw square, hexagonal, and triangle grid illustrations
# amitp@cs.stanford.edu
# 8 Jan 2006

SQRT_3_2 = Math.sqrt(3)/2 # Used in triangle and hexagon math

class Shape
  def slope(edge)
    v1, v2 = endpoints(edge)
    x1, y1 = vertex_to_world(1.0, v1)
    x2, y2 = vertex_to_world(1.0, v2)
    distance = Math.sqrt((x1-x2)**2 + (y1-y2)**2)
    [(x2-x1)/distance, (y2-y1)/distance]
  end
end

class Triangle < Shape
  def faces(m, n)
    [[m, n, :L], [m, n, :R]]
  end
  
  def corners(face)
    m, n, side = face
    case side
    when :L
      [[m, n+1], [m+1, n], [m, n]]
    when :R
      [[m+1, n+1], [m+1, n], [m, n+1]]
    end
  end

  def endpoints(edge)
    p, q, side = edge
    case side
    when :W
      [[p, q+1], [p, q]]
    when :E
      [[p+1, q], [p, q+1]]
    when :S
      [[p+1, q], [p, q]]
    end
  end
  
  def vertex_to_world(scale, corner)
    i, j = corner
    x = (i*1.0*scale + j*0.5*scale)/SQRT_3_2
    y = j*scale
    [x, y]
  end
end

class Square < Shape
  def faces(m, n)
    [[m, n]]
  end
  
  def corners(face)
    m, n = face
    [[m+1, n+1], [m+1, n], [m, n], [m, n+1]]
  end

  def endpoints(edge)
    p, q, side = edge
    case side
    when :S
      [[p+1, q], [p, q]]
    when :W
      [[p, q+1], [p, q]]
    end
  end
  
  def vertex_to_world(scale, corner)
    i, j = corner
    [i*scale, j*scale]
  end
end

class Rhombus < Square
  def vertex_to_world(scale, corner)
    i, j = corner
    x = (i*1.0*scale + j*0.5*scale)/SQRT_3_2
    y = (j+1)*scale
    [x, y]
  end
end

class Hexagon < Shape
  def initialize(edge_bend=1.0)
    @edge_bend = edge_bend # 0.0 for squares, 1.0 for hexagons
  end
  
  def faces(m, n)
    [[m, n]]
  end
  
  def corners(face)
    m, n = face
    [[m+1, n, :L],
      [m, n, :R],
      [m+1, n-1, :L],
      [m-1, n, :R],
      [m, n, :L],
      [m-1, n+1, :R]]
  end

  def endpoints(edge)
    p, q, side = edge
    case side
    when :N
      [[p+1, q, :L], [p-1, q+1, :R]]
    when :E
      [[p, q, :R], [p+1, q, :L]]
    when :W
      [[p-1, q+1, :R], [p, q, :L]]
    end
  end
  
  def vertex_to_world(scale, corner)
    i, j, side = corner
    x = scale*SQRT_3_2*i
    y = scale*1.0*0.5*(j*2 + i)
    if side == :R
      x = x + scale*(0.75+0.25*@edge_bend)/SQRT_3_2
    end
    [x, y]
  end
end

class Canvas
  attr :width
  attr :height

  def initialize(width, height, grid)
    @width = width
    @height = height
    @grid = grid
  end

  def transform(x, y)
    x = 10 + x
    y = @height - 10 - y
    [x, y]
  end
  
  def to_svg
    output = ''
    
