shithub: rgbds

ref: 12458aae6fba3065f671847b70edb6dd77312b6e
dir: /src/extern/utf8decoder.c/

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/*
 * Copyright (c) 2008-2009, Björn Höhrmann <[email protected]>
 *
 * SPDX-License-Identifier: MIT
 */

/*
 * UTF-8 decoder: http://bjoern.hoehrmann.de/utf-8/decoder/dfa/
 */

#include <stdint.h>

static const uint8_t utf8d[] = {
	  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, /* 00..0f */
	  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, /* 10..1f */
	  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, /* 20..2f */
	  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, /* 30..3f */
	  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, /* 40..4f */
	  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, /* 50..5f */
	  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, /* 60..6f */
	  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, /* 70..7f */
	  1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, /* 80..8f */
	  9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, /* 90..9f */
	  7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, /* a0..af */
	  7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, /* b0..bf */
	  8, 8, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, /* c0..cf */
	  2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, /* d0..df */
	 10, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 4, 3, 3, /* e0..ef */
	 11, 6, 6, 6, 5, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, /* f0..ff */
	  0, 1, 2, 3, 5, 8, 7, 1, 1, 1, 4, 6, 1, 1, 1, 1, /* s0 */
	  1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, /* s1 */
	  1, 0, 1, 1, 1, 1, 1, 0, 1, 0, 1, 1, 1, 1, 1, 1, /* s1 */
	  1, 2, 1, 1, 1, 1, 1, 2, 1, 2, 1, 1, 1, 1, 1, 1, /* s3 */
	  1, 1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 1, 1, 1, /* s4 */
	  1, 2, 1, 1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 1, /* s5 */
	  1, 1, 1, 1, 1, 1, 1, 3, 1, 3, 1, 1, 1, 1, 1, 1, /* s6 */
	  1, 3, 1, 1, 1, 1, 1, 3, 1, 3, 1, 1, 1, 1, 1, 1, /* s7 */
	  1, 3, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, /* s8 */
};

uint32_t decode(uint32_t *state, uint32_t *codep, uint32_t byte)
{
	uint32_t type = utf8d[byte];

	*codep = (*state != 0) ?
			(byte & 0x3fu) | (*codep << 6) :
			(0xff >> type) & (byte);

	*state = utf8d[256 + *state * 16 + type];
	return *state;
}