ply.c

C语言滤波程序

  for (j = 0; j < elem->nprops; j++) {

    prop = elem->props[j];
    store_it = (elem->store_prop[j] | other_flag);

    /* store either in the user's structure or in other_props */
    if (elem->store_prop[j])
      elem_data = elem_ptr;
    else
      elem_data = other_data;

    if (prop->is_list == PLY_LIST) {       /* a list */

      /* get and store the number of items in the list */
      get_ascii_item (words[which_word++], prop->count_external,
                      &int_val, &uint_val, &double_val);
      if (store_it) {
        item = elem_data + prop->count_offset;
        store_item(item, prop->count_internal, int_val, uint_val, double_val);
      }

      /* allocate space for an array of items and store a ptr to the array */
      list_count = int_val;
      item_size = ply_type_size[prop->internal_type];
      store_array = (char **) (elem_data + prop->offset);

      if (list_count == 0) {
        if (store_it)
          *store_array = NULL;
      }
      else {
        if (store_it) {
          item_ptr = (char *) myalloc (sizeof (char) * item_size * list_count);
          item = item_ptr;
          *store_array = item_ptr;
        }

        /* read items and store them into the array */
        for (k = 0; k < list_count; k++) {
          get_ascii_item (words[which_word++], prop->external_type,
                          &int_val, &uint_val, &double_val);
          if (store_it) {
            store_item (item, prop->internal_type,
                        int_val, uint_val, double_val);
            item += item_size;
          }
        }
      }

    }
    else if (prop->is_list == PLY_STRING) {   /* a string */
      if (store_it) {
	char *str;
	char **str_ptr;
	str = strdup (words[which_word++]);
        item = elem_data + prop->offset;
	str_ptr = (char **) item;
	*str_ptr = str;
      }
      else {
        which_word++;
      }
    }
    else {                     /* a scalar */
      get_ascii_item (words[which_word++], prop->external_type,
                      &int_val, &uint_val, &double_val);
      if (store_it) {
        item = elem_data + prop->offset;
        store_item (item, prop->internal_type, int_val, uint_val, double_val);
      }
    }

  }

  free (words);
}


/******************************************************************************
Read an element from a binary file.

Entry:
  plyfile  - file identifier
  elem_ptr - pointer to an element
******************************************************************************/

void binary_get_element(PlyFile *plyfile, char *elem_ptr)
{
  int i,j,k;
  PlyElement *elem;
  PlyProperty *prop;
  FILE *fp = plyfile->fp;
  char *elem_data;
  char *item;
  char *item_ptr;
  int item_size;
  int int_val;
  unsigned int uint_val;
  double double_val;
  int list_count;
  int store_it;
  char **store_array;
  char *other_data;
  int other_flag;

  /* the kind of element we're reading currently */
  elem = plyfile->which_elem;

  /* do we need to setup for other_props? */

  if (elem->other_offset != NO_OTHER_PROPS) {
    char **ptr;
    other_flag = 1;
    /* make room for other_props */
    other_data = (char *) myalloc (elem->other_size);
    /* store pointer in user's structure to the other_props */
    ptr = (char **) (elem_ptr + elem->other_offset);
    *ptr = other_data;
  }
  else
    other_flag = 0;

  /* read in a number of elements */

  for (j = 0; j < elem->nprops; j++) {

    prop = elem->props[j];
    store_it = (elem->store_prop[j] | other_flag);

    /* store either in the user's structure or in other_props */
    if (elem->store_prop[j])
      elem_data = elem_ptr;
    else
      elem_data = other_data;

    if (prop->is_list == PLY_LIST) {          /* list */

      /* get and store the number of items in the list */
      get_binary_item (fp, prop->count_external,
                      &int_val, &uint_val, &double_val);
      if (store_it) {
        item = elem_data + prop->count_offset;
        store_item(item, prop->count_internal, int_val, uint_val, double_val);
      }