    output << '<?xml version="1.0" encoding="UTF-8" ?>'
    output << '<svg xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink"'
    output << " width=\"#{@width}\" height=\"#{@height}\">"
    output << %{
  <defs>
    <linearGradient id="gradient" x1="0%" y1="0%" x2="100%" y2="40%">
      <stop offset="10%" stop-color="lightgray" stop-opacity="1.0" />
      <stop offset="90%" stop-color="white" stop-opacity="1.0" />
    </linearGradient>
    <linearGradient id="graygradient" x1="0%" y1="0%" x2="130%" y2="40%">
      <stop offset="20%" stop-color="darkgray" />
      <stop offset="90%" stop-color="lightgray" />
    </linearGradient>
    <linearGradient id="redgradient" x1="0%" y1="0%" x2="130%" y2="60%">
      <stop offset="20%" stop-color="pink" />
      <stop offset="90%" stop-color="red" />
    </linearGradient>
    <linearGradient id="purplegradient" x1="0%" y1="0%" x2="130%" y2="60%">
      <stop offset="20%" stop-color="#dcf" />
      <stop offset="90%" stop-color="#96a" />
    </linearGradient>
  </defs>
  }
    
    output << @grid.to_svg(self)
    
    output << '</svg>'
    
    output
  end
  
end

class Grid
  attr_accessor :highlight_faces
  attr_accessor :highlight_edges
  attr_accessor :highlight_vertices
  attr_accessor :annotate_faces
  attr_accessor :annotate_edges
  attr_accessor :annotate_vertices
  
  def initialize(shape, scale)
    @shape = shape
    @scale = scale
    @faces = []
    
    @highlight_faces = []
    @highlight_edges = []
    @highlight_vertices = []
    @annotate_faces = {}
    @annotate_edges = {}
    @annotate_vertices = {}
  end

  def add_faces(*faces)
    faces.each { |face|
      @faces << face
    }
  end
  
  def add_facearray(m_list, n_list)
    m_list.each { |m|
      n_list.each { |n|
        @shape.faces(m, n).each { |face| 
          add_faces(face)
        }
      }
    }
  end

  def vertex_midpoint(vertices)
    # Calculate the centroid of a set of vertices
    total_x, total_y, count = 0, 0, 0
    vertices.each { |vertex|
      x, y = @shape.vertex_to_world(@scale, vertex)
      total_x += x
      total_y += y
      count += 1
    }
    x = (total_x / count)
    y = (total_y / count)
    [x, y]
  end
  
  def to_svg(canvas)
    output = ''

    output << '<g fill="url(#gradient)">'
    @faces.each { |face|
      if @highlight_faces.include?(face)
        color = @highlight_faces[face]
        output << "<g fill=\"url(##{color}gradient)\">"
      end
      
      output << '<polygon stroke="black" stroke-width="1"'
      output << ' points="'
      
      @shape.corners(face).each { |corner|
        x, y = @shape.vertex_to_world(@scale, corner)
        x, y = canvas.transform(x, y)
        
        output << "#{x},#{y} "
      }
      
      output << '" />'
      
      if @highlight_faces.include?(face)
        output << '</g>'
      end
    }
    output << '</g>'

    @highlight_edges.each { |edge, color|
      c = 0.2 # cut off this much from each end
      
      v1, v2 = @shape.endpoints(edge)
      x1, y1 = @shape.vertex_to_world(@scale, v1)
      x1, y1 = canvas.transform(x1, y1)
      x2, y2 = @shape.vertex_to_world(@scale, v2)
      x2, y2 = canvas.transform(x2, y2)

      dx, dy = x2-x1, y2-y1
      
      output << "<line x1=\"#{x1+c*dx}\" y1=\"#{y1+c*dy}\" x2=\"#{x2-c*dx}\" y2=\"#{y2-c*dy}\" stroke=\"#{color}\" stroke-width=\"4\" />"
    }
    
    @highlight_vertices.each { |vertex, color|
      x, y = @shape.vertex_to_world(@scale, vertex)
      x, y = canvas.transform(x, y)
      output << "<circle cx=\"#{x}\" cy=\"#{y}\" r=\"5\" fill=\"#{color}\" />"
    }

    @annotate_faces.each { |face, text|
      x, y = vertex_midpoint(@shape.corners(face))
      x, y = canvas.transform(x, y)
      output << "<text text-anchor=\"middle\" x=\"#{x}\" y=\"#{y}\">#{text}</text>"
    }
    
    @annotate_edges.each { |edge, text|
      x, y = vertex_midpoint(@shape.endpoints(edge))
      
