如何输出*.ply文件
所谓ply文件格式，是由斯坦福大学开发的一套三维mesh模型数据格式，图形学领域内很多著名的模型数据，比如斯坦福的三维扫描数据库（其中包括很多文章中会见到的Happy Buddha, Dragon, Bunny兔子）最初的模型都是基于这个格式的。其开发目标是，建立一套针对多边形模型的，结构简单但是能够满足大多数图形应用需要的模型格式，而且它允许以ASCII码格式或二进制形式存储文件。这样一套既简单又灵活的文件格式，能够帮助开发人员避免重复开发文件格式的问题。尽管在工业领域内，新的文件格式仍然在不断的出现，但是在图形学的研究领域中，PLY还是种常用且重要的文件格式。
ply数据文件格式中包含用来描述多边形的一系列点的信息：
<顶点列表>
<面片列表>
<其他元素列表>
头部是一系列以回车结尾的文本行，用来描述文件的剩余部分。头部包含一个对每个元素类型的描述，包括元素名（如“边”），这个元素在工程里有多少，以及一个与这个元素关联的不同属性的列表。头部还说明这个文件是二进制的或者是ASCII的。头部后面的是一个每个元素类型的元素列表，按照在头部中描述的顺序出现。
以下是一个立方体的完整ASCII描述。相同工程的二进制版本头部的唯一不同是用词“binary_little_endian”或者“binary_big_endian”替换词“ascii”。大括号中的注释不是文件的一部分，它们是这个例子的注解。文件中的注释一般在“comment”开始的关键词。
format ascii 1.0;
comment made by anonymous;
/*comment this is a cube*/
element vertex 8;
property float32 x ;
property float32 y ;
property float32 z ;
element face 6 ;
property list uint8 int32 vertex_index ;
end_header;
/*list vertex*/
0 0 0
0 0 1
0 1 1
0 1 0
1 0 0
1 0 1
1 1 1
1 1 0
/*list face*/
4 0 1 2 3
4 7 6 5 4
4 0 4 5 1
4 1 5 6 2
4 2 6 7 3
4 3 7 4 0 这个例子说明头部的基本组成。头部的每个部分都是以一个关键词开头以回车结尾的ASCII串。即使是头部的开始和结尾（“ply”和“end_header”）也是以这种形式。因为字符“ply”是文件的魔法数字，必须是文件的头四个字符。跟在文件头部开头之后的是关键词“format”和一个特定的ASCII或者二进制的格式，接下来是一个版本号。再下面是多边形文件中每个元素的描述，在每个元素里还有多属性的说明。一般元素以下面的格式描述：
element <元素名> <在文件中的个数>
property <数据类型> <属性名-1>
property <数据类型> <属性名-2>
property <数据类型> <属性名-3>
...
属性罗列在“element”（元素）行后面定义，既包含属性的数据类型也包含属性在每个元素中出现的次序。一个属性可以有三种数据类型：标量，字符串和列表。属性可能具有的标量数据类型列表如下：
int8 字符 1
uint8 非负字符 1
int16 短整型 2
uint16 非负短整型 2
int32 整型 4
uint32 非负整型 4
float32 单精度浮点数 4
float64 双精度浮点数 8
这些字节计数很重要，而且在实现过程中不能修改以使这些文件可移植。使用列表数据类型的属性定义有一种特殊的格式：
property list <数值类型> <数值类型> <属性名>
这种格式的一类例子是上面的立方体文件中的property list uint8 int32 vertex_index，这表示属性“vertex_index”首先包含一个非负字符报苏在属性里包含多少索引，接下来是一个列表包含许多整数。在这个边长列表里的每个整数都是一个顶点的索引。
以下是一个基于C++的读入ASCII文件或二进制文件，输出ply文件的程序。首先定义头文件ply.h
/*
Header for PLY polygon files.
- Greg Turk, March 1994
A PLY file contains a single polygonal _object_.
An object is composed of lists of _elements_. Typical elements are
vertices, faces, edges and materials.
Each type of element for a given object has one or more _properties_
associated with the element type. For instance, a vertex element may
have as properties three floating-point values x,y,z and three unsigned
chars for red, green and blue.
