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/*
 *  li_recognizer.c
 *
 *      Copyright 2000 Compaq Computer Corporation.
 *      Copying or modifying this code for any purpose is permitted,
 *      provided that this copyright notice is preserved in its entirety
 *      in all copies or modifications.
 *      COMPAQ COMPUTER CORPORATION MAKES NO WARRANTIES, EXPRESSED OR
 *      IMPLIED, AS TO THE USEFULNESS OR CORRECTNESS OF THIS CODE OR
 *
 *
 *  Adapted from cmu_recognizer.c by Jay Kistler.
 *
 *  Where is the CMU copyright???? Gotta track it down - Jim Gettys
 *
 *  Credit to Dean Rubine, Jim Kempf, and Ari Rapkin.
 */
 
 
#include <sys/types.h>
#include <stdio.h>
#include <string.h>
#ifndef ELX
#include <stdlib.h>
#endif
#include <math.h>
#include <locale.h>
#include <hre_internal.h>
#include <setjmp.h>
#include "util.h"
#include "matrix.h"
#include "sc.h"
#include "li_recognizer.h"
#include "li_recognizer_internal.h"
 
 
int lidebug = 0;
 
/*LI Magic Number.*/
 
#define LI_MAGIC 0xACCBADDD
 
#define CHECK_LI_MAGIC(_a) \
  ((_a) != NULL && ((li_recognizer*)(_a))->li_magic == LI_MAGIC)
 
 
static void lialg_initialize(rClassifier *);
static int lialg_read_classifier_digest(rClassifier *);
static int lialg_canonicalize_examples(rClassifier *);
static char *lialg_recognize_stroke(rClassifier *, point_list *);
 
 
char* li_err_msg = NULL;
char _zdebug_flag[128];
 
#ifndef __ECOS
// This is standard - defined in <stdlib.h>
#define bcopy(s1,s2,n) memcpy(s2,s1,n)
#endif
 
#if 0 /* was #ifdef mips*/
char *strdup(char* from) {
   char* to;
   int len = strlen(from) + 1;
 
   /*   to = (char *) safe_malloc( len * sizeof(char) );*/
   to = allocate(len, char);
   memcpy(to, from, len);
   return to;
}
#endif
 
 
/*Freeing classifier*/
 
static void
free_rClassifier(rClassifier* rc);
 
/*
 * Point List Support
*/
 
static point_list*
add_example(point_list* l,int npts,pen_point* pts)
{
    pen_point* lpts = make_pen_point_array(npts);
    /*    point_list* p = (point_list*)safe_malloc(sizeof(point_list));*/
    point_list *p = allocate(1, point_list);
 
    p->npts = npts;
    p->pts = lpts;
    p->next = l;       /*Order doesn't matter, so we stick on end.*/
 
    /*Copy points.*/
 
    bcopy(pts,lpts,npts * sizeof(pen_point));
 
    return(p);
}
 
 
static void
delete_examples(point_list* l)
{
    point_list* p;
 
    for( ; l != NULL; l = p ) {
        p = l->next;
        free(l->pts);
        free(l);
    }
}
 
/*
 * Local functions
 */
 
/*
 * recognize_internal-Form Vector, use Classifier to classify, return char.
 */
 
static char*
  recognize_internal(rClassifier* rec,pen_stroke* str,int* rconf)
{
    char *res = NULL;
    point_list *stroke = NULL;
 
    stroke = add_example(NULL, str->ps_npts, str->ps_pts);
    if (stroke == NULL) return(NULL);
 
    res = lialg_recognize_stroke(rec, stroke);
 
    delete_examples(stroke);
    return(res);
}
 
/*
 * file_path-Construct pathname, check for proper extension.
 */
 
static int
  file_path(char* dir,char* filename,char* pathname)
{
    char* dot;
 
    /*Check for proper extension on file name.*/
 
    dot = strrchr(filename,'.');
 
    if( dot == NULL ) {
        return(-1);
    }
 
    /*Determine whether a gesture or character classifier.*/
 
    if( strcmp(dot,LI_CLASSIFIER_EXTENSION) != 0 ) {
        return(-1);
    }
 
    /*Concatenate directory and filename into pathname.*/
 
    strcpy(pathname,dir);
    strcat(pathname,"/");
    strcat(pathname,filename);
 
    return(0);
}
 
/*read_classifier_points-Read points so classifier can be extended.*/
 
static int
read_classifier_points(FILE* fd,int nclss,point_list** ex,char** cnames)
{
    int i,j,k;
    char buf[BUFSIZ];
    int nex = 0;
    char* names[MAXSCLASSES];
    point_list* examples[MAXSCLASSES];
    pen_point* pts;
    int npts;
 
    /*Initialize*/
 
    for( i = 0; i < MAXSCLASSES; i++ ) {
        names[i] = NULL;
        examples[i] = NULL;
    }
 
    /*Go thru classes.*/
 
/* ari */
/* fprintf(stderr, "Classes: [ "); */
 
    for( k = 0; k < nclss; k++ ) {
 
        /*Read class name and number of examples.*/
 
        if( fscanf(fd,"%d %s",&nex,buf) != 2 ) {
            printf("%s *FAILED* - line: %d\n", __FUNCTION__, __LINE__);
            goto unallocate;
        }
 
        /*Save class name*/
 
        names[k] = strdup(buf);
/* ari */
/* fprintf(stderr, "%s ", buf); */
 
        /*Read examples.*/
 
        for( i = 0; i < nex; i++ ) {
 
            /*Read number of points.*/
 
            if( fscanf(fd,"%d",&npts) != 1 ) {
                printf("%s *FAILED* - line: %d\n", __FUNCTION__, __LINE__);
                goto unallocate; /*Boy would I like exceptions!*/
            }
 
            /*Allocate array for points.*/
 
            if( (pts = make_pen_point_array(npts)) == NULL ) {
                printf("%s *FAILED* - line: %d\n", __FUNCTION__, __LINE__);
                goto unallocate;
            }
 
            /*Read in points.*/
 
            for( j = 0; j < npts; j++ ) {
                int x,y;
                int jj;
                if( fscanf(fd,"%d %d",&x,&y) != 2 ) {
                    delete_pen_point_array(pts);
                    printf("%s *FAILED* - line: %d\n", __FUNCTION__, __LINE__);
                    printf("class = %d/%d/%s, ex = %d/%d, pt: %d/%d\n",
                                k, nclss, names[k], i, nex, j, npts);
                    for (jj = 0;  jj < j;  jj++) {
                        printf("pts[%d] = %d/%d\n", jj, pts[jj].x, pts[jj].y);
                    }
                    goto unallocate;
                }
                pts[j].x = x;
                pts[j].y = y;
            }
 
            /*Add example*/
 
            if( (examples[k] = add_example(examples[k],npts,pts)) == NULL ) {
                delete_pen_point_array(pts);
                printf("%s *FAILED* - line: %d\n", __FUNCTION__, __LINE__);
                goto unallocate;
            }
 
            delete_pen_point_array(pts);
 
          }
      }
 
/* ari -- end of list of classes */
/* fprintf(stderr, "]\n"); */
 
    /*Transfer to recognizer.*/
 
    bcopy(examples,ex,sizeof(examples));
    bcopy(names,cnames,sizeof(names));
 
    return(0);
 
    /*Error. Deallocate memory and return.*/
 
  unallocate:
 
    for( ; k >= 0; k-- ) {
        delete_examples(examples[k]);
        free(names[k]);
    }
 
    error("Error in reading example points from classifier file");
    return(-1);
}
 
/*read_classifier-Read a classifier file.*/
 
static int read_classifier(FILE* fd,rClassifier* rc)
{
    sClassifier sc;
 
    li_err_msg = NULL;
 
    /*Read in classifier file.*/
 
    if( (sc = sRead(fd)) == NULL ) {
        return(-1);
    }
 
    /*Read in the example points, so classifier can be extended.*/
 
    if( read_classifier_points(fd,sc->nclasses,rc->ex,rc->cnames) != 0 ) {
        sFreeClassifier(sc);
        return(-1);
    }
 
    /*Transfer sClassifier to the rClassifier*/
 
    rc->sc = sc;
 
    return(0);
}
 
/*
 * Extension Functions
*/
 
/* getClasses and clearState are by Ari */
 
static int
recognizer_getClasses (recognizer r, char ***list, int *nc)
{
    int i, nclasses;
    li_recognizer* rec;
    sClassifier sc;
    char **ret;
 
    rec = (li_recognizer*)r->recognizer_specific;
 
    /*Check for LI recognizer.*/
 
    if( !CHECK_LI_MAGIC(rec) ) {
        li_err_msg = "Not a LI recognizer";
        return(-1);
    }
 
    sc = rec->li_rc.sc;
    *nc = nclasses = sc->nclasses;
    /*    ret = (char **) safe_malloc (nclasses * sizeof(char*));*/
    ret = allocate(nclasses, char*);
 
    for (i = 0; i < nclasses; i++) {
      ret[i] = rec->li_rc.cnames[i];   /* only the 1st char of the cname */
    }
    *list = ret;
    return 0;
}
 
static int
recognizer_clearState (recognizer r)
{
  /*This operation isn't supported by the LI recognizer.*/
 
  li_err_msg = "Clearing state is not supported by the LI recognizer";
 
  return(-1);
}
 
static bool isa_li(recognizer r)
{ return(CHECK_LI_MAGIC(r)); }
 
static int
recognizer_train(recognizer r,rc* rec_xt,u_int nstrokes,
                    pen_stroke* strokes,rec_element* re,
                    bool replace_p)
{
  /*This operation isn't supported by the LI recognizer.*/
 
  li_err_msg = "Training is not supported by the LI recognizer";
 
  return(-1);
}
 
int
li_recognizer_get_example (recognizer   r,
                           int          class,
                           int          instance,
                           char         **name,
                           pen_point    **points,
                           int          *npts)
{
    li_recognizer   *rec = (li_recognizer*)r->recognizer_specific;
    sClassifier     sc = rec->li_rc.sc;
    point_list      *pl;
 
    if( !CHECK_LI_MAGIC(rec) ) {
        li_err_msg = "Not a LI recognizer";
        return(-1);
    }
    if (class > sc->nclasses)
        return -1;
    pl = rec->li_rc.canonex[class];
    while (instance && pl)
    {
        pl = pl->next;
        instance--;
    }
    if (!pl)
        return -1;
    *name = rec->li_rc.cnames[class];
    *points = pl->pts;
    *npts = pl->npts;
    return 0;
}
 
