simple_fold.c

Support library to access and manipulate FAT12 / FAT16 / FAT32 file systems - Includes a FUSE filesy

	0x21A0, 0x21A1, 0x21A2, 0x21A3, 0x21A4, 0x21A5, 0x21A6, 0x21A7, 
	0x21A8, 0x21A9, 0x21AA, 0x21AB, 0x21AC, 0x21AD, 0x21AE, 0x21AF, 
	0x21B0, 0x21B1, 0x21B2, 0x21B3, 0x21B4, 0x21B5, 0x21B6, 0x21B7, 
	0x21B8, 0x21B9, 0x21BA, 0x21BB, 0x21BC, 0x21BD, 0x21BE, 0x21BF, 
	0x21C0, 0x21C1, 0x21C2, 0x21C3, 0x21C4, 0x21C5, 0x21C6, 0x21C7, 
	0x21C8, 0x21C9, 0x21CA, 0x21CB, 0x21CC, 0x21CD, 0x21CE, 0x21CF, 
	0x21D0, 0x21D1, 0x21D2, 0x21D3, 0x21D4, 0x21D5, 0x21D6, 0x21D7, 
	0x21D8, 0x21D9, 0x21DA, 0x21DB, 0x21DC, 0x21DD, 0x21DE, 0x21DF, 
	0x21E0, 0x21E1, 0x21E2, 0x21E3, 0x21E4, 0x21E5, 0x21E6, 0x21E7, 
	0x21E8, 0x21E9, 0x21EA, 0x21EB, 0x21EC, 0x21ED, 0x21EE, 0x21EF, 
	0x21F0, 0x21F1, 0x21F2, 0x21F3, 0x21F4, 0x21F5, 0x21F6, 0x21F7, 
	0x21F8, 0x21F9, 0x21FA, 0x21FB, 0x21FC, 0x21FD, 0x21FE, 0x21FF
};

static const uint16_t page_24[256] = 
{
	0x2400, 0x2401, 0x2402, 0x2403, 0x2404, 0x2405, 0x2406, 0x2407, 
	0x2408, 0x2409, 0x240A, 0x240B, 0x240C, 0x240D, 0x240E, 0x240F, 
	0x2410, 0x2411, 0x2412, 0x2413, 0x2414, 0x2415, 0x2416, 0x2417, 
	0x2418, 0x2419, 0x241A, 0x241B, 0x241C, 0x241D, 0x241E, 0x241F, 
	0x2420, 0x2421, 0x2422, 0x2423, 0x2424, 0x2425, 0x2426, 0x2427, 
	0x2428, 0x2429, 0x242A, 0x242B, 0x242C, 0x242D, 0x242E, 0x242F, 
	0x2430, 0x2431, 0x2432, 0x2433, 0x2434, 0x2435, 0x2436, 0x2437, 
	0x2438, 0x2439, 0x243A, 0x243B, 0x243C, 0x243D, 0x243E, 0x243F, 
	0x2440, 0x2441, 0x2442, 0x2443, 0x2444, 0x2445, 0x2446, 0x2447, 
	0x2448, 0x2449, 0x244A, 0x244B, 0x244C, 0x244D, 0x244E, 0x244F, 
	0x2450, 0x2451, 0x2452, 0x2453, 0x2454, 0x2455, 0x2456, 0x2457, 
	0x2458, 0x2459, 0x245A, 0x245B, 0x245C, 0x245D, 0x245E, 0x245F, 
	0x2460, 0x2461, 0x2462, 0x2463, 0x2464, 0x2465, 0x2466, 0x2467, 
	0x2468, 0x2469, 0x246A, 0x246B, 0x246C, 0x246D, 0x246E, 0x246F, 
	0x2470, 0x2471, 0x2472, 0x2473, 0x2474, 0x2475, 0x2476, 0x2477, 
	0x2478, 0x2479, 0x247A, 0x247B, 0x247C, 0x247D, 0x247E, 0x247F, 
	0x2480, 0x2481, 0x2482, 0x2483, 0x2484, 0x2485, 0x2486, 0x2487, 
	0x2488, 0x2489, 0x248A, 0x248B, 0x248C, 0x248D, 0x248E, 0x248F, 
