/************************************************************************
 * $Id$
 *
 * ------------
 * Description:
 * ------------
 * This is an implemention of Unicode's Bidirectional Algorithm
 * (known as UAX #9).
 *
 *   http://www.unicode.org/reports/tr9/
 *
 * Author: Ahmad Khalifa
 *
 * -----------------
 * Revision Details:    (Updated by Revision Control System)
 * -----------------
 *  $Date$
 *  $Author$
 *  $Revision$
 *
 * (www.arabeyes.org - under MIT license)
 *
 ************************************************************************/

/*
 * TODO:
 * =====
 * - Explicit marks need to be handled (they are not 100% now)
 * - Ligatures
 */

#include <stdlib.h>	/* definition of wchar_t*/

#include "misc.h"

#define LMASK	0x3F	/* Embedding Level mask */
#define OMASK	0xC0	/* Override mask */
#define OISL	0x80	/* Override is L */
#define OISR	0x40	/* Override is R */

/* For standalone compilation in a testing mode.
 * Still depends on the PuTTY headers for snewn and sfree, but can avoid
 * _linking_ with any other PuTTY code. */
#ifdef TEST_GETTYPE
#define safemalloc malloc
#define safefree free
#endif

/* Shaping Helpers */
#define STYPE(xh) ((((xh) >= SHAPE_FIRST) && ((xh) <= SHAPE_LAST)) ? \
shapetypes[(xh)-SHAPE_FIRST].type : SU) /*))*/
#define SISOLATED(xh) (shapetypes[(xh)-SHAPE_FIRST].form_b)
#define SFINAL(xh) ((xh)+1)
#define SINITIAL(xh) ((xh)+2)
#define SMEDIAL(ch) ((ch)+3)

#define leastGreaterOdd(x) ( ((x)+1) | 1 )
#define leastGreaterEven(x) ( ((x)+2) &~ 1 )

typedef struct bidi_char {
    wchar_t origwc, wc;
    unsigned short index;
} bidi_char;

/* function declarations */
void flipThisRun(bidi_char *from, unsigned char* level, int max, int count);
int findIndexOfRun(unsigned char* level , int start, int count, int tlevel);
unsigned char getType(int ch);
unsigned char setOverrideBits(unsigned char level, unsigned char override);
int getPreviousLevel(unsigned char* level, int from);
int do_shape(bidi_char *line, bidi_char *to, int count);
int do_bidi(bidi_char *line, int count);
void doMirror(wchar_t* ch);

/* character types */
enum {
    L,
    LRE,
    LRO,
    R,
    AL,
    RLE,
    RLO,
    PDF,
    EN,
    ES,
    ET,
    AN,
    CS,
    NSM,
    BN,
    B,
    S,
    WS,
    ON
};

/* Shaping Types */
enum {
    SL, /* Left-Joining, doesnt exist in U+0600 - U+06FF */
    SR, /* Right-Joining, ie has Isolated, Final */
    SD, /* Dual-Joining, ie has Isolated, Final, Initial, Medial */
    SU, /* Non-Joining */
    SC  /* Join-Causing, like U+0640 (TATWEEL) */
};

typedef struct {
    char type;
    wchar_t form_b;
} shape_node;

/* Kept near the actual table, for verification. */
#define SHAPE_FIRST 0x621
#define SHAPE_LAST 0x64A

const shape_node shapetypes[] = {
    /* index, Typ, Iso, Ligature Index*/
    /* 621 */ {SU, 0xFE80},
    /* 622 */ {SR, 0xFE81},
    /* 623 */ {SR, 0xFE83},
    /* 624 */ {SR, 0xFE85},
    /* 625 */ {SR, 0xFE87},
    /* 626 */ {SD, 0xFE89},
    /* 627 */ {SR, 0xFE8D},
    /* 628 */ {SD, 0xFE8F},
    /* 629 */ {SR, 0xFE93},
    /* 62A */ {SD, 0xFE95},
    /* 62B */ {SD, 0xFE99},
    /* 62C */ {SD, 0xFE9D},
    /* 62D */ {SD, 0xFEA1},
    /* 62E */ {SD, 0xFEA5},
    /* 62F */ {SR, 0xFEA9},
    /* 630 */ {SR, 0xFEAB},
    /* 631 */ {SR, 0xFEAD},
    /* 632 */ {SR, 0xFEAF},
    /* 633 */ {SD, 0xFEB1},
    /* 634 */ {SD, 0xFEB5},
    /* 635 */ {SD, 0xFEB9},
    /* 636 */ {SD, 0xFEBD},
    /* 637 */ {SD, 0xFEC1},
    /* 638 */ {SD, 0xFEC5},
    /* 639 */ {SD, 0xFEC9},
    /* 63A */ {SD, 0xFECD},
    /* 63B */ {SU, 0x0},
    /* 63C */ {SU, 0x0},
    /* 63D */ {SU, 0x0},
    /* 63E */ {SU, 0x0},
    /* 63F */ {SU, 0x0},
    /* 640 */ {SC, 0x0},
    /* 641 */ {SD, 0xFED1},
    /* 642 */ {SD, 0xFED5},
    /* 643 */ {SD, 0xFED9},
    /* 644 */ {SD, 0xFEDD},
    /* 645 */ {SD, 0xFEE1},
    /* 646 */ {SD, 0xFEE5},
    /* 647 */ {SD, 0xFEE9},
    /* 648 */ {SR, 0xFEED},
    /* 649 */ {SR, 0xFEEF}, /* SD */
    /* 64A */ {SD, 0xFEF1}
};

/*
 * Flips the text buffer, according to max level, and
 * all higher levels
 *
 * Input:
 * from: text buffer, on which to apply flipping
 * level: resolved levels buffer
 * max: the maximum level found in this line (should be unsigned char)
 * count: line size in bidi_char
 */
void flipThisRun(bidi_char *from, unsigned char *level, int max, int count)
{
    int i, j, k, tlevel;
    bidi_char temp;

    j = i = 0;
    while (i<count && j<count) {

	/* find the start of the run of level=max */
	tlevel = max;
	i = j = findIndexOfRun(level, i, count, max);
	/* find the end of the run */
	while (i<count && tlevel <= level[i]) {
	    i++;
	}
	for (k = i - 1; k > j; k--, j++) {
	    temp = from[k];
	    from[k] = from[j];
	    from[j] = temp;
	}
    }
}

/*
 * Finds the index of a run with level equals tlevel
 */
int findIndexOfRun(unsigned char* level , int start, int count, int tlevel)
{
    int i;
    for (i=start; i<count; i++) {
	if (tlevel == level[i]) {
	    return i;
	}
    }
    return count;
}

/*
 * Returns the bidi character type of ch.
 *
 * The data table in this function is constructed from the Unicode
 * Character Database, downloadable from unicode.org at the URL
 * 
 *     http://www.unicode.org/Public/UNIDATA/UnicodeData.txt
 * 
 * by the following fragment of Perl:

perl -ne 'split ";"; $num = hex $_[0]; $type = $_[4];' \
      -e '$fl = ($_[1] =~ /First/ ? 1 : $_[1] =~ /Last/ ? 2 : 0);' \
      -e 'if ($type eq $runtype and ($runend == $num-1 or ' \
      -e '    ($fl==2 and $pfl==1))) {$runend = $num;} else { &reset; }' \
      -e '$pfl=$fl; END { &reset }; sub reset {' \
      -e 'printf"        {0x%04x, 0x%04x, %s},\n",$runstart,$runend,$runtype' \
      -e '  if defined $runstart and $runtype ne "ON";' \
      -e '$runstart=$runend=$num; $runtype=$type;}' \
    UnicodeData.txt

