1 files changed, 164 insertions, 0 deletions
diff --git a/xc/lib/X11/lcUniConv/big5_emacs.h b/xc/lib/X11/lcUniConv/big5_emacs.h
new file mode 100644
index 000000000..914755399
--- /dev/null
+++ b/xc/lib/X11/lcUniConv/big5_emacs.h
@@ -0,0 +1,164 @@
+/* $XFree86: xc/lib/X11/lcUniConv/big5_emacs.h,v 1.1 2000/11/28 18:50:06 dawes Exp $ */
+
+/*
+ * BIG5-0 and BIG5-1
+ */
+
+/*
+   BIG5 with its 13494 characters doesn't fit in a single 94x94 or 96x96
+   block. Therefore Emacs/Mule developers, in a typically Japanese way of
+   thinking, have developed an alternative encoding of BIG5 in two 94x94
+   planes, very similar to the SHIFT_JIS encoding for JISX0208.
+
+   Conversion between BIG5 codes (s1,s2) and BIG5-0 codes (c1,c2):
+   Example. (s1,s2) = 0xA140, (c1,c2) = 0x2121.
+   0xA1 <= s1 <= 0xC7, 0x40 <= s2 <= 0x7E || 0xA1 <= s2 <= 0xFE,
+   0x21 <= c1 <= 0x62, 0x21 <= c2 <= 0x7E.
+   Invariant:
+     157*(s1-0xA1) + (s2 < 0x80 ? s2-0x40 : s2-0x62)
+     = 94*(c1-0x21)+(c2-0x21)
+   Conversion (s1,s2) -> (c1,c2):
+     t := 157*(s1-0xA1) + (s2 < 0x80 ? s2-0x40 : s2-0x62)
+     c1 := (t div 94) + 0x21
+     c2 := (t mod 94) + 0x21
+   Conversion (c1,c2) -> (s1,s2):
+     t := 94*(c1-0x21)+(c2-0x21)
+     t2 := t mod 157
+     s1 := (t div 157) + 0xA1
+     s2 := (t2 < 0x3F ? t2+0x40 : t2+0x62)
+
+   Conversion between BIG5 codes (s1,s2) and BIG5-1 codes (c1,c2):
+   Example. (s1,s2) = 0xC940, (c1,c2) = 0x2121.
+   0xC9 <= s1 <= 0xF9, 0x40 <= s2 <= 0x7E || 0xA1 <= s2 <= 0xFE,
+   0x21 <= c1 <= 0x72, 0x21 <= c2 <= 0x7E.
+   Invariant:
+     157*(s1-0xC9) + (s2 < 0x80 ? s2-0x40 : s2-0x62)
+     = 94*(c1-0x21)+(c2-0x21)
+   Conversion (s1,s2) -> (c1,c2):
+     t := 157*(s1-0xC9) + (s2 < 0x80 ? s2-0x40 : s2-0x62)
+     c1 := (t div 94) + 0x21
+     c2 := (t mod 94) + 0x21
+   Conversion (c1,c2) -> (s1,s2):
+     t := 94*(c1-0x21)+(c2-0x21)
+     t2 := t mod 157
+     s1 := (t div 157) + 0xC9
+     s2 := (t2 < 0x3F ? t2+0x40 : t2+0x62)
+ */
+
+static int
+big5_0_mbtowc (conv_t conv, ucs4_t *pwc, const unsigned char *s, int n)
+{
+  unsigned char c1 = s[0];
+  if (c1 >= 0x21 && c1 <= 0x62) {
+    if (n >= 2) {
+      unsigned char c2 = s[1];
+      if (c2 >= 0x21 && c2 <= 0x7e) {
+        unsigned int i = 94 * (c1 - 0x21) + (c2 - 0x21);
+        if (0) {
+          /* Unoptimized. */
+          unsigned char buf[2];
+          buf[0] = (i / 157) + 0xa1;
+          i = i % 157;
+          buf[1] = i + (i < 0x3f ? 0x40 : 0x62);
+          return big5_mbtowc(conv,pwc,buf,2);
+        } else {
+          /* Inline the implementation of big5_mbtowc. */