      # We want to nudge this to the right to get the text off of the
      # edge.  Get the slope, rotate it 90 degrees, force it to not
      # point left (by reflecting if needed), and then nudge.  TODO:
      # ideally we'd also nudge towards the center of the face that
      # the text lies in.
      dx, dy = @shape.slope(edge)
      dx, dy = dy, -dx # rotate 90 degrees
      if dx < 0
        dx, dy = -dx, -dy # reflect if we're pointing left
      end
      x += dx*@scale/15
      y += dy*@scale/15

      align = ""
      if dx == 0
        # Special case: if the edge is horizontal, center the text
        # along the edge.  TODO: can we extend this to other cases?
        align = " text-anchor=\"middle\""
      end
      
      x, y = canvas.transform(x, y)
      output << "<text#{align} x=\"#{x}\" y=\"#{y}\">#{text}</text>"
    }
    
    @annotate_vertices.each { |vertex, text|
      total_x, total_y, count = 0
      x, y = @shape.vertex_to_world(@scale, vertex)

      # We will nudge this up and to the right
      x += @scale/10
      y += @scale/20
      
      x, y = canvas.transform(x, y)
      output << "<text x=\"#{x}\" y=\"#{y}\">#{text}</text>"
    }
    
    output
  end
end

class Diagrams
  def shape_grid(shape, max)
    grid = Grid.new(shape, 20)
    grid.add_facearray(0...max, 0...max)
    h = 5*max/9
    grid.highlight_faces = { [h, h] => "red", [h, h, :L] => "red" }
    canvas = Canvas.new(400, 300, grid)
    canvas.to_svg
  end
  
  def square_grid(max=9)
    shape_grid(Square.new, max)
  end

  def rhombus_grid(max=9)
    shape_grid(Rhombus.new, max)
  end
  
  def hexagon_grid(max=9, edge_bend=1.0)
    shape_grid(Hexagon.new(edge_bend), max)
  end

  def triangle_grid(max=9)
    shape_grid(Triangle.new, max)
  end

  def triangle_grid_small
    # We want to highlight two triangles to show how they are related
    # to the rhombus
    grid = Grid.new(Triangle.new, 20)
    grid.add_facearray(0...5, 0...5)
    grid.highlight_faces = { [2, 2, :L] => "red", [2, 2, :R] => "red" }
    canvas = Canvas.new(400, 300, grid)
    canvas.to_svg
  end

  ####################
  def square_grid_face_coordinates
    grid = Grid.new(Square.new, 70)
    grid.add_facearray(0...3, 0...3)
    grid.highlight_faces = {
      [1, 1] => "red",
    }
    grid.annotate_faces = {
      [0, 0] => "0,0",
      [1, 0] => "1,0",
      [0, 1] => "0,1",
      [1, 1] => "1,1",
      [0, 2] => "0,2",
      [2, 0] => "2,0",
      [1, 2] => "1,2",
      [2, 1] => "2,1",
      [2, 2] => "2,2",
    }
    canvas = Canvas.new(400, 300, grid)
    canvas.to_svg
  end
  
  def square_grid_vertex_coordinates
    grid = Grid.new(Square.new, 70)
    grid.add_facearray(0...3, 0...3)
    grid.highlight_faces = {
      [1, 1] => "red",
      [2, 1] => "gray",
      [1, 2] => "gray",
      [2, 2] => "gray",
    }
    grid.highlight_vertices = {
      [1, 1] => "red",
      [2, 1] => "black",
      [1, 2] => "black",
      [2, 2] => "black",
    }
    grid.annotate_vertices = {
      [1, 1] => "1,1",
      [2, 1] => "2,1",
      [1, 2] => "1,2",
      [2, 2] => "2,2",
    }
    canvas = Canvas.new(400, 300, grid)
    canvas.to_svg
  end
  
  def square_grid_edge_coordinates
    grid = Grid.new(Square.new, 70)
    grid.add_facearray(0...3, 0...3)
    grid.highlight_faces = {
      [1, 1] => "red",
      [1, 2] => "gray",
      [2, 1] => "gray",
    }
    grid.highlight_edges = {
      [1, 1, :S] => "red",
      [1, 1, :W] => "red",
      [1, 2, :S] => "black",
      [2, 1, :W] => "black",
    }
    grid.annotate_edges = {
      [1, 1, :S] => "1,1 S",
      [1, 1, :W] => "1,1 W",
      [1, 2, :S] => "1,2 S",
      [2, 1, :W] => "2,1 W",
    }
    canvas = Canvas.new(400, 300, grid)
    canvas.to_svg
  end

