diff options
author | Jörg Frings-Fürst <debian@jff-webhosting.net> | 2016-12-28 16:52:56 +0100 |
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committer | Jörg Frings-Fürst <debian@jff-webhosting.net> | 2016-12-28 16:52:56 +0100 |
commit | 7b358424ebad9349421acd533c2fa1cbf6cf3e3e (patch) | |
tree | 686678532eefed525c242fd214d0cfb2914726c5 /app/tools/halibut/charset/big5enc.c |
Initial import of xtrkcad version 1:4.0.2-2
Diffstat (limited to 'app/tools/halibut/charset/big5enc.c')
-rw-r--r-- | app/tools/halibut/charset/big5enc.c | 93 |
1 files changed, 93 insertions, 0 deletions
diff --git a/app/tools/halibut/charset/big5enc.c b/app/tools/halibut/charset/big5enc.c new file mode 100644 index 0000000..d3e48ff --- /dev/null +++ b/app/tools/halibut/charset/big5enc.c @@ -0,0 +1,93 @@ +/* + * big5enc.c - multibyte encoding of Big5 + */ + +#ifndef ENUM_CHARSETS + +#include "charset.h" +#include "internal.h" + +/* + * Big5 has no associated data, so `charset' may be ignored. + */ + +static void read_big5(charset_spec const *charset, long int input_chr, + charset_state *state, + void (*emit)(void *ctx, long int output), void *emitctx) +{ + UNUSEDARG(charset); + + /* + * For reading Big5, 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 >= 0xA1 && input_chr <= 0xFE) { + /* + * Lead byte. Just store it. + */ + state->s0 = input_chr; + } else { + /* + * Anything else we pass straight through unchanged. + */ + emit(emitctx, input_chr); + } + } else { + /* + * We have a stored lead byte. We expect a valid followup + * byte. + */ + if ((input_chr >= 0x40 && input_chr <= 0x7E) || + (input_chr >= 0xA1 && input_chr <= 0xFE)) { + emit(emitctx, big5_to_unicode(state->s0 - 0xA1, input_chr - 0x40)); + } else { + emit(emitctx, ERROR); + } + state->s0 = 0; + } +} + +/* + * Big5 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_big5(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) { + emit(emitctx, input_chr); + return TRUE; + } else { + int r, c; + if (unicode_to_big5(input_chr, &r, &c)) { + emit(emitctx, r + 0xA1); + emit(emitctx, c + 0x40); + return TRUE; + } else { + return FALSE; + } + } +} + +const charset_spec charset_CS_BIG5 = { + CS_BIG5, read_big5, write_big5, NULL +}; + +#else /* ENUM_CHARSETS */ + +ENUM_CHARSET(CS_BIG5) + +#endif /* ENUM_CHARSETS */ |