zint/backend/maxicode.c

/* maxicode.c - Handles Maxicode */

/*
    libzint - the open source barcode library
    Copyright (C) 2010-2016 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.
 */

/* Includes corrections thanks to Monica Swanson @ Source Technologies */

#include "common.h"
#include "maxicode.h"
#include "reedsol.h"
#include <string.h>
#include <stdlib.h>

int maxi_codeword[144];

/* Handles error correction of primary message */
void maxi_do_primary_check() {
    unsigned char data[15];
    unsigned char results[15];
    int j;
    int datalen = 10;
    int ecclen = 10;

    rs_init_gf(0x43);
    rs_init_code(ecclen, 1);

    for (j = 0; j < datalen; j += 1)
        data[j] = maxi_codeword[j];

    rs_encode(datalen, data, results);

    for (j = 0; j < ecclen; j += 1)
        maxi_codeword[ datalen + j] = results[ecclen - 1 - j];
    rs_free();
}

/* Handles error correction of odd characters in secondary */
void maxi_do_secondary_chk_odd(int ecclen) {
    unsigned char data[100];
    unsigned char results[30];
    int j;
    int datalen = 68;

    rs_init_gf(0x43);
    rs_init_code(ecclen, 1);

    if (ecclen == 20)
        datalen = 84;

    for (j = 0; j < datalen; j += 1)
        if (j & 1) // odd
            data[(j - 1) / 2] = maxi_codeword[j + 20];

    rs_encode(datalen / 2, data, results);

    for (j = 0; j < (ecclen); j += 1)
        maxi_codeword[ datalen + (2 * j) + 1 + 20 ] = results[ecclen - 1 - j];
    rs_free();
}

/* Handles error correction of even characters in secondary */
void maxi_do_secondary_chk_even(int ecclen) {
    unsigned char data[100];
    unsigned char results[30];
    int j;
    int datalen = 68;

    if (ecclen == 20)
        datalen = 84;

    rs_init_gf(0x43);
    rs_init_code(ecclen, 1);

    for (j = 0; j < datalen + 1; j += 1)
        if (!(j & 1)) // even
            data[j / 2] = maxi_codeword[j + 20];

    rs_encode(datalen / 2, data, results);

    for (j = 0; j < (ecclen); j += 1)
        maxi_codeword[ datalen + (2 * j) + 20] = results[ecclen - 1 - j];
    rs_free();
}

/* Moves everything up so that a shift or latch can be inserted */
void maxi_bump(int set[], int character[], int bump_posn) {
    int i;

    for (i = 143; i > bump_posn; i--) {
        set[i] = set[i - 1];
        character[i] = character[i - 1];
    }
}

/* Format text according to Appendix A */
int maxi_text_process(int mode, unsigned char source[], int length, int eci) {
    /* This code doesn't make use of [Lock in C], [Lock in D]
    and [Lock in E] and so is not always the most efficient at
    compressing data, but should suffice for most applications */

    int set[144], character[144], i, j, done, count, current_set;

    if (length > 138) {
        return ZINT_ERROR_TOO_LONG;
    }

    for (i = 0; i < 144; i++) {
        set[i] = -1;
        character[i] = 0;
    }

    for (i = 0; i < length; i++) {
        /* Look up characters in table from Appendix A - this gives
         value and code set for most characters */
        set[i] = maxiCodeSet[source[i]];
        character[i] = maxiSymbolChar[source[i]];
    }

    /* If a character can be represented in more than one code set,
    pick which version to use */
    if (set[0] == 0) {
        if (character[0] == 13) {
            character[0] = 0;
        }
        set[0] = 1;
    }

    for (i = 1; i < length; i++) {
        if (set[i] == 0) {
            done = 0;
            /* Special character */
            if (character[i] == 13) {
                /* Carriage Return */
                if (set[i - 1] == 5) {
                    character[i] = 13;
                    set[i] = 5;
                } else {
                    if ((i != length - 1) && (set[i + 1] == 5)) {
                        character[i] = 13;
                        set[i] = 5;
                    } else {
                        character[i] = 0;
                        set[i] = 1;
                    }
                }
                done = 1;
            }

