zint/backend/ultra.c

/*  ultra.c - Ultracode */
/*
    libzint - the open source barcode library
    Copyright (C) 2020-2024 Robin Stuart <rstuart114@gmail.com>

    Redistribution and use in source and binary forms, with or without
    modification, are permitted provided that the following conditions
    are met:

    1. Redistributions of source code must retain the above copyright
       notice, this list of conditions and the following disclaimer.
    2. Redistributions in binary form must reproduce the above copyright
       notice, this list of conditions and the following disclaimer in the
       documentation and/or other materials provided with the distribution.
    3. Neither the name of the project nor the names of its contributors
       may be used to endorse or promote products derived from this software
       without specific prior written permission.

    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
    ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
    IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
    ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE
    FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
    DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
    OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
    HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
    LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
    OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
    SUCH DAMAGE.
 */
/* SPDX-License-Identifier: BSD-3-Clause */

/* This version was developed using AIMD/TSC15032-43 v0.99c Edit 60, dated 4th Nov 2015 */

#include <stdio.h>
#include "common.h"

#define ULT_EIGHTBIT_MODE       10
#define ULT_ASCII_MODE          20
#define ULT_C43_MODE            30

#define ULT_PREDICT_WINDOW      12

#define ULT_GFMUL(i, j) ((((i) == 0)||((j) == 0)) ? 0 : gfPwr[(gfLog[i] + gfLog[j])])

static const char *const ult_fragment[27] = {
    "http://", "https://", "http://www.", "https://www.",
    "ftp://", "www.", ".com", ".edu", ".gov", ".int", ".mil", ".net", ".org",
    ".mobi", ".coop", ".biz", ".info", "mailto:", "tel:", ".cgi", ".asp",
    ".aspx", ".php", ".htm", ".html", ".shtml", "file:"
};

static const char ult_c43_set1[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789 .,%";
static const char ult_c43_set2[] = "abcdefghijklmnopqrstuvwxyz:/?#[]@=_~!.,-";
static const char ult_c43_set3[] = "{}`()\"+'<>|$;&\\^*";
static const char ult_digit[] = "0123456789,/";
static const char ult_colour[] = "0CBMRYGKW";

/* Max size and min cols adjusted to BWIPP values as updated 2021-07-14
   https://github.com/bwipp/postscriptbarcode/commit/4255810845fa8d45c6192dd30aee1fdad1aaf0cc */
static const short ult_maxsize[] = { 37, 84, 161, 282 };

static const char ult_mincols[] = { 5, 13, 22, 29 };

static const char ult_kec[] = { 0, 1, 2, 4, 6, 8 }; /* Value K(EC) from Table 12 */

/* Taken from BWIPP - change in DCCU/DCCL tiles for revision 2 2021-09-28 */
static const unsigned short ult_dccu[2][32] = {
    { /* Revision 1 */
        051363, 051563, 051653, 053153, 053163, 053513, 053563, 053613, /*  0-7 */
        053653, 056153, 056163, 056313, 056353, 056363, 056513, 056563, /*  8-15 */
        051316, 051356, 051536, 051616, 053156, 053516, 053536, 053616, /* 16-23 */
        053636, 053656, 056136, 056156, 056316, 056356, 056516, 056536  /* 24-31 */
    },
    { /* Revision 2 (inversion of DCCL Revision 1) */
        015316, 016316, 013516, 016516, 013616, 015616, 013136, 015136, /*  0-7 */
        016136, 013536, 016536, 013636, 013156, 016156, 015356, 013656, /*  8-15 */
        015313, 016313, 013513, 016513, 013613, 015613, 013153, 015153, /* 16-23 */
        016153, 016353, 013653, 015653, 013163, 015163, 015363, 013563  /* 24-31 */
    },
};

static const unsigned short ult_dccl[2][32] = {
    { /* Revision 1 */
        061351, 061361, 061531, 061561, 061631, 061651, 063131, 063151, /*  0-7 */
        063161, 063531, 063561, 063631, 065131, 065161, 065351, 065631, /*  8-15 */
        031351, 031361, 031531, 031561, 031631, 031651, 035131, 035151, /* 16-23 */
        035161, 035361, 035631, 035651, 036131, 036151, 036351, 036531  /* 24-31 */
    },
    { /* Revision 2 (inversion of DCCU Revision 1) */
        036315, 036515, 035615, 035135, 036135, 031535, 036535, 031635, /*  0-7 */
        035635, 035165, 036165, 031365, 035365, 036365, 031565, 036565, /*  8-15 */
        061315, 065315, 063515, 061615, 065135, 061535, 063535, 061635, /* 16-23 */
        063635, 065635, 063165, 065165, 061365, 065365, 061565, 063565  /* 24-31 */
    },
};

