lib_quilt

quilt.rb

# -*- coding: utf-8 -*-
##source from https://github.com/swdyh/quilt

require 'digest/sha1'

module Quilt
  SALT = ''
  PATCHES = [[0,4,24,20,0],[0,4,20,0],[2,24,20,2],[0,2,22,20,0],[2,14,22,10,2],[0,14,24,22,0],[2,24,22,13,11,22,20,2],[0,14,22,0],[6,8,18,16,6],[4,20,10,12,2,4],[0,2,12,10,0],[10,14,22,10],[20,12,24,20],[10,2,12,10],[0,2,10,0],[]]
  CENTER_PATCHES = [0,4,8,15]
  PATCH_SIZE = 5
  SCALE = PATCH_SIZE * 3
  BACK_COLOR = 'rgb(255,255,255)'
  def self.process(str)
    str = Digest::SHA1.digest("#{str}#{SALT}")
    code = [str.getbyte(0) << 24, str.getbyte(1) << 16, str.getbyte(2) << 8, str.getbyte(3)].inject(0){|r,i| r | ((i[31] == 1) ? -(i & 0x7fffffff) : i)}
    fore_color = 'rgb(%d,%d,%d)' % [(((code >> 16) & 0x01f) << 3),(((code >> 21) & 0x01f) << 3),(((code >> 27) & 0x01f) << 3)]
    return %(<svg xmlns="http://www.w3.org/2000/svg" version="1.1" viewBox="0 0 #{SCALE} #{SCALE}">#{
      draw_patches(fore_color,[[1,1]],CENTER_PATCHES[code & 0x3],0,(((code >> 2) & 0x01) != 0))
    }#{
      draw_patches(fore_color,[[1,0],[2,1],[1,2],[0,1]],((code >> 10) & 0x0f),((code >> 15) & 0x03),(((code >> 14) & 0x01) != 0))
    }#{
      draw_patches(fore_color,[[0,0],[2,0],[2,2],[0,2]],((code >> 3) & 0x0f),((code >> 8) & 0x03),(((code >> 7) & 0x01) != 0))
    }</svg>)
  end

  def self.draw_patches(fore_color,list, patch, turn, invert)
    return list.map{|i|
      temp = draw(fore_color , i[0] * PATCH_SIZE , i[1] * PATCH_SIZE , patch , turn % 4 , invert)
      turn += 1
      temp
    }.join
  end

  def self.draw(fore_color,x,y,patch,turn,invert)
    if invert
      back_color = fore_color
      fore_color = BACK_COLOR
    else
      back_color = BACK_COLOR
    end
    return %(<rect x="#{x}" y="#{y}" width="#{PATCH_SIZE}" height="#{PATCH_SIZE}" fill="#{back_color}" stroke-width="0" stroke="white"/><polygon points="#{
      PATCHES[patch % PATCHES.size].map{|pt|
        px = (pt % PATCH_SIZE).to_f / (PATCH_SIZE - 1) * PATCH_SIZE
        py = (pt / PATCH_SIZE).to_f / (PATCH_SIZE - 1) * PATCH_SIZE
        case turn
        when 1
          px , py = PATCH_SIZE - py , px
        when 2
          px , py = PATCH_SIZE - px , PATCH_SIZE - py
        when 3
          px , py = py , PATCH_SIZE - px
        end
        "#{x + px},#{y + py}"
      }.join(' ')
    }" stroke-width="0" fill="#{fore_color}"/>)
  end
end