*/
#ifndef __PLY_H__
#define __PLY_H__
#ifdef __cplusplus
extern "C" {
#endif
#include
#include
#define PLY_ASCII 1 /* ascii PLY file */
#define PLY_BINARY_BE 2 /* binary PLY file, big endian */
#define PLY_BINARY_LE 3 /* binary PLY file, little endian */
#define PLY_OKAY 0 /* ply routine worked okay */
#define PLY_ERROR -1 /* error in ply routine */
/* scalar data types supported by PLY format */
#define PLY_START_TYPE 0
#define PLY_CHAR 1
#define PLY_SHORT 2
#define PLY_INT 3
#define PLY_UCHAR 4
#define PLY_USHORT 5
#define PLY_UINT 6
#define PLY_FLOAT 7
#define PLY_DOUBLE 8
#define PLY_END_TYPE 9
#define PLY_SCALAR 0
#define PLY_LIST 1
typedef struct PlyProperty { /* description of a property */
char *name; /* property name */
int external_type; /* file's data type */
int internal_type; /* program's data type */
int offset; /* offset bytes of prop in a struct */
int is_list; /* 1 = list, 0 = scalar */
int count_external; /* file's count type */
int count_internal; /* program's count type */
int count_offset; /* offset byte for list count */
} PlyProperty;
typedef struct PlyElement { /* description of an element */
char *name; /* element name */
int num; /* number of elements in this object */
int size; /* size of element (bytes) or -1 if variable */
int nprops; /* number of properties for this element */
PlyProperty **props; /* list of properties in the file */
char *store_prop; /* flags: property wanted by user? */
int other_offset; /* offset to un-asked-for props, or -1 if none*/
int other_size; /* size of other_props structure */
} PlyElement;
typedef struct PlyOtherProp { /* describes other properties in an element */
char *name; /* element name */
int size; /* size of other_props */
int nprops; /* number of properties in other_props */
PlyProperty **props; /* list of properties in other_props */
} PlyOtherProp;
typedef struct OtherData { /* for storing other_props for an other element */
void *other_props;
} OtherData;
typedef struct OtherElem { /* data for one "other" element */
char *elem_name; /* names of other elements */
int elem_count; /* count of instances of each element */
OtherData **other_data; /* actual property data for the elements */
PlyOtherProp *other_props; /* description of the property data */
} OtherElem;
typedef struct PlyOtherElems { /* "other" elements, not interpreted by user */
int num_elems; /* number of other elements */
OtherElem *other_list; /* list of data for other elements */
} PlyOtherElems;
typedef struct PlyFile { /* description of PLY file */
FILE *fp; /* file pointer */
int file_type; /* ascii or binary */
float version; /* version number of file */
int nelems; /* number of elements of object */
PlyElement **elems; /* list of elements */
int num_comments; /* number of comments */
char **comments; /* list of comments */
int num_obj_info; /* number of items of object information */
char **obj_info; /* list of object info items */
PlyElement *which_elem; /* which element we're currently writing */
PlyOtherElems *other_elems; /* "other" elements from a PLY file */
} PlyFile;
/* memory allocation */
extern char *my_alloc();
#define myalloc(mem_size) my_alloc((mem_size), __LINE__, __FILE__)
/*** delcaration of routines ***/
extern PlyFile *ply_write(FILE *, int, char **, int);
extern PlyFile *ply_open_for_writing(char *, int, char **, int, float *);
extern void ply_describe_element(PlyFile *, char *, int, int, PlyProperty *);
extern void ply_describe_property(PlyFile *, char *, PlyProperty *);
extern void ply_element_count(PlyFile *, char *, int);
extern void ply_header_complete(PlyFile *);
extern void ply_put_element_setup(PlyFile *, char *);
extern void ply_put_element(PlyFile *, void *);
extern void ply_put_comment(PlyFile *, char *);
extern void ply_put_obj_info(PlyFile *, char *);
extern PlyFile *ply_read(FILE *, int *, char ***);
extern PlyFile *ply_open_for_reading( char *, int *, char ***, int *, float *);
extern PlyProperty **ply_get_element_description(PlyFile *, char *, int*, int*);
extern void ply_get_element_setup( PlyFile *, char *, int, PlyProperty *);
extern void ply_get_property(PlyFile *, char *, PlyProperty *);
extern PlyOtherProp *ply_get_other_properties(PlyFile *, char *, int);
extern ply_get_element(PlyFile *, void *);
extern char **ply_get_comments(PlyFile *, int *);
extern char **ply_get_obj_info(PlyFile *, int *);
extern void ply_close(PlyFile *);
extern void ply_get_info(PlyFile *, float *, int *);
extern PlyOtherElems *ply_get_other_element (PlyFile *, char *, int);
extern void ply_describe_other_elements ( PlyFile *, PlyOtherElems *);
extern void ply_put_other_elements (PlyFile *);
extern void ply_free_other_elements (PlyOtherElems *);
#ifdef __cplusplus
}
#endif
#endif /* !__PLY_H__ */
Part 1 preparation
/*
The interface routines for reading and writing PLY polygon files.