	0x2490, 0x2491, 0x2492, 0x2493, 0x2494, 0x2495, 0x2496, 0x2497, 
	0x2498, 0x2499, 0x249A, 0x249B, 0x249C, 0x249D, 0x249E, 0x249F, 
	0x24A0, 0x24A1, 0x24A2, 0x24A3, 0x24A4, 0x24A5, 0x24A6, 0x24A7, 
	0x24A8, 0x24A9, 0x24AA, 0x24AB, 0x24AC, 0x24AD, 0x24AE, 0x24AF, 
	0x24B0, 0x24B1, 0x24B2, 0x24B3, 0x24B4, 0x24B5, 0x24D0, 0x24D1, 
	0x24D2, 0x24D3, 0x24D4, 0x24D5, 0x24D6, 0x24D7, 0x24D8, 0x24D9, 
	0x24DA, 0x24DB, 0x24DC, 0x24DD, 0x24DE, 0x24DF, 0x24E0, 0x24E1, 
	0x24E2, 0x24E3, 0x24E4, 0x24E5, 0x24E6, 0x24E7, 0x24E8, 0x24E9, 
	0x24D0, 0x24D1, 0x24D2, 0x24D3, 0x24D4, 0x24D5, 0x24D6, 0x24D7, 
	0x24D8, 0x24D9, 0x24DA, 0x24DB, 0x24DC, 0x24DD, 0x24DE, 0x24DF, 
	0x24E0, 0x24E1, 0x24E2, 0x24E3, 0x24E4, 0x24E5, 0x24E6, 0x24E7, 
	0x24E8, 0x24E9, 0x24EA, 0x24EB, 0x24EC, 0x24ED, 0x24EE, 0x24EF, 
	0x24F0, 0x24F1, 0x24F2, 0x24F3, 0x24F4, 0x24F5, 0x24F6, 0x24F7, 
	0x24F8, 0x24F9, 0x24FA, 0x24FB, 0x24FC, 0x24FD, 0x24FE, 0x24FF
};

static const uint16_t page_2C[256] = 
{
	0x2C30, 0x2C31, 0x2C32, 0x2C33, 0x2C34, 0x2C35, 0x2C36, 0x2C37, 
	0x2C38, 0x2C39, 0x2C3A, 0x2C3B, 0x2C3C, 0x2C3D, 0x2C3E, 0x2C3F, 
	0x2C40, 0x2C41, 0x2C42, 0x2C43, 0x2C44, 0x2C45, 0x2C46, 0x2C47, 
	0x2C48, 0x2C49, 0x2C4A, 0x2C4B, 0x2C4C, 0x2C4D, 0x2C4E, 0x2C4F, 
	0x2C50, 0x2C51, 0x2C52, 0x2C53, 0x2C54, 0x2C55, 0x2C56, 0x2C57, 
	0x2C58, 0x2C59, 0x2C5A, 0x2C5B, 0x2C5C, 0x2C5D, 0x2C5E, 0x2C2F, 
	0x2C30, 0x2C31, 0x2C32, 0x2C33, 0x2C34, 0x2C35, 0x2C36, 0x2C37, 
	0x2C38, 0x2C39, 0x2C3A, 0x2C3B, 0x2C3C, 0x2C3D, 0x2C3E, 0x2C3F, 
	0x2C40, 0x2C41, 0x2C42, 0x2C43, 0x2C44, 0x2C45, 0x2C46, 0x2C47, 
	0x2C48, 0x2C49, 0x2C4A, 0x2C4B, 0x2C4C, 0x2C4D, 0x2C4E, 0x2C4F, 
	0x2C50, 0x2C51, 0x2C52, 0x2C53, 0x2C54, 0x2C55, 0x2C56, 0x2C57, 
	0x2C58, 0x2C59, 0x2C5A, 0x2C5B, 0x2C5C, 0x2C5D, 0x2C5E, 0x2C5F, 
	0x2C60, 0x2C61, 0x2C62, 0x2C63, 0x2C64, 0x2C65, 0x2C66, 0x2C67, 
	0x2C68, 0x2C69, 0x2C6A, 0x2C6B, 0x2C6C, 0x2C6D, 0x2C6E, 0x2C6F, 
	0x2C70, 0x2C71, 0x2C72, 0x2C73, 0x2C74, 0x2C75, 0x2C76, 0x2C77, 
	0x2C78, 0x2C79, 0x2C7A, 0x2C7B, 0x2C7C, 0x2C7D, 0x2C7E, 0x2C7F, 
	0x2C81, 0x2C81, 0x2C83, 0x2C83, 0x2C85, 0x2C85, 0x2C87, 0x2C87, 