/*
 * API Functions
 */
 
 
/*li_recognizer_load-Load a classifier file.*/
 
static int li_recognizer_load(recognizer r,char* dir,char* filename)
{
    FILE *fd;
    char* pathname;
    li_recognizer* rec;
    rClassifier* rc;
 
    rec = (li_recognizer*)r->recognizer_specific;
 
    /*Make sure recognizer's OK*/
 
    if( !CHECK_LI_MAGIC(rec) ) {
        li_err_msg = "Not a LI recognizer";
        return(-1);
    }
 
    rc = &(rec->li_rc);
 
    /*Check parameters.*/
 
    if( filename == NULL ) {
        li_err_msg = "Invalid parameters";
        return(-1);
    }
 
    /*We let the directory be null.*/
 
    if( dir == NULL || (int)strlen(dir) <= 0 ) {
        dir = ".";
    }
 
    /*Make full pathname and check filename*/
 
    /* pathname = (char*)safe_malloc(strlen(dir) + strlen(filename) + 2)); */
 
    pathname = allocate(strlen(dir) + strlen(filename) + 2, char);
    if( file_path(dir,filename,pathname) == -1 ) {
        free(pathname);
        li_err_msg = "Not a LI recognizer classifier file";
        return(-1);
    }
 
    /* Try to short-circuit the full classifier-file processing. */
    rc->file_name = pathname;
    if (lialg_read_classifier_digest(rc) == 0)
        return(0);
    rc->file_name = NULL;
 
    /*Open the file*/
 
    if( (fd = fopen(pathname,"r")) == NULL ) {
        free(pathname);
        li_err_msg = "Can't open classifier file";
/* ari */
        /* fprintf(stderr, "Trying to open %s.\n", pathname); */
        return(-1);
 
    }
 
    /*If rClassifier is OK, then delete it first.*/
 
    if( rc->file_name != NULL ) {
      free_rClassifier(rc);
    }
 
    /*Read classifier.*/
 
    if( read_classifier(fd,rc) < 0 ) {
        free(pathname);
        return(-1);
    }
 
    /*Close file.*/
 
    fclose(fd);
 
    /*Add classifier name.*/
 
    rc->file_name = pathname;
 
    /* Canonicalize examples. */
    if (lialg_canonicalize_examples(rc) != 0) {
        free(pathname);
        rc->file_name = NULL;
        return(-1);
    }
 
    return(0);
}
 
/*li_recognizer_save-Save a classifier file.*/
 
static int li_recognizer_save(recognizer r,char* dir,char* filename)
{
  /*This operation isn't supported by the LI recognizer.*/
 
  li_err_msg = "Saving is not supported by the LI recognizer";
 
  return(-1);
}
 
static wordset
li_recognizer_load_dictionary(recognizer rec,char* directory,char* name)
{
  /*This operation isn't supported by the LI recognizer.*/
 
  li_err_msg = "Dictionaries are not supported by the LI recognizer";
 
  return(NULL);
 
}
 
static int
li_recognizer_save_dictionary(recognizer rec,
                               char* directory,
                               char* name,
                               wordset dict)
{
  /*This operation isn't supported by the LI recognizer.*/
 
  li_err_msg = "Dictionaries are not supported by the LI recognizer";
 
  return(-1);
 
}
 
static int
li_recognizer_free_dictionary(recognizer rec,wordset dict)
{
  /*This operation isn't supported by the LI recognizer.*/
 
  li_err_msg = "Dictionaries are not supported by the LI recognizer";
 
  return(-1);
 
}
 
static int
li_recognizer_add_to_dictionary(recognizer rec,letterset* word,wordset dict)
{
  /*This operation isn't supported by the LI recognizer.*/
 
  li_err_msg = "Dictionaries are not supported by the LI recognizer";
 
  return(-1);
 
}
 
static int
li_recognizer_delete_from_dictionary(recognizer rec,
                                      letterset* word,
                                      wordset dict)
{
  /*This operation isn't supported by the LI recognizer.*/
 
  li_err_msg = "Dictionaries are not supported by the LI recognizer";
 
  return(-1);
 
}
 
static char*
li_recognizer_error(recognizer rec)
{
    char* ret = li_err_msg;
 
    /*Check for LI recognizer.*/
 
    if( !CHECK_LI_MAGIC(rec->recognizer_specific) ) {
        li_err_msg = "Not a LI recognizer";
        return(NULL);
    }
 
    li_err_msg = NULL;
 
    return(ret);
}
 
static int
li_recognizer_clear(recognizer r,bool delete_points_p)
{
    li_recognizer* rec;
 
    rec = (li_recognizer*)r->recognizer_specific;
 
    /*Check for LI recognizer.*/
 
    if( !CHECK_LI_MAGIC(rec) ) {
        li_err_msg = "Not a LI recognizer";
        return(0);
    }
 
    return(0);
}
 
static int
li_recognizer_set_context(recognizer r,rc* rec_xt)
{
  /*This operation isn't supported by the LI recognizer.*/
 
  li_err_msg = "Contexts are not supported by the LI recognizer";
 
  return(-1);
}
 
static rc*
li_recognizer_get_context(recognizer r)
{
  /*This operation isn't supported by the LI recognizer.*/
 
  li_err_msg = "Contexts are not supported by the LI recognizer";
 
  return(NULL);
}
 
static int
li_recognizer_get_buffer(recognizer r, u_int* nstrokes,pen_stroke** strokes)
{
  /*This operation isn't supported by the LI recognizer.*/
 
  li_err_msg = "Buffer get/set are not supported by the LI recognizer";
 
  return(-1);
}
 
static int
li_recognizer_set_buffer(recognizer r,u_int nstrokes,pen_stroke* strokes)
{
  /*This operation isn't supported by the LI recognizer.*/
 
  li_err_msg = "Buffer get/set are not supported by the LI recognizer";
 
  return(-1);
}
 
static int
li_recognizer_translate(recognizer r,
                         u_int ncs,
                         pen_stroke* tps,
                         bool correlate_p,
                         int* nret,
                         rec_alternative** ret)
{
    char* clss = NULL;
    li_recognizer* rec;
    int conf;
    rClassifier* rc;
 
    rec = (li_recognizer*)r->recognizer_specific;
 
    *nret = 0;
    *ret = NULL;
 
    /*Check for LI recognizer.*/
 
    if( !CHECK_LI_MAGIC(rec) ) {
        li_err_msg = "Not a LI recognizer";
        return(-1);
    }
 
   rc = &(rec->li_rc);
 
    /*Check for valid parameters.*/
    if (ncs < 1) {
        li_err_msg = "Invalid parameters: ncs";
        return(-1);
    }
    if( tps == NULL) {
        li_err_msg = "Invalid parameters: tps";
        return(-1);
    }
    if( nret == NULL) {
        li_err_msg = "Invalid parameters: nret";
        return(-1);
    }
    if( ret == NULL) {
        li_err_msg = "Invalid parameters: ret";
        return(-1);
    }
 
/*    if( ncs < 1 || tps == NULL || nret == NULL || ret == NULL) {
        li_err_msg = "Invalid parameters";
        return(-1);
    }
*/
 
    /*Check for null classifier. It must have at least one.*/
/*
    if( rec->li_rc.sc == NULL ) {
        li_err_msg = "No classifier";
        return(-1);
    }
*/
 
    /*
     * Go through the stroke array and recognize. Since this is a single
     *   stroke recognizer, each stroke is treated as a separate
     *   character or gesture. We allow only characters or gestures
     *   to be recognized at one time, since otherwise, handling
     *   the display of segmentation would be difficult.
    */
    clss = recognize_internal(rc,tps,&conf);
    if (clss == NULL) {
/*
        li_err_msg = "unrecognized character";
        return(-1);
*/
        *nret = 1;
        return(0);
    }
 
    /*Return values.*/
    *nret = 1;
    return(*clss);
}
 
 
static rec_fn*
li_recognizer_get_extension_functions(recognizer rec)
{
    rec_fn* ret;
 
    /*Check for LI recognizer.*/
 
    if( !CHECK_LI_MAGIC(rec->recognizer_specific) ) {
        li_err_msg = "Not a LI recognizer";
        return(NULL);
    }
 
    ret = make_rec_fn_array(LI_NUM_EX_FNS);
 
/* ari -- clearState & getClasses are mine */
    ret[LI_GET_CLASSES] = (rec_fn)recognizer_getClasses;
    ret[LI_CLEAR] = (rec_fn)recognizer_clearState;
    ret[LI_ISA_LI] = (rec_fn)isa_li;
    ret[LI_TRAIN] = (rec_fn)recognizer_train;
 
    return(ret);
}
 
static char**
li_recognizer_get_gesture_names(recognizer r)
{
  /*This operation isn't supported by the LI recognizer.*/
 
  li_err_msg = "Gestures are not supported by the LI recognizer";
 
  return(NULL);
}
 
static xgesture
li_recognizer_set_gesture_action(recognizer r,
                                  char* name,
                                  xgesture fn,
                                  void* wsinfo)
{
  /*This operation isn't supported by the LI recognizer.*/
 
  li_err_msg = "Gestures are not supported by the LI recognizer";
 
  return(NULL);
}
 
/*
 * Exported Functions
*/
 
/*RECOGNIZER_INITIALIZE-Initialize the recognizer.*/
 
/* note from ari:  this expands via pre-processor to
 *
 * recognizer __recognizer_internal_initialize(rec_info* ri)
*/
 
RECOGNIZER_INITIALIZE(ri)
{
    recognizer r;
    li_recognizer* rec;
    int i;
 
    /*Check that locale matches.*/
 
    if( strcmp(ri->ri_locale,LI_SUPPORTED_LOCALE) != 0 ) {
        li_err_msg = "Not a supported locale";
fprintf(stderr, "Locale error.\n");
#if 0
        return(NULL);
#endif
    }
 