 */
unsigned char getType(int ch)
{
    static const struct {
	int first, last, type;
    } lookup[] = {
        {0x0000, 0x0008, BN},
        {0x0009, 0x0009, S},
        {0x000a, 0x000a, B},
        {0x000b, 0x000b, S},
        {0x000c, 0x000c, WS},
        {0x000d, 0x000d, B},
        {0x000e, 0x001b, BN},
        {0x001c, 0x001e, B},
        {0x001f, 0x001f, S},
        {0x0020, 0x0020, WS},
        {0x0023, 0x0025, ET},
        {0x002b, 0x002b, ES},
        {0x002c, 0x002c, CS},
        {0x002d, 0x002d, ES},
        {0x002e, 0x002f, CS},
        {0x0030, 0x0039, EN},
        {0x003a, 0x003a, CS},
        {0x0041, 0x005a, L},
        {0x0061, 0x007a, L},
        {0x007f, 0x0084, BN},
        {0x0085, 0x0085, B},
        {0x0086, 0x009f, BN},
        {0x00a0, 0x00a0, CS},
        {0x00a2, 0x00a5, ET},
        {0x00aa, 0x00aa, L},
        {0x00ad, 0x00ad, BN},
        {0x00b0, 0x00b1, ET},
        {0x00b2, 0x00b3, EN},
        {0x00b5, 0x00b5, L},
        {0x00b9, 0x00b9, EN},
        {0x00ba, 0x00ba, L},
        {0x00c0, 0x00d6, L},
        {0x00d8, 0x00f6, L},
        {0x00f8, 0x0236, L},
        {0x0250, 0x02b8, L},
        {0x02bb, 0x02c1, L},
        {0x02d0, 0x02d1, L},
        {0x02e0, 0x02e4, L},
        {0x02ee, 0x02ee, L},
        {0x0300, 0x0357, NSM},
        {0x035d, 0x036f, NSM},
        {0x037a, 0x037a, L},
        {0x0386, 0x0386, L},
        {0x0388, 0x038a, L},
        {0x038c, 0x038c, L},
        {0x038e, 0x03a1, L},
        {0x03a3, 0x03ce, L},
        {0x03d0, 0x03f5, L},
        {0x03f7, 0x03fb, L},
        {0x0400, 0x0482, L},
        {0x0483, 0x0486, NSM},
        {0x0488, 0x0489, NSM},
        {0x048a, 0x04ce, L},
        {0x04d0, 0x04f5, L},
        {0x04f8, 0x04f9, L},
        {0x0500, 0x050f, L},
        {0x0531, 0x0556, L},
        {0x0559, 0x055f, L},
        {0x0561, 0x0587, L},
        {0x0589, 0x0589, L},
        {0x0591, 0x05a1, NSM},
        {0x05a3, 0x05b9, NSM},
        {0x05bb, 0x05bd, NSM},
        {0x05be, 0x05be, R},
        {0x05bf, 0x05bf, NSM},
        {0x05c0, 0x05c0, R},
        {0x05c1, 0x05c2, NSM},
        {0x05c3, 0x05c3, R},
        {0x05c4, 0x05c4, NSM},
        {0x05d0, 0x05ea, R},
        {0x05f0, 0x05f4, R},
        {0x0600, 0x0603, AL},
        {0x060c, 0x060c, CS},
        {0x060d, 0x060d, AL},
        {0x0610, 0x0615, NSM},
        {0x061b, 0x061b, AL},
        {0x061f, 0x061f, AL},
        {0x0621, 0x063a, AL},
        {0x0640, 0x064a, AL},
        {0x064b, 0x0658, NSM},
        {0x0660, 0x0669, AN},
        {0x066a, 0x066a, ET},
        {0x066b, 0x066c, AN},
        {0x066d, 0x066f, AL},
        {0x0670, 0x0670, NSM},
        {0x0671, 0x06d5, AL},
        {0x06d6, 0x06dc, NSM},
        {0x06dd, 0x06dd, AL},
        {0x06de, 0x06e4, NSM},
        {0x06e5, 0x06e6, AL},
        {0x06e7, 0x06e8, NSM},
        {0x06ea, 0x06ed, NSM},
        {0x06ee, 0x06ef, AL},
        {0x06f0, 0x06f9, EN},
        {0x06fa, 0x070d, AL},
        {0x070f, 0x070f, BN},
        {0x0710, 0x0710, AL},
        {0x0711, 0x0711, NSM},
        {0x0712, 0x072f, AL},
        {0x0730, 0x074a, NSM},
        {0x074d, 0x074f, AL},
        {0x0780, 0x07a5, AL},
        {0x07a6, 0x07b0, NSM},
        {0x07b1, 0x07b1, AL},
        {0x0901, 0x0902, NSM},
        {0x0903, 0x0939, L},
        {0x093c, 0x093c, NSM},
        {0x093d, 0x0940, L},
        {0x0941, 0x0948, NSM},
        {0x0949, 0x094c, L},
        {0x094d, 0x094d, NSM},
        {0x0950, 0x0950, L},
        {0x0951, 0x0954, NSM},
        {0x0958, 0x0961, L},
        {0x0962, 0x0963, NSM},
        {0x0964, 0x0970, L},
        {0x0981, 0x0981, NSM},
        {0x0982, 0x0983, L},
        {0x0985, 0x098c, L},
        {0x098f, 0x0990, L},
        {0x0993, 0x09a8, L},
        {0x09aa, 0x09b0, L},
        {0x09b2, 0x09b2, L},
        {0x09b6, 0x09b9, L},
        {0x09bc, 0x09bc, NSM},
        {0x09bd, 0x09c0, L},
        {0x09c1, 0x09c4, NSM},
        {0x09c7, 0x09c8, L},
        {0x09cb, 0x09cc, L},
        {0x09cd, 0x09cd, NSM},
        {0x09d7, 0x09d7, L},
        {0x09dc, 0x09dd, L},
        {0x09df, 0x09e1, L},
        {0x09e2, 0x09e3, NSM},
        {0x09e6, 0x09f1, L},
        {0x09f2, 0x09f3, ET},
        {0x09f4, 0x09fa, L},
        {0x0a01, 0x0a02, NSM},
        {0x0a03, 0x0a03, L},
        {0x0a05, 0x0a0a, L},
        {0x0a0f, 0x0a10, L},
        {0x0a13, 0x0a28, L},
        {0x0a2a, 0x0a30, L},
        {0x0a32, 0x0a33, L},
        {0x0a35, 0x0a36, L},
        {0x0a38, 0x0a39, L},
        {0x0a3c, 0x0a3c, NSM},
        {0x0a3e, 0x0a40, L},
        {0x0a41, 0x0a42, NSM},
        {0x0a47, 0x0a48, NSM},
        {0x0a4b, 0x0a4d, NSM},
        {0x0a59, 0x0a5c, L},
        {0x0a5e, 0x0a5e, L},
        {0x0a66, 0x0a6f, L},
        {0x0a70, 0x0a71, NSM},
        {0x0a72, 0x0a74, L},
        {0x0a81, 0x0a82, NSM},
        {0x0a83, 0x0a83, L},
        {0x0a85, 0x0a8d, L},
        {0x0a8f, 0x0a91, L},
        {0x0a93, 0x0aa8, L},
        {0x0aaa, 0x0ab0, L},
        {0x0ab2, 0x0ab3, L},
        {0x0ab5, 0x0ab9, L},
        {0x0abc, 0x0abc, NSM},
        {0x0abd, 0x0ac0, L},
        {0x0ac1, 0x0ac5, NSM},
        {0x0ac7, 0x0ac8, NSM},
        {0x0ac9, 0x0ac9, L},
        {0x0acb, 0x0acc, L},
        {0x0acd, 0x0acd, NSM},
        {0x0ad0, 0x0ad0, L},
        {0x0ae0, 0x0ae1, L},
        {0x0ae2, 0x0ae3, NSM},
        {0x0ae6, 0x0aef, L},
        {0x0af1, 0x0af1, ET},
        {0x0b01, 0x0b01, NSM},
        {0x0b02, 0x0b03, L},
        {0x0b05, 0x0b0c, L},
        {0x0b0f, 0x0b10, L},
        {0x0b13, 0x0b28, L},
        {0x0b2a, 0x0b30, L},
        {0x0b32, 0x0b33, L},
        {0x0b35, 0x0b39, L},
        {0x0b3c, 0x0b3c, NSM},
        {0x0b3d, 0x0b3e, L},
        {0x0b3f, 0x0b3f, NSM},
        {0x0b40, 0x0b40, L},
        {0x0b41, 0x0b43, NSM},
        {0x0b47, 0x0b48, L},
        {0x0b4b, 0x0b4c, L},
        {0x0b4d, 0x0b4d, NSM},
        {0x0b56, 0x0b56, NSM},
        {0x0b57, 0x0b57, L},
        {0x0b5c, 0x0b5d, L},
        {0x0b5f, 0x0b61, L},
        {0x0b66, 0x0b71, L},
        {0x0b82, 0x0b82, NSM},
        {0x0b83, 0x0b83, L},
        {0x0b85, 0x0b8a, L},
        {0x0b8e, 0x0b90, L},
        {0x0b92, 0x0b95, L},
        {0x0b99, 0x0b9a, L},
        {0x0b9c, 0x0b9c, L},
        {0x0b9e, 0x0b9f, L},
        {0x0ba3, 0x0ba4, L},
        {0x0ba8, 0x0baa, L},
        {0x0bae, 0x0bb5, L},
        {0x0bb7, 0x0bb9, L},
        {0x0bbe, 0x0bbf, L},
        {0x0bc0, 0x0bc0, NSM},
        {0x0bc1, 0x0bc2, L},
        {0x0bc6, 0x0bc8, L},
        {0x0bca, 0x0bcc, L},
        {0x0bcd, 0x0bcd, NSM},
        {0x0bd7, 0x0bd7, L},
        {0x0be7, 0x0bf2, L},
        {0x0bf9, 0x0bf9, ET},
        {0x0c01, 0x0c03, L},
        {0x0c05, 0x0c0c, L},
        {0x0c0e, 0x0c10, L},
        {0x0c12, 0x0c28, L},
        {0x0c2a, 0x0c33, L},
        {0x0c35, 0x0c39, L},
        {0x0c3e, 0x0c40, NSM},
        {0x0c41, 0x0c44, L},
        {0x0c46, 0x0c48, NSM},
        {0x0c4a, 0x0c4d, NSM},
        {0x0c55, 0x0c56, NSM},
        {0x0c60, 0x0c61, L},
        {0x0c66, 0x0c6f, L},
        {0x0c82, 0x0c83, L},
        {0x0c85, 0x0c8c, L},
        {0x0c8e, 0x0c90, L},
        {0x0c92, 0x0ca8, L},
        {0x0caa, 0x0cb3, L},
        {0x0cb5, 0x0cb9, L},
        {0x0cbc, 0x0cbc, NSM},
        {0x0cbd, 0x0cc4, L},
        {0x0cc6, 0x0cc8, L},
        {0x0cca, 0x0ccb, L},
        {0x0ccc, 0x0ccd, NSM},
        {0x0cd5, 0x0cd6, L},
        {0x0cde, 0x0cde, L},
        {0x0ce0, 0x0ce1, L},
        {0x0ce6, 0x0cef, L},
        {0x0d02, 0x0d03, L},
        {0x0d05, 0x0d0c, L},
        {0x0d0e, 0x0d10, L},
        {0x0d12, 0x0d28, L},
        {0x0d2a, 0x0d39, L},
        {0x0d3e, 0x0d40, L},
        {0x0d41, 0x0d43, NSM},
        {0x0d46, 0x0d48, L},
        {0x0d4a, 0x0d4c, L},
        {0x0d4d, 0x0d4d, NSM},
        {0x0d57, 0x0d57, L},
        {0x0d60, 0x0d61, L},
        {0x0d66, 0x0d6f, L},
        {0x0d82, 0x0d83, L},
        {0x0d85, 0x0d96, L},
        {0x0d9a, 0x0db1, L},
        {0x0db3, 0x0dbb, L},
        {0x0dbd, 0x0dbd, L},
        {0x0dc0, 0x0dc6, L},
        {0x0dca, 0x0dca, NSM},
        {0x0dcf, 0x0dd1, L},
        {0x0dd2, 0x0dd4, NSM},
        {0x0dd6, 0x0dd6, NSM},
        {0x0dd8, 0x0ddf, L},
        {0x0df2, 0x0df4, L},
        {0x0e01, 0x0e30, L},
        {0x0e31, 0x0e31, NSM},
        {0x0e32, 0x0e33, L},
        {0x0e34, 0x0e3a, NSM},
        {0x0e3f, 0x0e3f, ET},
        {0x0e40, 0x0e46, L},
        {0x0e47, 0x0e4e, NSM},
        {0x0e4f, 0x0e5b, L},
        {0x0e81, 0x0e82, L},
        {0x0e84, 0x0e84, L},
        {0x0e87, 0x0e88, L},
        {0x0e8a, 0x0e8a, L},
        {0x0e8d, 0x0e8d, L},
        {0x0e94, 0x0e97, L},
        {0x0e99, 0x0e9f, L},
        {0x0ea1, 0x0ea3, L},
        {0x0ea5, 0x0ea5, L},
        {0x0ea7, 0x0ea7, L},
        {0x0eaa, 0x0eab, L},
        {0x0ead, 0x0eb0, L},
        {0x0eb1, 0x0eb1, NSM},
        {0x0eb2, 0x0eb3, L},
        {0x0eb4, 0x0eb9, NSM},
        {0x0ebb, 0x0ebc, NSM},
        {0x0ebd, 0x0ebd, L},
        {0x0ec0, 0x0ec4, L},
        {0x0ec6, 0x0ec6, L},
        {0x0ec8, 0x0ecd, NSM},
        {0x0ed0, 0x0ed9, L},
        {0x0edc, 0x0edd, L},
        {0x0f00, 0x0f17, L},
        {0x0f18, 0x0f19, NSM},
        {0x0f1a, 0x0f34, L},
        {0x0f35, 0x0f35, NSM},
        {0x0f36, 0x0f36, L},
        {0x0f37, 0x0f37, NSM},
        {0x0f38, 0x0f38, L},
