ply.c

C语言滤波程序

  /* Examine each property in decreasing order of size. */
  /* We do this so that all data types will be aligned by */
  /* word, half-word, or whatever within the structure. */

  for (type_size = 8; type_size > 0; type_size /= 2) {

    /* add up the space taken by each property, and save this information */
    /* away in the property descriptor */

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

      /* don't bother with properties we've been asked to store explicitly */
      if (elem->store_prop[i])
        continue;

      prop = elem->props[i];

      /* internal types will be same as external */
      prop->internal_type = prop->external_type;
      prop->count_internal = prop->count_external;

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

        /* pointer to list */
        if (type_size == sizeof (void *)) {
          prop->offset = size;
          size += sizeof (void *);    /* always use size of a pointer here */
        }

        /* count of number of list elements */
        if (type_size == ply_type_size[prop->count_external]) {
          prop->count_offset = size;
          size += ply_type_size[prop->count_external];
        }
      }
      /* string */
      else if (prop->is_list == PLY_STRING) {
        /* pointer to string */
        if (type_size == sizeof (char *)) {
          prop->offset = size;
          size += sizeof (char *);
        }
      }
      /* scalar */
      else if (type_size == ply_type_size[prop->external_type]) {
        prop->offset = size;
        size += ply_type_size[prop->external_type];
      }
    }

  }

  /* save the size for the other_props structure */
  elem->other_size = size;
}


/******************************************************************************
Specify that we want the "other" properties of an element to be tucked
away within the user's structure.

Entry:
  plyfile - file identifier
  elem    - the element that we want to store other_props in
  offset  - offset to where other_props will be stored inside user's structure

Exit:
  returns pointer to structure containing description of other_props
******************************************************************************/

static PlyOtherProp *get_other_properties(
  PlyFile *plyfile,
  PlyElement *elem,
  int offset
)
{
  int i;
  PlyOtherProp *other;
  PlyProperty *prop;
  int nprops;

  /* remember that this is the "current" element */
  plyfile->which_elem = elem;

  /* save the offset to where to store the other_props */
  elem->other_offset = offset;

  /* place the appropriate pointers, etc. in the element's property list */
  setup_other_props (plyfile, elem);

  /* create structure for describing other_props */
  other = (PlyOtherProp *) myalloc (sizeof (PlyOtherProp));
  other->name = strdup (elem->name);
#if 0
  if (elem->other_offset == NO_OTHER_PROPS) {
    other->size = 0;
    other->props = NULL;
    other->nprops = 0;
    return (other);
  }
#endif
  other->size = elem->other_size;
  other->props = (PlyProperty **) myalloc (sizeof(PlyProperty) * elem->nprops);
  
  /* save descriptions of each "other" property */
  nprops = 0;
  for (i = 0; i < elem->nprops; i++) {
    if (elem->store_prop[i])
      continue;
    prop = (PlyProperty *) myalloc (sizeof (PlyProperty));
    copy_property (prop, elem->props[i]);
    other->props[nprops] = prop;
    nprops++;
  }
  other->nprops = nprops;

  /* set other_offset pointer appropriately if there are NO other properties */
  if (other->nprops == 0) {
    elem->other_offset = NO_OTHER_PROPS;
  }
 
  /* return structure */
  return (other);
}


/******************************************************************************
Specify that we want the "other" properties of an element to be tucked
away within the user's structure.  The user needn't be concerned for how
these properties are stored.

Entry:
  plyfile   - file identifier
  elem_name - name of element that we want to store other_props in
  offset    - offset to where other_props will be stored inside user's structure

Exit:
  returns pointer to structure containing description of other_props
******************************************************************************/

PlyOtherProp *ply_get_other_properties(
  PlyFile *plyfile,
  char *elem_name,
  int offset
)
{
  PlyElement *elem;
  PlyOtherProp *other;

  /* find information about the element */
  elem = find_element (plyfile, elem_name);
  if (elem == NULL) {
    fprintf (stderr, "ply_get_other_properties: Can't find element '%s'\n",
             elem_name);
    return (NULL);
  }

  other = get_other_properties (plyfile, elem, offset);
  return (other);
}




/*************************/
/*  Other Element Stuff  */
/*************************/





/******************************************************************************
Grab all the data for the current element that a user does not want to
explicitly read in.  Stores this in the PLY object's data structure.

Entry:
  plyfile - pointer to file

Exit:
  returns pointer to ALL the "other" element data for this PLY file
******************************************************************************/

PlyOtherElems *get_other_element_ply (PlyFile *plyfile)
{
  int i;
  PlyElement *elem;
  char *elem_name;
  int elem_count;
  PlyOtherElems *other_elems;
  OtherElem *other;

  elem = plyfile->which_elem;
  elem_name = elem->name;
  elem_count = elem->num;

  /* create room for the new "other" element, initializing the */
  /* other data structure if necessary */

  if (plyfile->other_elems == NULL) {
    plyfile->other_elems = (PlyOtherElems *) myalloc (sizeof (PlyOtherElems));
    other_elems = plyfile->other_elems;
    other_elems->other_list = (OtherElem *) myalloc (sizeof (OtherElem));
    other = &(other_elems->other_list[0]);
    other_elems->num_elems = 1;
  }
  else {
    other_elems = plyfile->other_elems;
    other_elems->other_list = (OtherElem *) realloc (other_elems->other_list,
                              sizeof (OtherElem) * other_elems->num_elems + 1);
    other = &(other_elems->other_list[other_elems->num_elems]);
    other_elems->num_elems++;
  }

