1 files changed, 128 insertions, 0 deletions
diff --git a/app/tools/halibut/charset/shiftjis.c b/app/tools/halibut/charset/shiftjis.c
new file mode 100644
index 0000000..4ad879f
--- /dev/null
+++ b/app/tools/halibut/charset/shiftjis.c
@@ -0,0 +1,128 @@
+/*
+ * shiftjis.c - multibyte encoding of Shift-JIS
+ */
+
+#ifndef ENUM_CHARSETS
+
+#include "charset.h"
+#include "internal.h"
+
+/*
+ * Shift-JIS has no associated data, so `charset' may be ignored.
+ */
+
+static void read_sjis(charset_spec const *charset, long int input_chr,
+		      charset_state *state,
+		      void (*emit)(void *ctx, long int output), void *emitctx)
+{
+    UNUSEDARG(charset);
+
+    /*
+     * For reading Shift-JIS, state->s0 simply contains the single
+     * stored lead byte when we are half way through a double-byte
+     * character, or 0 if we aren't.
+     */
+
+    if (state->s0 == 0) {
+	if ((input_chr >= 0x81 && input_chr <= 0x9F) ||
+	    (input_chr >= 0xE0 && input_chr <= 0xEF)) {
+	    /*
+	     * Lead byte. Just store it.
+	     */
+	    state->s0 = input_chr;
+	} else {
+	    /*
+	     * Anything else we translate through JIS X 0201.
+	     */
+	    if (input_chr == 0x5C)
+		input_chr = 0xA5;
+	    else if (input_chr == 0x7E)
+		input_chr = 0x203E;
+	    else if (input_chr >= 0xA1 && input_chr <= 0xDF)
+		input_chr += 0xFF61 - 0xA1;
+	    else if (input_chr < 0x80)
+		/* do nothing */;
+	    else
+		input_chr = ERROR;
+	    emit(emitctx, input_chr);
+	}
+    } else {
+	/*
+	 * We have a stored lead byte. We expect a valid followup
+	 * byte.
+	 */
+	if (input_chr >= 0x40 && input_chr <= 0xFC && input_chr != 0x7F) {
+	    int r, c;
+	    r = state->s0;
+	    if (r >= 0xE0) r -= (0xE0 - 0xA0);
+	    r -= 0x81;
+	    c = input_chr;
+	    if (c > 0x7F) c--;
+	    c -= 0x40;
+	    r *= 2;
+	    if (c >= 94)
+		r++, c -= 94;
+	    emit(emitctx, jisx0208_to_unicode(r, c));
+	} else {
+	    emit(emitctx, ERROR);
+	}
+	state->s0 = 0;
+    }
+}
+
+/*
+ * Shift-JIS is a stateless multi-byte encoding (in the sense that
+ * just after any character has been completed, the state is always
+ * the same); hence when writing it, there is no need to use the
+ * charset_state.
+ */
+
+static int write_sjis(charset_spec const *charset, long int input_chr,
+		      charset_state *state,
+		      void (*emit)(void *ctx, long int output), void *emitctx)
+{
+    UNUSEDARG(charset);
+    UNUSEDARG(state);
+
+    if (input_chr == -1)
+	return TRUE;		       /* stateless; no cleanup required */
+
+    if (input_chr < 0x80 && input_chr != 0x5C && input_chr != 0x7E) {
+	emit(emitctx, input_chr);
+	return TRUE;
+    } else if (input_chr == 0xA5) {
+	emit(emitctx, 0x5C);
+	return TRUE;
+    } else if (input_chr == 0x203E) {
+	emit(emitctx, 0x7E);
+	return TRUE;
+    } else if (input_chr >= 0xFF61 && input_chr <= 0xFF9F) {
+	emit(emitctx, input_chr - (0xFF61 - 0xA1));
+	return TRUE;
+    } else {
+	int r, c;
+	if (unicode_to_jisx0208(input_chr, &r, &c)) {
+	    c += 94 * (r % 2);
+	    r /= 2;
+	    r += 0x81;
+	    if (r >= 0xA0) r += 0xE0 - 0xA0;
+	    c += 0x40;
+	    if (c >= 0x7F) c++;
+	    emit(emitctx, r);
+	    emit(emitctx, c);
+	    return TRUE;
+	} else {
+	    return FALSE;
+	}
+    }
+}
+
+const charset_spec charset_CS_SHIFT_JIS = {
+    CS_SHIFT_JIS, read_sjis, write_sjis, NULL
+};
+
+#else /* ENUM_CHARSETS */
+
+ENUM_CHARSET(CS_SHIFT_JIS)
+
+#endif /* ENUM_CHARSETS */