      /* allocate space for an array of items and store a ptr to the array */
      list_count = int_val;
      item_size = ply_type_size[prop->internal_type];
      store_array = (char **) (elem_data + prop->offset);
      if (list_count == 0) {
        if (store_it)
          *store_array = NULL;
      }
      else {
        if (store_it) {
          item_ptr = (char *) myalloc (sizeof (char) * item_size * list_count);
          item = item_ptr;
          *store_array = item_ptr;
        }

        /* read items and store them into the array */
        for (k = 0; k < list_count; k++) {
          get_binary_item (fp, prop->external_type,
                          &int_val, &uint_val, &double_val);
          if (store_it) {
            store_item (item, prop->internal_type,
                        int_val, uint_val, double_val);
            item += item_size;
          }
        }
      }

    }
    else if (prop->is_list == PLY_STRING) {     /* string */
      int len;
      char *str;
      fread (&len, sizeof(int), 1, fp);
      str = (char *) myalloc (len);
      fread (str, len, 1, fp);
      if (store_it) {
	char **str_ptr;
        item = elem_data + prop->offset;
	str_ptr = (char **) item;
	*str_ptr = str;
      }
    }
    else {                                      /* scalar */
      get_binary_item (fp, prop->external_type,
                      &int_val, &uint_val, &double_val);
      if (store_it) {
        item = elem_data + prop->offset;
        store_item (item, prop->internal_type, int_val, uint_val, double_val);
      }
    }

  }
}


/******************************************************************************
Write to a file the word that represents a PLY data type.

Entry:
  fp   - file pointer
  code - code for type
******************************************************************************/

void write_scalar_type (FILE *fp, int code)
{
  /* make sure this is a valid code */

  if (code <= StartType || code >= EndType) {
    fprintf (stderr, "write_scalar_type: bad data code = %d\n", code);
    exit (-1);
  }

  /* write the code to a file */

  fprintf (fp, "%s", type_names[code]);
}


/******************************************************************************
Get a text line from a file and break it up into words.

IMPORTANT: The calling routine should call "free" on the returned pointer once
finished with it.

Entry:
  fp - file to read from

Exit:
  nwords    - number of words returned
  orig_line - the original line of characters
  returns a list of words from the line, or NULL if end-of-file
******************************************************************************/

char **get_words(FILE *fp, int *nwords, char **orig_line)
{
#define BIG_STRING 4096
  int i,j;
  static char str[BIG_STRING];
  static char str_copy[BIG_STRING];
  char **words;
  int max_words = 10;
  int num_words = 0;
  char *ptr,*ptr2;
  char *result;

  words = (char **) myalloc (sizeof (char *) * max_words);

  /* read in a line */
  result = fgets (str, BIG_STRING, fp);
  if (result == NULL) {
    *nwords = 0;
    *orig_line = NULL;
    return (NULL);
  }

  /* convert line-feed and tabs into spaces */
  /* (this guarentees that there will be a space before the */
  /*  null character at the end of the string) */

  str[BIG_STRING-2] = ' ';
  str[BIG_STRING-1] = '\0';

  for (ptr = str, ptr2 = str_copy; *ptr != '\0'; ptr++, ptr2++) {
    *ptr2 = *ptr;
    if (*ptr == '\t') {
      *ptr = ' ';
      *ptr2 = ' ';
    }
    else if (*ptr == '\n') {
      *ptr = ' ';
      *ptr2 = '\0';
      break;
    }
  }

  /* find the words in the line */

  ptr = str;
  while (*ptr != '\0') {

    /* jump over leading spaces */
    while (*ptr == ' ')
      ptr++;

    /* break if we reach the end */
    if (*ptr == '\0')
      break;

    /* allocate more room for words if necessary */
    if (num_words >= max_words) {
      max_words += 10;
      words = (char **) realloc (words, sizeof (char *) * max_words);
    }

    if (*ptr == '\"') {  /* a quote indidicates that we have a string */

      /* skip over leading quote */
      ptr++;

      /* save pointer to beginning of word */
      words[num_words++] = ptr;

      /* find trailing quote or end of line */
      while (*ptr != '\"' && *ptr != '\0')
        ptr++;