  ####################
  def square_rel_face_face
    grid = Grid.new(Square.new, 50)
    grid.add_facearray(0...3, 0...3)
    grid.highlight_faces = {
      [1, 1] => "gray",
      [1, 0] => "red",
      [2, 1] => "red",
      [1, 2] => "red",
      [0, 1] => "red",
    }
    grid.annotate_faces = {
      [1, 1] => "A",
      [1, 0] => "B",
      [2, 1] => "B",
      [1, 2] => "B",
      [0, 1] => "B",
    }

    canvas = Canvas.new(400, 300, grid)
    canvas.to_svg
  end
  
  def square_rel_face_edge
    grid = Grid.new(Square.new, 50)
    grid.add_facearray(0...3, 0...3)
    grid.highlight_faces = {
      [1, 1] => "gray",
    }
    grid.highlight_edges = {
      [1, 1, :W] => "red",
      [1, 1, :S] => "red",
      [2, 1, :W] => "red",
      [1, 2, :S] => "red",
    }
    grid.annotate_faces = {
      [1, 1] => "A",
      [1, 0] => "B",
      [2, 1] => "B",
      [1, 2] => "B",
      [0, 1] => "B",
    }

    canvas = Canvas.new(400, 300, grid)
    canvas.to_svg
  end
  
  def square_rel_face_vertex
    grid = Grid.new(Square.new, 50)
    grid.add_facearray(0...3, 0...3)
    grid.highlight_faces = {
      [1, 1] => "gray",
    }
    grid.highlight_vertices = {
      [1, 1] => "red",
      [1, 2] => "red",
      [2, 1] => "red",
      [2, 2] => "red",
    }
    grid.annotate_faces = {
      [1, 1] => "A",
      [0, 0] => "B",
      [2, 0] => "B",
      [0, 2] => "B",
      [2, 2] => "B",
    }

    canvas = Canvas.new(400, 300, grid)
    canvas.to_svg
  end
  
  def square_rel_edge_face
    grid = Grid.new(Square.new, 50)
    grid.add_facearray(0...3, 0...2)
    grid.highlight_edges = {
      [1, 1, :S] => "black",
    }
    grid.highlight_faces = {
      [1, 1] => "red",
      [1, 0] => "red",
    }
    grid.annotate_edges = {
      [1, 1, :S] => "A",
    }
    grid.annotate_faces = {
      [1, 1] => "B",
      [1, 0] => "B",
    }

    canvas = Canvas.new(400, 300, grid)
    canvas.to_svg
  end
  
  def square_rel_edge_edge
    grid = Grid.new(Square.new, 50)
    grid.add_facearray(0...3, 0...2)
    grid.highlight_edges = {
      [1, 1, :S] => "black",
      [0, 1, :S] => "red",
      [2, 1, :S] => "red",
    }
    grid.annotate_edges = {
      [1, 1, :S] => "A",
      [0, 1, :S] => "B",
      [2, 1, :S] => "B",
    }

    canvas = Canvas.new(400, 300, grid)
    canvas.to_svg
  end
  
  def square_rel_edge_vertex
    grid = Grid.new(Square.new, 50)
    grid.add_facearray(0...3, 0...2)
    grid.highlight_edges = {
      [1, 1, :S] => "black",
    }
    grid.highlight_vertices = {
      [1, 1] => "red",
      [2, 1] => "red",
    }
    grid.annotate_edges = {
      [1, 1, :S] => "A",
      [0, 1, :S] => "B",
      [2, 1, :S] => "B",
    }