            if ((character[i] == 28) && (done == 0)) {
                /* FS */
                if (set[i - 1] == 5) {
                    character[i] = 32;
                    set[i] = 5;
                } else {
                    set[i] = set[i - 1];
                }
                done = 1;
            }

            if ((character[i] == 29) && (done == 0)) {
                /* GS */
                if (set[i - 1] == 5) {
                    character[i] = 33;
                    set[i] = 5;
                } else {
                    set[i] = set[i - 1];
                }
                done = 1;
            }

            if ((character[i] == 30) && (done == 0)) {
                /* RS */
                if (set[i - 1] == 5) {
                    character[i] = 34;
                    set[i] = 5;
                } else {
                    set[i] = set[i - 1];
                }
                done = 1;
            }

            if ((character[i] == 32) && (done == 0)) {
                /* Space */
                if (set[i - 1] == 1) {
                    character[i] = 32;
                    set[i] = 1;
                }
                if (set[i - 1] == 2) {
                    character[i] = 47;
                    set[i] = 2;
                }
                if (set[i - 1] >= 3) {
                    if (i != length - 1) {
                        if (set[i + 1] == 1) {
                            character[i] = 32;
                            set[i] = 1;
                        }
                        if (set[i + 1] == 2) {
                            character[i] = 47;
                            set[i] = 2;
                        }
                        if (set[i + 1] >= 3) {
                            character[i] = 59;
                            set[i] = set[i - 1];
                        }
                    } else {
                        character[i] = 59;
                        set[i] = set[i - 1];
                    }
                }
                done = 1;
            }

            if ((character[i] == 44) && (done == 0)) {
                /* Comma */
                if (set[i - 1] == 2) {
                    character[i] = 48;
                    set[i] = 2;
                } else {
                    if ((i != length - 1) && (set[i + 1] == 2)) {
                        character[i] = 48;
                        set[i] = 2;
                    } else {
                        set[i] = 1;
                    }
                }
                done = 1;
            }

            if ((character[i] == 46) && (done == 0)) {
                /* Full Stop */
                if (set[i - 1] == 2) {
                    character[i] = 49;
                    set[i] = 2;
                } else {
                    if ((i != length - 1) && (set[i + 1] == 2)) {
                        character[i] = 49;
                        set[i] = 2;
                    } else {
                        set[i] = 1;
                    }
                }
                done = 1;
            }

            if ((character[i] == 47) && (done == 0)) {
                /* Slash */
                if (set[i - 1] == 2) {
                    character[i] = 50;
                    set[i] = 2;
                } else {
                    if ((i != length - 1) && (set[i + 1] == 2)) {
                        character[i] = 50;
                        set[i] = 2;
                    } else {
                        set[i] = 1;
                    }
                }
                done = 1;
            }

            if ((character[i] == 58) && (done == 0)) {
                /* Colon */
                if (set[i - 1] == 2) {
                    character[i] = 51;
                    set[i] = 2;
                } else {
                    if ((i != length - 1) && (set[i + 1] == 2)) {
                        character[i] = 51;
                        set[i] = 2;
                    } else {
                        set[i] = 1;
                    }
                }
                done = 1;
            }
        }
    }

    for (i = length; i < 144; i++) {
        /* Add the padding */
        if (set[length - 1] == 2) {
            set[i] = 2;
        } else {
            set[i] = 1;
        }
        character[i] = 33;
    }

    /* Find candidates for number compression */
    if ((mode == 2) || (mode == 3)) {
        j = 0;
    } else {
        j = 9;
    }
    /* Number compression not allowed in primary message */
    count = 0;
    for (i = j; i < 143; i++) {
        if ((set[i] == 1) && ((character[i] >= 48) && (character[i] <= 57))) {
            /* Character is a number */
            count++;
        } else {
            count = 0;
        }
        if (count == 9) {
            /* Nine digits in a row can be compressed */
            set[i] = 6;
            set[i - 1] = 6;
            set[i - 2] = 6;
            set[i - 3] = 6;
            set[i - 4] = 6;
            set[i - 5] = 6;
            set[i - 6] = 6;
            set[i - 7] = 6;
            set[i - 8] = 6;
            count = 0;
        }
    }