    /*
     * Check that character sets match. Note that this is only approximate,
     * since the classifier file will have more information.
    */
 
    if( ri->ri_subset != NULL ) {
      for(i = 0; ri->ri_subset[i] != NULL; i++ ) {
 
        if( strcmp(ri->ri_subset[i],UPPERCASE) != 0 &&
            strcmp(ri->ri_subset[i],LOWERCASE) != 0  &&
            strcmp(ri->ri_subset[i],DIGITS) != 0 &&
            strcmp(ri->ri_subset[i],GESTURE) != 0 ) {
          li_err_msg = "Not a supported character set";
fprintf(stderr, "charset error.\n");
 
          return(NULL);
        }
      }
    }
 
/* ari */
    r = make_recognizer(ri);
    /*fprintf(stderr, "past make_recognizer.\n");*/
 
    if( r == NULL ) {
        li_err_msg = "Can't allocate storage";
 
        return(NULL);
    }
 
    /*Make a LI recognizer structure.*/
 
 
    /* rec = (li_recognizer*)safe_malloc(sizeof(li_recognizer))) == NULL ); */
 
    rec = allocate(1, li_recognizer);
 
    r->recognizer_specific = rec;
 
    rec->li_rc.file_name = NULL;
    rec->li_rc.sc = NULL;
 
    /*Initialize the recognizer struct.*/
 
    r->recognizer_load_state = li_recognizer_load;
    r->recognizer_save_state = li_recognizer_save;
    r->recognizer_load_dictionary = li_recognizer_load_dictionary;
    r->recognizer_save_dictionary = li_recognizer_save_dictionary;
    r->recognizer_free_dictionary = li_recognizer_free_dictionary;
    r->recognizer_add_to_dictionary = li_recognizer_add_to_dictionary;
    r->recognizer_delete_from_dictionary = li_recognizer_delete_from_dictionary;
    r->recognizer_error = li_recognizer_error;
    r->recognizer_translate = li_recognizer_translate;
    r->recognizer_get_context = li_recognizer_get_context;
    r->recognizer_set_context = li_recognizer_set_context;
    r->recognizer_get_buffer = li_recognizer_get_buffer;
    r->recognizer_set_buffer = li_recognizer_set_buffer;
    r->recognizer_clear = li_recognizer_clear;
    r->recognizer_get_extension_functions =
      li_recognizer_get_extension_functions;
    r->recognizer_get_gesture_names = li_recognizer_get_gesture_names;
    r->recognizer_set_gesture_action =
      li_recognizer_set_gesture_action;
 
    /*Initialize LI Magic Number.*/
 
    rec->li_magic = LI_MAGIC;
 
    /*Initialize rClassifier.*/
 
    rec->li_rc.file_name = NULL;
 
    for( i = 0; i < MAXSCLASSES; i++ ) {
        rec->li_rc.ex[i] = NULL;
        rec->li_rc.cnames[i] = NULL;
    }
 
    lialg_initialize(&rec->li_rc);
 
    /*Get rid of error message. Not needed here.*/
    li_err_msg = NULL;
 
    return(r);
}
 
/*free_rClassifier-Free the rClassifier.*/
 
static void
free_rClassifier(rClassifier* rc)
{
    int i;
 
    if( rc->file_name != NULL) {
        free(rc->file_name);
    }
 
    for( i = 0; rc->ex[i] != NULL; i++) {
        delete_examples(rc->ex[i]);
        free(rc->cnames[i]);
    }
 
    if(rc->sc != NULL ) {
        sFreeClassifier(rc->sc);
    }
}
 
/*RECOGNIZER_FINALIZE-Deallocate the recognizer, finalize.*/
 
RECOGNIZER_FINALIZE(r)
{
    li_recognizer* rec = (li_recognizer*)r->recognizer_specific;
 
    /*Make sure this is a li_recognizer first*/
 
    if( !CHECK_LI_MAGIC(rec) ) {
        li_err_msg = "Not a LI recognizer";
        return(-1);
    }
 
    /*Deallocate rClassifier resources.*/
 
    free_rClassifier(&(rec->li_rc));
 
    /*Deallocate the li_recognizer struct.*/
 
    free(rec);
 
    /*Deallocate the recognizer*/
 
    delete_recognizer(r);
 
    return(0);
}
 
 
/* **************************************************
 
  Implementation of the Li/Yeung recognition algorithm
 
************************************************** */
 
/*#include <assert.h>*/
#ifdef __ECOS
#define MAXINT 0x7FFFFFFF
#else
#include <values.h>
#endif
#include <sys/time.h>
 
#ifdef  __ultrix
/* Ultrix doesn't have these declarations in math.h! */
extern double rint(double);
extern float expf(float);
#endif
 
#ifdef  ELX
extern double rint (double);
extern float expf (float);      /* N.B.  exp() appears to be broken on ELX! */
#endif
 
#define WORST_SCORE     MAXINT
 
/* Dynamic programming parameters */
#define DP_BAND         3
#define MIN_SIM         0
#define MAX_DIST        MAXINT
#define SIM_THLD        60      /* x 100 */
#define DIST_THLD       3200    /* x 100 */
 
/* Low-pass filter parameters -- empirically derived */
#define LP_FILTER_WIDTH 6
#define LP_FILTER_ITERS 8
#define LP_FILTER_THLD  250     /* x 100 */
#define LP_FILTER_MIN   5
 
/* Pseudo-extrema parameters -- empirically derived */
#define PE_AL_THLD      1500    /* x 100 */
#define PE_ATCR_THLD    135     /* x 100 */
 
/* Contour-angle derivation parameters */
#define T_ONE           1
#define T_TWO           20
 
/* Pre-processing and canonicalization parameters */
#define CANONICAL_X     108
#define CANONICAL_Y     128
#define DIST_SQ_THRESHOLD   (3*3)       /* copied from fv.h */
#define NCANONICAL      50
 
/* Tap-handling parameters */
#define TAP_CHAR        "."
#define TAP_TIME_THLD   150         /* msec */
#define TAP_DIST_THLD   75          /* dx * dx + dy * dy */
#define TAP_PATHLEN     1000        /* x 100 */
 
 
/* Overload the time field of the pen_point struct with the chain-code. */
#define chaincode   time
 
/* region types */
#define RGN_CONVEX  0
#define RGN_CONCAVE 1
#define RGN_PLAIN   2
#define RGN_PSEUDO  3
 
 
typedef struct RegionList {
    int start;
    int end;
    int type;
    struct RegionList *next;
} region_list;
 
 
/* direction-code table; indexed by dx, dy */
static int lialg_dctbl[3][3] = {{1, 0, 7}, {2, 0x7FFFFFFF, 6}, {3, 4, 5}};
 
/* low-pass filter weights */
static int lialg_lpfwts[2 * LP_FILTER_WIDTH + 1];
static int lialg_lpfconst = -1;
 
 
static int lialg_preprocess_stroke(point_list *);
static point_list *lialg_compute_dominant_points(point_list *);
static point_list *lialg_interpolate_points(point_list *);
static void lialg_bresline(pen_point *, pen_point *, point_list *, int *);
static void lialg_compute_chain_code(point_list *);
static void lialg_compute_unit_chain_code(point_list *);
static region_list *lialg_compute_regions(point_list *);
static point_list *lialg_compute_dompts(point_list *, region_list *);
static int *lialg_compute_contour_angle_set(point_list *, region_list *);
static void lialg_score_stroke(point_list *, point_list *, int *, int *);
static int lialg_compute_similarity(point_list *, point_list *);
static int lialg_compute_distance(point_list *, point_list *);
 
static int lialg_read_classifier_digest(rClassifier *);
 
static int lialg_canonicalize_examples(rClassifier *);
static int lialg_canonicalize_example_stroke(point_list *);
static int lialg_compute_equipoints(point_list *);
 
static int lialg_compute_pathlen(point_list *);
static int lialg_compute_pathlen_subset(point_list *, int, int);
static int lialg_filter_points(point_list *);
static int lialg_translate_points(point_list *, int, int, int, int);
static void lialg_get_bounding_box(point_list *, int *, int *, int *, int *);
static void lialg_compute_lpf_parameters();
static int isqrt(int);
static int likeatan(int, int);
static int quadr(int);
 
 
/*************************************************************
 
  Core routines for the Li/Yeung recognition algorithm
 
 *************************************************************/
 
static void lialg_initialize(rClassifier *rec) {
    int i;
 
    /* Initialize the dompts arrays. */
    for (i = 0; i < MAXSCLASSES; i++) {
        rec->dompts[i] = NULL;
    }
}
 
 
/*
 *  Main recognition routine -- called by HRE API.
 */
static char *lialg_recognize_stroke(rClassifier *rec, point_list *stroke) {
    int i;
    char *name = NULL;
    point_list *input_dompts = NULL;
    char *best_name = NULL;
    int best_score = WORST_SCORE;
    char *curr_name;
    point_list *curr_dompts = NULL;
    /*struct timeval stv, etv;
    int elapsed;*/
 
    /*    (void)gettimeofday(&stv, NULL);*/
 
    if (stroke->npts < 1) goto done;
 
    /* Check for tap. */
    {
/*
        pen_point *startpt = &stroke->pts[0];
        pen_point *endpt = &stroke->pts[stroke->npts - 1];
        int dt = endpt->time - startpt->time;
        int dx = endpt->x - startpt->x;
        int dy = endpt->y - startpt->y;
        int magsq = dx * dx + dy * dy;
*/
 
        /* First thing is to filter out ``close points.'' */
        if (lialg_filter_points(stroke) != 0) return(NULL);
 
        /* Unfortunately, we don't have the actual time that each point */
        /* was recorded (i.e., dt is invalid).  Hence, we have to use a */
        /* heuristic based on total distance and the number of points. */
        if (stroke->npts == 1 || lialg_compute_pathlen(stroke) < TAP_PATHLEN)
            return(TAP_CHAR);
    }
 
    /* Pre-process input stroke. */
    if (lialg_preprocess_stroke(stroke) != 0) goto done;
 
    /* Compute its dominant points. */
    input_dompts = lialg_compute_dominant_points(stroke);
    if (input_dompts == NULL) goto done;
 