	0x2C89, 0x2C89, 0x2C8B, 0x2C8B, 0x2C8D, 0x2C8D, 0x2C8F, 0x2C8F, 
	0x2C91, 0x2C91, 0x2C93, 0x2C93, 0x2C95, 0x2C95, 0x2C97, 0x2C97, 
	0x2C99, 0x2C99, 0x2C9B, 0x2C9B, 0x2C9D, 0x2C9D, 0x2C9F, 0x2C9F, 
	0x2CA1, 0x2CA1, 0x2CA3, 0x2CA3, 0x2CA5, 0x2CA5, 0x2CA7, 0x2CA7, 
	0x2CA9, 0x2CA9, 0x2CAB, 0x2CAB, 0x2CAD, 0x2CAD, 0x2CAF, 0x2CAF, 
	0x2CB1, 0x2CB1, 0x2CB3, 0x2CB3, 0x2CB5, 0x2CB5, 0x2CB7, 0x2CB7, 
	0x2CB9, 0x2CB9, 0x2CBB, 0x2CBB, 0x2CBD, 0x2CBD, 0x2CBF, 0x2CBF, 
	0x2CC1, 0x2CC1, 0x2CC3, 0x2CC3, 0x2CC5, 0x2CC5, 0x2CC7, 0x2CC7, 
	0x2CC9, 0x2CC9, 0x2CCB, 0x2CCB, 0x2CCD, 0x2CCD, 0x2CCF, 0x2CCF, 
	0x2CD1, 0x2CD1, 0x2CD3, 0x2CD3, 0x2CD5, 0x2CD5, 0x2CD7, 0x2CD7, 
	0x2CD9, 0x2CD9, 0x2CDB, 0x2CDB, 0x2CDD, 0x2CDD, 0x2CDF, 0x2CDF, 
	0x2CE1, 0x2CE1, 0x2CE3, 0x2CE3, 0x2CE4, 0x2CE5, 0x2CE6, 0x2CE7, 
	0x2CE8, 0x2CE9, 0x2CEA, 0x2CEB, 0x2CEC, 0x2CED, 0x2CEE, 0x2CEF, 
	0x2CF0, 0x2CF1, 0x2CF2, 0x2CF3, 0x2CF4, 0x2CF5, 0x2CF6, 0x2CF7, 
	0x2CF8, 0x2CF9, 0x2CFA, 0x2CFB, 0x2CFC, 0x2CFD, 0x2CFE, 0x2CFF
};

static const uint16_t page_FF[256] = 
{
	0xFF00, 0xFF01, 0xFF02, 0xFF03, 0xFF04, 0xFF05, 0xFF06, 0xFF07, 
	0xFF08, 0xFF09, 0xFF0A, 0xFF0B, 0xFF0C, 0xFF0D, 0xFF0E, 0xFF0F, 
	0xFF10, 0xFF11, 0xFF12, 0xFF13, 0xFF14, 0xFF15, 0xFF16, 0xFF17, 
	0xFF18, 0xFF19, 0xFF1A, 0xFF1B, 0xFF1C, 0xFF1D, 0xFF1E, 0xFF1F, 
	0xFF20, 0xFF41, 0xFF42, 0xFF43, 0xFF44, 0xFF45, 0xFF46, 0xFF47, 
	0xFF48, 0xFF49, 0xFF4A, 0xFF4B, 0xFF4C, 0xFF4D, 0xFF4E, 0xFF4F, 
	0xFF50, 0xFF51, 0xFF52, 0xFF53, 0xFF54, 0xFF55, 0xFF56, 0xFF57, 
	0xFF58, 0xFF59, 0xFF5A, 0xFF3B, 0xFF3C, 0xFF3D, 0xFF3E, 0xFF3F, 
	0xFF40, 0xFF41, 0xFF42, 0xFF43, 0xFF44, 0xFF45, 0xFF46, 0xFF47, 
	0xFF48, 0xFF49, 0xFF4A, 0xFF4B, 0xFF4C, 0xFF4D, 0xFF4E, 0xFF4F, 
	0xFF50, 0xFF51, 0xFF52, 0xFF53, 0xFF54, 0xFF55, 0xFF56, 0xFF57, 
	0xFF58, 0xFF59, 0xFF5A, 0xFF5B, 0xFF5C, 0xFF5D, 0xFF5E, 0xFF5F, 
	0xFF60, 0xFF61, 0xFF62, 0xFF63, 0xFF64, 0xFF65, 0xFF66, 0xFF67, 
	0xFF68, 0xFF69, 0xFF6A, 0xFF6B, 0xFF6C, 0xFF6D, 0xFF6E, 0xFF6F, 
	0xFF70, 0xFF71, 0xFF72, 0xFF73, 0xFF74, 0xFF75, 0xFF76, 0xFF77, 
	0xFF78, 0xFF79, 0xFF7A, 0xFF7B, 0xFF7C, 0xFF7D, 0xFF7E, 0xFF7F, 