    /* Add shift and latch characters */
    current_set = 1;
    i = 0;
    do {

        if ((set[i] != current_set) && (set[i] != 6)) {
            switch (set[i]) {
                case 1:
                    if (set[i + 1] == 1) {
                        if (set[i + 2] == 1) {
                            if (set[i + 3] == 1) {
                                /* Latch A */
                                maxi_bump(set, character, i);
                                character[i] = 63;
                                current_set = 1;
                                length++;
                            } else {
                                /* 3 Shift A */
                                maxi_bump(set, character, i);
                                character[i] = 57;
                                length++;
                                i += 2;
                            }
                        } else {
                            /* 2 Shift A */
                            maxi_bump(set, character, i);
                            character[i] = 56;
                            length++;
                            i++;
                        }
                    } else {
                        /* Shift A */
                        maxi_bump(set, character, i);
                        character[i] = 59;
                        length++;
                    }
                    break;
                case 2:
                    if (set[i + 1] == 2) {
                        /* Latch B */
                        maxi_bump(set, character, i);
                        character[i] = 63;
                        current_set = 2;
                        length++;
                    } else {
                        /* Shift B */
                        maxi_bump(set, character, i);
                        character[i] = 59;
                        length++;
                    }
                    break;
                case 3:
                    /* Shift C */
                    maxi_bump(set, character, i);
                    character[i] = 60;
                    length++;
                    break;
                case 4:
                    /* Shift D */
                    maxi_bump(set, character, i);
                    character[i] = 61;
                    length++;
                    break;
                case 5:
                    /* Shift E */
                    maxi_bump(set, character, i);
                    character[i] = 62;
                    length++;
                    break;
            }
            i++;
        }
        i++;
    } while (i < 144);

    /* Number compression has not been forgotten! - It's handled below */
    i = 0;
    do {
        if (set[i] == 6) {
            /* Number compression */
            char substring[11];
            int value;

            for (j = 0; j < 9; j++) {
                substring[j] = character[i + j];
            }
            substring[9] = '\0';
            value = atoi(substring);

            character[i] = 31; /* NS */
            character[i + 1] = (value & 0x3f000000) >> 24;
            character[i + 2] = (value & 0xfc0000) >> 18;
            character[i + 3] = (value & 0x3f000) >> 12;
            character[i + 4] = (value & 0xfc0) >> 6;
            character[i + 5] = (value & 0x3f);

            i += 6;
            for (j = i; j < 140; j++) {
                set[j] = set[j + 3];
                character[j] = character[j + 3];
            }
            length -= 3;
        } else {
            i++;
        }
    } while (i <= 143);

    /* Insert ECI at the beginning of message if needed */
    if (eci != 3) {
        maxi_bump(set, character, 0);
        character[0] = 27; // ECI
        maxi_bump(set, character, 1);
        character[1] = eci;
        length += 2;
    }
    
    if (((mode == 2) || (mode == 3)) && (length > 84)) {
        return ZINT_ERROR_TOO_LONG;
    }

    if (((mode == 4) || (mode == 6)) && (length > 93)) {
        return ZINT_ERROR_TOO_LONG;
    }

    if ((mode == 5) && (length > 77)) {
        return ZINT_ERROR_TOO_LONG;
    }


    /* Copy the encoded text into the codeword array */
    if ((mode == 2) || (mode == 3)) {
        for (i = 0; i < 84; i++) { /* secondary only */
            maxi_codeword[i + 20] = character[i];
        }
    }

    if ((mode == 4) || (mode == 6)) {
        for (i = 0; i < 9; i++) { /* primary */
            maxi_codeword[i + 1] = character[i];
        }
        for (i = 0; i < 84; i++) { /* secondary */
            maxi_codeword[i + 20] = character[i + 9];
        }
    }

    if (mode == 5) {
        for (i = 0; i < 9; i++) { /* primary */
            maxi_codeword[i + 1] = character[i];
        }
        for (i = 0; i < 68; i++) { /* secondary */
            maxi_codeword[i + 20] = character[i + 9];
        }
    }

    return 0;
}

/* Format structured primary for Mode 2 */
void maxi_do_primary_2(char postcode[], int country, int service) {
    size_t postcode_length;
   int    postcode_num, i;