    /* Score input stroke against every class in classifier. */
    for (i = 0, curr_name = rec->cnames[i], curr_dompts = rec->dompts[i];
          i < MAXSCLASSES && curr_name != NULL && curr_dompts != NULL;
          i++, curr_name = rec->cnames[i], curr_dompts = rec->dompts[i]) {
        int sim;
        int dist;
        int curr_score;
 
        lialg_score_stroke(input_dompts, curr_dompts, &sim, &dist);
        curr_score = dist;
 
        if (lidebug && curr_score < DIST_THLD)
            fprintf(stderr, "(%s, %d, %d) ", curr_name, sim, dist);
 
        /* Is it the best so far? */
        if (curr_score < best_score && curr_score <= DIST_THLD) {
            best_score = curr_score;
            best_name = curr_name;
        }
    }
 
    if (lidebug)
        fprintf(stderr, "\n");
 
    /* No errors. */
    name = best_name;
 
done:
    delete_examples(input_dompts);
    /*    (void)gettimeofday(&etv, NULL);
          elapsed = (1000 * (etv.tv_sec - stv.tv_sec)) + ((etv.tv_usec - stv.tv_usec + 500) / 1000);
          fprintf(stderr, "elapsed = %d\n", elapsed);
     */
    return(name);
}
 
 
static int lialg_preprocess_stroke(point_list *points) {
    int minx, miny, maxx, maxy, xrange, yrange, scale, xoff, yoff;
 
    /* Filter out points that are too close. */
    /* We did this earlier, when we checked for a tap. */
/*
    if (lialg_filter_points(points) != 0) return(-1);
*/
 
/*    assert(points->npts > 0);*/
 
    /* Scale up to avoid conversion errors. */
    lialg_get_bounding_box(points, &minx, &miny, &maxx, &maxy);
    xrange = maxx - minx;
    yrange = maxy - miny;
    scale = ( ((100 * xrange + CANONICAL_X / 2) / CANONICAL_X) >
              ((100 * yrange + CANONICAL_Y / 2) / CANONICAL_Y))
      ? (100 * CANONICAL_X + xrange / 2) / xrange
      : (100 * CANONICAL_Y + yrange / 2) / yrange;
    if (lialg_translate_points(points, minx, miny, scale, scale) != 0)
        return(-1);
 
    /* Center the stroke. */
    lialg_get_bounding_box(points, &minx, &miny, &maxx, &maxy);
    xrange = maxx - minx;
    yrange = maxy - miny;
    xoff = -((CANONICAL_X - xrange + 1) / 2);
    yoff = -((CANONICAL_Y - yrange + 1) / 2);
    if (lialg_translate_points(points, xoff, yoff, 100, 100) != 0) return(-1);
 
    /* Store the x and y ranges in the point list. */
    xrange = maxx - minx;
    yrange = maxy - miny;
    points->xrange = xrange;
    points->yrange = yrange;
 
    if (lidebug) {
        int i;
        fprintf(stderr, "After pre-processing:   %d %d %d %d\n",
                minx, miny, maxx, maxy);
        for (i = 0; i < points->npts; i++)
            fprintf(stderr, "      (%d %d)\n",
                    points->pts[i].x, points->pts[i].y);
        fflush(stderr);
    }
 
    return(0);
}
 
 
static point_list *lialg_compute_dominant_points(point_list *points) {
    point_list *ipts = NULL;
    region_list *regions = NULL;
    point_list *dpts = NULL;
 
    /* Interpolate points. */
    ipts = lialg_interpolate_points(points);
    if (ipts == NULL) return(NULL);
    if (lidebug) {
        int j;
        fprintf(stderr, "After interpolation:  %d ipts\n", ipts->npts);
        for (j = 0; j < ipts->npts; j++) {
            fprintf(stderr, "  (%d, %d), %ld\n",
                    ipts->pts[j].x, ipts->pts[j].y, ipts->pts[j].chaincode);
        }
        fflush(stderr);
    }
 
    /* Compute regions. */
    regions = lialg_compute_regions(ipts);
/*    assert(regions != NULL);*/
 
    /* Compute dominant points. */
    dpts = lialg_compute_dompts(ipts, regions);
    if (lidebug) {
        int j;
        fprintf(stderr, "Dominant points:  ");
        for (j = 0; j < dpts->npts; j++) {
            fprintf(stderr, "%d %d (%ld)  ",
                    dpts->pts[j].x, dpts->pts[j].y, dpts->pts[j].chaincode);
        }
        fprintf(stderr, "\n");
        fflush(stderr);
    }
 
    /* Delete region data structure. */
    {
        region_list *curr, *next;
        for (curr = regions; curr != NULL; ) {
            next = curr->next;
            free(curr);
            curr = next;
        }
    }
    delete_examples(ipts);
    return(dpts);
}
 
 
/* Input points are assumed to be integer-valued! */
static point_list *lialg_interpolate_points(point_list *points) {
    int i, j;
    int maxpts;
    point_list *newpts;
 
    /* Compute an upper-bound on the number of interpolated points. */
    maxpts = 0;
    for (i = 0; i < (points->npts - 1); i++) {
        pen_point *pta = &(points->pts[i]);
        pen_point *ptb = &(points->pts[i+1]);
        maxpts += abs(pta->x - ptb->x) + abs(pta->y - ptb->y);
    }
 
    /* Allocate an array of the requisite size. */
    maxpts += points->npts;
    /* newpts = (point_list *)safe_malloc(sizeof(point_list)); */
    newpts = allocate(1, point_list);
    newpts->pts = make_pen_point_array(maxpts);
    if (newpts->pts == NULL) {
        free(newpts);
        return(NULL);
    }
    newpts->npts = maxpts;
    newpts->next = NULL;
 
    /* Interpolate each of the segments. */
    j = 0;
    for (i = 0; i < (points->npts - 1); i++) {
        pen_point *startpt = &(points->pts[i]);
        pen_point *endpt = &(points->pts[i+1]);
 
        lialg_bresline(startpt, endpt, newpts, &j);
 
        j--;    /* end point gets recorded as start point of next segment! */
    }
 
    /* Add-in last point. */
    newpts->pts[j++] = points->pts[points->npts - 1];
    newpts->npts = j;
 
    /* Compute the chain code for P (the list of points). */
    lialg_compute_unit_chain_code(newpts);
 
    return(newpts);
}
 
 
/* This implementation is due to Kenny Hoff. */
static void lialg_bresline(pen_point *startpt, pen_point *endpt,
                            point_list *newpts, int *j) {
    int Ax, Ay, Bx, By, dX, dY, Xincr, Yincr;
 
    Ax = startpt->x;
    Ay = startpt->y;
    Bx = endpt->x;
    By = endpt->y;
 
    /* INITIALIZE THE COMPONENTS OF THE ALGORITHM THAT ARE NOT AFFECTED */
    /* BY THE SLOPE OR DIRECTION OF THE LINE */
    dX = abs(Bx-Ax);    /* store the change in X and Y of the line endpoints */
    dY = abs(By-Ay);
 
    /* DETERMINE "DIRECTIONS" TO INCREMENT X AND Y (REGARDLESS OF DECISION) */
    if (Ax > Bx) { Xincr=-1; } else { Xincr=1; }    /* which direction in X? */
    if (Ay > By) { Yincr=-1; } else { Yincr=1; }    /* which direction in Y? */
 
    /* DETERMINE INDEPENDENT VARIABLE (ONE THAT ALWAYS INCREMENTS BY 1 (OR -1) ) */
    /* AND INITIATE APPROPRIATE LINE DRAWING ROUTINE (BASED ON FIRST OCTANT */
    /* ALWAYS). THE X AND Y'S MAY BE FLIPPED IF Y IS THE INDEPENDENT VARIABLE. */
    if (dX >= dY) {         /* if X is the independent variable */
        int dPr = dY<<1;            /* amount to increment decision if right is chosen (always) */
        int dPru = dPr - (dX<<1);   /* amount to increment decision if up is chosen */
        int P = dPr - dX;           /* decision variable start value */
 
        /* process each point in the line one at a time (just use dX) */
        for (; dX>=0; dX--) {
            newpts->pts[*j].x = Ax;
            newpts->pts[*j].y = Ay;
            (*j)++;
 
            if (P > 0) { /* is the pixel going right AND up? */
                Ax+=Xincr;      /* increment independent variable */
                Ay+=Yincr;      /* increment dependent variable */
                P+=dPru;        /* increment decision (for up) */
            }
            else {              /* is the pixel just going right? */
                Ax+=Xincr;      /* increment independent variable */
                P+=dPr;         /* increment decision (for right) */
            }
        }
    }
    else {                  /* if Y is the independent variable */
        int dPr = dX<<1;            /* amount to increment decision if right is chosen (always) */
        int dPru = dPr - (dY<<1);   /* amount to increment decision if up is chosen */
        int P  = dPr - dY;          /* decision variable start value */
 
        /* process each point in the line one at a time (just use dY) */
        for (; dY>=0; dY--) {
            newpts->pts[*j].x = Ax;
            newpts->pts[*j].y = Ay;
            (*j)++;
 
            if (P > 0) { /* is the pixel going up AND right? */
                Ax+=Xincr;      /* increment dependent variable */
                Ay+=Yincr;      /* increment independent variable */
                P+=dPru;        /* increment decision (for up) */
            }
            else {              /* is the pixel just going up? */
                Ay+=Yincr;      /* increment independent variable */
                P+=dPr;         /* increment decision (for right) */
            }
        }
    }
}
 
 
static void lialg_compute_chain_code(point_list *pts) {
    int i;
 
    for (i = 0; i < (pts->npts - 1); i++) {
        pen_point *startpt = &(pts->pts[i]);
        pen_point *endpt = &(pts->pts[i+1]);
        int dx = endpt->x - startpt->x;
        int dy = endpt->y - startpt->y;
/*
        int tmp = rint(4.0 * atan2((double)dx, (double)dy) / M_PI);
        int dircode = (10 + tmp) % 8;
*/
        int tmp = quadr(likeatan(dy, dx));
        int dircode = (12 - tmp) % 8;
 
        startpt->chaincode = dircode;
    }
}
 
 
static void lialg_compute_unit_chain_code(point_list *pts) {
    int i;
 
    for (i = 0; i < (pts->npts - 1); i++) {
        pen_point *startpt = &(pts->pts[i]);
        pen_point *endpt = &(pts->pts[i+1]);
        int dx = endpt->x - startpt->x;
        int dy = endpt->y - startpt->y;
        int dircode = lialg_dctbl[dx+1][dy+1];
 