	0xFF80, 0xFF81, 0xFF82, 0xFF83, 0xFF84, 0xFF85, 0xFF86, 0xFF87, 
	0xFF88, 0xFF89, 0xFF8A, 0xFF8B, 0xFF8C, 0xFF8D, 0xFF8E, 0xFF8F, 
	0xFF90, 0xFF91, 0xFF92, 0xFF93, 0xFF94, 0xFF95, 0xFF96, 0xFF97, 
	0xFF98, 0xFF99, 0xFF9A, 0xFF9B, 0xFF9C, 0xFF9D, 0xFF9E, 0xFF9F, 
	0xFFA0, 0xFFA1, 0xFFA2, 0xFFA3, 0xFFA4, 0xFFA5, 0xFFA6, 0xFFA7, 
	0xFFA8, 0xFFA9, 0xFFAA, 0xFFAB, 0xFFAC, 0xFFAD, 0xFFAE, 0xFFAF, 
	0xFFB0, 0xFFB1, 0xFFB2, 0xFFB3, 0xFFB4, 0xFFB5, 0xFFB6, 0xFFB7, 
	0xFFB8, 0xFFB9, 0xFFBA, 0xFFBB, 0xFFBC, 0xFFBD, 0xFFBE, 0xFFBF, 
	0xFFC0, 0xFFC1, 0xFFC2, 0xFFC3, 0xFFC4, 0xFFC5, 0xFFC6, 0xFFC7, 
	0xFFC8, 0xFFC9, 0xFFCA, 0xFFCB, 0xFFCC, 0xFFCD, 0xFFCE, 0xFFCF, 
	0xFFD0, 0xFFD1, 0xFFD2, 0xFFD3, 0xFFD4, 0xFFD5, 0xFFD6, 0xFFD7, 
	0xFFD8, 0xFFD9, 0xFFDA, 0xFFDB, 0xFFDC, 0xFFDD, 0xFFDE, 0xFFDF, 
	0xFFE0, 0xFFE1, 0xFFE2, 0xFFE3, 0xFFE4, 0xFFE5, 0xFFE6, 0xFFE7, 
	0xFFE8, 0xFFE9, 0xFFEA, 0xFFEB, 0xFFEC, 0xFFED, 0xFFEE, 0xFFEF, 
	0xFFF0, 0xFFF1, 0xFFF2, 0xFFF3, 0xFFF4, 0xFFF5, 0xFFF6, 0xFFF7, 
	0xFFF8, 0xFFF9, 0xFFFA, 0xFFFB, 0xFFFC, 0xFFFD, 0xFFFE, 0xFFFF
};

static const uint16_t *pages[256] =
{
	page_00, page_01, page_02, page_03, page_04, page_05, NULL,    NULL,
	NULL,    NULL,    NULL,    NULL,    NULL,    NULL,    NULL,    NULL,
	page_10, NULL,    NULL,    NULL,    NULL,    NULL,    NULL,    NULL,
	NULL,    NULL,    NULL,    NULL,    NULL,    NULL,    page_1E, page_1F,
	NULL,    page_21, NULL,    NULL,    page_24, NULL,    NULL,    NULL,
	NULL,    NULL,    NULL,    NULL,    page_2C, NULL,    NULL,    NULL,
	NULL,    NULL,    NULL,    NULL,    NULL,    NULL,    NULL,    NULL,
	NULL,    NULL,    NULL,    NULL,    NULL,    NULL,    NULL,    NULL,
	NULL,    NULL,    NULL,    NULL,    NULL,    NULL,    NULL,    NULL,
	NULL,    NULL,    NULL,    NULL,    NULL,    NULL,    NULL,    NULL,
	NULL,    NULL,    NULL,    NULL,    NULL,    NULL,    NULL,    NULL,
	NULL,    NULL,    NULL,    NULL,    NULL,    NULL,    NULL,    NULL,
	NULL,    NULL,    NULL,    NULL,    NULL,    NULL,    NULL,    NULL,
	NULL,    NULL,    NULL,    NULL,    NULL,    NULL,    NULL,    NULL,
	NULL,    NULL,    NULL,    NULL,    NULL,    NULL,    NULL,    NULL,