    canvas = Canvas.new(400, 300, grid)
    canvas.to_svg
  end
  
  def square_rel_vertex_face
    grid = Grid.new(Square.new, 50)
    grid.add_facearray(0...2, 0...2)
    grid.highlight_vertices = {
      [1, 1] => "black",
    }
    grid.highlight_faces = {
      [0, 0] => "red",
      [1, 1] => "red",
      [0, 1] => "red",
      [1, 0] => "red",
    }
    grid.annotate_vertices = {
      [1, 1] => "A",
    }
    grid.annotate_faces = {
      [0, 0] => "B",
      [1, 1] => "B",
      [0, 1] => "B",
      [1, 0] => "B",
    }

    canvas = Canvas.new(400, 300, grid)
    canvas.to_svg
  end
  
  def square_rel_vertex_edge
    grid = Grid.new(Square.new, 50)
    grid.add_facearray(0...2, 0...2)
    grid.highlight_vertices = {
      [1, 1] => "black",
    }
    grid.highlight_edges = {
      [1, 0, :W] => "red",
      [1, 1, :W] => "red",
      [0, 1, :S] => "red",
      [1, 1, :S] => "red",
    }
    grid.annotate_vertices = {
      [1, 1] => "A",
    }
    grid.annotate_edges = {
      [1, 0, :W] => "B",
      [1, 1, :W] => "B",
      [0, 1, :S] => "B",
      [1, 1, :S] => "B",
    }

    canvas = Canvas.new(400, 300, grid)
    canvas.to_svg
  end
  
  def square_rel_vertex_vertex
    grid = Grid.new(Square.new, 50)
    grid.add_facearray(0...2, 0...2)
    grid.highlight_vertices = {
      [1, 1] => "black",
      [0, 1] => "red",
      [2, 1] => "red",
      [1, 0] => "red",
      [1, 2] => "red",
    }
    grid.annotate_vertices = {
      [1, 1] => "A",
      [0, 1] => "B",
      [2, 1] => "B",
      [1, 0] => "B",
      [1, 2] => "B",
    }

    canvas = Canvas.new(400, 300, grid)
    canvas.to_svg
  end
  
  ####################
  def hexagon_grid_face_coordinates
    grid = Grid.new(Hexagon.new, 70)
    grid.add_facearray(0...3, 0...3)
    grid.highlight_faces = {
      [1, 1] => "red",
    }
    grid.annotate_faces = {
      [0, 0] => "0,0",
      [1, 0] => "1,0",
      [0, 1] => "0,1",
      [1, 1] => "1,1",
      [0, 2] => "0,2",
      [2, 0] => "2,0",
      [1, 2] => "1,2",
      [2, 1] => "2,1",
      [2, 2] => "2,2",
    }
    canvas = Canvas.new(400, 300, grid)
    canvas.to_svg
  end
  
  def hexagon_grid_vertex_coordinates
    grid = Grid.new(Hexagon.new, 70)
    grid.add_facearray(0...3, 0...3)
    grid.highlight_faces = {
      [1, 1] => "red",
      [2, 1] => "gray",
      [2, 0] => "gray",
      [0, 2] => "gray",
      [0, 1] => "gray",
    }
    grid.highlight_vertices = {
      [1, 1, :L] => "red",
      [1, 1, :R] => "red",
      [2, 1, :L] => "black",
      [2, 0, :L] => "black",
      [0, 2, :R] => "black",
      [0, 1, :R] => "black",
    }
    grid.annotate_vertices = {
      [1, 1, :L] => "1,1 L",
      [1, 1, :R] => "1,1 R",
      [2, 1, :L] => "2,1 L",
      [2, 0, :L] => "2,0 L",
      [0, 2, :R] => "0,2 R",
      [0, 1, :R] => "0,1 R",
    }
    canvas = Canvas.new(400, 300, grid)
    canvas.to_svg
  end
  