static const unsigned short ult_tiles[] = {
    013135, 013136, 013153, 013156, 013163, 013165, 013513, 013515, 013516, 013531, /*   0-9 */
    013535, 013536, 013561, 013563, 013565, 013613, 013615, 013616, 013631, 013635, /*  10-19 */
    013636, 013651, 013653, 013656, 015135, 015136, 015153, 015163, 015165, 015313, /*  20-29 */
    015315, 015316, 015351, 015353, 015356, 015361, 015363, 015365, 015613, 015615, /*  30-39 */
    015616, 015631, 015635, 015636, 015651, 015653, 015656, 016135, 016136, 016153, /*  40-49 */
    016156, 016165, 016313, 016315, 016316, 016351, 016353, 016356, 016361, 016363, /*  50-59 */
    016365, 016513, 016515, 016516, 016531, 016535, 016536, 016561, 016563, 016565, /*  60-69 */
    031315, 031316, 031351, 031356, 031361, 031365, 031513, 031515, 031516, 031531, /*  70-79 */
    031535, 031536, 031561, 031563, 031565, 031613, 031615, 031631, 031635, 031636, /*  80-89 */
    031651, 031653, 031656, 035131, 035135, 035136, 035151, 035153, 035156, 035161, /*  90-99 */
    035163, 035165, 035315, 035316, 035351, 035356, 035361, 035365, 035613, 035615, /* 100-109 */
    035616, 035631, 035635, 035636, 035651, 035653, 035656, 036131, 036135, 036136, /* 110-119 */
    036151, 036153, 036156, 036163, 036165, 036315, 036316, 036351, 036356, 036361, /* 120-129 */
    036365, 036513, 036515, 036516, 036531, 036535, 036536, 036561, 036563, 036565, /* 130-139 */
    051313, 051315, 051316, 051351, 051353, 051356, 051361, 051363, 051365, 051513, /* 140-149 */
    051516, 051531, 051536, 051561, 051563, 051613, 051615, 051616, 051631, 051635, /* 150-159 */
    051636, 051651, 051653, 051656, 053131, 053135, 053136, 053151, 053153, 053156, /* 160-169 */
    053161, 053163, 053165, 053513, 053516, 053531, 053536, 053561, 053563, 053613, /* 170-179 */
    053615, 053616, 053631, 053635, 053636, 053651, 053653, 053656, 056131, 056135, /* 180-189 */
    056136, 056151, 056153, 056156, 056161, 056163, 056165, 056313, 056315, 056316, /* 190-199 */
    056351, 056353, 056356, 056361, 056363, 056365, 056513, 056516, 056531, 056536, /* 200-209 */
    056561, 056563, 061313, 061315, 061316, 061351, 061353, 061356, 061361, 061363, /* 210-219 */
    061365, 061513, 061515, 061516, 061531, 061535, 061536, 061561, 061563, 061565, /* 220-229 */
    061615, 061631, 061635, 061651, 061653, 063131, 063135, 063136, 063151, 063153, /* 230-239 */
    063156, 063161, 063163, 063165, 063513, 063515, 063516, 063531, 063535, 063536, /* 240-249 */
    063561, 063563, 063565, 063613, 063615, 063631, 063635, 063651, 063653, 065131, /* 250-259 */
    065135, 065136, 065151, 065153, 065156, 065161, 065163, 065165, 065313, 065315, /* 260-269 */
    065316, 065351, 065353, 065356, 065361, 065363, 065365, 065613, 065615, 065631, /* 270-279 */
    065635, 065651, 065653, 056565, 051515                                          /* 280-284 */
};

/* The following adapted from ECC283.C "RSEC codeword generator"
 * from Annex B of Ultracode draft
 * originally written by Ted Williams of Symbol Vision Corp.
 * Dated 2001-03-09
 * Corrected thanks to input from Terry Burton */

/*
 * NOTE: Included here is an attempt to allow code compression within Ultracode. Unfortunately
 * the copy of the standard this was written from was an early draft which includes self
 * contradictions, so this is a "best guess" implementation. Because it is not guaranteed
 * to be correct this compression is not applied by default. To enable compression set
 *
 * symbol->option_3 = ULTRA_COMPRESSION;
 *
 * Code compression should be enabled by default when it has been implemented according to
 * a more reliable version of the specification.
 */

/* Generate divisor polynomial gQ(x) for GF283() given the required ECC size, 3 to 101 */
static void ult_genPoly(const short EccSize, unsigned short gPoly[], const unsigned short gfPwr[],
            const unsigned short gfLog[]) {
    int i, j;

    gPoly[0] = 1;
    for (i = 1; i < (EccSize + 1); i++) gPoly[i] = 0;

    for (i = 0; i < EccSize; i++) {
        for (j = i; j >= 0; j--)
            gPoly[j + 1] = (gPoly[j] + ULT_GFMUL(gPoly[j + 1], gfPwr[i + 1])) % 283;
        gPoly[0] = ULT_GFMUL(gPoly[0], gfPwr[i + 1]);
    }
    for (i = EccSize - 1; i >= 0; i -= 2) gPoly[i] = 283 - gPoly[i];

    /* gPoly[i] is > 0 so modulo operation not needed */
}

/* Generate the log and antilog tables for GF283() multiplication & division */
static void ult_initLogTables(unsigned short gfPwr[], unsigned short gfLog[]) {
    int i, j;

    for (j = 0; j < 283; j++) gfLog[j] = 0;
    i = 1;
    for (j = 0; j < 282; j++) {
        /* j + 282 indices save doing the modulo operation in ULT_GFMUL */
        gfPwr[j + 282] = gfPwr[j] = (short) i;
        gfLog[i] = (short) j;
        i = (i * 3) % 283;
    }
}

static void ult_gf283(const short DataSize, const short EccSize, int Message[]) {
    /* Input is complete message codewords in array Message[282]
     * DataSize is number of message codewords
     * EccSize is number of Reed-Solomon GF(283) check codewords to generate
     *
     * Upon exit, Message[282] contains complete 282 codeword Symbol Message
     * including leading zeroes corresponding to each truncated codeword */

    unsigned short gPoly[283], gfPwr[(282 * 2)], gfLog[283];
    int i, j, n;
    unsigned short t;

    /* first build the log & antilog tables used in multiplication & division */
    ult_initLogTables(gfPwr, gfLog);

    /* then generate the division polynomial of length EccSize */
    ult_genPoly(EccSize, gPoly, gfPwr, gfLog);

    /* zero all EccSize codeword values */
    for (j = 281; (j > (281 - EccSize)); j--) Message[j] = 0;

    /* shift message codewords to the right, leave space for ECC checkwords */
    for (i = DataSize - 1; (i >= 0); j--, i--) Message[j] = Message[i];

    /* add zeroes to pad left end Message[] for truncated codewords */
    j++;
    for (i = 0; i < j; i++) Message[i] = 0;

    /* generate (EccSize) Reed-Solomon checkwords */
    for (n = j; n < (j + DataSize); n++) {
        t = (Message[j + DataSize] + Message[n]) % 283;
        for (i = 0; i < (EccSize - 1); i++) {
            Message[j + DataSize + i] = (Message[j + DataSize + i + 1] + 283
                                        - ULT_GFMUL(t, gPoly[EccSize - 1 - i])) % 283;
        }
        Message[j + DataSize + EccSize - 1] = (283 - ULT_GFMUL(t, gPoly[0])) % 283;
    }
    for (i = j + DataSize; i < (j + DataSize + EccSize); i++)
        Message[i] = (283 - Message[i]) % 283;
}