/*      assert(dircode < 8);*/
        startpt->chaincode = dircode;
    }
}
 
 
static region_list *lialg_compute_regions(point_list *pts) {
    region_list *regions = NULL;
    region_list *curr_reg = NULL;
    int *R[2 + LP_FILTER_ITERS];
    int *junk;
    int *curr, *next;
    int i, j;
 
    /* Initialize low-pass filter parameters if necessary. */
    if (lialg_lpfconst == -1)
        lialg_compute_lpf_parameters();
 
    /* Allocate a 2 x pts->npts array for use in computing the (filtered) Angle set, A_n. */
    /*    junk = (int *)safe_malloc((2 + LP_FILTER_ITERS) * pts->npts * sizeof(int)); */
    junk = allocate((2 + LP_FILTER_ITERS) * pts->npts, int);
    for (i = 0; i < (2 + LP_FILTER_ITERS); i++)
        R[i] = junk + (i * pts->npts);
    curr = R[0];
 
    /* Compute the Angle set, A, in the first element of array R. */
    /* Values in R are in degrees, x 100. */
    curr[0] = 18000;                             /* a_0 */
    for (i = 1; i < (pts->npts - 1); i++) {
        int d_i = pts->pts[i].chaincode;
        int d_iminusone = pts->pts[i-1].chaincode;
        int a_i;
 
        if (d_iminusone < d_i)
            d_iminusone += 8;
 
        a_i = (d_iminusone - d_i) % 8;
 
        /* convert to degrees, x 100 */
        curr[i] = ((12 - a_i) % 8) * 45 * 100;
    }
    curr[pts->npts - 1] = 18000;                /* a_L-1 */
 
    /* Perform a number of filtering iterations. */
    next = R[1];
    for (j = 0; j < LP_FILTER_ITERS; j++, curr = R[j], next = R[j+1]) {
        for (i = 0; i < pts->npts; i++) {
            int k;
 
            next[i] = 0;
 
            for (k = i - LP_FILTER_WIDTH; k <= i + LP_FILTER_WIDTH; k++) {
                int oldval = (k < 0 || k >= pts->npts) ? 18000 : curr[k];
                next[i] += oldval * lialg_lpfwts[k - (i - LP_FILTER_WIDTH)];    /* overflow? */
            }
 
            next[i] /= lialg_lpfconst;
        }
    }
 
    /* Do final thresholding around PI. */
    /* curr and next are set-up correctly at end of previous loop! */
    for (i = 0; i < pts->npts; i++) {
        next[i] = (abs(curr[i] - 18000) < LP_FILTER_THLD)
          ? 18000
          : curr[i];
    }
    curr = next;
 
    /* Debugging. */
    if (lidebug > 1) {
        for (i = 0; i < pts->npts; i++) {
            fprintf(stderr, "%3d:  (%3d, %3d)  %ld  ",
                    i, pts->pts[i].x, pts->pts[i].y, pts->pts[i].chaincode);
            for (j = 0; j < 2 + LP_FILTER_ITERS; j++)
                fprintf(stderr, "%d  ", R[j][i]);
            fprintf(stderr, "\n");
        }
    }
 
    /* Do the region segmentation. */
    {
        int start, end;
        int currtype;
 
#define RGN_TYPE(val)\
    (((val) == 18000)\
        ? RGN_PLAIN\
        : ((val) < 18000 ? RGN_CONCAVE : RGN_CONVEX))
 
        start = 0;
        currtype = RGN_TYPE(curr[0]);
        /*      regions = (region_list *)safe_malloc(sizeof(region_list));*/
        regions = allocate(1, region_list);
        curr_reg = regions;
        curr_reg->start = start;
        curr_reg->end = 0;
        curr_reg->type = currtype;
        curr_reg->next = NULL;
        for (i = 1; i < pts->npts; i++) {
            int nexttype = RGN_TYPE(curr[i]);
 
            if (nexttype != currtype) {
                region_list *next_reg = NULL;
 
                end = i - 1;
                curr_reg->end = end;
                if (lidebug > 1)
                    fprintf(stderr, "  (%d, %d), %d\n", start, end, currtype);
 
                start = i;
                currtype = nexttype;
                /* next_reg = (region_list *)safe_malloc(sizeof(region_list));*/
                next_reg = allocate(1, region_list);
                next_reg->start = start;
                next_reg->end = 0;
                next_reg->type = nexttype;
                next_reg->next = NULL;
 
                curr_reg->next = next_reg;
                curr_reg = next_reg;
            }
        }
        end = i - 1;
        curr_reg->end = end;
        if (lidebug > 1)
            fprintf(stderr, "  (%d, %d), %d\n", start, end, currtype);
 
        /* Filter out convex/concave regions that are too short. */
        for (curr_reg = regions; curr_reg; curr_reg = curr_reg->next)
            if (curr_reg->type == RGN_PLAIN) {
                region_list *next_reg;
 
                for (next_reg = curr_reg->next;
                     next_reg != NULL &&
                       (next_reg->end - next_reg->start) < LP_FILTER_MIN;
                     next_reg = curr_reg->next) {
                    /* next_reg must not be plain, and it must be followed by a plain */
                    /* assert(next_reg->type != RGN_PLAIN); */
                    /* assert(next_reg->next != NULL && (next_reg->next)->type == RGN_PLAIN); */
 
                    curr_reg->next = (next_reg->next)->next;
                    curr_reg->end = (next_reg->next)->end;
 
                    free(next_reg->next);
                    free(next_reg);
                }
            }
 
        /* Add-in pseudo-extremes. */
        {
            region_list *tmp, *prev_reg;
 
            tmp = regions;
            regions = NULL;
            prev_reg = NULL;
            for (curr_reg = tmp; curr_reg; curr_reg = curr_reg->next) {
                if (curr_reg->type == RGN_PLAIN) {
                    int arclen = lialg_compute_pathlen_subset(pts,
                                                                curr_reg->start,
                                                                curr_reg->end);
                    int dx = pts->pts[curr_reg->end].x -
                      pts->pts[curr_reg->start].x;
                    int dy = pts->pts[curr_reg->end].y -
                      pts->pts[curr_reg->start].y;
                    int chordlen = isqrt(10000 * (dx * dx + dy * dy));
                    int atcr = (chordlen == 0) ? 0 : (100 * arclen + chordlen / 2) / chordlen;
 
                    if (lidebug)
                        fprintf(stderr, "%d, %d, %d\n", arclen, chordlen, atcr);
 
                    /* Split region if necessary. */
                    if (arclen >= PE_AL_THLD && atcr >= PE_ATCR_THLD) {
                        int mid = curr_reg->start + (curr_reg->end - curr_reg->start) / 2;
                        int end = curr_reg->end;
                        region_list *saved_next = curr_reg->next;
 
                        curr_reg->end = mid - 1;
                        if (prev_reg == NULL)
                            regions = curr_reg;
                        else
                            prev_reg->next = curr_reg;
                        prev_reg = curr_reg;
 
                        /* curr_reg = (region_list *)safe_malloc(sizeof(region_list));*/
                        curr_reg = allocate(1, region_list);
                        curr_reg->start = mid;
                        curr_reg->end = mid;
                        curr_reg->type = RGN_PSEUDO;
                        curr_reg->next = NULL;
                        prev_reg->next = curr_reg;
                        prev_reg = curr_reg;
 
                        /* curr_reg = (region_list *)safe_malloc(sizeof(region_list)); */
                        curr_reg = allocate(1, region_list);
                        curr_reg->start = mid + 1;
                        curr_reg->end = end;
                        curr_reg->type = RGN_PLAIN;
                        curr_reg->next = NULL;
                        prev_reg->next = curr_reg;
                        prev_reg = curr_reg;
 
                        curr_reg->next = saved_next;
                        continue;
                    }
                }
 
                if (prev_reg == NULL)
                    regions = curr_reg;
                else
                    prev_reg->next = curr_reg;
                prev_reg = curr_reg;
            }
        }
    }
 
    free(junk);
    return(regions);
}
 
 
static point_list *lialg_compute_dompts(point_list *pts, region_list *regions) {
    point_list *dpts = NULL;
    int ndpts;
    int *cas = NULL;
    int nonplain;
    region_list *r;
 
    /* Compute contour angle set. */
    cas = lialg_compute_contour_angle_set(pts, regions);
/*    assert(cas != NULL);*/
 
    /* Dominant points include:  start_pt, end_pt, extrema_of_non_plain_regions, midpts of the preceding. */
    nonplain = 0;
    for (r = regions; r != NULL; r = r->next)
        if (r->type != RGN_PLAIN) nonplain++;
    ndpts = 2 * (2 + nonplain) - 1;
    /* dpts = (point_list *)safe_malloc(sizeof(point_list)); */
    dpts = allocate(1, point_list);
    dpts->pts = make_pen_point_array(ndpts);
    if (dpts->pts == NULL) {
        free(dpts);
        return(NULL);
    }
    dpts->npts = ndpts;
    dpts->next = NULL;
 
    /* Pick out dominant points. */
    {
        region_list *curr;
        int dp;
        int previx;
        int currix;
 
        /* Record start point. */
        dp = 0;
        previx = 0;
        dpts->pts[dp++] = pts->pts[previx];
 
        for (curr = regions; curr != NULL; curr = curr->next)
            if (curr->type != RGN_PLAIN) {
                int max_v = 0;
                int min_v = MAXINT;
                int max_ix = -1;
                int min_ix = -1;
                int i;
 
                for (i = curr->start; i <= curr->end; i++) {
                    int v = cas[i];
                    if (v > max_v) { max_v = v; max_ix = i; }
                    if (v < min_v) { min_v = v; min_ix = i; }
                    if (lidebug > 1)
                        fprintf(stderr, "  %d\n", v);
                }
 
                currix = (curr->type == RGN_CONVEX ? max_ix : min_ix);
 
