2002 年 10 月のよしだむメモ

--- u2s.h~	Thu Oct  3 21:49:27 2002
+++ u2s.h	Fri Oct  4 22:28:20 2002
@@ -12883,7 +12883,11 @@
   0x0000, /* U+322e */
   0x0000, /* U+322f */
   0x0000, /* U+3230 */
+#ifdef COMPAT_WIN32API
+  0x878a, /* U+3231 */
+#else
   0xfa58, /* U+3231 */
+#endif
   0x878b, /* U+3232 */
   0x0000, /* U+3233 */
   0x0000, /* U+3234 */

 #! /usr/local/bin/ruby
 
 ## markers
 FF = 0xff
 RST0  = 0xd0
 RST7  = 0xd7
 SOI   = 0xd8
 EOI   = 0xd9
 APP1  = 0xe1
 APP15 = 0xef
 TEM   = 0x01
 
 def stripAppMarkers(fin, fout)
   while c = fin.getc
     if c != FF
       fout.putc(c)
       next
     end
     marker = fin.getc
     if marker == 0 or marker == FF
       fout.putc(FF)
       fout.putc(marker)
       next
     end
 
     case marker
     when APP1..APP15
       length = fin.read(2).unpack("n")[0]
       app = fin.read(length - 2)
       printf("strip %d bytes\n", length + 2)
       next
 
     when SOI, EOI, RST0..RST7, TEM
       fout.putc(FF)
       fout.putc(marker)
       next
 
     else
       length = fin.read(2).unpack("n")[0]
       segment = fin.read(length - 2)
       fout.putc(FF)
       fout.putc(marker)
       fout.write([length].pack("n") + segment)
     end
   end
 end
 
 open(ARGV[0], "rb") do |fin|
   open(ARGV[1], "wb") do |fout|
     stripAppMarkers(fin, fout)
   end
 end

 #! /usr/local/bin/ruby
 
 require 'parsearg'
 
 ## JPEG markers
 FF = 0xff
 APP0 = 0xe0
 
 UNITS = ['pixels', 'pixels/inch', 'pixels/cm']
 
 def jpeg_changeDensity(fin, fout, unit, xdensity, ydensity)
   while c = fin.getc
     if c != FF
       if fout
         fout.putc(c)
       end
       next
     end
     marker = fin.getc
     if marker == 0 or marker == FF
       if fout
         fout.putc(FF)
         fout.putc(marker)
       end
       next
     end
 
     case marker
       when APP0
       length = fin.read(2).unpack("n")[0]
       app0 = fin.read(length - 2)
       identifier, version, u, xd, yd, xt, yt, rest = app0.unpack("a4xa2cnncca*")
       printf("%dx%d %s\n", xd, yd, UNITS[u])
 
       if fout
         app0 = [identifier, version, unit, xdensity, ydensity,
           xt, yt, rest].pack("a4xa2cnncca*")
         fout.putc(FF)
         fout.putc(marker)
         fout.write([length].pack("n") + app0)
         fout.write(fin.read)
         printf("->%dx%d %s\n", xdensity, ydensity, UNITS[unit])
         return
       end
       next
 
     when SOI, EOI, RST0..RST7, TEM
       if fout
         fout.putc(FF)
         fout.putc(marker)
       end
       next
 
     else
       length = fin.read(2).unpack("n")[0]
       segment = fin.read(length - 2)
       if fout
         fout.putc(FF)
         fout.putc(marker)
         fout.write([length].pack("n") + segment)
       end
     end
   end
 end
 
 
 PNG_SIGNATURE = "\x89\x50\x4e\x47\x0d\x0a\x1a\x0a"
 CRC_TABLE = []
 
 def png_changeDensity(fin, fout, xdensity, ydensity)
   sig = fin.read(8)
   if sig != PNG_SIGNATURE
     puts "not PNG file!"
     return
   end
   if fout
     fout.write(sig)
   end
 
   while chunk = fin.read(8)
     len, ctype = chunk.unpack("Na4")
     cbody = fin.read(len)
     crc = fin.read(4)
     case ctype
     when "pHYs"
       xppu, yppu, u = cbody.unpack("NNc")
       if u == 0
         printf("aspect ratio = %f\n", 1.0*xppu/yppu)
       else
         printf("%dx%d pixel/inch\n",
                (xppu*0.0254).round,
                (yppu*0.0254).round)
       end
       if fout
         xppu = (xdensity / 0.0254).round
         yppu = (ydensity / 0.0254).round
         cbody = [xppu, yppu, 1].pack("NNc")
         crc = crc(ctype + cbody)
         printf("->%dx%d pixel/inch\n", xdensity, ydensity)
       end
     end
     if fout
       fout.write(chunk)
       fout.write(cbody)
       fout.write(crc)
     end
   end
 end
 
 def mk_crc_tab
   for n in 0..255
     c = n
     for k in 0..7
       if c & 1 == 1
         c = 0xedb88320 ^ (c >> 1)
       else
         c >>= 1
       end
     end
     CRC_TABLE[n] = c
   end
 end
  
 
 def update_crc(crc, buf)
   if CRC_TABLE.length == 0
     mk_crc_tab
   end
   c = crc
   for n in 0...buf.length
     c = CRC_TABLE[(c ^ buf[n]) & 0xff] ^ (c >> 8)
   end
   c
 end
 
 def crc(buf)
   [update_crc(0xffffffff, buf) ^ 0xffffffff].pack("N")
 end
 
 unit = 1
 xd = 72
 yd = 72
 
 $USAGE = %q(puts "Usage: #$0 [-i ppi] in [out]")
 
 parseArgs(0, nil, nil, "i:")
 
 if $OPT_i
   xd = yd = $OPT_i.to_i
 end
 
 open(ARGV[0], "rb") do |fin|
   fout = ARGV[1] ? open(ARGV[1], "wb") : nil
   if ARGV[0] =~ /\.png/i
     png_changeDensity(fin, fout, xd, yd)
   else
     jpeg_changeDensity(fin, fout, unit, xd, yd)
   end
   fout.close if fout
 end