    for (i = 0; i < 10; i++) {
        if ((postcode[i] < '0') || (postcode[i] > '9')) {
            postcode[i] = '\0';
        }
    }

    postcode_length = strlen(postcode);
    postcode_num = atoi(postcode);

    maxi_codeword[0] = ((postcode_num & 0x03) << 4) | 2;
    maxi_codeword[1] = ((postcode_num & 0xfc) >> 2);
    maxi_codeword[2] = ((postcode_num & 0x3f00) >> 8);
    maxi_codeword[3] = ((postcode_num & 0xfc000) >> 14);
    maxi_codeword[4] = ((postcode_num & 0x3f00000) >> 20);
    maxi_codeword[5] = ((postcode_num & 0x3c000000) >> 26) | ((postcode_length & 0x3) << 4);
    maxi_codeword[6] = ((postcode_length & 0x3c) >> 2) | ((country & 0x3) << 4);
    maxi_codeword[7] = (country & 0xfc) >> 2;
    maxi_codeword[8] = ((country & 0x300) >> 8) | ((service & 0xf) << 2);
    maxi_codeword[9] = ((service & 0x3f0) >> 4);
}

/* Format structured primary for Mode 3 */
void maxi_do_primary_3(char postcode[], int country, int service) {
    int i, h;

    h = strlen(postcode);
    to_upper((unsigned char*) postcode);
    for (i = 0; i < h; i++) {
        if ((postcode[i] >= 'A') && (postcode[i] <= 'Z')) {
            /* (Capital) letters shifted to Code Set A values */
            postcode[i] -= 64;
        }
        if (((postcode[i] == 27) || (postcode[i] == 31)) || ((postcode[i] == 33) || (postcode[i] >= 59))) {
            /* Not a valid postcode character */
            postcode[i] = ' ';
        }
        /* Input characters lower than 27 (NUL - SUB) in postcode are
        interpreted as capital letters in Code Set A (e.g. LF becomes 'J') */
    }

    maxi_codeword[0] = ((postcode[5] & 0x03) << 4) | 3;
    maxi_codeword[1] = ((postcode[4] & 0x03) << 4) | ((postcode[5] & 0x3c) >> 2);
    maxi_codeword[2] = ((postcode[3] & 0x03) << 4) | ((postcode[4] & 0x3c) >> 2);
    maxi_codeword[3] = ((postcode[2] & 0x03) << 4) | ((postcode[3] & 0x3c) >> 2);
    maxi_codeword[4] = ((postcode[1] & 0x03) << 4) | ((postcode[2] & 0x3c) >> 2);
    maxi_codeword[5] = ((postcode[0] & 0x03) << 4) | ((postcode[1] & 0x3c) >> 2);
    maxi_codeword[6] = ((postcode[0] & 0x3c) >> 2) | ((country & 0x3) << 4);
    maxi_codeword[7] = (country & 0xfc) >> 2;
    maxi_codeword[8] = ((country & 0x300) >> 8) | ((service & 0xf) << 2);
    maxi_codeword[9] = ((service & 0x3f0) >> 4);
}

int maxicode(struct zint_symbol *symbol, unsigned char local_source[], int length) {
    int i, j, block, bit, mode, countrycode = 0, service = 0, lp = 0;
    int bit_pattern[7], internal_error = 0, eclen;
    char postcode[12], countrystr[4], servicestr[4];

    mode = symbol->option_1;
    strcpy(postcode, "");
    strcpy(countrystr, "");
    strcpy(servicestr, "");

    memset(maxi_codeword, 0, sizeof (maxi_codeword));

    if (mode == -1) { /* If mode is unspecified */
        lp = strlen(symbol->primary);
        if (lp == 0) {
            mode = 4;
        } else {
            mode = 2;
            for (i = 0; i < 10 && i < lp; i++) {
                if ((symbol->primary[i] < 48) || (symbol->primary[i] > 57)) {
                    mode = 3;
                    break;
                }
            }
        }
    }

    if ((mode < 2) || (mode > 6)) { /* Only codes 2 to 6 supported */
        strcpy(symbol->errtxt, "Invalid Maxicode Mode (E50)");
        return ZINT_ERROR_INVALID_OPTION;
    }