Greg Turk, February 1994
---------------------------------------------------------------
A PLY file contains a single polygonal _object_.
An object is composed of lists of _elements_. Typical elements are
vertices, faces, edges and materials.
Each type of element for a given object has one or more _properties_
associated with the element type. For instance, a vertex element may
have as properties the floating-point values x,y,z and the three unsigned
chars representing red, green and blue.
*/
#include
#include
#include
#include
#include
#include
#include "ply.h"
#include
using namespace std;
char *type_names[] = {
"invalid",
"char", "short", "int",
"uchar", "ushort", "uint",
"float", "double",
};
int ply_type_size[] = {
0, 1, 2, 4, 1, 2, 4, 4, 8
};
#define NO_OTHER_PROPS -1
#define DONT_STORE_PROP 0
#define STORE_PROP 1
#define OTHER_PROP 0
#define NAMED_PROP 1
/* returns 1 if strings are equal, 0 if not */
/* find an element in a plyfile's list */
PlyElement *find_element(PlyFile *, char *);
/* find a property in an element's list */
PlyProperty *find_property(PlyElement *, char *, int *);
/* write to a file the word describing a PLY file data type */
void write_scalar_type (FILE *, int);
/* read a line from a file and break it up into separate words */
char **get_words(FILE *, int *, char **);
char **old_get_words(FILE *, int *);
/* write an item to a file */
void write_binary_item(FILE *, int, unsigned int, double, int);
void write_ascii_item(FILE *, int, unsigned int, double, int);
double old_write_ascii_item(FILE *, char *, int);
/* add information to a PLY file descriptor */
void add_element(PlyFile *, char **, int);
void add_property(PlyFile *, char **, int);
void add_comment(PlyFile *, char *);
void add_obj_info(PlyFile *, char *);
/* copy a property */
void copy_property(PlyProperty *, PlyProperty *);
/* store a value into where a pointer and a type specify */
void store_item(char *, int, int, unsigned int, double);
/* return the value of a stored item */
void get_stored_item( void *, int, int *, unsigned int *, double *);
/* return the value stored in an item, given ptr to it and its type */
double get_item_value(char *, int);
/* get binary or ascii item and store it according to ptr and type */
void get_ascii_item(char *, int, int *, unsigned int *, double *);
void get_binary_item(FILE *, int, int *, unsigned int *, double *);
/* get a bunch of elements from a file */
void ascii_get_element(PlyFile *, char *);
void binary_get_element(PlyFile *, char *);
/* memory allocation */
char *my_alloc(int, int, char *);
/*************/
/* Writing */
/*************/
/******************************************************************************
Given a file pointer, get ready to write PLY data to the file.
Entry:
fp - the given file pointer
nelems - number of elements in object
elem_names - list of element names
file_type - file type, either ascii or binary
Exit:
returns a pointer to a PlyFile, used to refer to this file, or NULL if error
******************************************************************************/
PlyFile *ply_write(
FILE *fp,
int nelems,
char **elem_names,
int file_type
)
{
int i;
PlyFile *plyfile;
PlyElement *elem;
/* check for NULL file pointer */
if (fp == NULL)
return (NULL);
/* create a record for this object */
plyfile = (PlyFile *) myalloc (sizeof (PlyFile));
plyfile->file_type = file_type;
plyfile->num_comments = 0;
plyfile->num_obj_info = 0;
plyfile->nelems = nelems;
plyfile->version = 1.0;
plyfile->fp = fp;
plyfile->other_elems = NULL;
/* tuck aside the names of the elements */
plyfile->elems = (PlyElement **) myalloc (sizeof (PlyElement *) * nelems);
for (i = 0; i < nelems; i++) {
elem = (PlyElement *) myalloc (sizeof (PlyElement));
plyfile->elems[i] = elem;
elem->name = strdup (elem_names[i]);
elem->num = 0;
elem->nprops = 0;
}
/* return pointer to the file descriptor */
return (plyfile);
}
/******************************************************************************
Open a polygon file for writing.