  def hexagon_grid_edge_coordinates
    grid = Grid.new(Hexagon.new, 70)
    grid.add_facearray(0...3, 0...3)
    grid.highlight_faces = {
      [1, 1] => "red",
      [0, 1] => "gray",
      [1, 0] => "gray",
      [2, 0] => "gray",
    }
    grid.highlight_edges = {
      [1, 1, :N] => "red",
      [1, 1, :W] => "red",
      [1, 1, :E] => "red",
      [0, 1, :E] => "black",
      [1, 0, :N] => "black",
      [2, 0, :W] => "black",
    }
    grid.annotate_edges = {
      [1, 1, :N] => "1,1 N",
      [1, 1, :W] => "1,1 W",
      [1, 1, :E] => "1,1 E",
      [0, 1, :E] => "0,1 E",
      [1, 0, :N] => "1,0 N",
      [2, 0, :W] => "2,0 W",
    }
    canvas = Canvas.new(400, 300, grid)
    canvas.to_svg
  end

  def hex_grid_metrics
    grid = Grid.new(Hexagon.new, 100)
    grid.add_facearray(0..1, 0..1)
    canvas = Canvas.new(400, 300, grid)
    # TODO: this does not include the lines we want; I'm adding them
    # manually in Inkscape. :-(
    canvas.to_svg
  end
  
  ####################
  def triangle_grid_face_coordinates
    grid = Grid.new(Triangle.new, 70)
    grid.add_facearray(0...3, 0...3)
    grid.highlight_faces = {
      [1, 1, :L] => "red",
      [1, 1, :R] => "red",
    }
    grid.annotate_faces = {
      [0, 0, :L] => "0,0 L",
      [1, 0, :L] => "1,0 L",
      [0, 1, :L] => "0,1 L",
      [1, 1, :L] => "1,1 L",
      [0, 2, :L] => "0,2 L",
      [2, 0, :L] => "2,0 L",
      [1, 2, :L] => "1,2 L",
      [2, 1, :L] => "2,1 L",
      [2, 2, :L] => "2,2 L",
      [0, 0, :R] => "0,0 R",
      [1, 0, :R] => "1,0 R",
      [0, 1, :R] => "0,1 R",
      [1, 1, :R] => "1,1 R",
      [0, 2, :R] => "0,2 R",
      [2, 0, :R] => "2,0 R",
      [1, 2, :R] => "1,2 R",
      [2, 1, :R] => "2,1 R",
      [2, 2, :R] => "2,2 R",
    }
    canvas = Canvas.new(400, 300, grid)
    canvas.to_svg
  end
  
  def triangle_grid_vertex_coordinates
    grid = Grid.new(Triangle.new, 70)
    grid.add_facearray(0...3, 0...3)
    grid.highlight_faces = {
      [1, 1, :L] => "red",
      [1, 1, :R] => "red",
      [2, 1, :L] => "gray",
      [2, 1, :R] => "gray",
      [1, 2, :L] => "gray",
      [1, 2, :R] => "gray",
      [2, 2, :L] => "gray",
      [2, 2, :R] => "gray",
    }
    grid.highlight_vertices = {
      [1, 1] => "red",
      [2, 1] => "black",
      [1, 2] => "black",
      [2, 2] => "black",
    }
    grid.annotate_vertices = {
      [1, 1] => "1,1",
      [2, 1] => "2,1",
      [1, 2] => "1,2",
      [2, 2] => "2,2",
    }
    canvas = Canvas.new(400, 300, grid)
    canvas.to_svg
  end
  
  def triangle_grid_edge_coordinates
    grid = Grid.new(Triangle.new, 70)
    grid.add_facearray(0...3, 0...3)
    grid.highlight_faces = {
      [1, 1, :L] => "red",
      [1, 1, :R] => "red",
      [1, 2, :L] => "gray",
      [2, 1, :L] => "gray",
    }
    grid.highlight_edges = {
      [1, 1, :S] => "red",
      [1, 1, :W] => "red",
      [1, 1, :E] => "red",
      [1, 2, :S] => "black",
      [2, 1, :W] => "black",
    }
    grid.annotate_edges = {
      [1, 1, :S] => "1,1 S",
      [1, 1, :W] => "1,1 W",
      [1, 1, :E] => "1,1 E",
      [1, 2, :S] => "1,2 S",
      [2, 1, :W] => "2,1 W",
    }
    canvas = Canvas.new(400, 300, grid)
    canvas.to_svg
  end