    if ((mode == 2) || (mode == 3)) { /* Modes 2 and 3 need data in symbol->primary */
        if (lp == 0) { /* Mode set manually means lp doesn't get set */
            lp = strlen(symbol->primary);
        }
        if (lp != 15) {
            strcpy(symbol->errtxt, "Invalid Primary String (E51)");
            return ZINT_ERROR_INVALID_DATA;
        }

        for (i = 9; i < 15; i++) { /* check that country code and service are numeric */
            if ((symbol->primary[i] < '0') || (symbol->primary[i] > '9')) {
                strcpy(symbol->errtxt, "Invalid Primary String (E52)");
                return ZINT_ERROR_INVALID_DATA;
            }
        }

        memcpy(postcode, symbol->primary, 9);
        postcode[9] = '\0';

        if (mode == 2) {
            for (i = 0; i < 10; i++) {
                if (postcode[i] == ' ') {
                    postcode[i] = '\0';
                }
            }
        } else if (mode == 3) {
            postcode[6] = '\0';
        }

        countrystr[0] = symbol->primary[9];
        countrystr[1] = symbol->primary[10];
        countrystr[2] = symbol->primary[11];
        countrystr[3] = '\0';

        servicestr[0] = symbol->primary[12];
        servicestr[1] = symbol->primary[13];
        servicestr[2] = symbol->primary[14];
        servicestr[3] = '\0';

        countrycode = atoi(countrystr);
        service = atoi(servicestr);

        if (mode == 2) {
            maxi_do_primary_2(postcode, countrycode, service);
        }
        if (mode == 3) {
            maxi_do_primary_3(postcode, countrycode, service);
        }
    } else {
        maxi_codeword[0] = mode;
    }

    i = maxi_text_process(mode, local_source, length, symbol->eci);
    if (i == ZINT_ERROR_TOO_LONG) {
        strcpy(symbol->errtxt, "Input data too long (E53)");
        return i;
    }

    /* All the data is sorted - now do error correction */
    maxi_do_primary_check(); /* always EEC */

    if (mode == 5)
        eclen = 56; // 68 data codewords , 56 error corrections
    else
        eclen = 40; // 84 data codewords,  40 error corrections

    maxi_do_secondary_chk_even(eclen / 2); // do error correction of even
    maxi_do_secondary_chk_odd(eclen / 2); // do error correction of odd

    /* Copy data into symbol grid */
    for (i = 0; i < 33; i++) {
        for (j = 0; j < 30; j++) {
            block = (MaxiGrid[(i * 30) + j] + 5) / 6;
            bit = (MaxiGrid[(i * 30) + j] + 5) % 6;

            if (block != 0) {

                bit_pattern[0] = (maxi_codeword[block - 1] & 0x20) >> 5;
                bit_pattern[1] = (maxi_codeword[block - 1] & 0x10) >> 4;
                bit_pattern[2] = (maxi_codeword[block - 1] & 0x8) >> 3;
                bit_pattern[3] = (maxi_codeword[block - 1] & 0x4) >> 2;
                bit_pattern[4] = (maxi_codeword[block - 1] & 0x2) >> 1;
                bit_pattern[5] = (maxi_codeword[block - 1] & 0x1);

                if (bit_pattern[bit] != 0) {
                    set_module(symbol, i, j);
                }
            }
        }
    }

    /* Add orientation markings */
    set_module(symbol, 0, 28); // Top right filler
    set_module(symbol, 0, 29);
    set_module(symbol, 9, 10); // Top left marker
    set_module(symbol, 9, 11);
    set_module(symbol, 10, 11);
    set_module(symbol, 15, 7); // Left hand marker
    set_module(symbol, 16, 8);
    set_module(symbol, 16, 20); // Right hand marker
    set_module(symbol, 17, 20);
    set_module(symbol, 22, 10); // Bottom left marker
    set_module(symbol, 23, 10);
    set_module(symbol, 22, 17); // Bottom right marker
    set_module(symbol, 23, 17);

    symbol->width = 30;
    symbol->rows = 33;

    return internal_error;
}