        {0x0f39, 0x0f39, NSM},
        {0x0f3e, 0x0f47, L},
        {0x0f49, 0x0f6a, L},
        {0x0f71, 0x0f7e, NSM},
        {0x0f7f, 0x0f7f, L},
        {0x0f80, 0x0f84, NSM},
        {0x0f85, 0x0f85, L},
        {0x0f86, 0x0f87, NSM},
        {0x0f88, 0x0f8b, L},
        {0x0f90, 0x0f97, NSM},
        {0x0f99, 0x0fbc, NSM},
        {0x0fbe, 0x0fc5, L},
        {0x0fc6, 0x0fc6, NSM},
        {0x0fc7, 0x0fcc, L},
        {0x0fcf, 0x0fcf, L},
        {0x1000, 0x1021, L},
        {0x1023, 0x1027, L},
        {0x1029, 0x102a, L},
        {0x102c, 0x102c, L},
        {0x102d, 0x1030, NSM},
        {0x1031, 0x1031, L},
        {0x1032, 0x1032, NSM},
        {0x1036, 0x1037, NSM},
        {0x1038, 0x1038, L},
        {0x1039, 0x1039, NSM},
        {0x1040, 0x1057, L},
        {0x1058, 0x1059, NSM},
        {0x10a0, 0x10c5, L},
        {0x10d0, 0x10f8, L},
        {0x10fb, 0x10fb, L},
        {0x1100, 0x1159, L},
        {0x115f, 0x11a2, L},
        {0x11a8, 0x11f9, L},
        {0x1200, 0x1206, L},
        {0x1208, 0x1246, L},
        {0x1248, 0x1248, L},
        {0x124a, 0x124d, L},
        {0x1250, 0x1256, L},
        {0x1258, 0x1258, L},
        {0x125a, 0x125d, L},
        {0x1260, 0x1286, L},
        {0x1288, 0x1288, L},
        {0x128a, 0x128d, L},
        {0x1290, 0x12ae, L},
        {0x12b0, 0x12b0, L},
        {0x12b2, 0x12b5, L},
        {0x12b8, 0x12be, L},
        {0x12c0, 0x12c0, L},
        {0x12c2, 0x12c5, L},
        {0x12c8, 0x12ce, L},
        {0x12d0, 0x12d6, L},
        {0x12d8, 0x12ee, L},
        {0x12f0, 0x130e, L},
        {0x1310, 0x1310, L},
        {0x1312, 0x1315, L},
        {0x1318, 0x131e, L},
        {0x1320, 0x1346, L},
        {0x1348, 0x135a, L},
        {0x1361, 0x137c, L},
        {0x13a0, 0x13f4, L},
        {0x1401, 0x1676, L},
        {0x1680, 0x1680, WS},
        {0x1681, 0x169a, L},
        {0x16a0, 0x16f0, L},
        {0x1700, 0x170c, L},
        {0x170e, 0x1711, L},
        {0x1712, 0x1714, NSM},
        {0x1720, 0x1731, L},
        {0x1732, 0x1734, NSM},
        {0x1735, 0x1736, L},
        {0x1740, 0x1751, L},
        {0x1752, 0x1753, NSM},
        {0x1760, 0x176c, L},
        {0x176e, 0x1770, L},
        {0x1772, 0x1773, NSM},
        {0x1780, 0x17b6, L},
        {0x17b7, 0x17bd, NSM},
        {0x17be, 0x17c5, L},
        {0x17c6, 0x17c6, NSM},
        {0x17c7, 0x17c8, L},
        {0x17c9, 0x17d3, NSM},
        {0x17d4, 0x17da, L},
        {0x17db, 0x17db, ET},
        {0x17dc, 0x17dc, L},
        {0x17dd, 0x17dd, NSM},
        {0x17e0, 0x17e9, L},
        {0x180b, 0x180d, NSM},
        {0x180e, 0x180e, WS},
        {0x1810, 0x1819, L},
        {0x1820, 0x1877, L},
        {0x1880, 0x18a8, L},
        {0x18a9, 0x18a9, NSM},
        {0x1900, 0x191c, L},
        {0x1920, 0x1922, NSM},
        {0x1923, 0x1926, L},
        {0x1927, 0x192b, NSM},
        {0x1930, 0x1931, L},
        {0x1932, 0x1932, NSM},
        {0x1933, 0x1938, L},
        {0x1939, 0x193b, NSM},
        {0x1946, 0x196d, L},
        {0x1970, 0x1974, L},
        {0x1d00, 0x1d6b, L},
        {0x1e00, 0x1e9b, L},
        {0x1ea0, 0x1ef9, L},
        {0x1f00, 0x1f15, L},
        {0x1f18, 0x1f1d, L},
        {0x1f20, 0x1f45, L},
        {0x1f48, 0x1f4d, L},
        {0x1f50, 0x1f57, L},
        {0x1f59, 0x1f59, L},
        {0x1f5b, 0x1f5b, L},
        {0x1f5d, 0x1f5d, L},
        {0x1f5f, 0x1f7d, L},
        {0x1f80, 0x1fb4, L},
        {0x1fb6, 0x1fbc, L},
        {0x1fbe, 0x1fbe, L},
        {0x1fc2, 0x1fc4, L},
        {0x1fc6, 0x1fcc, L},
        {0x1fd0, 0x1fd3, L},
        {0x1fd6, 0x1fdb, L},
        {0x1fe0, 0x1fec, L},
        {0x1ff2, 0x1ff4, L},
        {0x1ff6, 0x1ffc, L},
        {0x2000, 0x200a, WS},
        {0x200b, 0x200d, BN},
        {0x200e, 0x200e, L},
        {0x200f, 0x200f, R},
        {0x2028, 0x2028, WS},
        {0x2029, 0x2029, B},
        {0x202a, 0x202a, LRE},
        {0x202b, 0x202b, RLE},
        {0x202c, 0x202c, PDF},
        {0x202d, 0x202d, LRO},
        {0x202e, 0x202e, RLO},
        {0x202f, 0x202f, WS},
        {0x2030, 0x2034, ET},
        {0x2044, 0x2044, CS},
        {0x205f, 0x205f, WS},
        {0x2060, 0x2063, BN},
        {0x206a, 0x206f, BN},
        {0x2070, 0x2070, EN},
        {0x2071, 0x2071, L},
        {0x2074, 0x2079, EN},
        {0x207a, 0x207b, ET},
        {0x207f, 0x207f, L},
        {0x2080, 0x2089, EN},
        {0x208a, 0x208b, ET},
        {0x20a0, 0x20b1, ET},
        {0x20d0, 0x20ea, NSM},
        {0x2102, 0x2102, L},
        {0x2107, 0x2107, L},
        {0x210a, 0x2113, L},
        {0x2115, 0x2115, L},
        {0x2119, 0x211d, L},
        {0x2124, 0x2124, L},
        {0x2126, 0x2126, L},
        {0x2128, 0x2128, L},
        {0x212a, 0x212d, L},
        {0x212e, 0x212e, ET},
        {0x212f, 0x2131, L},
        {0x2133, 0x2139, L},
        {0x213d, 0x213f, L},
        {0x2145, 0x2149, L},
        {0x2160, 0x2183, L},
        {0x2212, 0x2213, ET},
        {0x2336, 0x237a, L},
        {0x2395, 0x2395, L},
        {0x2488, 0x249b, EN},
        {0x249c, 0x24e9, L},
        {0x2800, 0x28ff, L},
        {0x3000, 0x3000, WS},
        {0x3005, 0x3007, L},
        {0x3021, 0x3029, L},
        {0x302a, 0x302f, NSM},
        {0x3031, 0x3035, L},
        {0x3038, 0x303c, L},
        {0x3041, 0x3096, L},
        {0x3099, 0x309a, NSM},
        {0x309d, 0x309f, L},
        {0x30a1, 0x30fa, L},
        {0x30fc, 0x30ff, L},
        {0x3105, 0x312c, L},
        {0x3131, 0x318e, L},
        {0x3190, 0x31b7, L},
        {0x31f0, 0x321c, L},
        {0x3220, 0x3243, L},
        {0x3260, 0x327b, L},
        {0x327f, 0x32b0, L},
        {0x32c0, 0x32cb, L},
        {0x32d0, 0x32fe, L},
        {0x3300, 0x3376, L},
        {0x337b, 0x33dd, L},
        {0x33e0, 0x33fe, L},
        {0x3400, 0x4db5, L},
        {0x4e00, 0x9fa5, L},
        {0xa000, 0xa48c, L},
        {0xac00, 0xd7a3, L},
        {0xd800, 0xfa2d, L},
        {0xfa30, 0xfa6a, L},
        {0xfb00, 0xfb06, L},
        {0xfb13, 0xfb17, L},
        {0xfb1d, 0xfb1d, R},
        {0xfb1e, 0xfb1e, NSM},
        {0xfb1f, 0xfb28, R},
        {0xfb29, 0xfb29, ET},
        {0xfb2a, 0xfb36, R},
        {0xfb38, 0xfb3c, R},
        {0xfb3e, 0xfb3e, R},
        {0xfb40, 0xfb41, R},
        {0xfb43, 0xfb44, R},
        {0xfb46, 0xfb4f, R},
        {0xfb50, 0xfbb1, AL},
        {0xfbd3, 0xfd3d, AL},
        {0xfd50, 0xfd8f, AL},
        {0xfd92, 0xfdc7, AL},
        {0xfdf0, 0xfdfc, AL},
        {0xfe00, 0xfe0f, NSM},
        {0xfe20, 0xfe23, NSM},
        {0xfe50, 0xfe50, CS},
        {0xfe52, 0xfe52, CS},
        {0xfe55, 0xfe55, CS},
        {0xfe5f, 0xfe5f, ET},
        {0xfe62, 0xfe63, ET},
        {0xfe69, 0xfe6a, ET},
        {0xfe70, 0xfe74, AL},
        {0xfe76, 0xfefc, AL},
        {0xfeff, 0xfeff, BN},
        {0xff03, 0xff05, ET},
        {0xff0b, 0xff0b, ET},
        {0xff0c, 0xff0c, CS},
        {0xff0d, 0xff0d, ET},
        {0xff0e, 0xff0e, CS},
        {0xff0f, 0xff0f, ES},
        {0xff10, 0xff19, EN},
        {0xff1a, 0xff1a, CS},
        {0xff21, 0xff3a, L},
        {0xff41, 0xff5a, L},
        {0xff66, 0xffbe, L},
        {0xffc2, 0xffc7, L},
        {0xffca, 0xffcf, L},
        {0xffd2, 0xffd7, L},
        {0xffda, 0xffdc, L},
        {0xffe0, 0xffe1, ET},
        {0xffe5, 0xffe6, ET},
        {0x10000, 0x1000b, L},
        {0x1000d, 0x10026, L},
        {0x10028, 0x1003a, L},
        {0x1003c, 0x1003d, L},
        {0x1003f, 0x1004d, L},
        {0x10050, 0x1005d, L},
        {0x10080, 0x100fa, L},
        {0x10100, 0x10100, L},
        {0x10102, 0x10102, L},
        {0x10107, 0x10133, L},
        {0x10137, 0x1013f, L},
        {0x10300, 0x1031e, L},
        {0x10320, 0x10323, L},
        {0x10330, 0x1034a, L},
        {0x10380, 0x1039d, L},
        {0x1039f, 0x1039f, L},
        {0x10400, 0x1049d, L},
        {0x104a0, 0x104a9, L},
        {0x10800, 0x10805, R},
        {0x10808, 0x10808, R},
        {0x1080a, 0x10835, R},
        {0x10837, 0x10838, R},
        {0x1083c, 0x1083c, R},
        {0x1083f, 0x1083f, R},
        {0x1d000, 0x1d0f5, L},
        {0x1d100, 0x1d126, L},
        {0x1d12a, 0x1d166, L},
        {0x1d167, 0x1d169, NSM},
        {0x1d16a, 0x1d172, L},
        {0x1d173, 0x1d17a, BN},
        {0x1d17b, 0x1d182, NSM},
        {0x1d183, 0x1d184, L},
        {0x1d185, 0x1d18b, NSM},
        {0x1d18c, 0x1d1a9, L},
        {0x1d1aa, 0x1d1ad, NSM},
        {0x1d1ae, 0x1d1dd, L},
        {0x1d400, 0x1d454, L},
        {0x1d456, 0x1d49c, L},
        {0x1d49e, 0x1d49f, L},
        {0x1d4a2, 0x1d4a2, L},
        {0x1d4a5, 0x1d4a6, L},
        {0x1d4a9, 0x1d4ac, L},
        {0x1d4ae, 0x1d4b9, L},
        {0x1d4bb, 0x1d4bb, L},
        {0x1d4bd, 0x1d4c3, L},
        {0x1d4c5, 0x1d505, L},
        {0x1d507, 0x1d50a, L},
        {0x1d50d, 0x1d514, L},
        {0x1d516, 0x1d51c, L},
        {0x1d51e, 0x1d539, L},
        {0x1d53b, 0x1d53e, L},
        {0x1d540, 0x1d544, L},
        {0x1d546, 0x1d546, L},
        {0x1d54a, 0x1d550, L},
        {0x1d552, 0x1d6a3, L},
        {0x1d6a8, 0x1d7c9, L},
        {0x1d7ce, 0x1d7ff, EN},
        {0x20000, 0x2a6d6, L},
        {0x2f800, 0x2fa1d, L},
        {0xe0001, 0xe0001, BN},
        {0xe0020, 0xe007f, BN},
        {0xe0100, 0xe01ef, NSM},
        {0xf0000, 0xffffd, L},
        {0x100000, 0x10fffd, L}
    };