	NULL,    NULL,    NULL,    NULL,    NULL,    NULL,    NULL,    NULL,
	NULL,    NULL,    NULL,    NULL,    NULL,    NULL,    NULL,    NULL,
	NULL,    NULL,    NULL,    NULL,    NULL,    NULL,    NULL,    NULL,
	NULL,    NULL,    NULL,    NULL,    NULL,    NULL,    NULL,    NULL,
	NULL,    NULL,    NULL,    NULL,    NULL,    NULL,    NULL,    NULL,
	NULL,    NULL,    NULL,    NULL,    NULL,    NULL,    NULL,    NULL,
	NULL,    NULL,    NULL,    NULL,    NULL,    NULL,    NULL,    NULL,
	NULL,    NULL,    NULL,    NULL,    NULL,    NULL,    NULL,    NULL,
	NULL,    NULL,    NULL,    NULL,    NULL,    NULL,    NULL,    NULL,
	NULL,    NULL,    NULL,    NULL,    NULL,    NULL,    NULL,    NULL,
	NULL,    NULL,    NULL,    NULL,    NULL,    NULL,    NULL,    NULL,
	NULL,    NULL,    NULL,    NULL,    NULL,    NULL,    NULL,    NULL,
	NULL,    NULL,    NULL,    NULL,    NULL,    NULL,    NULL,    NULL,
	NULL,    NULL,    NULL,    NULL,    NULL,    NULL,    NULL,    NULL,
	NULL,    NULL,    NULL,    NULL,    NULL,    NULL,    NULL,    NULL,
	NULL,    NULL,    NULL,    NULL,    NULL,    NULL,    NULL,    NULL,
	NULL,    NULL,    NULL,    NULL,    NULL,    NULL,    NULL,    page_FF
};


/**
 * \brief Simple case folding of a wide character.
 * \param wc the wide character to fold.
 * \return If a simple folding is defined, the folded version of \c wc
 *         is returned, otherwise \c wc is returned unchanged.
 * \remarks This function performs simple case folding using two
 *          accesses in large lookup tables.
 *
 * Case folding provides a mapping between characters that only differ
 * in case. This is useful for case insensitive comparison. Simple case
 * folding maps a single wide character to another single wide character
 * (usually lower case). Full case folding, instead, may map a single
 * wide character to more wide characters.
 */
wchar_t unicode_simple_fold(wchar_t wc)
{
	if ((wc >= 0) && (wc < 0x10000))
	{
		const uint16_t *p = pages[wc >> 8];
		if (p) wc = (wchar_t) p[wc & 0xFF];
	}
	else if ((wc >= 0x10400) && (wc <= 0x10427)) wc += 0x28;
	return wc;
}

/* @} */