/* End of Ted Williams code */

static int ult_find_fragment(const unsigned char source[], const int length, const int position) {
    int retval = -1;
    int j, k, latch, fraglen;

    for (j = 0; j < 27; j++) {
        latch = 0;
        fraglen = (int) strlen(ult_fragment[j]);
        if ((position + fraglen) <= length) {
            latch = 1;
            for (k = 0; k < fraglen; k++) {
                if (source[position + k] != ult_fragment[j][k]) {
                    latch = 0;
                    break;
                }
            }
        }

        if (latch) {
            retval = j;
        }
    }

    return retval;
}

/* Encode characters in 8-bit mode */
static float ult_look_ahead_eightbit(const unsigned char source[], const int length, const int in_locn,
            const int current_mode, const int end_char, int cw[], int *cw_len, const int gs1) {
    int codeword_count = 0;
    int i;
    int letters_encoded = 0;

    if (current_mode != ULT_EIGHTBIT_MODE) {
        cw[codeword_count] = 282; /* Unlatch */
        codeword_count += 1;
    }

    i = in_locn;
    while ((i < length) && (i < end_char)) {
        if ((source[i] == '[') && gs1) {
            cw[codeword_count] = 268; /* FNC1 */
        } else {
            cw[codeword_count] = source[i];
        }
        i++;
        codeword_count++;
    }

    letters_encoded = i - in_locn;

    *cw_len = codeword_count;

    if (codeword_count == 0) {
        return 0.0f;
    }
    return (float) letters_encoded / (float) codeword_count;
}

/* Encode character in the ASCII mode/submode (including numeric compression) */
static float ult_look_ahead_ascii(unsigned char source[], const int length, const int in_locn,
            const int current_mode, const int symbol_mode, const int end_char, int cw[], int *cw_len, int *encoded,
            const int gs1) {
    int codeword_count = 0;
    int i;
    int first_digit, second_digit, done;
    int letters_encoded = 0;

    if (current_mode == ULT_EIGHTBIT_MODE) {
        cw[codeword_count] = 267; /* Latch ASCII Submode */
        codeword_count++;
    }

    if (current_mode == ULT_C43_MODE) {
        cw[codeword_count] = 282; /* Unlatch */
        codeword_count++;
        if (symbol_mode == ULT_EIGHTBIT_MODE) {
            cw[codeword_count] = 267; /* Latch ASCII Submode */
            codeword_count++;
        }
    }

    i = in_locn;
    do {
        /* Check for double digits */
        done = 0;
        if (i + 1 < length) {
            first_digit = posn(ult_digit, source[i]);
            second_digit = posn(ult_digit, source[i + 1]);
            if ((first_digit != -1) && (second_digit != -1)) {
                /* Double digit can be encoded */
                if ((first_digit >= 0) && (first_digit <= 9) && (second_digit >= 0) && (second_digit <= 9)) {
                    /* Double digit numerics */
                    cw[codeword_count] = (10 * first_digit) + second_digit + 128;
                    codeword_count++;
                    i += 2;
                    done = 1;
                } else if ((first_digit >= 0) && (first_digit <= 9) && (second_digit == 10)) {
                    /* Single digit followed by selected decimal point character */
                    cw[codeword_count] = first_digit + 228;
                    codeword_count++;
                    i += 2;
                    done = 1;
                } else if ((first_digit == 10) && (second_digit >= 0) && (second_digit <= 9)) {
                    /* Selected decimal point character followed by single digit */
                    cw[codeword_count] = second_digit + 238;
                    codeword_count++;
                    i += 2;
                    done = 1;
                } else if ((first_digit >= 0) && (first_digit <= 9) && (second_digit == 11)) {
                    /* Single digit or decimal point followed by field deliminator */
                    cw[codeword_count] = first_digit + 248;
                    codeword_count++;
                    i += 2;
                    done = 1;
                } else if ((first_digit == 11) && (second_digit >= 0) && (second_digit <= 9)) {
                    /* Field deliminator followed by single digit or decimal point */
                    cw[codeword_count] = second_digit + 259;
                    codeword_count++;
                    i += 2;
                    done = 1;
                }
            }
        }

        if (!done && source[i] < 0x80) {
            if ((source[i] == '[') && gs1) {
                cw[codeword_count] = 272; /* FNC1 */
            } else {
                cw[codeword_count] = source[i];
            }
            codeword_count++;
            i++;
        }
    } while ((i < length) && (i < end_char) && (source[i] < 0x80));

    letters_encoded = i - in_locn;
    if (encoded != NULL) {
        *encoded = letters_encoded;
    }

    *cw_len = codeword_count;

    if (codeword_count == 0) {
        return 0.0f;
    }
    return (float) letters_encoded / (float) codeword_count;
}

/* Returns true if should latch to subset other than given `subset` */
static int ult_c43_should_latch_other(const unsigned char source[], const int length, const int locn,
            const int subset, const int gs1) {
    int i, fraglen, predict_window;
    int cnt, alt_cnt, fragno;
    const char *const set = subset == 1 ? ult_c43_set1 : ult_c43_set2;
    const char *const alt_set = subset == 2 ? ult_c43_set1 : ult_c43_set2;

    if (locn + 3 > length) {
        return 0;
    }
    predict_window = locn + 3;

    for (i = locn, cnt = 0, alt_cnt = 0; i < predict_window; i++) {
        if (source[i] <= 0x1F || source[i] >= 0x7F || (gs1 && source[i] == '[')) {
            break;
        }

        fragno = ult_find_fragment(source, length, i);
        if (fragno != -1 && fragno != 26) {
            fraglen = (int) strlen(ult_fragment[fragno]);
            predict_window += fraglen;
            if (predict_window > length) {
                predict_window = length;
            }
            i += fraglen - 1;
        } else {
            if (posn(set, source[i]) != -1) {
                cnt++;
            }
            if (posn(alt_set, source[i]) != -1) {
                alt_cnt++;
            }
        }
    }

    return alt_cnt > cnt;
}

static int ult_get_subset(const unsigned char source[], const int length, const int in_locn,
            const int current_subset) {
    int fragno;
    int subset = 0;

    fragno = ult_find_fragment(source, length, in_locn);
    if ((fragno != -1) && (fragno != 26)) {
        subset = 3;
    } else if (current_subset == 2) {
        if (posn(ult_c43_set2, source[in_locn]) != -1) {
            subset = 2;
        } else if (posn(ult_c43_set1, source[in_locn]) != -1) {
            subset = 1;
        }
    } else {
        if (posn(ult_c43_set1, source[in_locn]) != -1) {
            subset = 1;
        } else if (posn(ult_c43_set2, source[in_locn]) != -1) {
            subset = 2;
        }
    }