    int i, j, k;

    i = -1;
    j = lenof(lookup);

    while (j - i > 1) {
	k = (i + j) / 2;
	if (ch < lookup[k].first)
	    j = k;
	else if (ch > lookup[k].last)
	    i = k;
	else
	    return lookup[k].type;
    }

    /*
     * If we reach here, the character was not in any of the
     * intervals listed in the lookup table. This means we return
     * ON (`Other Neutrals'). This is the appropriate code for any
     * character genuinely not listed in the Unicode table, and
     * also the table above has deliberately left out any
     * characters _explicitly_ listed as ON (to save space!).
     */
    return ON;
}

/*
 * Function exported to front ends to allow them to identify
 * bidi-active characters (in case, for example, the platform's
 * text display function can't conveniently be prevented from doing
 * its own bidi and so special treatment is required for characters
 * that would cause the bidi algorithm to activate).
 * 
 * This function is passed a single Unicode code point, and returns
 * nonzero if the presence of this code point can possibly cause
 * the bidi algorithm to do any reordering. Thus, any string
 * composed entirely of characters for which is_rtl() returns zero
 * should be safe to pass to a bidi-active platform display
 * function without fear.
 * 
 * (is_rtl() must therefore also return true for any character
 * which would be affected by Arabic shaping, but this isn't
 * important because all such characters are right-to-left so it
 * would have flagged them anyway.)
 */
int is_rtl(int c)
{
    /*
     * After careful reading of the Unicode bidi algorithm (URL as
     * given at the top of this file) I believe that the only
     * character classes which can possibly cause trouble are R,
     * AL, RLE and RLO. I think that any string containing no
     * character in any of those classes will be displayed
     * uniformly left-to-right by the Unicode bidi algorithm.
     */
    const int mask = (1<<R) | (1<<AL) | (1<<RLE) | (1<<RLO);

    return mask & (1 << (getType(c)));
}

/*
 * The most significant 2 bits of each level are used to store
 * Override status of each character
 * This function sets the override bits of level according
 * to the value in override, and reurns the new byte.
 */
unsigned char setOverrideBits(unsigned char level, unsigned char override)
{
    if (override == ON)
	return level;
    else if (override == R)
	return level | OISR;
    else if (override == L)
	return level | OISL;
    return level;
}