                /* Record midpoint. */
                dpts->pts[dp++] = pts->pts[previx + (currix - previx) / 2];
 
                /* Record extreme point. */
                dpts->pts[dp++] = pts->pts[currix];
 
                previx = currix;
            }
 
        /* Record last mid-point and end point. */
        currix = pts->npts - 1;
        dpts->pts[dp++] = pts->pts[previx + (currix - previx) / 2];
        dpts->pts[dp++] = pts->pts[currix];
    }
 
    /* Compute chain-code. */
    lialg_compute_chain_code(dpts);
 
    free(cas);
    return(dpts);
}
 
 
static int *lialg_compute_contour_angle_set(point_list *pts,
                                               region_list *regions) {
    int *V = NULL;
    region_list *curr_reg, *prev_reg;
    int i;
 
    /*    V = (int *)safe_malloc(pts->npts * sizeof(int));*/
    V = allocate(pts->npts, int);
 
    V[0] = 18000;
    for (curr_reg = regions; curr_reg != NULL;
            prev_reg = curr_reg, curr_reg = curr_reg->next) {
        for (i = curr_reg->start; i <= curr_reg->end; i++) {
            if (curr_reg->type == RGN_PLAIN) {
                V[i] = 18000;
            }
            else {
#ifdef  notdef
                /* XXX - eliminate floating point */
                region_list *next_reg = curr_reg->next;
                int b = curr_reg->start;
                int h = prev_reg->start;
                int t = next_reg->end;
                int pts_before = i - h;
                int pts_after = t - i;
                int min_pts = (pts_before < pts_after)
                  ? pts_before
                  : pts_after;
                int k = (min_pts < T_ONE)
                  ? T_ONE
                  : (min_pts > T_TWO)
                  ? T_TWO
                  : min_pts;
                float sum = 0.0;
 
                for (j = 1; j <= k; j++) {
                    int ptA = i - j;
                    int ptB = i + j - 1;
                    int d_A = pts->pts[ptA].chaincode;
                    int d_B = pts->pts[ptB].chaincode;
                    int a_i;
 
                    if (d_A < d_B)
                        d_A += 8;
 
                    a_i = (d_A - d_B) % 8;
 
                    /* convert to radians */
                    if (a_i == 4 && curr_reg->type == RGN_CONVEX)
                        sum += M_2_PI;
                    else
                        sum += (float)((12 - a_i) % 8) / 4.0 * M_PI;
                }
                V[i] = sum / (float)k;
#else
                /* For now, simply choose the mid-point. */
                int isMidPt = (i == (curr_reg->start +
                                     (curr_reg->end - curr_reg->start) / 2));
                V[i] = (curr_reg->type == RGN_CONVEX)
                  ? (isMidPt ? 18000 : 0)
                  : (isMidPt ? 0 : 18000);
#endif
            }
        }
    }
    V[pts->npts - 1] = 18000;
 
    return(V);
}
 
 
/*
 *  First compute the similarity between the two strings.
 *  If it's above a threshold, compute the distance between
 *  the two and return it as the ``score.''
 *  Otherwise, return the constant WORST_SCORE.
 *
 */
static void lialg_score_stroke(point_list *input_dompts, point_list *curr_dompts, int *sim, int *dist) {
    *sim = MIN_SIM;
    *dist = MAX_DIST;
 
    *sim = lialg_compute_similarity(input_dompts, curr_dompts);
    if (*sim < SIM_THLD) goto done;
 
    *dist = lialg_compute_distance(input_dompts, curr_dompts);
 
done:
    if (lidebug)
        fprintf(stderr, "%d, %d\n", *sim, *dist);
}
 
 
static int lialg_compute_similarity(point_list *input_dompts,
                                     point_list *curr_dompts) {
    int sim = 0;
    point_list *A, *B;
    int N, M;
    int **G = NULL;
    int *junk = NULL;
    int i, j;
 
    /* A is the longer sequence, length N. */
    /* B is the shorter sequence, length M. */
    if (input_dompts->npts >= curr_dompts->npts) {
        A = input_dompts;
        N = input_dompts->npts;
        B = curr_dompts;
        M = curr_dompts->npts;
    }
    else {
        A = curr_dompts;
        N = curr_dompts->npts;
        B = input_dompts;
        M = input_dompts->npts;
    }
 
    /* Allocate and initialize the Gain matrix, G. */
    /* The size of G is M x (N + 1). */
    /* Note that row 0 is unused. */
    /* Similarities are x 10. */
    {
        /*      G = (int **)safe_malloc(M * sizeof(int *));*/
        G = allocate(M, int *);
        /*      junk = (int *)safe_malloc(M * (N + 1) * sizeof(int)); */
        junk = allocate(M * (N + 1), int);
        for (i = 0; i < M; i++)
            G[i] = junk + (i * (N + 1));
 
        for (i = 1; i < M; i++) {
            int bval = B->pts[i-1].chaincode;
 
            /* Source column. */
            G[i][0] = 0;
 
            for (j = 1; j < N; j++) {
                int aval = A->pts[j-1].chaincode;
                int diff = abs(bval - aval);
                if (diff > 4) diff = 8 - diff;
 
                G[i][j] = (diff == 0)
                  ? 10
                  : (diff == 1)
                  ? 6
                  : 0;
            }
 
            /* Sink column. */
            G[i][N] = 0;
        }
    }
 
    /* Do the DP algorithm. */
    /* Proceed in column order, from highest column to the lowest. */
    /* Within each column, proceed from the highest row to the lowest. */
    /* Skip the highest column. */
    {
        for (j = N - 1; j >= 0; j--)
            for (i = M - 1; i > 0; i--) {
                int max = G[i][j + 1];
 
                if (i < (M - 1)) {
                    int tmp = G[i + 1][j + 1];
                    if (tmp > max) max = tmp;
                }
 
                G[i][j] += max;
            }
 
        sim = (10 * G[1][0] + (N - 1) / 2) / (N - 1);
    }
 
    if (G != NULL) free(G);
    if (junk != NULL) free(junk);
    return(sim);
}
 
 
static int lialg_compute_distance(point_list *input_dompts,
                                   point_list *curr_dompts) {
    int dist = MAX_DIST;
    point_list *A, *B;
    int N, M;
    int **C = NULL;
    int *junk = NULL;
    int *BE = NULL;
    int *TE = NULL;
    int i, j;
 
    /* A is the longer sequence, length N. */
    /* B is the shorter sequence, length M. */
    if (input_dompts->npts >= curr_dompts->npts) {
        A = input_dompts;
        N = input_dompts->npts;
        B = curr_dompts;
        M = curr_dompts->npts;
    }
    else {
        A = curr_dompts;
        N = curr_dompts->npts;
        B = input_dompts;
        M = input_dompts->npts;
    }
 
    /* Construct the helper vectors, BE and TE, which say for each column */
    /* what are the ``bottom'' and ``top'' rows of interest. */
    {
        /*      BE = (int *)safe_malloc((N + 1) * sizeof(int));*/
        BE = allocate((N + 1), int);
        /*      TE = (int *)safe_malloc((N + 1) * sizeof(int)); */
        TE = allocate((N + 1), int);
 
        for (j = 1; j <= N; j++) {
            int bot, top;
 
            bot = j + (M - DP_BAND);
            if (bot > M) bot = M;
            BE[j] = bot;
 
            top = j - (N - DP_BAND);
            if (top < 1) top = 1;
            TE[j] = top;
        }
    }
 
    /* Allocate and initialize the Cost matrix, C. */
    /* The size of C is (M + 1) x (N + 1). */
    /* Note that row and column 0 are unused. */
    /* Costs are x 100. */
    {
        /*      C = (int **)safe_malloc((M + 1) * sizeof(int *)); */
        C = allocate((M + 1), int *);
        /*      junk = (int *)safe_malloc((M + 1) * (N + 1) * sizeof(int)); */
        junk = allocate((M + 1) * (N + 1), int);
        for (i = 0; i <= M; i++)
            C[i] = junk + (i * (N + 1));
 
        for (i = 1; i <= M; i++) {
            int bx = B->pts[i-1].x;
            int by = B->pts[i-1].y;
 
            for (j = 1; j <= N; j++) {
                int ax = A->pts[j-1].x;
                int ay = A->pts[j-1].y;
                int dx = bx - ax;
                int dy = by - ay;
                int dist = isqrt(10000 * (dx * dx + dy * dy));
 
                C[i][j] = dist;
            }
        }
    }
 
    /* Do the DP algorithm. */
    /* Proceed in column order, from highest column to the lowest. */
    /* Within each column, proceed from the highest row to the lowest. */
    {
        for (j = N; j > 0; j--)
            for (i = M; i > 0; i--) {
                int min = MAX_DIST;
 
                if (i > BE[j] || i < TE[j] || (j == N && i == M))
                    continue;
 
                if (j < N) {
                    if (i >= TE[j+1]) {
                        int tmp = C[i][j+1];
                        if (tmp < min) min = tmp;
                    }
 
                    if (i < M) {
                        int tmp = C[i+1][j+1];
                        if (tmp < min) min = tmp;
                    }
                }
 
                if (i < BE[j]) {
                    int tmp = C[i+1][j];
                    if (tmp < min) min = tmp;
                }
 
                C[i][j] += min;
            }
 
        dist = (C[1][1] + N / 2) / N;
    }
 
    if (C != NULL) free(C);
    if (junk != NULL) free(junk);
    if (BE != NULL) free(BE);
    if (TE != NULL) free(TE);
    return(dist);
}
 
 
/*************************************************************
 
  Digest-processing routines
 
 *************************************************************/
 
static int lialg_read_classifier_digest(rClassifier *rec) {
    int nclasses;
    FILE *fp = NULL;
 
    /* Try to open the corresponding digest file. */
    {
        char *clx_path;
        char *dot;
 
        /* Get a copy of the filename, with some room on the end. */
        /*      clx_path = safe_malloc(strlen(rec->file_name) + 5); */
        clx_path = allocate(strlen(rec->file_name) + 5, char);
        strcpy(clx_path, rec->file_name);
 
        /* Truncate the path after the last dot. */
        dot = strrchr(clx_path, '.');
        if (dot == NULL) { free(clx_path); return(-1); }
        *(dot + 1) = 0;
 
