qr_finder.c

#include <config.h>
//#include <assert.h>

#include <zbar.h>
#include "decoder.h"

#include "vmsys.h"
#include "vmio.h"

#define malloc vm_malloc
#define free vm_free
#define calloc(x,y) vm_calloc(x*y)
#define realloc vm_realloc
#define assert(x) if(!(x)){vm_exit_app();while(1){};}


#ifdef DEBUG_QR_FINDER
# define DEBUG_LEVEL (DEBUG_QR_FINDER)
#endif
#include "debug.h"

/* at this point lengths are all decode unit offsets from the decode edge
 * NB owned by finder
 */
qr_finder_line *_zbar_decoder_get_qr_finder_line (zbar_decoder_t *dcode)
{
    return(&dcode->qrf.line);
}

zbar_symbol_type_t _zbar_find_qr (zbar_decoder_t *dcode)
{
	unsigned s = 0;
	int ei = 0;
	unsigned qz = 0;
    unsigned w = 0;
    qr_finder_t *qrf = &dcode->qrf;

    /* update latest finder pattern width */
    qrf->s5 -= get_width(dcode, 6);
    qrf->s5 += get_width(dcode, 1);
    s = qrf->s5;

    if(get_color(dcode) != ZBAR_SPACE || s < 7)
        return(0);

    dprintf(2, "    qrf: s=%d", s);

    ei = decode_e(pair_width(dcode, 1), s, 7);
    dprintf(2, " %d", ei);
    if(ei)
        goto invalid;

    ei = decode_e(pair_width(dcode, 2), s, 7);
    dprintf(2, "%d", ei);
    if(ei != 2)
        goto invalid;

    ei = decode_e(pair_width(dcode, 3), s, 7);
    dprintf(2, "%d", ei);
    if(ei != 2)
        goto invalid;

    ei = decode_e(pair_width(dcode, 4), s, 7);
    dprintf(2, "%d", ei);
    if(ei)
        goto invalid;

    /* valid QR finder symbol
     * mark positions needed by decoder
     */
    qz = get_width(dcode, 0);
    w = get_width(dcode, 1);
    qrf->line.eoffs = qz + (w + 1) / 2;
    qrf->line.len = qz + w + get_width(dcode, 2);
    qrf->line.pos[0] = qrf->line.len + get_width(dcode, 3);
    qrf->line.pos[1] = qrf->line.pos[0];
    w = get_width(dcode, 5);
    qrf->line.boffs = qrf->line.pos[0] + get_width(dcode, 4) + (w + 1) / 2;

    dprintf(2, " boff=%d pos=%d len=%d eoff=%d [valid]\n",
            qrf->line.boffs, qrf->line.pos[0], qrf->line.len,
            qrf->line.eoffs);

    return(ZBAR_QRCODE);

invalid:
    dprintf(2, " [invalid]\n");
    return(0);
}