/*
 * Find the most recent run of the same value in `level', and
 * return the value _before_ it. Used to process U+202C POP
 * DIRECTIONAL FORMATTING.
 */
int getPreviousLevel(unsigned char* level, int from)
{
    if (from > 0) {
        unsigned char current = level[--from];

        while (from >= 0 && level[from] == current)
            from--;

        if (from >= 0)
            return level[from];

        return -1;
    } else
        return -1;
}

/* The Main shaping function, and the only one to be used
 * by the outside world.
 *
 * line: buffer to apply shaping to. this must be passed by doBidi() first
 * to: output buffer for the shaped data
 * count: number of characters in line
 */
int do_shape(bidi_char *line, bidi_char *to, int count)
{
    int i, tempShape, ligFlag;

    for (ligFlag=i=0; i<count; i++) {
	to[i] = line[i];
	tempShape = STYPE(line[i].wc);
	switch (tempShape) {
	  case SC:
	    break;

	  case SU:
	    break;

	  case SR:
	    tempShape = (i+1 < count ? STYPE(line[i+1].wc) : SU);
	    if ((tempShape == SL) || (tempShape == SD) || (tempShape == SC))
		to[i].wc = SFINAL((SISOLATED(line[i].wc)));
	    else
		to[i].wc = SISOLATED(line[i].wc);
	    break;


	  case SD:
	    /* Make Ligatures */
	    tempShape = (i+1 < count ? STYPE(line[i+1].wc) : SU);
	    if (line[i].wc == 0x644) {
		if (i > 0) switch (line[i-1].wc) {
		  case 0x622:
		    ligFlag = 1;
		    if ((tempShape == SL) || (tempShape == SD) || (tempShape == SC))
			to[i].wc = 0xFEF6;
		    else
			to[i].wc = 0xFEF5;
		    break;
		  case 0x623:
		    ligFlag = 1;
		    if ((tempShape == SL) || (tempShape == SD) || (tempShape == SC))
			to[i].wc = 0xFEF8;
		    else
			to[i].wc = 0xFEF7;
		    break;
		  case 0x625:
		    ligFlag = 1;
		    if ((tempShape == SL) || (tempShape == SD) || (tempShape == SC))
			to[i].wc = 0xFEFA;
		    else
			to[i].wc = 0xFEF9;
		    break;
		  case 0x627:
		    ligFlag = 1;
		    if ((tempShape == SL) || (tempShape == SD) || (tempShape == SC))
			to[i].wc = 0xFEFC;
		    else
			to[i].wc = 0xFEFB;
		    break;
		}
		if (ligFlag) {
		    to[i-1].wc = 0x20;
		    ligFlag = 0;
		    break;
		}
	    }

	    if ((tempShape == SL) || (tempShape == SD) || (tempShape == SC)) {
                tempShape = (i > 0 ? STYPE(line[i-1].wc) : SU);
		if ((tempShape == SR) || (tempShape == SD) || (tempShape == SC))
		    to[i].wc = SMEDIAL((SISOLATED(line[i].wc)));
		else
		    to[i].wc = SFINAL((SISOLATED(line[i].wc)));
		break;
	    }

            tempShape = (i > 0 ? STYPE(line[i-1].wc) : SU);
	    if ((tempShape == SR) || (tempShape == SD) || (tempShape == SC))
		to[i].wc = SINITIAL((SISOLATED(line[i].wc)));
	    else
		to[i].wc = SISOLATED(line[i].wc);
	    break;


	}
    }
    return 1;
}

/*
 * The Main Bidi Function, and the only function that should
 * be used by the outside world.
 *
 * line: a buffer of size count containing text to apply
 * the Bidirectional algorithm to.
 */

int do_bidi(bidi_char *line, int count)
{
    unsigned char* types;
    unsigned char* levels;
    unsigned char paragraphLevel;
    unsigned char currentEmbedding;
    unsigned char currentOverride;
    unsigned char tempType;
    int i, j, imax, yes, bover;

    /* Check the presence of R or AL types as optimization */
    yes = 0;
    for (i=0; i<count; i++) {
	int type = getType(line[i].wc);
	if (type == R || type == AL) {
	    yes = 1;
	    break;
	}
    }
    if (yes == 0)
	return L;

    /* Initialize types, levels */
    types = snewn(count, unsigned char);
    levels = snewn(count, unsigned char);

    /* Rule (P1)  NOT IMPLEMENTED
     * P1. Split the text into separate paragraphs. A paragraph separator is
     * kept with the previous paragraph. Within each paragraph, apply all the
     * other rules of this algorithm.
     */

    /* Rule (P2), (P3)
     * P2. In each paragraph, find the first character of type L, AL, or R.
     * P3. If a character is found in P2 and it is of type AL or R, then set
     * the paragraph embedding level to one; otherwise, set it to zero.
     */
    paragraphLevel = 0;
    for (i=0; i<count ; i++) {
	int type = getType(line[i].wc);
	if (type == R || type == AL) {
	    paragraphLevel = 1;
	    break;
	} else if (type == L)
	    break;
    }

    /* Rule (X1)
     * X1. Begin by setting the current embedding level to the paragraph
     * embedding level. Set the directional override status to neutral.
     */
    currentEmbedding = paragraphLevel;
    currentOverride = ON;

    /* Rule (X2), (X3), (X4), (X5), (X6), (X7), (X8)
     * X2. With each RLE, compute the least greater odd embedding level.
     * X3. With each LRE, compute the least greater even embedding level.
     * X4. With each RLO, compute the least greater odd embedding level.
     * X5. With each LRO, compute the least greater even embedding level.
     * X6. For all types besides RLE, LRE, RLO, LRO, and PDF:
     *		a. Set the level of the current character to the current
     *		    embedding level.
     *		b.  Whenever the directional override status is not neutral,
     *               reset the current character type to the directional
     *               override status.
     * X7. With each PDF, determine the matching embedding or override code.
     * If there was a valid matching code, restore (pop) the last
     * remembered (pushed) embedding level and directional override.
     * X8. All explicit directional embeddings and overrides are completely
     * terminated at the end of each paragraph. Paragraph separators are not
     * included in the embedding. (Useless here) NOT IMPLEMENTED
     */
    bover = 0;
    for (i=0; i<count; i++) {
	tempType = getType(line[i].wc);
	switch (tempType) {
	  case RLE:
	    currentEmbedding = levels[i] = leastGreaterOdd(currentEmbedding);
	    levels[i] = setOverrideBits(levels[i], currentOverride);
	    currentOverride = ON;
	    break;

	  case LRE:
	    currentEmbedding = levels[i] = leastGreaterEven(currentEmbedding);
	    levels[i] = setOverrideBits(levels[i], currentOverride);
	    currentOverride = ON;
	    break;

	  case RLO:
	    currentEmbedding = levels[i] = leastGreaterOdd(currentEmbedding);
	    tempType = currentOverride = R;
	    bover = 1;
	    break;

	  case LRO:
	    currentEmbedding = levels[i] = leastGreaterEven(currentEmbedding);
	    tempType = currentOverride = L;
	    bover = 1;
	    break;

	  case PDF:
            {
                int prevlevel = getPreviousLevel(levels, i);

                if (prevlevel == -1) {
                    currentEmbedding = paragraphLevel;
                    currentOverride = ON;
                } else {
                    currentOverride = currentEmbedding & OMASK;
                    currentEmbedding = currentEmbedding & ~OMASK;
                }
            }
	    levels[i] = currentEmbedding;
	    break;

	    /* Whitespace is treated as neutral for now */
	  case WS:
	  case S:
	    levels[i] = currentEmbedding;
	    tempType = ON;
	    if (currentOverride != ON)
		tempType = currentOverride;
	    break;

	  default:
	    levels[i] = currentEmbedding;
	    if (currentOverride != ON)
		tempType = currentOverride;
	    break;

	}
	types[i] = tempType;
    }
    /* this clears out all overrides, so we can use levels safely... */
    /* checks bover first */
    if (bover)
	for (i=0; i<count; i++)
	    levels[i] = levels[i] & LMASK;

    /* Rule (X9)
     * X9. Remove all RLE, LRE, RLO, LRO, PDF, and BN codes.
     * Here, they're converted to BN.
     */
    for (i=0; i<count; i++) {
	switch (types[i]) {
	  case RLE:
	  case LRE:
	  case RLO:
	  case LRO:
	  case PDF:
	    types[i] = BN;
	    break;
	}
    }

    /* Rule (W1)
     * W1. Examine each non-spacing mark (NSM) in the level run, and change
     * the type of the NSM to the type of the previous character. If the NSM
     * is at the start of the level run, it will get the type of sor.
     */
    if (types[0] == NSM)
	types[0] = paragraphLevel;

    for (i=1; i<count; i++) {
	if (types[i] == NSM)
	    types[i] = types[i-1];
	/* Is this a safe assumption?
	 * I assumed the previous, IS a character.
	 */
    }

    /* Rule (W2)
     * W2. Search backwards from each instance of a European number until the
     * first strong type (R, L, AL, or sor) is found.  If an AL is found,
     * change the type of the European number to Arabic number.
     */
    for (i=0; i<count; i++) {
	if (types[i] == EN) {
	    j=i;
	    while (j >= 0) {
		if (types[j] == AL) {
		    types[i] = AN;
		    break;
		} else if (types[j] == R || types[j] == L) {
                    break;
                }
		j--;
	    }
	}
    }