        /* Append the classifier-digest extension. */
        strcat(clx_path, "clx");
 
        fp = fopen(clx_path, "r");
        if (fp == NULL) { free(clx_path); return(-1); }
 
        free(clx_path);
    }
 
    /* Read-in the name and dominant points for each class. */
    for (nclasses = 0; !feof(fp); nclasses++) {
        point_list *dpts = NULL;
        char class[BUFSIZ];
        int npts;
        int j;
 
        if (fscanf(fp, "%s %d", class, &npts) != 2) {
            if (feof(fp)) break;
 
            goto failed;
        }
        rec->cnames[nclasses] = strdup(class);
 
        /* Allocate a dominant-points list. */
        /* dpts = (point_list *)safe_malloc(sizeof(point_list)); */
        dpts = allocate(1, point_list);
        dpts->pts = make_pen_point_array(npts);
        if (dpts->pts == NULL) goto failed;
        dpts->npts = npts;
        dpts->next = NULL;
 
        /* Read in each point. */
        for (j = 0; j < npts; j++) {
            int x, y;
 
            if (fscanf(fp, "%d %d", &x, &y) != 2) goto failed;
            dpts->pts[j].x = x;
            dpts->pts[j].y = y;
        }
 
        /* Compute the chain-code. */
        lialg_compute_chain_code(dpts);
 
        /* Store the list in the rec data structure. */
        rec->dompts[nclasses] = dpts;
 
        continue;
 
failed:
        fprintf(stderr, "read_classifier_digest failed...\n");
        for (; nclasses >= 0; nclasses--) {
            if (rec->cnames[nclasses] != NULL) {
                free(rec->cnames[nclasses]);
                rec->cnames[nclasses] = NULL;
            }
            if (rec->dompts[nclasses] != NULL) {
                delete_examples(rec->dompts[nclasses]);
                rec->dompts[nclasses] = NULL;
            }
        }
        if (dpts != NULL)
            delete_examples(dpts);
        fclose(fp);
        return(-1);
    }
 
    fclose(fp);
    return(0);
}
 
 
/*************************************************************
 
  Canonicalization routines
 
 *************************************************************/
 
static int lialg_canonicalize_examples(rClassifier *rec) {
    int i;
    int nclasses;
 
    if (lidebug) {
        fprintf(stderr, "lialg_canonicalize_examples working on %s\n",
                rec->file_name);
    }
    /* Initialize canonical-example arrays. */
    for (i = 0; i < MAXSCLASSES; i++) {
        rec->canonex[i] = NULL;
    }
 
    /* Figure out number of classes. */
    for (nclasses = 0;
          nclasses < MAXSCLASSES && rec->cnames[nclasses] != NULL;
          nclasses++)
        ;
 
    /* Canonicalize the examples for each class. */
    for (i = 0; i < nclasses; i++) {
        int j, k;
        int nex;
        point_list *pts, *tmp, *avg;
        int maxxrange, maxyrange;
        int minx, miny, maxx, maxy;
        int avgxrange, avgyrange, avgxoff, avgyoff, avgscale;
 
 
        if (lidebug) {
            fprintf(stderr, "lialg_canonicalize_examples working on class %s\n",
                    rec->cnames[i]);
        }
        /* Make a copy of the examples. */
        pts = NULL;
        tmp = rec->ex[i];
        for (nex = 0; tmp != NULL; nex++, tmp = tmp->next) {
            if ((pts = add_example(pts, tmp->npts, tmp->pts)) == NULL) {
                delete_examples(pts);
                return(-1);
            }
        }
 
        /* Canonicalize each example, and derive the max x and y ranges. */
        maxxrange = 0;
        maxyrange = 0;
        for (j = 0, tmp = pts; j < nex; j++, tmp = tmp->next) {
            if (lialg_canonicalize_example_stroke(tmp) != 0) {
                if (lidebug) {
                    fprintf(stderr, "lialg_canonicalize_example_stroke returned error\n");
                }
                return(-1);
            }
 
            if (tmp->xrange > maxxrange) maxxrange = tmp->xrange;
            if (tmp->yrange > maxyrange) maxyrange = tmp->yrange;
        }
 
        /* Normalize max ranges. */
        if (((100 * maxxrange + CANONICAL_X / 2) / CANONICAL_X) >
            ((100 * maxyrange + CANONICAL_Y / 2) / CANONICAL_Y)) {
            maxyrange = (maxyrange * CANONICAL_X + maxxrange / 2) / maxxrange;
            maxxrange = CANONICAL_X;
        }
        else {
            maxxrange = (maxxrange * CANONICAL_Y + maxyrange / 2) / maxyrange;
            maxyrange = CANONICAL_Y;
        }
 
        /* Re-scale each example to max ranges. */
        for (j = 0, tmp = pts; j < nex; j++, tmp = tmp->next) {
            int scalex = (tmp->xrange == 0) ? 100 : (100 * maxxrange + tmp->xrange / 2) / tmp->xrange;
            int scaley = (tmp->yrange == 0) ? 100 : (100 * maxyrange + tmp->yrange / 2) / tmp->yrange;
            if (lialg_translate_points(tmp, 0, 0, scalex, scaley) != 0) {
                delete_examples(pts);
                return(-1);
            }
        }
 
        /* Average the examples; leave average in first example. */
        avg = pts;                              /* careful aliasing!! */
        for (k = 0; k < NCANONICAL; k++) {
            int xsum = 0;
            int ysum = 0;
 
            for (j = 0, tmp = pts; j < nex; j++, tmp = tmp->next) {
                xsum += tmp->pts[k].x;
                ysum += tmp->pts[k].y;
            }
 
            avg->pts[k].x = (xsum + j / 2) / j;
            avg->pts[k].y = (ysum + j / 2) / j;
        }
 
        /* Compute BB of averaged stroke and re-scale. */
        lialg_get_bounding_box(avg, &minx, &miny, &maxx, &maxy);
        avgxrange = maxx - minx;
        avgyrange = maxy - miny;
        avgscale = (((100 * avgxrange + CANONICAL_X / 2) / CANONICAL_X) >
                    ((100 * avgyrange + CANONICAL_Y / 2) / CANONICAL_Y))
          ? (100 * CANONICAL_X + avgxrange / 2) / avgxrange
          : (100 * CANONICAL_Y + avgyrange / 2) / avgyrange;
        if (lialg_translate_points(avg, minx, miny, avgscale, avgscale) != 0) {
            delete_examples(pts);
            return(-1);
        }
 
        /* Re-compute the x and y ranges and center the stroke. */
        lialg_get_bounding_box(avg, &minx, &miny, &maxx, &maxy);
        avgxrange = maxx - minx;
        avgyrange = maxy - miny;
        avgxoff = -((CANONICAL_X - avgxrange + 1) / 2);
        avgyoff = -((CANONICAL_Y - avgyrange + 1) / 2);
        if (lialg_translate_points(avg, avgxoff, avgyoff, 100, 100) != 0) {
            delete_examples(pts);
            return(-1);
        }
 
        /* Create a point list to serve as the ``canonical representation. */
        if ((rec->canonex[i] = add_example(NULL, avg->npts, avg->pts)) == NULL) {
            delete_examples(pts);
            return(-1);
        }
        (rec->canonex[i])->xrange = maxx - minx;
        (rec->canonex[i])->yrange = maxy - miny;
 
        if (lidebug) {
            fprintf(stderr, "%s, avgpts = %d\n", rec->cnames[i], avg->npts);
            for (j = 0; j < avg->npts; j++) {
                fprintf(stderr, "  (%d, %d)\n",
                        avg->pts[j].x, avg->pts[j].y);
            }
        }
 
        /* Compute dominant points of canonical representation. */
        rec->dompts[i] = lialg_compute_dominant_points(avg);
 
        /* Clean up. */
        delete_examples(pts);
    }
 
    /* Sanity check. */
    for (i = 0; i < nclasses; i++) {
        char *best_name = lialg_recognize_stroke(rec, rec->canonex[i]);
 
        if (best_name != rec->cnames[i])
            fprintf(stderr, "%s, best = %s\n", rec->cnames[i], best_name);
    }
 
    return(0);
}
 
 
static int lialg_canonicalize_example_stroke(point_list *points) {
    int minx, miny, maxx, maxy, xrange, yrange, scale;
 
    /* Filter out points that are too close. */
    if (lialg_filter_points(points) != 0) return(-1);
 
    /* Must be at least two points! */
    if (points->npts < 2) {
        if (lidebug) {
            fprintf(stderr, "lialg_canonicalize_example_stroke: npts=%d\n",
                    points->npts);
        }
        return(-1);
    }
 
    /* Scale up to avoid conversion errors. */
    lialg_get_bounding_box(points, &minx, &miny, &maxx, &maxy);
    xrange = maxx - minx;
    yrange = maxy - miny;
    scale = (((100 * xrange + CANONICAL_X / 2) / CANONICAL_X) >
             ((100 * yrange + CANONICAL_Y / 2) / CANONICAL_Y))
      ? (100 * CANONICAL_X + xrange / 2) / xrange
      : (100 * CANONICAL_Y + yrange / 2) / yrange;
    if (lialg_translate_points(points, minx, miny, scale, scale) != 0) {
        if (lidebug) {
            fprintf(stderr, "lialg_translate_points (minx=%d,miny=%d,scale=%d) returned error\n", minx, miny, scale);
        }
        return(-1);
    }
 
    /* Compute an equivalent stroke with equi-distant points. */
    if (lialg_compute_equipoints(points) != 0) return(-1);
 
    /* Re-translate the points to the origin. */
    lialg_get_bounding_box(points, &minx, &miny, &maxx, &maxy);
    if (lialg_translate_points(points, minx, miny, 100, 100) != 0) {
        if (lidebug) {
            fprintf(stderr, "lialg_translate_points (minx=%d,miny=%d) returned error\n", minx, miny);
        }
        return(-1);
    }
 