  /* count of element instances in file */
  other->elem_count = elem_count;

  /* save name of element */
  other->elem_name = strdup (elem_name);

  /* create a list to hold all the current elements */
  other->other_data = (OtherData **)
                  malloc (sizeof (OtherData *) * other->elem_count);

  /* set up for getting elements */
  other->other_props = ply_get_other_properties (plyfile, elem_name,
                         offsetof(OtherData,other_props));

  /* grab all these elements */
  for (i = 0; i < other->elem_count; i++) {
    /* grab and element from the file */
    other->other_data[i] = (OtherData *) malloc (sizeof (OtherData));
    ply_get_element (plyfile, (void *) other->other_data[i]);
  }

  /* return pointer to the other elements data */
  return (other_elems);
}


/******************************************************************************
Write out the "other" elements specified for this PLY file.

Entry:
  plyfile - pointer to PLY file to write out other elements for
******************************************************************************/

void put_other_elements_ply (PlyFile *plyfile)
{
  int i,j;
  OtherElem *other;

  /* make sure we have other elements to write */
  if (plyfile->other_elems == NULL)
    return;

  /* write out the data for each "other" element */

  for (i = 0; i < plyfile->other_elems->num_elems; i++) {

    other = &(plyfile->other_elems->other_list[i]);
    put_element_setup_ply (plyfile, other->elem_name);

    /* write out each instance of the current element */
    for (j = 0; j < other->elem_count; j++)
      put_element_ply (plyfile, (void *) other->other_data[j]);
  }
}


/******************************************************************************
Free up storage used by an "other" elements data structure.

Entry:
  other_elems - data structure to free up
******************************************************************************/

void free_other_elements_ply (PlyOtherElems *other_elems)
{

}



/*******************/
/*  Miscellaneous  */
/*******************/



/******************************************************************************
Close a PLY file.

Entry:
  plyfile - identifier of file to close
******************************************************************************/

void ply_close(PlyFile *plyfile)
{
  fclose (plyfile->fp);

  /* free up memory associated with the PLY file */
  free (plyfile);
}


/******************************************************************************
Get version number and file type of a PlyFile.

Entry:
  ply - pointer to PLY file

Exit:
  version - version of the file
  file_type - PLY_ASCII, PLY_BINARY_BE, or PLY_BINARY_LE
******************************************************************************/

void get_info_ply(PlyFile *ply, float *version, int *file_type)
{
  if (ply == NULL)
    return;

  *version = ply->version;
  *file_type = ply->file_type;
}


/******************************************************************************
Compare two strings.  Returns 1 if they are the same, 0 if not.
******************************************************************************/

int equal_strings(char *s1, char *s2)
{
  int i;

  while (*s1 && *s2)
    if (*s1++ != *s2++)
      return (0);

  if (*s1 != *s2)
    return (0);
  else
    return (1);
}


/******************************************************************************
Re-create the command line that was used to invoke this program.

Entry:
  argc - number of words in argv
  argv - array of words in command line
******************************************************************************/

char *recreate_command_line (int argc, char *argv[])
{
  int i;
  char *line;
  int len = 0;

  /* count total number of characters needed, including separating spaces */
  for (i = 0; i < argc; i++)
    len += strlen(argv[i]) + 1;

  /* create empty line */
  line = (char *) malloc (sizeof(char) * len);
  line[0] = '\0';

  /* repeatedly append argv */
  for (i = 0; i < argc; i++) {
    strcat (line, argv[i]);
    if (i != argc - 1)
      strcat (line, " ");
  }

  return (line);
}


/******************************************************************************
Find an element from the element list of a given PLY object.

Entry:
  plyfile - file id for PLY file
  element - name of element we're looking for

Exit:
  returns the element, or NULL if not found
******************************************************************************/

PlyElement *find_element(PlyFile *plyfile, char *element)
{
  int i;

  for (i = 0; i < plyfile->num_elem_types; i++)
    if (equal_strings (element, plyfile->elems[i]->name))
      return (plyfile->elems[i]);

  return (NULL);
}


/******************************************************************************
Find a property in the list of properties of a given element.

Entry:
  elem      - pointer to element in which we want to find the property
  prop_name - name of property to find

Exit:
  index - index to position in list
  returns a pointer to the property, or NULL if not found
******************************************************************************/

PlyProperty *find_property(PlyElement *elem, char *prop_name, int *index)
{
  int i;

  for (i = 0; i < elem->nprops; i++)
    if (equal_strings (prop_name, elem->props[i]->name)) {
      *index = i;
      return (elem->props[i]);
    }

  *index = -1;
  return (NULL);
}


/******************************************************************************
Read an element from an ascii file.

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

void ascii_get_element(PlyFile *plyfile, char *elem_ptr)
{
  int i,j,k;
  PlyElement *elem;
  PlyProperty *prop;
  char **words;
  int nwords;
  int which_word;
  FILE *fp = plyfile->fp;
  char *elem_data,*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 *orig_line;
  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 the element */

  words = get_words (plyfile->fp, &nwords, &orig_line);
  if (words == NULL) {
    fprintf (stderr, "ply_get_element: unexpected end of file\n");
    exit (-1);
  }

  which_word = 0;