    /* Rule (W3)
     * W3. Change all ALs to R.
     *
     * Optimization: on Rule Xn, we might set a flag on AL type
     * to prevent this loop in L R lines only...
     */
    for (i=0; i<count; i++) {
	if (types[i] == AL)
	    types[i] = R;
    }

    /* Rule (W4)
     * W4. A single European separator between two European numbers changes
     * to a European number. A single common separator between two numbers
     * of the same type changes to that type.
     */
    for (i=1; i<(count-1); i++) {
	if (types[i] == ES) {
	    if (types[i-1] == EN && types[i+1] == EN)
		types[i] = EN;
	} else if (types[i] == CS) {
            if (types[i-1] == EN && types[i+1] == EN)
                types[i] = EN;
            else if (types[i-1] == AN && types[i+1] == AN)
                types[i] = AN;
        }
    }

    /* Rule (W5)
     * W5. A sequence of European terminators adjacent to European numbers
     * changes to all European numbers.
     *
     * Optimization: lots here... else ifs need rearrangement
     */
    for (i=0; i<count; i++) {
	if (types[i] == ET) {
	    if (i > 0 && types[i-1] == EN) {
		types[i] = EN;
		continue;
	    } else if (i < count-1 && types[i+1] == EN) {
                types[i] = EN;
                continue;
            } else if (i < count-1 && types[i+1] == ET) {
                j=i;
                while (j <count && types[j] == ET) {
                    j++;
                }
                if (types[j] == EN)
                    types[i] = EN;
            }
	}
    }

    /* Rule (W6)
     * W6. Otherwise, separators and terminators change to Other Neutral:
     */
    for (i=0; i<count; i++) {
	switch (types[i]) {
	  case ES:
	  case ET:
	  case CS:
	    types[i] = ON;
	    break;
	}
    }

    /* Rule (W7)
     * W7. Search backwards from each instance of a European number until
     * the first strong type (R, L, or sor) is found. If an L is found,
     * then change the type of the European number to L.
     */
    for (i=0; i<count; i++) {
	if (types[i] == EN) {
	    j=i;
	    while (j >= 0) {
		if (types[j] == L) {
		    types[i] = L;
		    break;
		} else if (types[j] == R || types[j] == AL) {
		    break;
		}
		j--;
	    }
	}
    }

    /* Rule (N1)
     * N1. A sequence of neutrals takes the direction of the surrounding
     * strong text if the text on both sides has the same direction. European
     * and Arabic numbers are treated as though they were R.
     */
    if (count >= 2 && types[0] == ON) {
	if ((types[1] == R) || (types[1] == EN) || (types[1] == AN))
	    types[0] = R;
	else if (types[1] == L)
	    types[0] = L;
    }
    for (i=1; i<(count-1); i++) {
	if (types[i] == ON) {
	    if (types[i-1] == L) {
		j=i;
		while (j<(count-1) && types[j] == ON) {
		    j++;
		}
		if (types[j] == L) {
		    while (i<j) {
			types[i] = L;
			i++;
		    }
		}

	    } else if ((types[i-1] == R)  ||
                       (types[i-1] == EN) ||
                       (types[i-1] == AN)) {
                j=i;
                while (j<(count-1) && types[j] == ON) {
                    j++;
                }
                if ((types[j] == R)  ||
                    (types[j] == EN) ||
                    (types[j] == AN)) {
                    while (i<j) {
                        types[i] = R;
                        i++;
                    }
                }
            }
	}
    }
    if (count >= 2 && types[count-1] == ON) {
	if (types[count-2] == R || types[count-2] == EN || types[count-2] == AN)
	    types[count-1] = R;
	else if (types[count-2] == L)
	    types[count-1] = L;
    }

    /* Rule (N2)
     * N2. Any remaining neutrals take the embedding direction.
     */
    for (i=0; i<count; i++) {
	if (types[i] == ON) {
	    if ((levels[i] % 2) == 0)
		types[i] = L;
	    else
		types[i] = R;
	}
    }

    /* Rule (I1)
     * I1. For all characters with an even (left-to-right) embedding
     * direction, those of type R go up one level and those of type AN or
     * EN go up two levels.
     */
    for (i=0; i<count; i++) {
	if ((levels[i] % 2) == 0) {
	    if (types[i] == R)
		levels[i] += 1;
	    else if (types[i] == AN || types[i] == EN)
		levels[i] += 2;
	}
    }

    /* Rule (I2)
     * I2. For all characters with an odd (right-to-left) embedding direction,
     * those of type L, EN or AN go up one level.
     */
    for (i=0; i<count; i++) {
	if ((levels[i] % 2) == 1) {
	    if (types[i] == L || types[i] == EN || types[i] == AN)
		levels[i] += 1;
	}
    }

    /* Rule (L1)
     * L1. On each line, reset the embedding level of the following characters
     * to the paragraph embedding level:
     *		(1)segment separators, (2)paragraph separators,
     *           (3)any sequence of whitespace characters preceding
     *           a segment separator or paragraph separator,
     *           (4)and any sequence of white space characters
     *           at the end of the line.
     * The types of characters used here are the original types, not those
     * modified by the previous phase.
     */
    j=count-1;
    while (j>0 && (getType(line[j].wc) == WS)) {
	j--;
    }
    if (j < (count-1)) {
	for (j++; j<count; j++)
	    levels[j] = paragraphLevel;
    }
    for (i=0; i<count; i++) {
	tempType = getType(line[i].wc);
	if (tempType == WS) {
	    j=i;
	    while (j<count && (getType(line[j].wc) == WS)) {
		j++;
	    }
	    if (j==count || getType(line[j].wc) == B ||
                getType(line[j].wc) == S) {
		for (j--; j>=i ; j--) {
		    levels[j] = paragraphLevel;
		}
	    }
	} else if (tempType == B || tempType == S) {
            levels[i] = paragraphLevel;
        }
    }

    /* Rule (L4) NOT IMPLEMENTED
     * L4. A character that possesses the mirrored property as specified by
     * Section 4.7, Mirrored, must be depicted by a mirrored glyph if the
     * resolved directionality of that character is R.
     */
    /* Note: this is implemented before L2 for efficiency */
    for (i=0; i<count; i++)
	if ((levels[i] % 2) == 1)
	    doMirror(&line[i].wc);

    /* Rule (L2)
     * L2. From the highest level found in the text to the lowest odd level on
     * each line, including intermediate levels not actually present in the
     * text, reverse any contiguous sequence of characters that are at that
     * level or higher
     */
    /* we flip the character string and leave the level array */
    imax = 0;
    i=0;
    tempType = levels[0];
    while (i < count) {
	if (levels[i] > tempType) {
	    tempType = levels[i];
	    imax=i;
	}
	i++;
    }
    /* maximum level in tempType, its index in imax. */
    while (tempType > 0) {     /* loop from highest level to the least odd, */
        /* which i assume is 1 */
	flipThisRun(line, levels, tempType, count);
	tempType--;
    }

    /* Rule (L3) NOT IMPLEMENTED
     * L3. Combining marks applied to a right-to-left base character will at
     * this point precede their base character. If the rendering engine
     * expects them to follow the base characters in the final display
     * process, then the ordering of the marks and the base character must
     * be reversed.
     */
    sfree(types);
    sfree(levels);
    return R;
}