    /* Store the x and y ranges in the point list. */
    xrange = maxx - minx;
    yrange = maxy - miny;
    points->xrange = xrange;
    points->yrange = yrange;
 
    if (lidebug) {
        int i;
        fprintf(stderr, "Canonicalized:   %d, %d, %d, %d\n", minx, miny, maxx, maxy);
        for (i = 0; i < points->npts; i++)
            fprintf(stderr, "      (%d %d)\n",
                    points->pts[i].x, points->pts[i].y);
        fflush(stderr);
    }
 
    return(0);
}
 
 
static int lialg_compute_equipoints(point_list *points) {
    pen_point *equipoints = make_pen_point_array(NCANONICAL);
    int nequipoints = 0;
    int pathlen = lialg_compute_pathlen(points);
    int equidist = (pathlen + (NCANONICAL - 1) / 2) / (NCANONICAL - 1);
    int i;
    int dist_since_last_eqpt;
    int remaining_seglen;
    int dist_to_next_eqpt;
 
    if (equipoints == NULL) {
        error("can't allocate memory in lialg_compute_equipoints");
        return(-1);
    }
 
    if (lidebug) {
        fprintf(stderr, "compute_equipoints:  npts = %d, pathlen = %d, equidist = %d\n",
                points->npts, pathlen, equidist);
        fflush(stderr);
    }
 
    /* First original point is an equipoint. */
    equipoints[0] = points->pts[0];
    nequipoints++;
    dist_since_last_eqpt = 0;
 
    for (i = 1; i < points->npts; i++) {
        int dx1 = points->pts[i].x - points->pts[i-1].x;
        int dy1 = points->pts[i].y - points->pts[i-1].y;
        int endx = 100 * points->pts[i-1].x;
        int endy = 100 * points->pts[i-1].y;
        remaining_seglen = isqrt(10000 * (dx1 * dx1 + dy1 * dy1));
        dist_to_next_eqpt = equidist - dist_since_last_eqpt;
 
        while (remaining_seglen >= dist_to_next_eqpt) {
            if (dx1 == 0) {
                /* x-coordinate stays the same */
                if (dy1 >= 0)
                    endy += dist_to_next_eqpt;
                else
                    endy -= dist_to_next_eqpt;
            }
            else {
                int slope = (100 * dy1 + dx1 / 2) / dx1;
                int tmp = isqrt(10000 + slope * slope);
                int dx = (100 * dist_to_next_eqpt + tmp / 2) / tmp;
                int dy = (slope * dx + 50) / 100;
 
                if (dy < 0) dy = -dy;
                if (dx1 >= 0)
                    endx += dx;
                else
                    endx -= dx;
                if (dy1 >= 0)
                    endy += dy;
                else
                    endy -= dy;
            }
 
            equipoints[nequipoints].x = (endx + 50) / 100;
            equipoints[nequipoints].y = (endy + 50) / 100;
            nequipoints++;
/*          assert(nequipoints <= NCANONICAL);*/
            dist_since_last_eqpt = 0;
            remaining_seglen -= dist_to_next_eqpt;
            dist_to_next_eqpt = equidist;
        }
 
        dist_since_last_eqpt += remaining_seglen;
    }
 
    /* Take care of last equipoint. */
    if (nequipoints == NCANONICAL) {
        /* Good. */
    } else if (nequipoints == (NCANONICAL - 1)) {
        /* Make last original point the last equipoint. */
        equipoints[nequipoints] = points->pts[points->npts - 1];
    } else {
      if (lidebug) {
        fprintf(stderr,"lialg_compute_equipoints: nequipoints = %d\n",
                nequipoints);
      }
/*      assert(false);*/
        return(-1);
    }
 
    points->npts = NCANONICAL;
    delete_pen_point_array(points->pts);
    points->pts = equipoints;
    return(0);
}
 
 
/*************************************************************
 
  Utility routines
 
 *************************************************************/
 
/* Result is x 100. */
static int lialg_compute_pathlen(point_list *points) {
    return(lialg_compute_pathlen_subset(points, 0, points->npts - 1));
}
 
 
/* Result is x 100. */
static int lialg_compute_pathlen_subset(point_list *points,
                                           int start, int end) {
    int pathlen;
    int i;
 
    pathlen = 0;
    for (i = start + 1; i <= end; i++) {
        int dx = points->pts[i].x - points->pts[i-1].x;
        int dy = points->pts[i].y - points->pts[i-1].y;
        int dist = isqrt(10000 * (dx * dx + dy * dy));
        pathlen += dist;
    }
 
    return(pathlen);
}
 
 
/* Note that this does NOT update points->xrange and points->yrange! */
static int lialg_filter_points(point_list *points) {
    int filtered_npts;
    pen_point *filtered_pts = make_pen_point_array(points->npts);
    int i;
 
    if (filtered_pts == NULL) {
        error("can't allocate memory in lialg_filter_points");
        return(-1);
    }
 
    filtered_pts[0] = points->pts[0];
    filtered_npts = 1;
    for (i = 1; i < points->npts; i++) {
        int j = filtered_npts - 1;
        int dx = points->pts[i].x - filtered_pts[j].x;
        int dy = points->pts[i].y - filtered_pts[j].y;
        int magsq = dx * dx + dy * dy;
 
        if (magsq >= DIST_SQ_THRESHOLD) {
            filtered_pts[filtered_npts] = points->pts[i];
            filtered_npts++;
        }
    }
 
    points->npts = filtered_npts;
    delete_pen_point_array(points->pts);
    points->pts = filtered_pts;
    return(0);
}
 
 
/* scalex and scaley are x 100. */
/* Note that this does NOT update points->xrange and points->yrange! */
static int lialg_translate_points(point_list *points,
                                   int minx, int miny,
                                   int scalex, int scaley) {
    int i;
 
    for (i = 0; i < points->npts; i++) {
        points->pts[i].x = ((points->pts[i].x - minx) * scalex + 50) / 100;
        points->pts[i].y = ((points->pts[i].y - miny) * scaley + 50) / 100;
    }
 
    return(0);
}
 
 
static void lialg_get_bounding_box(point_list *points,
                                    int *pminx, int *pminy,
                                    int *pmaxx, int *pmaxy) {
    int minx, miny, maxx, maxy;
    int i;
 
    minx = maxx = points->pts[0].x;
    miny = maxy = points->pts[0].y;
    for (i = 1; i < points->npts; i++) {
        pen_point *pt = &(points->pts[i]);
        if (pt->x < minx) minx = pt->x;
        if (pt->x > maxx) maxx = pt->x;
        if (pt->y < miny) miny = pt->y;
        if (pt->y > maxy) maxy = pt->y;
    }
 
    *pminx = minx;
    *pminy = miny;
    *pmaxx = maxx;
    *pmaxy = maxy;
}
 
#ifdef __ECOS
float
expf(float x)
{
    return exp((double)x);
}
#endif
 
 
static void lialg_compute_lpf_parameters() {
    int i;
 
    for (i = LP_FILTER_WIDTH; i >= 0; i--) {
        float x = 0.04 * (i * i);
#if defined(ARM_LINUX) || !defined(__GLIBC__)
        double tmp = 100.0 * exp((double)x);
#else
        float tmp = 100.0 * expf(x);
#endif
        int wt = rint((double)tmp);
 
        lialg_lpfwts[LP_FILTER_WIDTH - i] = wt;
        lialg_lpfwts[LP_FILTER_WIDTH + i] = wt;
    }
    lialg_lpfconst = 0;
    for (i = 0; i < (2 * LP_FILTER_WIDTH + 1); i++) {
        lialg_lpfconst += lialg_lpfwts[i];
    }
}
 
 
/* Code from Joseph Hall (jnhall@sat.mot.com). */
static int isqrt(int n) {
    register int i;
    register long k0, k1, nn;
 
    for (nn = i = n, k0 = 2; i > 0; i >>= 2, k0 <<= 1)
        ;
    nn <<= 2;
    for (;;) {
        k1 = (nn / k0 + k0) >> 1;
        if (((k0 ^ k1) & ~1) == 0)
            break;
        k0 = k1;
    }
    return (int) ((k1 + 1) >> 1);
}
 
 
/* Helper routines from Mark Hayter. */
static int likeatan(int tantop, int tanbot) {
    int t;
    /* Use tan(theta)=top/bot --> order for t */
    /* t in range 0..0x40000 */
 
    if ((tantop == 0) && (tanbot == 0))
        t = 0;
    else
    {
        t = (tantop << 16) / (abs(tantop) + abs(tanbot));
        if (tanbot < 0)
            t = 0x20000 - t;
        else
            if (tantop < 0) t = 0x40000 + t;
    }
    return t;
}
 
 
static int quadr(int t) {
    return (8 - (((t + 0x4000) >> 15) & 7)) & 7;
}
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[/] [or1k/] [tags/] [MW_0_8_9PRE7/] [mw/] [src/] [demos/] [nxscribble/] [li_recognizer.c] - Blame information for rev 1765

Line No.	Rev	Author	Line
1	673	markom	`/*`
2			`* li_recognizer.c`
3			`*`
4			`* Copyright 2000 Compaq Computer Corporation.`
5			`* Copying or modifying this code for any purpose is permitted,`
6			`* provided that this copyright notice is preserved in its entirety`
7			`* in all copies or modifications.`
8			`* COMPAQ COMPUTER CORPORATION MAKES NO WARRANTIES, EXPRESSED OR`
9			`* IMPLIED, AS TO THE USEFULNESS OR CORRECTNESS OF THIS CODE OR`
10			`*`
11			`*`
12			`* Adapted from cmu_recognizer.c by Jay Kistler.`
13			`*`
14			`* Where is the CMU copyright???? Gotta track it down - Jim Gettys`
15			`*`
16			`* Credit to Dean Rubine, Jim Kempf, and Ari Rapkin.`
17			`*/`
18
19
20			`#include <sys/types.h>`
21			`#include <stdio.h>`
22			`#include <string.h>`
23			`#ifndef ELX`
24			`#include <stdlib.h>`
25			`#endif`
26			`#include <math.h>`
27			`#include <locale.h>`
28			`#include <hre_internal.h>`
29			`#include <setjmp.h>`
30			`#include "util.h"`
31			`#include "matrix.h"`
32			`#include "sc.h"`
33			`#include "li_recognizer.h"`
34			`#include "li_recognizer_internal.h"`
35
36
37			`int lidebug = 0;`
38
39			`/LI Magic Number./`
40