    if (subset == 0) {
        if (posn(ult_c43_set3, source[in_locn]) != -1) {
            subset = 3;
        }
    }

    return subset;
}

/* Encode characters in the C43 compaction submode */
static float ult_look_ahead_c43(const unsigned char source[], const int length, const int in_locn,
            const int current_mode, const int end_char, int subset, int cw[], int *cw_len, int *encoded,
            const int gs1, const int debug_print) {
    int codeword_count = 0;
    int subcodeword_count = 0;
    int i;
    int fragno;
    int sublocn = in_locn;
    int new_subset;
    int unshift_set;
    int base43_value;
    int letters_encoded = 0;
    int pad;
    int *subcw = (int *) z_alloca(sizeof(int) * (length + 3) * 2);

    if (current_mode == ULT_EIGHTBIT_MODE) {
        /* Check for permissable URL C43 macro sequences, otherwise encode directly */
        fragno = ult_find_fragment(source, length, sublocn);

        if ((fragno == 2) || (fragno == 3)) {
            /* http://www. > http:// */
            /* https://www. > https:// */
            fragno -= 2;
        }

        switch (fragno) {
            case 17: /* mailto: */
                cw[codeword_count] = 276;
                sublocn += (int) strlen(ult_fragment[fragno]);
                codeword_count++;
                break;
            case 18: /* tel: */
                cw[codeword_count] = 277;
                sublocn += (int) strlen(ult_fragment[fragno]);
                codeword_count++;
                break;
            case 26: /* file: */
                cw[codeword_count] = 278;
                sublocn += (int) strlen(ult_fragment[fragno]);
                codeword_count++;
                break;
            case 0: /* http:// */
                cw[codeword_count] = 279;
                sublocn += (int) strlen(ult_fragment[fragno]);
                codeword_count++;
                break;
            case 1: /* https:// */
                cw[codeword_count] = 280;
                sublocn += (int) strlen(ult_fragment[fragno]);
                codeword_count++;
                break;
            case 4: /* ftp:// */
                cw[codeword_count] = 281;
                sublocn += (int) strlen(ult_fragment[fragno]);
                codeword_count++;
                break;
            default:
                if (subset == 1) {
                    cw[codeword_count] = 260; /* C43 Compaction Submode C1 */
                    codeword_count++;
                } else if ((subset == 2) || (subset == 3)) {
                    cw[codeword_count] = 266; /* C43 Compaction Submode C2 */
                    codeword_count++;
                }
                break;
        }

    } else if (current_mode == ULT_ASCII_MODE) {
        if (subset == 1) {
            cw[codeword_count] = 278; /* C43 Compaction Submode C1 */
            codeword_count++;
        } else if ((subset == 2) || (subset == 3)) {
            cw[codeword_count] = 280; /* C43 Compaction Submode C2 */
            codeword_count++;
        }
    }
    unshift_set = subset;

    while ((sublocn < length) && (sublocn < end_char)) {
        /* Check for FNC1 */
        if (gs1 && source[sublocn] == '[') {
            break;
        }

        new_subset = ult_get_subset(source, length, sublocn, subset);

        if (new_subset == 0) {
            break;
        }

        if ((new_subset != subset) && ((new_subset == 1) || (new_subset == 2))) {
            if (ult_c43_should_latch_other(source, length, sublocn, subset, gs1)) {
                subcw[subcodeword_count] = 42; /* Latch to other C43 set */
                subcodeword_count++;
                unshift_set = new_subset;
            } else {
                subcw[subcodeword_count] = 40; /* Shift to other C43 set for 1 char */
                subcodeword_count++;
                subcw[subcodeword_count] = posn(new_subset == 1 ? ult_c43_set1 : ult_c43_set2, source[sublocn]);
                subcodeword_count++;
                sublocn++;
                continue;
            }
        }

        subset = new_subset;

        if (subset == 1) {
            subcw[subcodeword_count] = posn(ult_c43_set1, source[sublocn]);
            subcodeword_count++;
            sublocn++;
        } else if (subset == 2) {
            subcw[subcodeword_count] = posn(ult_c43_set2, source[sublocn]);
            subcodeword_count++;
            sublocn++;
        } else if (subset == 3) {
            subcw[subcodeword_count] = 41; /* Shift to set 3 */
            subcodeword_count++;

            fragno = ult_find_fragment(source, length, sublocn);
            if (fragno != -1 && fragno != 26) {
                if (fragno <= 18) {
                    subcw[subcodeword_count] = fragno; /* C43 Set 3 codewords 0 to 18 */
                    subcodeword_count++;
                    sublocn += (int) strlen(ult_fragment[fragno]);
                } else {
                    subcw[subcodeword_count] = fragno + 17; /* C43 Set 3 codewords 36 to 42 */
                    subcodeword_count++;
                    sublocn += (int) strlen(ult_fragment[fragno]);
                }
            } else {
                /* C43 Set 3 codewords 19 to 35 */
                subcw[subcodeword_count] = posn(ult_c43_set3, source[sublocn]) + 19;
                subcodeword_count++;
                sublocn++;
            }
            subset = unshift_set;
        }
    }

    pad = 3 - (subcodeword_count % 3);
    if (pad == 3) {
        pad = 0;
    }

    for (i = 0; i < pad; i++) {
        subcw[subcodeword_count] = 42; /* Latch to other C43 set used as pad */
        subcodeword_count++;
    }

    if (debug_print) {
        printf("C43 codewords %.*s: (%d)", length, source + in_locn, subcodeword_count);
        for (i = 0; i < subcodeword_count; i++) printf( " %d", subcw[i]);
        fputc('\n', stdout);
    }

    letters_encoded = sublocn - in_locn;
    if (encoded != NULL) {
        *encoded = letters_encoded;
    }

    for (i = 0; i < subcodeword_count; i += 3) {
        base43_value = (43 * 43 * subcw[i]) + (43 * subcw[i + 1]) + subcw[i + 2];
        cw[codeword_count] = base43_value / 282;
        codeword_count++;
        cw[codeword_count] = base43_value % 282;
        codeword_count++;
    }