/*
 * Bad, Horrible function
 * takes a pointer to a character that is checked for
 * having a mirror glyph.
 */
void doMirror(wchar_t* ch)
{
    if ((*ch & 0xFF00) == 0) {
	switch (*ch) {
	  case 0x0028: *ch = 0x0029; break;
	  case 0x0029: *ch = 0x0028; break;
	  case 0x003C: *ch = 0x003E; break;
	  case 0x003E: *ch = 0x003C; break;
	  case 0x005B: *ch = 0x005D; break;
	  case 0x005D: *ch = 0x005B; break;
	  case 0x007B: *ch = 0x007D; break;
	  case 0x007D: *ch = 0x007B; break;
	  case 0x00AB: *ch = 0x00BB; break;
	  case 0x00BB: *ch = 0x00AB; break;
	}
    } else if ((*ch & 0xFF00) == 0x2000) {
	switch (*ch) {
	  case 0x2039: *ch = 0x203A; break;
	  case 0x203A: *ch = 0x2039; break;
	  case 0x2045: *ch = 0x2046; break;
	  case 0x2046: *ch = 0x2045; break;
	  case 0x207D: *ch = 0x207E; break;
	  case 0x207E: *ch = 0x207D; break;
	  case 0x208D: *ch = 0x208E; break;
	  case 0x208E: *ch = 0x208D; break;
	}
    } else if ((*ch & 0xFF00) == 0x2200) {
	switch (*ch) {
	  case 0x2208: *ch = 0x220B; break;
	  case 0x2209: *ch = 0x220C; break;
	  case 0x220A: *ch = 0x220D; break;
	  case 0x220B: *ch = 0x2208; break;
	  case 0x220C: *ch = 0x2209; break;
	  case 0x220D: *ch = 0x220A; break;
	  case 0x2215: *ch = 0x29F5; break;
	  case 0x223C: *ch = 0x223D; break;
	  case 0x223D: *ch = 0x223C; break;
	  case 0x2243: *ch = 0x22CD; break;
	  case 0x2252: *ch = 0x2253; break;
	  case 0x2253: *ch = 0x2252; break;
	  case 0x2254: *ch = 0x2255; break;
	  case 0x2255: *ch = 0x2254; break;
	  case 0x2264: *ch = 0x2265; break;
	  case 0x2265: *ch = 0x2264; break;
	  case 0x2266: *ch = 0x2267; break;
	  case 0x2267: *ch = 0x2266; break;
	  case 0x2268: *ch = 0x2269; break;
	  case 0x2269: *ch = 0x2268; break;
	  case 0x226A: *ch = 0x226B; break;
	  case 0x226B: *ch = 0x226A; break;
	  case 0x226E: *ch = 0x226F; break;
	  case 0x226F: *ch = 0x226E; break;
	  case 0x2270: *ch = 0x2271; break;
	  case 0x2271: *ch = 0x2270; break;
	  case 0x2272: *ch = 0x2273; break;
	  case 0x2273: *ch = 0x2272; break;
	  case 0x2274: *ch = 0x2275; break;
	  case 0x2275: *ch = 0x2274; break;
	  case 0x2276: *ch = 0x2277; break;
	  case 0x2277: *ch = 0x2276; break;
	  case 0x2278: *ch = 0x2279; break;
	  case 0x2279: *ch = 0x2278; break;
	  case 0x227A: *ch = 0x227B; break;
	  case 0x227B: *ch = 0x227A; break;
	  case 0x227C: *ch = 0x227D; break;
	  case 0x227D: *ch = 0x227C; break;
	  case 0x227E: *ch = 0x227F; break;
	  case 0x227F: *ch = 0x227E; break;
	  case 0x2280: *ch = 0x2281; break;
	  case 0x2281: *ch = 0x2280; break;
	  case 0x2282: *ch = 0x2283; break;
	  case 0x2283: *ch = 0x2282; break;
	  case 0x2284: *ch = 0x2285; break;
	  case 0x2285: *ch = 0x2284; break;
	  case 0x2286: *ch = 0x2287; break;
	  case 0x2287: *ch = 0x2286; break;
	  case 0x2288: *ch = 0x2289; break;
	  case 0x2289: *ch = 0x2288; break;
	  case 0x228A: *ch = 0x228B; break;
	  case 0x228B: *ch = 0x228A; break;
	  case 0x228F: *ch = 0x2290; break;
	  case 0x2290: *ch = 0x228F; break;
	  case 0x2291: *ch = 0x2292; break;
	  case 0x2292: *ch = 0x2291; break;
	  case 0x2298: *ch = 0x29B8; break;
	  case 0x22A2: *ch = 0x22A3; break;
	  case 0x22A3: *ch = 0x22A2; break;
	  case 0x22A6: *ch = 0x2ADE; break;
	  case 0x22A8: *ch = 0x2AE4; break;
	  case 0x22A9: *ch = 0x2AE3; break;
	  case 0x22AB: *ch = 0x2AE5; break;
	  case 0x22B0: *ch = 0x22B1; break;
	  case 0x22B1: *ch = 0x22B0; break;
	  case 0x22B2: *ch = 0x22B3; break;
	  case 0x22B3: *ch = 0x22B2; break;
	  case 0x22B4: *ch = 0x22B5; break;
	  case 0x22B5: *ch = 0x22B4; break;
	  case 0x22B6: *ch = 0x22B7; break;
	  case 0x22B7: *ch = 0x22B6; break;
	  case 0x22C9: *ch = 0x22CA; break;
	  case 0x22CA: *ch = 0x22C9; break;
	  case 0x22CB: *ch = 0x22CC; break;
	  case 0x22CC: *ch = 0x22CB; break;
	  case 0x22CD: *ch = 0x2243; break;
	  case 0x22D0: *ch = 0x22D1; break;
	  case 0x22D1: *ch = 0x22D0; break;
	  case 0x22D6: *ch = 0x22D7; break;
	  case 0x22D7: *ch = 0x22D6; break;
	  case 0x22D8: *ch = 0x22D9; break;
	  case 0x22D9: *ch = 0x22D8; break;
	  case 0x22DA: *ch = 0x22DB; break;
	  case 0x22DB: *ch = 0x22DA; break;
	  case 0x22DC: *ch = 0x22DD; break;
	  case 0x22DD: *ch = 0x22DC; break;
	  case 0x22DE: *ch = 0x22DF; break;
	  case 0x22DF: *ch = 0x22DE; break;
	  case 0x22E0: *ch = 0x22E1; break;
	  case 0x22E1: *ch = 0x22E0; break;
	  case 0x22E2: *ch = 0x22E3; break;
	  case 0x22E3: *ch = 0x22E2; break;
	  case 0x22E4: *ch = 0x22E5; break;
	  case 0x22E5: *ch = 0x22E4; break;
	  case 0x22E6: *ch = 0x22E7; break;
	  case 0x22E7: *ch = 0x22E6; break;
	  case 0x22E8: *ch = 0x22E9; break;
	  case 0x22E9: *ch = 0x22E8; break;
	  case 0x22EA: *ch = 0x22EB; break;
	  case 0x22EB: *ch = 0x22EA; break;
	  case 0x22EC: *ch = 0x22ED; break;
	  case 0x22ED: *ch = 0x22EC; break;
	  case 0x22F0: *ch = 0x22F1; break;
	  case 0x22F1: *ch = 0x22F0; break;
	  case 0x22F2: *ch = 0x22FA; break;
	  case 0x22F3: *ch = 0x22FB; break;
	  case 0x22F4: *ch = 0x22FC; break;
	  case 0x22F6: *ch = 0x22FD; break;
	  case 0x22F7: *ch = 0x22FE; break;
	  case 0x22FA: *ch = 0x22F2; break;
	  case 0x22FB: *ch = 0x22F3; break;
	  case 0x22FC: *ch = 0x22F4; break;
	  case 0x22FD: *ch = 0x22F6; break;
	  case 0x22FE: *ch = 0x22F7; break;
	}
    } else if ((*ch & 0xFF00) == 0x2300) {
        switch (*ch) {
          case 0x2308: *ch = 0x2309; break;
          case 0x2309: *ch = 0x2308; break;
          case 0x230A: *ch = 0x230B; break;
          case 0x230B: *ch = 0x230A; break;
          case 0x2329: *ch = 0x232A; break;
          case 0x232A: *ch = 0x2329; break;
        }
    } else if ((*ch & 0xFF00) == 0x2700) {
	switch (*ch) {
	  case 0x2768: *ch = 0x2769; break;
	  case 0x2769: *ch = 0x2768; break;
	  case 0x276A: *ch = 0x276B; break;
	  case 0x276B: *ch = 0x276A; break;
	  case 0x276C: *ch = 0x276D; break;
	  case 0x276D: *ch = 0x276C; break;
	  case 0x276E: *ch = 0x276F; break;
	  case 0x276F: *ch = 0x276E; break;
	  case 0x2770: *ch = 0x2771; break;
	  case 0x2771: *ch = 0x2770; break;
	  case 0x2772: *ch = 0x2773; break;
	  case 0x2773: *ch = 0x2772; break;
	  case 0x2774: *ch = 0x2775; break;
	  case 0x2775: *ch = 0x2774; break;
	  case 0x27D5: *ch = 0x27D6; break;
	  case 0x27D6: *ch = 0x27D5; break;
	  case 0x27DD: *ch = 0x27DE; break;
	  case 0x27DE: *ch = 0x27DD; break;
	  case 0x27E2: *ch = 0x27E3; break;
	  case 0x27E3: *ch = 0x27E2; break;
	  case 0x27E4: *ch = 0x27E5; break;
	  case 0x27E5: *ch = 0x27E4; break;
	  case 0x27E6: *ch = 0x27E7; break;
	  case 0x27E7: *ch = 0x27E6; break;
	  case 0x27E8: *ch = 0x27E9; break;
	  case 0x27E9: *ch = 0x27E8; break;
	  case 0x27EA: *ch = 0x27EB; break;
	  case 0x27EB: *ch = 0x27EA; break;
	}