      /* replace quote with a null character to mark the end of the word */
      /* if we are not already at the end of the line */
      if (*ptr != '\0')
	*ptr++ = '\0';
    }
    else {               /* non-string */

      /* save pointer to beginning of word */
      words[num_words++] = ptr;

      /* jump over non-spaces */
      while (*ptr != ' ')
	ptr++;

      /* place a null character here to mark the end of the word */
      *ptr++ = '\0';
    }
  }

  /* return the list of words */
  *nwords = num_words;
  *orig_line = str_copy;
  return (words);
}


/******************************************************************************
Return the value of an item, given a pointer to it and its type.

Entry:
  item - pointer to item
  type - data type that "item" points to

Exit:
  returns a double-precision float that contains the value of the item
******************************************************************************/

double get_item_value(char *item, int type)
{
  unsigned char *puchar;
  char *pchar;
  short int *pshort;
  unsigned short int *pushort;
  int *pint;
  unsigned int *puint;
  float *pfloat;
  double *pdouble;
  int int_value;
  unsigned int uint_value;
  double double_value;

  switch (type) {
    case Int8:
      pchar = (char *) item;
      int_value = *pchar;
      return ((double) int_value);
    case Uint8:
      puchar = (unsigned char *) item;
      int_value = *puchar;
      return ((double) int_value);
    case Int16:
      pshort = (short int *) item;
      int_value = *pshort;
      return ((double) int_value);
    case Uint16:
      pushort = (unsigned short int *) item;
      int_value = *pushort;
      return ((double) int_value);
    case Int32:
      pint = (int *) item;
      int_value = *pint;
      return ((double) int_value);
    case Uint32:
      puint = (unsigned int *) item;
      uint_value = *puint;
      return ((double) uint_value);
    case Float32:
      pfloat = (float *) item;
      double_value = *pfloat;
      return (double_value);
    case Float64:
      pdouble = (double *) item;
      double_value = *pdouble;
      return (double_value);
    default:
      fprintf (stderr, "get_item_value: bad type = %d\n", type);
      exit (-1);
  }

  return (0.0);  /* never actually gets here */
}


/******************************************************************************
Write out an item to a file as raw binary bytes.

Entry:
  fp         - file to write to
  int_val    - integer version of item
  uint_val   - unsigned integer version of item
  double_val - double-precision float version of item
  type       - data type to write out
******************************************************************************/

void write_binary_item(
  FILE *fp,
  int int_val,
  unsigned int uint_val,
  double double_val,
  int type
)
{
  unsigned char uchar_val;
  char char_val;
  unsigned short ushort_val;
  short short_val;
  float float_val;

  switch (type) {
    case Int8:
      char_val = int_val;
      fwrite (&char_val, 1, 1, fp);
      break;
    case Int16:
      short_val = int_val;
      fwrite (&short_val, 2, 1, fp);
      break;
    case Int32:
      fwrite (&int_val, 4, 1, fp);
      break;
    case Uint8:
      uchar_val = uint_val;
      fwrite (&uchar_val, 1, 1, fp);
      break;
    case Uint16:
      ushort_val = uint_val;
      fwrite (&ushort_val, 2, 1, fp);
      break;
    case Uint32:
      fwrite (&uint_val, 4, 1, fp);
      break;
    case Float32:
      float_val = double_val;
      fwrite (&float_val, 4, 1, fp);
      break;
    case Float64:
      fwrite (&double_val, 8, 1, fp);
      break;
    default:
      fprintf (stderr, "write_binary_item: bad type = %d\n", type);
      exit (-1);
  }
}


/******************************************************************************
Write out an item to a file as ascii characters.

Entry:
  fp         - file to write to
  int_val    - integer version of item
  uint_val   - unsigned integer version of item
  double_val - double-precision float version of item
  type       - data type to write out
******************************************************************************/

void write_ascii_item(
  FILE *fp,
  int int_val,
  unsigned int uint_val,
  double double_val,
  int type
)
{
  switch (type) {