    *cw_len = codeword_count;

    if (codeword_count == 0) {
        return 0.0f;
    }
    return (float) letters_encoded / (float) codeword_count;
}

/* Produces a set of codewords which are "somewhat" optimised - this could be improved on */
static int ult_generate_codewords(struct zint_symbol *symbol, const unsigned char source[], const int length,
            const int eci, const int gs1, const int symbol_mode, int *p_current_mode, int codewords[],
            int codeword_count) {
    int i;
    int crop_length;
    int input_locn = 0;
    int current_mode;
    int subset;
    float eightbit_score;
    float ascii_score;
    float c43_score;
    int end_char;
    int block_length;
    int fragment_length;
    int ascii_encoded, c43_encoded;
    const int debug_print = (symbol->debug & ZINT_DEBUG_PRINT);
    unsigned char *crop_source = (unsigned char *) z_alloca(length + 1);
    char *mode = (char *) z_alloca(length + 1);
    int *cw_fragment = (int *) z_alloca(sizeof(int) * (length * 2 + 1));

    /* Check for 06 Macro Sequence and crop accordingly */
    if (length >= 9
            && source[0] == '[' && source[1] == ')' && source[2] == '>' && source[3] == '\x1e'
            && source[4] == '0' && source[5] == '6' && source[6] == '\x1d'
            && source[length - 2] == '\x1e' && source[length - 1] == '\x04') {

        if (symbol_mode == ULT_EIGHTBIT_MODE) {
            codewords[codeword_count] = 271; /* 06 Macro */
        } else {
            codewords[codeword_count] = 273; /* 06 Macro */
        }
        codeword_count++;

        for (i = 7; i < (length - 2); i++) {
            crop_source[i - 7] = source[i];
        }
        crop_length = length - 9;
        crop_source[crop_length] = '\0';
   } else {
        /* Make a cropped version of input data - removes http:// and https:// if needed */
        for (i = input_locn; i < length; i++) {
            crop_source[i - input_locn] = source[i];
        }
        crop_length = length - input_locn;
        crop_source[crop_length] = '\0';
    }

    /* Attempt encoding in all three modes to see which offers best compaction and store results */
    if (symbol->option_3 == ULTRA_COMPRESSION || gs1) {
        current_mode = symbol_mode;
        input_locn = 0;
        do {
            end_char = input_locn + ULT_PREDICT_WINDOW;
            eightbit_score = ult_look_ahead_eightbit(crop_source, crop_length, input_locn, current_mode, end_char,
                                cw_fragment, &fragment_length, gs1);
            ascii_score = ult_look_ahead_ascii(crop_source, crop_length, input_locn, current_mode, symbol_mode,
                                end_char, cw_fragment, &fragment_length, &ascii_encoded, gs1);
            subset = ult_c43_should_latch_other(crop_source, crop_length, input_locn, 1 /*subset*/, gs1) ? 2 : 1;
            c43_score = ult_look_ahead_c43(crop_source, crop_length, input_locn, current_mode, end_char,
                                subset, cw_fragment, &fragment_length, &c43_encoded, gs1, 0 /*debug_print*/);

            mode[input_locn] = 'a';
            current_mode = ULT_ASCII_MODE;

            if ((c43_score > ascii_score) && (c43_score > eightbit_score)) {
                mode[input_locn] = 'c';
                current_mode = ULT_C43_MODE;
            } else if ((eightbit_score > ascii_score) && (eightbit_score > c43_score)) {
                mode[input_locn] = '8';
                current_mode = ULT_EIGHTBIT_MODE;
            }
            if (mode[input_locn] == 'a') {
                for (i = 0; i < ascii_encoded; i++) {
                    mode[input_locn + i] = 'a';
                }
                input_locn += ascii_encoded;
            } else if (mode[input_locn] == 'c') {
                for (i = 0; i < c43_encoded; i++) {
                    mode[input_locn + i] = 'c';
                }
                input_locn += c43_encoded;
            } else {
                input_locn++;
            }
        } while (input_locn < crop_length);
    } else {
        /* Force eight-bit mode */
        for (input_locn = 0; input_locn < crop_length; input_locn++) {
            mode[input_locn] = '8';
        }
    }
    mode[crop_length] = '\0';

    if (debug_print) {
        printf("Mode (%d): %s\n", (int) strlen(mode), mode);
    }

    if (symbol_mode == ULT_EIGHTBIT_MODE && *p_current_mode != ULT_EIGHTBIT_MODE) {
        codewords[codeword_count++] = 282; /* Unlatch to 8-bit mode */
    }

    if (eci) {
        if (eci < 899) {
            codewords[codeword_count++] = 272;
            codewords[codeword_count++] = eci / 256;
            codewords[codeword_count++] = eci % 256;
        } else if (eci < 10000) {
            codewords[codeword_count++] = 274;
            codewords[codeword_count++] = eci / 100 + 128;
            codewords[codeword_count++] = eci % 100 + 128;
        } else {
            codewords[codeword_count++] = 275;
            codewords[codeword_count++] = eci / 10000 + 128;
            codewords[codeword_count++] = (eci % 10000) / 100 + 128;
            codewords[codeword_count++] = eci % 100 + 128;
        }
    }

    /* Use results from test to perform actual mode switching */
    current_mode = symbol_mode;
    input_locn = 0;
    do {
        fragment_length = 0;
        block_length = 0;
        while (input_locn + block_length < crop_length && mode[input_locn + block_length] == mode[input_locn]) {
            block_length++;
        }

        switch (mode[input_locn]) {
            case 'a':
                ult_look_ahead_ascii(crop_source, crop_length, input_locn, current_mode, symbol_mode,
                                    input_locn + block_length, cw_fragment, &fragment_length, NULL, gs1);
                current_mode = ULT_ASCII_MODE;
                break;
            case 'c':
                subset = ult_c43_should_latch_other(crop_source, crop_length, input_locn, 1 /*subset*/, gs1) ? 2 : 1;
                ult_look_ahead_c43(crop_source, crop_length, input_locn, current_mode, input_locn + block_length,
                                    subset, cw_fragment, &fragment_length, NULL, gs1, debug_print);