    } else if ((*ch & 0xFF00) == 0x2900) {
	switch (*ch) {
	  case 0x2983: *ch = 0x2984; break;
	  case 0x2984: *ch = 0x2983; break;
	  case 0x2985: *ch = 0x2986; break;
	  case 0x2986: *ch = 0x2985; break;
	  case 0x2987: *ch = 0x2988; break;
	  case 0x2988: *ch = 0x2987; break;
	  case 0x2989: *ch = 0x298A; break;
	  case 0x298A: *ch = 0x2989; break;
	  case 0x298B: *ch = 0x298C; break;
	  case 0x298C: *ch = 0x298B; break;
	  case 0x298D: *ch = 0x2990; break;
	  case 0x298E: *ch = 0x298F; break;
	  case 0x298F: *ch = 0x298E; break;
	  case 0x2990: *ch = 0x298D; break;
	  case 0x2991: *ch = 0x2992; break;
	  case 0x2992: *ch = 0x2991; break;
	  case 0x2993: *ch = 0x2994; break;
	  case 0x2994: *ch = 0x2993; break;
	  case 0x2995: *ch = 0x2996; break;
	  case 0x2996: *ch = 0x2995; break;
	  case 0x2997: *ch = 0x2998; break;
	  case 0x2998: *ch = 0x2997; break;
	  case 0x29B8: *ch = 0x2298; break;
	  case 0x29C0: *ch = 0x29C1; break;
	  case 0x29C1: *ch = 0x29C0; break;
	  case 0x29C4: *ch = 0x29C5; break;
	  case 0x29C5: *ch = 0x29C4; break;
	  case 0x29CF: *ch = 0x29D0; break;
	  case 0x29D0: *ch = 0x29CF; break;
	  case 0x29D1: *ch = 0x29D2; break;
	  case 0x29D2: *ch = 0x29D1; break;
	  case 0x29D4: *ch = 0x29D5; break;
	  case 0x29D5: *ch = 0x29D4; break;
	  case 0x29D8: *ch = 0x29D9; break;
	  case 0x29D9: *ch = 0x29D8; break;
	  case 0x29DA: *ch = 0x29DB; break;
	  case 0x29DB: *ch = 0x29DA; break;
	  case 0x29F5: *ch = 0x2215; break;
	  case 0x29F8: *ch = 0x29F9; break;
	  case 0x29F9: *ch = 0x29F8; break;
	  case 0x29FC: *ch = 0x29FD; break;
	  case 0x29FD: *ch = 0x29FC; break;
	}
    } else if ((*ch & 0xFF00) == 0x2A00) {
	switch (*ch) {
	  case 0x2A2B: *ch = 0x2A2C; break;
	  case 0x2A2C: *ch = 0x2A2B; break;
	  case 0x2A2D: *ch = 0x2A2C; break;
	  case 0x2A2E: *ch = 0x2A2D; break;
	  case 0x2A34: *ch = 0x2A35; break;
	  case 0x2A35: *ch = 0x2A34; break;
	  case 0x2A3C: *ch = 0x2A3D; break;
	  case 0x2A3D: *ch = 0x2A3C; break;
	  case 0x2A64: *ch = 0x2A65; break;
	  case 0x2A65: *ch = 0x2A64; break;
	  case 0x2A79: *ch = 0x2A7A; break;
	  case 0x2A7A: *ch = 0x2A79; break;
	  case 0x2A7D: *ch = 0x2A7E; break;
	  case 0x2A7E: *ch = 0x2A7D; break;
	  case 0x2A7F: *ch = 0x2A80; break;
	  case 0x2A80: *ch = 0x2A7F; break;
	  case 0x2A81: *ch = 0x2A82; break;
	  case 0x2A82: *ch = 0x2A81; break;
	  case 0x2A83: *ch = 0x2A84; break;
	  case 0x2A84: *ch = 0x2A83; break;
	  case 0x2A8B: *ch = 0x2A8C; break;
	  case 0x2A8C: *ch = 0x2A8B; break;
	  case 0x2A91: *ch = 0x2A92; break;
	  case 0x2A92: *ch = 0x2A91; break;
	  case 0x2A93: *ch = 0x2A94; break;
	  case 0x2A94: *ch = 0x2A93; break;
	  case 0x2A95: *ch = 0x2A96; break;
	  case 0x2A96: *ch = 0x2A95; break;
	  case 0x2A97: *ch = 0x2A98; break;
	  case 0x2A98: *ch = 0x2A97; break;
	  case 0x2A99: *ch = 0x2A9A; break;
	  case 0x2A9A: *ch = 0x2A99; break;
	  case 0x2A9B: *ch = 0x2A9C; break;
	  case 0x2A9C: *ch = 0x2A9B; break;
	  case 0x2AA1: *ch = 0x2AA2; break;
	  case 0x2AA2: *ch = 0x2AA1; break;
	  case 0x2AA6: *ch = 0x2AA7; break;
	  case 0x2AA7: *ch = 0x2AA6; break;
	  case 0x2AA8: *ch = 0x2AA9; break;
	  case 0x2AA9: *ch = 0x2AA8; break;
	  case 0x2AAA: *ch = 0x2AAB; break;
	  case 0x2AAB: *ch = 0x2AAA; break;
	  case 0x2AAC: *ch = 0x2AAD; break;
	  case 0x2AAD: *ch = 0x2AAC; break;
	  case 0x2AAF: *ch = 0x2AB0; break;
	  case 0x2AB0: *ch = 0x2AAF; break;
	  case 0x2AB3: *ch = 0x2AB4; break;
	  case 0x2AB4: *ch = 0x2AB3; break;
	  case 0x2ABB: *ch = 0x2ABC; break;
	  case 0x2ABC: *ch = 0x2ABB; break;
	  case 0x2ABD: *ch = 0x2ABE; break;
	  case 0x2ABE: *ch = 0x2ABD; break;
	  case 0x2ABF: *ch = 0x2AC0; break;
	  case 0x2AC0: *ch = 0x2ABF; break;
	  case 0x2AC1: *ch = 0x2AC2; break;
	  case 0x2AC2: *ch = 0x2AC1; break;
	  case 0x2AC3: *ch = 0x2AC4; break;
	  case 0x2AC4: *ch = 0x2AC3; break;
	  case 0x2AC5: *ch = 0x2AC6; break;
	  case 0x2AC6: *ch = 0x2AC5; break;
	  case 0x2ACD: *ch = 0x2ACE; break;
	  case 0x2ACE: *ch = 0x2ACD; break;
	  case 0x2ACF: *ch = 0x2AD0; break;
	  case 0x2AD0: *ch = 0x2ACF; break;
	  case 0x2AD1: *ch = 0x2AD2; break;
	  case 0x2AD2: *ch = 0x2AD1; break;
	  case 0x2AD3: *ch = 0x2AD4; break;
	  case 0x2AD4: *ch = 0x2AD3; break;
	  case 0x2AD5: *ch = 0x2AD6; break;
	  case 0x2AD6: *ch = 0x2AD5; break;
	  case 0x2ADE: *ch = 0x22A6; break;
	  case 0x2AE3: *ch = 0x22A9; break;
	  case 0x2AE4: *ch = 0x22A8; break;
	  case 0x2AE5: *ch = 0x22AB; break;
	  case 0x2AEC: *ch = 0x2AED; break;
	  case 0x2AED: *ch = 0x2AEC; break;
	  case 0x2AF7: *ch = 0x2AF8; break;
	  case 0x2AF8: *ch = 0x2AF7; break;
	  case 0x2AF9: *ch = 0x2AFA; break;
	  case 0x2AFA: *ch = 0x2AF9; break;
	}
    } else if ((*ch & 0xFF00) == 0x3000) {
	switch (*ch) {
	  case 0x3008: *ch = 0x3009; break;
	  case 0x3009: *ch = 0x3008; break;
	  case 0x300A: *ch = 0x300B; break;
	  case 0x300B: *ch = 0x300A; break;
	  case 0x300C: *ch = 0x300D; break;
	  case 0x300D: *ch = 0x300C; break;
	  case 0x300E: *ch = 0x300F; break;
	  case 0x300F: *ch = 0x300E; break;
	  case 0x3010: *ch = 0x3011; break;
	  case 0x3011: *ch = 0x3010; break;
	  case 0x3014: *ch = 0x3015; break;
	  case 0x3015: *ch = 0x3014; break;
	  case 0x3016: *ch = 0x3017; break;
	  case 0x3017: *ch = 0x3016; break;
	  case 0x3018: *ch = 0x3019; break;
	  case 0x3019: *ch = 0x3018; break;
	  case 0x301A: *ch = 0x301B; break;
	  case 0x301B: *ch = 0x301A; break;
	}
    } else if ((*ch & 0xFF00) == 0xFF00) {
	switch (*ch) {
	  case 0xFF08: *ch = 0xFF09; break;
	  case 0xFF09: *ch = 0xFF08; break;
	  case 0xFF1C: *ch = 0xFF1E; break;
	  case 0xFF1E: *ch = 0xFF1C; break;
	  case 0xFF3B: *ch = 0xFF3D; break;
	  case 0xFF3D: *ch = 0xFF3B; break;
	  case 0xFF5B: *ch = 0xFF5D; break;
	  case 0xFF5D: *ch = 0xFF5B; break;
	  case 0xFF5F: *ch = 0xFF60; break;
	  case 0xFF60: *ch = 0xFF5F; break;
	  case 0xFF62: *ch = 0xFF63; break;
	  case 0xFF63: *ch = 0xFF62; break;
	}
    }
}

#ifdef TEST_GETTYPE

#include <stdio.h>
#include <assert.h>

int main(int argc, char **argv)
{
    static const struct { int type; char *name; } typetoname[] = {
#define TYPETONAME(X) { X , #X }
	TYPETONAME(L),
	TYPETONAME(LRE),
	TYPETONAME(LRO),
	TYPETONAME(R),
	TYPETONAME(AL),
	TYPETONAME(RLE),
	TYPETONAME(RLO),
	TYPETONAME(PDF),
	TYPETONAME(EN),
	TYPETONAME(ES),
	TYPETONAME(ET),
	TYPETONAME(AN),
	TYPETONAME(CS),
	TYPETONAME(NSM),
	TYPETONAME(BN),
	TYPETONAME(B),
	TYPETONAME(S),
	TYPETONAME(WS),
	TYPETONAME(ON),
#undef TYPETONAME
    };
    int i;

    for (i = 1; i < argc; i++) {
	unsigned long chr = strtoul(argv[i], NULL, 0);
	int type = getType(chr);
	assert(typetoname[type].type == type);
	printf("U+%04x: %s\n", chr, typetoname[type].name);
    }

    return 0;
}

#endif