  ####################
  def grid_parts
    grid = Grid.new(Triangle.new, 86)
    grid.add_faces([0, 0, :R], [2, 1, :L])
    grid.add_facearray(1...3, 0...1)
    grid.add_facearray(0...2, 1...2)
    grid.highlight_faces = { [1, 0, :L] => "red" }
    grid.highlight_edges = { [0, 1, :E] => "red" }
    grid.highlight_vertices = { [2, 1] => "red" }
    grid.annotate_faces = { [1, 0, :L] => "face" }
    grid.annotate_edges = { [0, 1, :E] => "edge" }
    grid.annotate_vertices = { [2, 1] => "vertex" }
    canvas = Canvas.new(400, 300, grid)
    canvas.to_svg
  end
  
end

diagrams = Diagrams.new
File.new('square-grid.svg', 'w') << diagrams.square_grid
File.new('hexagon-grid.svg', 'w') << diagrams.hexagon_grid
File.new('triangle-grid.svg', 'w') << diagrams.triangle_grid
File.new('grid-parts.svg', 'w') << diagrams.grid_parts
File.new('square-to-hexagon-2.svg', 'w') << diagrams.hexagon_grid(9, 0.0)
File.new('square-to-hexagon-3.svg', 'w') << diagrams.hexagon_grid(9, 0.5)
File.new('square-grid-small.svg', 'w') << diagrams.square_grid(5)
File.new('rhombus-grid-small.svg', 'w') << diagrams.rhombus_grid(5)
File.new('triangle-grid-small.svg', 'w') << diagrams.triangle_grid_small

File.new('square-grid-face-coordinates.svg', 'w') << diagrams.square_grid_face_coordinates
File.new('square-grid-vertex-coordinates.svg', 'w') << diagrams.square_grid_vertex_coordinates
File.new('square-grid-edge-coordinates.svg', 'w') << diagrams.square_grid_edge_coordinates

File.new('hexagon-grid-face-coordinates.svg', 'w') << diagrams.hexagon_grid_face_coordinates
File.new('hexagon-grid-vertex-coordinates.svg', 'w') << diagrams.hexagon_grid_vertex_coordinates
File.new('hexagon-grid-edge-coordinates.svg', 'w') << diagrams.hexagon_grid_edge_coordinates

File.new('triangle-grid-face-coordinates.svg', 'w') << diagrams.triangle_grid_face_coordinates
File.new('triangle-grid-vertex-coordinates.svg', 'w') << diagrams.triangle_grid_vertex_coordinates
File.new('triangle-grid-edge-coordinates.svg', 'w') << diagrams.triangle_grid_edge_coordinates

File.new('square-rel-face-face.svg', 'w') << diagrams.square_rel_face_face
File.new('square-rel-face-edge.svg', 'w') << diagrams.square_rel_face_edge
File.new('square-rel-face-vertex.svg', 'w') << diagrams.square_rel_face_vertex
File.new('square-rel-edge-face.svg', 'w') << diagrams.square_rel_edge_face
File.new('square-rel-edge-edge.svg', 'w') << diagrams.square_rel_edge_edge
File.new('square-rel-edge-vertex.svg', 'w') << diagrams.square_rel_edge_vertex
File.new('square-rel-vertex-face.svg', 'w') << diagrams.square_rel_vertex_face
File.new('square-rel-vertex-edge.svg', 'w') << diagrams.square_rel_vertex_edge
File.new('square-rel-vertex-vertex.svg', 'w') << diagrams.square_rel_vertex_vertex
File.new('hex-grid-metrics.svg', 'w') << diagrams.hex_grid_metrics