                /* Substitute temporary latch if possible */
                if (current_mode == ULT_EIGHTBIT_MODE && cw_fragment[0] == 260 && fragment_length >= 5
                        && fragment_length <= 11) {
                    cw_fragment[0] = 256 + (fragment_length - 5) / 2; /* Temporary latch to submode 1 from Table 11 */
                } else if (current_mode == ULT_EIGHTBIT_MODE && cw_fragment[0] == 266 && fragment_length >= 5
                        && fragment_length <= 11) {
                    cw_fragment[0] = 262 + (fragment_length - 5) / 2; /* Temporary latch to submode 2 from Table 11 */
                } else if (current_mode == ULT_ASCII_MODE && cw_fragment[0] == 278 && fragment_length >= 5
                        && fragment_length <= 11) {
                    cw_fragment[0] = 274 + (fragment_length - 5) / 2; /* Temporary latch to submode 1 from Table 9 */
                } else {
                    current_mode = ULT_C43_MODE;
                }
                break;
            case '8':
                ult_look_ahead_eightbit(crop_source, crop_length, input_locn, current_mode, input_locn + block_length,
                                        cw_fragment, &fragment_length, gs1);
                current_mode = ULT_EIGHTBIT_MODE;
                break;
        }

        for (i = 0; i < fragment_length; i++) {
            codewords[codeword_count + i] = cw_fragment[i];
        }
        codeword_count += fragment_length;

        input_locn += block_length;
    } while (input_locn < crop_length);

    *p_current_mode = current_mode;

    return codeword_count;
}

/* Call `ult_generate_codewords()` for each segment, dealing with symbol mode and start codeword beforehand */
static int ult_generate_codewords_segs(struct zint_symbol *symbol, struct zint_seg segs[], const int seg_count,
            int codewords[]) {
    int i;
    int codeword_count = 0;
    int symbol_mode;
    int current_mode;
    int have_eci = 0;
    const unsigned char *source = segs[0].source;
    int length = segs[0].length;
    const int eci = segs[0].eci;
    const int gs1 = (symbol->input_mode & 0x07) == GS1_MODE;

    for (i = 0; i < seg_count; i++) {
        if (segs[i].eci) {
            have_eci = 1;
            break;
        }
    }

    if (have_eci || (symbol->option_3 != ULTRA_COMPRESSION && !gs1)) {
        /* Force eight-bit mode by default as other modes are poorly documented */
        symbol_mode = ULT_EIGHTBIT_MODE;
    } else {
        /* Decide start character codeword (from Table 5) */
        symbol_mode = ULT_ASCII_MODE;
        for (i = 0; i < length; i++) {
            if (source[i] >= 0x80) {
                symbol_mode = ULT_EIGHTBIT_MODE;
                break;
            }
        }
    }

    if (symbol->output_options & READER_INIT) {
        /* Reader Initialisation mode */
        codeword_count = 2;
        if (symbol_mode == ULT_ASCII_MODE) {
            codewords[0] = 272; /* 7-bit ASCII mode */
            codewords[1] = 271; /* FNC3 */
        } else {
            codewords[0] = 257; /* 8859-1 */
            codewords[1] = 269; /* FNC3 */
        }
    } else {
        /* Calculate start character codeword */
        codeword_count = 1;
        if (symbol_mode == ULT_ASCII_MODE) {
            if (gs1) {
                codewords[0] = 273;
            } else {
                codewords[0] = 272;
            }
        } else {
            if ((eci >= 3) && (eci <= 18) && (eci != 14)) {
                /* ECI indicates use of character set within ISO/IEC 8859 */
                codewords[0] = 257 + (eci - 3);
                if (codewords[0] > 267) {
                    /* Avoids ECI 14 for non-existant ISO/IEC 8859-12 */
                    codewords[0]--;
                }
            } else if ((eci > 18) && (eci <= 898)) {
                /* ECI indicates use of character set outside ISO/IEC 8859 */
                codewords[0] = 275 + (eci / 256);
                codewords[1] = eci % 256;
                codeword_count = 2;
            } else if (eci == 899) {
                /* Non-language byte data */
                codewords[0] = 280;
            } else if ((eci > 899) && (eci <= 9999)) {
                /* ECI beyond 899 needs to use fixed length encodable ECI invocation (section 7.6.2) */
                /* Encode as 3 codewords */
                codewords[0] = 257; /* ISO/IEC 8859-1 used to enter 8-bit mode */
                codewords[1] = 274; /* Encode ECI as 3 codewords */
                codewords[2] = (eci / 100) + 128;
                codewords[3] = (eci % 100) + 128;
                codeword_count = 4;
            } else if (eci >= 10000) {
                /* Encode as 4 codewords */
                codewords[0] = 257; /* ISO/IEC 8859-1 used to enter 8-bit mode */
                codewords[1] = 275; /* Encode ECI as 4 codewords */
                codewords[2] = (eci / 10000) + 128;
                codewords[3] = ((eci % 10000) / 100) + 128;
                codewords[4] = (eci % 100) + 128;
                codeword_count = 5;
            } else {
                codewords[0] = 257; /* Default is assumed to be ISO/IEC 8859-1 (ECI 3) */
            }
        }

        if ((codewords[0] == 257) || (codewords[0] == 272)) {
            int fragno = ult_find_fragment(source, length, 0);

            /* Check for http:// at start of input */
            if ((fragno == 0) || (fragno == 2)) {
                codewords[0] = 281;
                source += 7;
                length -= 7;
                symbol_mode = ULT_EIGHTBIT_MODE;

            /* Check for https:// at start of input */
            } else if ((fragno == 1) || (fragno == 3)) {
                codewords[0] = 282;
                source += 8;
                length -= 8;
                symbol_mode = ULT_EIGHTBIT_MODE;
            }
        }
    }

    current_mode = symbol_mode;
    codeword_count = ult_generate_codewords(symbol, source, length, 0 /*eci*/, gs1, symbol_mode, &current_mode,
                                            codewords, codeword_count);

    for (i = 1; i < seg_count; i++) {
        codeword_count = ult_generate_codewords(symbol, segs[i].source, segs[i].length, segs[i].eci, gs1, symbol_mode,
                                                &current_mode, codewords, codeword_count);
    }

    return codeword_count;
}

INTERNAL int ultra(struct zint_symbol *symbol, struct zint_seg segs[], const int seg_count) {
    int data_cw_count = 0;
    int acc, qcc;
    int scr[3] = {0}, scr_cw_count = 0; /* Symbol Control Region (only if have Structured Append) */
    int dr_count;
    int ecc_level;
    int rows, columns;
    int total_cws;
    int pads;
    int cw_memalloc;
    /* Allow for 3 pads in final 57th (60th incl. clock tracks) column of 5-row symbol (57 * 5 == 285) */
    int codeword[282 + 3];
    int i, j, locn;
    int total_height, total_width;
    char tilepat[6];
    int tilex, tiley;
    int dcc;
    int revision_idx = 0;
    const int debug_print = (symbol->debug & ZINT_DEBUG_PRINT);
    int *data_codewords;
    char *pattern;