+          if (i < 6121) {
+            unsigned short wc = big5_2uni_pagea1[i];
+            if (wc != 0xfffd) {
+              *pwc = (ucs4_t) wc;
+              return 2;
+            }
+          }
+        }
+      }
+      return RET_ILSEQ;
+    }
+    return RET_TOOFEW(0);
+  }
+  return RET_ILSEQ;
+}
+
+static int
+big5_1_mbtowc (conv_t conv, ucs4_t *pwc, const unsigned char *s, int n)
+{
+  unsigned char c1 = s[0];
+  if (c1 >= 0x21 && c1 <= 0x72) {
+    if (n >= 2) {
+      unsigned char c2 = s[1];
+      if (c2 >= 0x21 && c2 <= 0x7e) {
+        unsigned int i = 94 * (c1 - 0x21) + (c2 - 0x21);
+        if (0) {
+          /* Unoptimized. */
+          unsigned char buf[2];
+          buf[0] = (i / 157) + 0xc9;
+          i = i % 157;
+          buf[1] = i + (i < 0x3f ? 0x40 : 0x62);
+          return big5_mbtowc(conv,pwc,buf,2);
+        } else {
+          /* Inline the implementation of big5_mbtowc. */
+          if (i < 7652) {
+            unsigned short wc = big5_2uni_pagec9[i];
+            if (wc != 0xfffd) {
+              *pwc = (ucs4_t) wc;
+              return 2;
+            }
+          }
+        }
+      }
+      return RET_ILSEQ;
+    }
+    return RET_TOOFEW(0);
+  }
+  return RET_ILSEQ;
+}
+
+static int
+big5_0_wctomb (conv_t conv, unsigned char *r, ucs4_t wc, int n)
+{
+  if (n >= 2) {
+    unsigned char buf[2];
+    int ret = big5_wctomb(conv,buf,wc,2);
+    if (ret != RET_ILSEQ) {
+      unsigned char s1, s2;
+      if (ret != 2) abort();
+      s1 = buf[0];
+      s2 = buf[1];
+      if (!(s1 >= 0xa1)) abort();
+      if (!((s2 >= 0x40 && s2 <= 0x7e) || (s2 >= 0xa1 && s2 <= 0xfe))) abort();
+      if (s1 < 0xc9) {
+        unsigned int t = 157 * (s1 - 0xa1) + s2 - (s2 < 0x80 ? 0x40 : 0x62);
+        r[0] = (t / 94) + 0x21;
+        r[1] = (t % 94) + 0x21;
+        return 2;
+      }
+    }
+    return RET_ILSEQ;
+  }
+  return RET_TOOSMALL;
+}
+
+static int
+big5_1_wctomb (conv_t conv, unsigned char *r, ucs4_t wc, int n)
+{
+  if (n >= 2) {
+    unsigned char buf[2];
+    int ret = big5_wctomb(conv,buf,wc,2);
+    if (ret != RET_ILSEQ) {
+      unsigned char s1, s2;
+      if (ret != 2) abort();
+      s1 = buf[0];
+      s2 = buf[1];
+      if (!(s1 <= 0xf9)) abort();
+      if (!((s2 >= 0x40 && s2 <= 0x7e) || (s2 >= 0xa1 && s2 <= 0xfe))) abort();
+      if (s1 >= 0xc9) {
+        unsigned int t = 157 * (s1 - 0xc9) + s2 - (s2 < 0x80 ? 0x40 : 0x62);
+        r[0] = (t / 94) + 0x21;
+        r[1] = (t % 94) + 0x21;
+        return 2;
+      }
+    }
+    return RET_ILSEQ;
+  }
+  return RET_TOOSMALL;
+}