Method: Pixelart::Image#transparent

Defined in:
lib/pixelart/transparent.rb

#transparent(style = :solid, fuzzy: false) ⇒ Object 



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# File 'lib/pixelart/transparent.rb', line 5

def transparent( style = :solid, fuzzy: false )
  img = Image.new( width, height )


  background = self[0,0]

  bh,bs,bl =  Color.to_hsl( background )
  bh = (bh % 360)  ## might might negative degree (always make positive)

  height.times do |y|
      if style == :linear
        background = self[0,y]

        bh,bs,bl =  Color.to_hsl( background )
        bh = (bh % 360)  ## might might negative degree (always make positive)
      end
    width.times do |x|
      pixel = self[x,y]

      if background == 0  ## special case if background is already transparent keep going
        img[x,y] =  pixel
      elsif fuzzy
        ## check for more transparents
          ##   not s  is 0.0 to 0.99  (100%)
          ##   and l  is 0.0 to 0.99  (100%)
        h,s,l =  Color.to_hsl( pixel )
        h = (h % 360)  ## might might negative degree (always make positive)

        ## try some kind-of fuzzy "heuristic" match on background color
        if ((h >= bh-5) && (h <= bh+5)) &&
           ((s >= bs-0.07) && (s <= bs+0.07)) &&
           ((l >= bl-0.07) && (l <= bl+0.07))
         img[x,y] = 0  ## Color::TRANSPARENT

         if h != bh || s != bs || l != bl
            # report fuzzy background color
            puts "  #{x}/#{y} fuzzy background #{[h,s,l]} ~= #{[bh,bs,bl]}"
         end
        else
          img[x,y] =  pixel
        end
      else
         if pixel == background
          img[x,y] = 0   ## Color::TRANSPARENT
         else
           img[x,y] =  pixel
         end
      end
    end
  end
  img
end