Class: CTioga2::Graphics::Styles::ColorMap

Inherits:
Object
  • Object
show all
Defined in:
lib/ctioga2/graphics/styles/colormap.rb

Overview

TODO:

For now, ColorMap relies on the intrisic tioga color

A mapping Z values -> color.

It can be a simple two-point gradient, but it can also be much more complex.

Basically, a ColorMap is a series of colors with an optional Z value (taken as the average of the ones around if missing) + a color for above and a color for below.

map, but it would be interesting to implement that “by hand” for the case when a byte of resolution isn’t enough (which are going to be rare, I think)

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(values = [], colors = []) ⇒ ColorMap

Returns a new instance of ColorMap.



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# File 'lib/ctioga2/graphics/styles/colormap.rb', line 59

def initialize(values = [], colors = [])
  @values = values.dup
  @colors = colors.dup

  @rgb = true
end

Instance Attribute Details

#above ⇒ Object

TODO:

These are currently not implemented.

Colors for points of Z value below and above the limit; nil for no specific value, :mask for masking them out



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# File 'lib/ctioga2/graphics/styles/colormap.rb', line 50

def above
  @above
end

#below ⇒ Object

TODO:

These are currently not implemented.

Colors for points of Z value below and above the limit; nil for no specific value, :mask for masking them out



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# File 'lib/ctioga2/graphics/styles/colormap.rb', line 50

def below
  @below
end

#colors ⇒ Object

Corresponding colors



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# File 'lib/ctioga2/graphics/styles/colormap.rb', line 44

def colors
  @colors
end

#rgb ⇒ Object

Whether the map follows RGB (true) or HLS (false). On by default.

It does not change anything with respect to how the colors are interpreted: whatever happens, the values are RGB.



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# File 'lib/ctioga2/graphics/styles/colormap.rb', line 57

def rgb
  @rgb
end

#values ⇒ Object

Z values



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# File 'lib/ctioga2/graphics/styles/colormap.rb', line 41

def values
  @values
end

Class Method Details

.from_text(str) ⇒ Object

Creates a ColorMap from a text specification of the kind:

Red--Blue(1.0)--Green
The specification can optionally be surrounded by colors with

Green::Red–Blue::Orange

Means that Green are for colors below, Orange for above. These colors can also be “cut” or “mask”, meaning that the corresponding side isn’t displayed.



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# File 'lib/ctioga2/graphics/styles/colormap.rb', line 77

def self.from_text(str)
  str = str.dup
  hls = false
  re = /natural:?/i     # Not too bad ?
  if str =~ re
    str.sub!(re,'')
    hls = true
  end

  l = str.split(/::/)
  

  if l.size == 2        # This is the complex case
    if l[1] =~ /--/
      l.push('')
    else
      l.unshift('')
    end
  elsif l.size == 1
    l.push('')
    l.unshift('')
  end

  ## @todo More and more I find that this metabuilder thing is
  ## a little cumbersome, especially since I have an
  ## additional type system on top of this one.
  colortype = Commands::CommandType.get_type('color')

  
  # Now, we have three elements
  if l[0].size > 0
    if l[0] =~ /mask|cut/i
      below = :mask
    else
      below = colortype.string_to_type(l[0])
    end
  else
    below = nil
  end

  if l[2].size > 0
    if l[2] =~ /mask|cut/i
      above = :mask
    else
      above = colortype.string_to_type(l[2])
    end
  else
    above = nil
  end

  specs = l[1].split(/--/)

  values = []
  colors = []
  for s in specs
    if s =~ /([^(]+)\((.*)\)/
      values << $2.to_f
      colors << colortype.string_to_type($1)
    else
      values << nil
      colors << colortype.string_to_type(s)
    end
  end
  cm = ColorMap.new(values, colors)
  cm.above = above
  cm.below = below
  cm.rgb = ! hls
  return cm
end

Instance Method Details

#prepare_data_display(t, data, zmin, zmax) ⇒ Object

TODO:

handle masking + in and out of range.

TODO:

I don’t think this function is named properly.

Prepares the ‘data’, ‘colormap’ and ‘value_mask’ arguments to t.create_image based on the given data, and the min and max Z levels



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# File 'lib/ctioga2/graphics/styles/colormap.rb', line 155

def prepare_data_display(t, data, zmin, zmax)
  # We correct zmin and zmax
  cmap, zmin, zmax = *self.to_colormap(t, zmin, zmax)
  
  data = t.create_image_data(data.reverse_rows,
                             'min_value' => zmin,
                             'max_value' => zmax)
  
  return { 'data' => data,
    'colormap' => cmap
  }
end

#to_colormap(t, zmin, zmax) ⇒ Object

TODO:

That won’t work when there are things inside/outside

Converts to a Tioga color_map

of the map.



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# File 'lib/ctioga2/graphics/styles/colormap.rb', line 191

def to_colormap(t, zmin, zmax)

  # OK. Now, we have correct z values. We just need to scale
  # them between z_values[0] and z_values.last, to get a [0:1]
  # interval.
  zvs = z_values(zmin, zmax)
  p_values = zvs.dup
  p_values.sub!(p_values.first)
  p_values.div!(p_values.last)
  
  dict = {
    'points' => p_values
  }
  if @rgb
    dict['Rs'] = []
    dict['Gs'] = []
    dict['Bs'] = []
    for col in @colors
      dict['Rs'] << col[0]
      dict['Gs'] << col[1]
      dict['Bs'] << col[2]
    end
  else
    dict['Hs'] = []
    dict['Ls'] = []
    dict['Ss'] = []
    for col in @colors
      col = t.rgb_to_hls(col)
      dict['Hs'] << col[0]
      dict['Ls'] << col[1]
      dict['Ss'] << col[2]
    end
  end
  return [t.create_colormap(dict), zvs.first, zvs.last]
end

#z_color(z, zmin, zmax) ⇒ Object

TODO:

For now, the HSV parameter isn’t honored.

Returns a color triplet corresponding to the given z value



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# File 'lib/ctioga2/graphics/styles/colormap.rb', line 171

def z_color(z, zmin, zmax)
  zvs = z_values(zmin, zmax)
  
  idx = zvs.where_first_ge(z)
  if idx && idx > 0
    x = (zvs[idx] - z)/(zvs[idx] - zvs[idx-1])
    c = Utils::mix_objects(@colors[idx-1],@colors[idx], x)
    # p [c, idx, z, zmin, zmax]
    return c
  elsif idx == 0
    return @colors.first
  else
    return @colors.last
  end
end