    (void)seg_count;

    if (symbol->eci > 811799) {
        strcpy(symbol->errtxt, "590: ECI value not supported by Ultracode");
        return ZINT_ERROR_INVALID_OPTION;
    }

    if (symbol->structapp.count) {
        int link2 = 2; /* Draft Table 7, Structured Append Group (SAG) with no File Number */

        if (symbol->structapp.count < 2 || symbol->structapp.count > 8) {
            strcpy(symbol->errtxt, "596: Structured Append count out of range (2-8)");
            return ZINT_ERROR_INVALID_OPTION;
        }
        if (symbol->structapp.index < 1 || symbol->structapp.index > symbol->structapp.count) {
            sprintf(symbol->errtxt, "597: Structured Append index out of range (1-%d)", symbol->structapp.count);
            return ZINT_ERROR_INVALID_OPTION;
        }
        scr_cw_count = 1;

        if (symbol->structapp.id[0]) {
            int id, id_len;

            for (id_len = 1; id_len < 6 && symbol->structapp.id[id_len]; id_len++);

            if (id_len > 5) { /* 282 * 283 + 282 = 80088 */
                strcpy(symbol->errtxt, "593: Structured Append ID too long (5 digit maximum)");
                return ZINT_ERROR_INVALID_OPTION;
            }

            id = to_int((const unsigned char *) symbol->structapp.id, id_len);
            if (id == -1) {
                strcpy(symbol->errtxt, "594: Invalid Structured Append ID (digits only)");
                return ZINT_ERROR_INVALID_OPTION;
            }
            if (id > 80088) {
                sprintf(symbol->errtxt, "595: Structured Append ID '%d' out of range (1-80088)", id);
                return ZINT_ERROR_INVALID_OPTION;
            }
            if (id) {
                link2 = 3; /* Missing from draft Table 7 but mentioned 7.4.3 - SAG with File Number */
                scr[1] = id / 283;
                scr[2] = id % 283; /* 7.4.3.2 says 1-282 but can be 0 if id >= 283 */
                scr_cw_count += 2;
            }
        }

        scr[0] = link2 * 70 + (symbol->structapp.count - 1) * 8 + symbol->structapp.index - 1;
    }

    cw_memalloc = segs_length(segs, seg_count) * 2;
    if (cw_memalloc < 283) {
        cw_memalloc = 283;
    }

    data_codewords = (int *) z_alloca(sizeof(int) * cw_memalloc);

    data_cw_count = ult_generate_codewords_segs(symbol, segs, seg_count, data_codewords);

    if (debug_print) {
        printf("Codewords (%d):", data_cw_count);
        for (i = 0; i < data_cw_count; i++) {
            printf(" %d", data_codewords[i]);
        }
        fputc('\n', stdout);
    }
#ifdef ZINT_TEST
    if (symbol->debug & ZINT_DEBUG_TEST) {
        debug_test_codeword_dump_int(symbol, data_codewords, data_cw_count);
    }
#endif

    data_cw_count += 2 + scr_cw_count; /* 2 == MCC + ACC (data codeword count includes start char) */

    if (symbol->option_2 > 0) {
        if (symbol->option_2 > 2) {
            strcpy(symbol->errtxt, "592: Revision must be 1 or 2");
            return ZINT_ERROR_INVALID_OPTION;
        }
        if (symbol->option_2 == 2) { /* Revision 2, swop and inversion of DCCU/DCCL tiles */
            revision_idx = 1;
        }
    }

    /* Default ECC level is EC2 */
    if ((symbol->option_1 <= 0) || (symbol->option_1 > 6)) {
        ecc_level = 2;
    } else {
        ecc_level = symbol->option_1 - 1;
    }

    /* ECC calculation from section 7.7.2 */
    if (ecc_level == 0) {
        qcc = 3;
    } else {
        if ((data_cw_count % 25) == 0) {
            qcc = (ult_kec[ecc_level] * (data_cw_count / 25)) + 3 + 2;
        } else {
            qcc = (ult_kec[ecc_level] * ((data_cw_count / 25) + 1)) + 3 + 2;
        }

    }
    if (debug_print) {
        printf("EC%d codewords: %d\n", ecc_level, qcc);
    }

    acc = qcc - 3;
    if (scr_cw_count) {
        acc += 70; /* Link1 = 1 (* 70) means SCR present */
    }
    if (debug_print) {
        printf("MCC: %d, ACC: %d, SCR: %d", data_cw_count, acc, scr_cw_count);
        if (scr_cw_count) {
            printf(", SCR0: %d", scr[0]);
            if (scr_cw_count > 1) {
                printf(", SCR1: %d, SCR2: %d", scr[1], scr[2]);
            }
        }
        fputc('\n', stdout);
    }

    /* Maximum capacity is 282 codewords */
    total_cws = data_cw_count + qcc + 3; /* 3 == TCC pattern + RSEC pattern + QCC pattern */
    if (total_cws - 3 > 282) {
        strcpy(symbol->errtxt, "591: Data too long for selected error correction capacity");
        return ZINT_ERROR_TOO_LONG;
    }

    rows = 5;
    for (i = 2; i >= 0; i--) {
        /* Total codewords less 6 (+ SCR) overhead (Start + MCC + ACC (+ SCR) + 3 TCC/RSEC/QCC patterns) */
        if (total_cws - (6 + scr_cw_count) <= ult_maxsize[i]) {
            rows--;
        }
    }

    if ((total_cws % rows) == 0) {
        pads = 0;
        columns = total_cws / rows;
    } else {
        pads = rows - (total_cws % rows);
        columns = (total_cws / rows) + 1;
    }
    columns += columns / 15; /* Secondary vertical clock tracks */

    if (debug_print) {
        printf("Calculated size is %d rows by %d columns (pads %d)\n", rows, columns, pads);
    }

