Class: Colors::Colormap

Inherits:
Object
  • Object
show all
Defined in:
lib/colors/colormap.rb

Direct Known Subclasses

LinearSegmentedColormap, ListedColormap

Constant Summary collapse

PNG_WIDTH = 
512
PNG_HEIGHT = 
64

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(name, n_colors) ⇒ Colormap

Returns a new instance of Colormap.



3
4
5
6
7
8
9
10
11
12
13
 
# File 'lib/colors/colormap.rb', line 3

def initialize(name, n_colors)
  @name = name
  @n_colors = n_colors.to_int
  @bad_color = RGBA.new(0r, 0r, 0r, 0r)
  @under_color = nil
  @over_color = nil
  @under_index = self.n_colors
  @over_index = self.n_colors + 1
  @bad_index = self.n_colors + 2
  @initialized = false
end

Instance Attribute Details

#n_colors ⇒ Object (readonly)

Returns the value of attribute n_colors.



15
16
17
 
# File 'lib/colors/colormap.rb', line 15

def n_colors
  @n_colors
end

#name ⇒ Object (readonly)

Returns the value of attribute name.



15
16
17
 
# File 'lib/colors/colormap.rb', line 15

def name
  @name
end

Instance Method Details

#[](x) ⇒ Object 



17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
 
# File 'lib/colors/colormap.rb', line 17

def [](x)
  init_colormap unless @initialized

  xs = Array(x)
  scalar_p = (xs.length == 1) && xs[0] == x

  if all_ratio?(xs)
    xs.map! do |v|
      v *= self.n_colors
      v = -1 if v < 0
      v = self.n_colors - 1 if v == self.n_colors
      v.clamp(-1, self.n_colors).to_i
    end
  end
  ys = xs.map do |v|
    v = case
        when v >= self.n_colors
          @over_index
        when v < 0
          @under_index
        else
          v
        end
    @lookup_table[v]
  end

  if scalar_p
    ys[0]
  else
    ys
  end
end

#over_color ⇒ Object 



50
51
52
53
 
# File 'lib/colors/colormap.rb', line 50

def over_color
  init_colormap unless @initialized
  @lookup_table[@over_index]
end

#over_color=(color) ⇒ Object 



55
56
57
58
 
# File 'lib/colors/colormap.rb', line 55

def over_color=(color)
  @over_color = color
  update_extreme_colors if @initialized
end

#reversed ⇒ Object 



70
71
72
73
74
75
76
 
# File 'lib/colors/colormap.rb', line 70

def reversed
  rev_name = "#{self.name}_r" unless self.name.nil?
  rev = make_reverse_colormap(rev_name)
  rev.over_color = self.over_color
  rev.under_color = self.under_color
  return rev
end

#to_html ⇒ Object 



97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
 
# File 'lib/colors/colormap.rb', line 97

def to_html
  require "base64"
  png_blob = to_png
  png_base64 = Base64.encode64(png_blob)
  html = %Q[<div style="vertical-align: middle;">] +
         %Q[<strong>#{self.name}</strong> ] +
         %Q[</div>] +
         %Q[<div class="cmap"><img alt="#{self.name} colormap" ] +
         %Q[title="#{self.name}" style="border: 1px solid #555;" ] +
         %Q[src="data:image/png;base64,#{png_base64}"></div>] +
         %Q[<div style="vertical-align: middle; ] +
         %Q[max-width: #{PNG_WIDTH + 2}px; ] +
         %Q[display: flex; justify-content: space-between;">] +
         %Q[<div style="float: left;">] +
         %Q[#{html_color_block(under_color)} under</div>] +
         # TODO: bad_color support
         # %Q[<div style="margin: 0 auto; display: inline-block;">] +
         # %Q[bad #{html_color_block(bad_color)}</div>] +
         %Q[<div style="float: right;">] +
         %Q[over #{html_color_block(over_color)}</div>]
  ["text/html", html]
end

#to_png ⇒ Object 



85
86
87
88
89
90
91
92
93
94
95
 
# File 'lib/colors/colormap.rb', line 85

def to_png
  require "chunky_png"
  png = ChunkyPNG::Image.new(PNG_WIDTH, PNG_HEIGHT, ChunkyPNG::Color::TRANSPARENT)
  x = Utils.linspace(0, 1, PNG_WIDTH)
  (0 ... PNG_WIDTH).each do |i|
    color = self[x[i].to_f]
    png_color = ChunkyPNG::Color.rgba(*color.components.map{|v| (v*255).to_i })
    png.line(i, 0, i, PNG_HEIGHT-1, png_color)
  end
  png.to_blob
end

#under_color ⇒ Object 



60
61
62
63
 
# File 'lib/colors/colormap.rb', line 60

def under_color
  init_colormap unless @initialized
  @lookup_table[@under_index]
end

#under_color=(color) ⇒ Object 



65
66
67
68
 
# File 'lib/colors/colormap.rb', line 65

def under_color=(color)
  @under_color = color
  update_extreme_colors if @initialized
end