Class: Sh::Plasma

Inherits:
Object show all
Defined in:
lib/sh_plasma.rb

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(width, height, grid_size = 5) ⇒ Plasma

Returns a new instance of Plasma.



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# File 'lib/sh_plasma.rb', line 5

def initialize width, height, grid_size = 5
  @width, @height = width.to_f, height.to_f
@grid_size = grid_size.to_f
end

Instance Attribute Details

#grid_size ⇒ Object (readonly)

Returns the value of attribute grid_size.



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# File 'lib/sh_plasma.rb', line 3

def grid_size
  @grid_size
end

#height ⇒ Object (readonly)

Returns the value of attribute height.



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# File 'lib/sh_plasma.rb', line 3

def height
  @height
end

#width ⇒ Object (readonly)

Returns the value of attribute width.



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# File 'lib/sh_plasma.rb', line 3

def width
  @width
end

Instance Method Details

#generate_map ⇒ Object 



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# File 'lib/sh_plasma.rb', line 10

def generate_map
  map = [[rand, rand, nil],[rand, rand, nil], nil]
  w = @width / 2
  h = @height / 2

  while w > @grid_size or h > @grid_size
    w /= 2
    h /= 2

    new_map = []
    map.each_cons(2) do |row, next_row|
      next_row ||= map.first

      r = []
      row.each_cons(2) do |v, nv|
        nv ||= row.first
        r << v
        r << (v + nv) / 2
      end
      r << nil
      new_map << r

      r = []
      (row.size - 1).times do |x|
        r << (row[x] + next_row[x]) / 2
        midpoint = nil
        if row[x+1]
          midpoint = (row[x] + next_row[x] + row[x+1] + next_row[x+1]) / 4
        else
          midpoint = (row[x] + next_row[x] + row.first + next_row.first) / 4
        end
        midpoint += displace(w + h)
        midpoint = midpoint > 1 ? 1 : midpoint < 0 ? 0 : midpoint
        r << midpoint
      end
      r << nil
      new_map << r
    end

    map = new_map << nil
  end
  # Get rid of all the nil values introduced as part of the processing
  map = map[0..-2].collect {|r| r[0..-2]}
end

#generate_pixmap(color1 = [0, 0, 0], color2 = [65535, 65535, 65535]) ⇒ Object 



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# File 'lib/sh_plasma.rb', line 55

def generate_pixmap color1=[0, 0, 0], color2=[65535, 65535, 65535]
  if try_require 'gtk2'
    depth = 24
    begin
      depth = Gdk::Window.default_root_window.geometry.last
    rescue
      depth = 24
    end
    pixmap = Gdk::Pixmap.new(nil, @width, @height, depth)
    gc = Gdk::GC.new(pixmap)
    map = generate_map
    h = @height / map.size
    w = @width / map.first.size
    x = y = 0
    map.each do |row|
      row.each do |v|
        r1, g1, b1 = *color1
        r2, g2, b2 = *color2
        # Simulate alpha transparency overlay of one colour over the other
        red = v*r1+(1-v)*r2
        green = v*g1+(1-v)*g2
        blue = v*b1+(1-v)*b2
        # Draw rectangle in pixmap
        color = Gdk::Color.new red, green, blue
        gc.rgb_fg_color = color
        pixmap.draw_rectangle(gc, true, x, y, @grid_size, @grid_size)
        # Increment horizontal position
        x += w
      end
      x = 0
      y += h
    end
    return pixmap
  else
    raise "GTK is required to create a pixmap!"
  end
end