    /* Insert MCC and ACC and possibly SCR into data codewords */
    for (i = 282; i > 2 + scr_cw_count; i--) {
        data_codewords[i] = data_codewords[i - (2 + scr_cw_count)];
    }
    data_codewords[1] = data_cw_count; /* MCC */
    data_codewords[2] = acc; /* ACC */
    for (i = 0; i < scr_cw_count; i++) { /* SCR */
        data_codewords[3 + i] = scr[i];
    }

    /* Calculate error correction codewords (RSEC) */

    ult_gf283((short) data_cw_count, (short) qcc, data_codewords);

    if (debug_print) {
        printf("ECCs (%d):", qcc);
        for (i = 0; i < qcc; i++) {
            printf(" %d", data_codewords[(282 - qcc) + i]);
        }
        fputc('\n', stdout);
    }

    /* Rearrange to make final codeword sequence */
    locn = 0;
    codeword[locn++] = data_codewords[282 - (data_cw_count + qcc)]; /* Start Character */
    codeword[locn++] = data_cw_count; /* MCC */
    for (i = 0; i < qcc; i++) {
        codeword[locn++] = data_codewords[(282 - qcc) + i]; /* RSEC Region */
    }
    codeword[locn++] = data_cw_count + qcc; /* TCC = C + Q - section 6.11.4 */
    codeword[locn++] = 283; /* Separator */
    codeword[locn++] = acc; /* ACC */
    for (i = 0; i < scr_cw_count; i++) { /* SCR */
        codeword[locn++] = scr[i];
    }
    dr_count = data_cw_count - (3 + scr_cw_count);
    for (i = 0; i < dr_count; i++) {
        codeword[locn++] = data_codewords[(282 - (dr_count + qcc)) + i]; /* Data Region */
    }
    for (i = 0; i < pads; i++) {
        codeword[locn++] = 284; /* Pad pattern */
    }
    codeword[locn++] = qcc; /* QCC */

    if (debug_print) {
        printf("Rearranged codewords with ECC (%d):\n", locn);
        for (i = 0; i < locn; i++) {
            printf(" %d", codeword[i]);
        }
        fputc('\n', stdout);
    }

    total_height = (rows * 6) + 1;
    total_width = columns + 6;

    /* Build symbol */
    pattern = (char *) z_alloca(total_height * total_width);

    for (i = 0; i < (total_height * total_width); i++) {
        pattern[i] = 'W';
    }

    /* Border */
    for (i = 0; i < total_width; i++) {
        pattern[i] = 'K'; /* Top */
        pattern[(total_height * total_width) - i - 1] = 'K'; /* Bottom */
    }
    for (i = 0; i < total_height; i++) {
        pattern[total_width * i] = 'K'; /* Left */
        pattern[(total_width * i) + 3] = 'K';
        pattern[(total_width * i) + (total_width - 1)] = 'K'; /* Right */
    }

    /* Clock tracks */
    for (i = 0; i < total_height; i += 2) {
        pattern[(total_width * i) + 1] = 'K'; /* Primary vertical clock track */
        if (total_width > 20) {
            pattern[(total_width * i) + 19] = 'K'; /* Secondary vertical clock track */
        }
        if (total_width > 36) {
            pattern[(total_width * i) + 35] = 'K'; /* Secondary vertical clock track */
        }
        if (total_width > 52) {
            pattern[(total_width * i) + 51] = 'K'; /* Secondary vertical clock track */
        }
    }
    for (i = 6; i < total_height; i += 6) {
        for (j = 5; j < total_width; j += 2) {
            pattern[(total_width * i) + j] = 'K'; /* Horizontal clock track */
        }
    }

    /* Place tiles */
    tilepat[5] = '\0';
    tilex = 0;
    tiley = 0;
    for (i = 0; i < locn; i++) {
        for (j = 0; j < 5; j++) {
            tilepat[4 - j] = ult_colour[(ult_tiles[codeword[i]] >> (3 * j)) & 0x07];
        }
        if ((tiley + 1) >= total_height) {
            tiley = 0;
            tilex++;

            if (tilex == 14) {
                tilex++;
            } else if (tilex == 30) {
                tilex++;
            } else if (tilex == 46) {
                tilex++;
            }
        }

        for (j = 0; j < 5; j++) {
            pattern[((tiley + j + 1) * total_width) + (tilex + 5)] = tilepat[j];
        }
        tiley += 6;
    }

    /* Add data column count */
    dcc = columns - ult_mincols[rows - 2];
    tilex = 2;
    tiley = (total_height - 11) / 2;
    /* DCCU */
    for (j = 0; j < 5; j++) {
        tilepat[4 - j] = ult_colour[(ult_dccu[revision_idx][dcc] >> (3 * j)) & 0x07];
    }
    for (j = 0; j < 5; j++) {
        pattern[((tiley + j) * total_width) + tilex] = tilepat[j];
    }
    /* DCCL */
    tiley += 6;
    for (j = 0; j < 5; j++) {
        tilepat[4 - j] = ult_colour[(ult_dccl[revision_idx][dcc] >> (3 * j)) & 0x07];
    }
    for (j = 0; j < 5; j++) {
        pattern[((tiley + j) * total_width) + tilex] = tilepat[j];
    }

    if (debug_print) {
        printf("DCC: %d\n", dcc);

        for (i = 0; i < (total_height * total_width); i++) {
            printf("%c", pattern[i]);
            if ((i + 1) % total_width == 0) {
                fputc('\n', stdout);
            }
        }
    }

    /* Put pattern into symbol */
    symbol->rows = total_height;
    symbol->width = total_width;

    for (i = 0; i < total_height; i++) {
        symbol->row_height[i] = 1;
        for (j = 0; j < total_width; j++) {
            set_module_colour(symbol, i, j, posn(ult_colour, pattern[(i * total_width) + j]));
        }
    }
    symbol->height = total_height;

    return 0;
}

/* vim: set ts=4 sw=4 et : */