Entry:
filename - name of file to read from
nelems - number of elements in object
elem_names - list of element names
file_type - file type, either ascii or binary
Exit:
version - version number of PLY file
returns a file identifier, used to refer to this file, or NULL if error
******************************************************************************/
PlyFile *ply_open_for_writing(
char *filename,
int nelems,
char **elem_names,
int file_type,
float *version
)
{
int i;
PlyFile *plyfile;
PlyElement *elem;
char *name;
FILE *fp;
/* tack on the extension .ply, if necessary */
name = (char *) myalloc (sizeof (char) * (strlen (filename) + 5));
strcpy (name, filename);
if (strlen (name) < 4 ||
strcmp (name + strlen (name) - 4, ".ply") != 0)
strcat (name, ".ply");
/* open the file for writing */
fp = inFile (name, "w");
if (fp == NULL) {
return (NULL);
}
/* create the actual PlyFile structure */
plyfile = ply_write (fp, nelems, elem_names, file_type);
if (plyfile == NULL)
return (NULL);
/* say what PLY file version number we're writing */
*version = plyfile->version;
/* return pointer to the file descriptor */
return (plyfile);
}Part 2 description
/******************************************************************************
Describe an element, including its properties and how many will be written
to the file.
Entry:
plyfile - file identifier
elem_name - name of element that information is being specified about
nelems - number of elements of this type to be written
nprops - number of properties contained in the element
prop_list - list of properties
******************************************************************************/
void ply_describe_element(
PlyFile *plyfile,
char *elem_name,
int nelems,
int nprops,
PlyProperty *prop_list
)
{
int i;
PlyElement *elem;
PlyProperty *prop;
/* look for appropriate element */
elem = find_element (plyfile, elem_name);
if (elem == NULL) {
cerr << " ply_describe_element: can't find element" << elem_name << endl;
exit (-1);
}
elem->num = nelems;
/* copy the list of properties */
elem->nprops = nprops;
elem->props = (PlyProperty **) myalloc (sizeof (PlyProperty *) * nprops);
elem->store_prop = (char *) myalloc (sizeof (char) * nprops);
for (i = 0; i < nprops; i++) {
prop = (PlyProperty *) myalloc (sizeof (PlyProperty));
elem->props[i] = prop;
elem->store_prop[i] = NAMED_PROP;
copy_property (prop, &prop_list[i]);
}
}
/******************************************************************************
Describe a property of an element.
Entry:
plyfile - file identifier
elem_name - name of element that information is being specified about
prop - the new property
******************************************************************************/
void ply_describe_property(
PlyFile *plyfile,
char *elem_name,
PlyProperty *prop
)
{
PlyElement *elem;
PlyProperty *elem_prop;
/* look for appropriate element */
elem = find_element (plyfile, elem_name);
if (elem == NULL) {
cerr << " ply_describe_property: can't find element" << elem_name << endl;
return;
}
/* create room for new property */
if (elem->nprops == 0) {
elem->props = (PlyProperty **) myalloc (sizeof (PlyProperty *));
elem->store_prop = (char *) myalloc (sizeof (char));
elem->nprops = 1;
}
else {
elem->nprops++;
elem->props = (PlyProperty **)
realloc (elem->props, sizeof (PlyProperty *) * elem->nprops);
elem->store_prop = (char *)
realloc (elem->store_prop, sizeof (char) * elem->nprops);
}
/* copy the new property */
elem_prop = (PlyProperty *) myalloc (sizeof (PlyProperty));
elem->props[elem->nprops - 1] = elem_prop;
elem->store_prop[elem->nprops - 1] = NAMED_PROP;
copy_property (elem_prop, prop);
}
/******************************************************************************
Describe what the "other" properties are that are to be stored, and where
they are in an element.
******************************************************************************/
void ply_describe_other_properties(
PlyFile *plyfile,
PlyOtherProp *other,
int offset
)
{
int i;
PlyElement *elem;
PlyProperty *prop;
/* look for appropriate element */
elem = find_element (plyfile, other->name);
if (elem == NULL) {
cerr << " ply_describe_element: can't find element" << other->name << endl;
return;
}
/* create room for other properties */
if (elem->nprops == 0) {
elem->props = (PlyProperty **)
myalloc (sizeof (PlyProperty *) * other->nprops);
elem->store_prop = (char *) myalloc (sizeof (char) * other->nprops);
elem->nprops = 0;
}
else {
int newsize;
newsize = elem->nprops + other->nprops;
elem->props = (PlyProperty **)
realloc (elem->props, sizeof (PlyProperty *) * newsize);
elem->store_prop = (char *)
realloc (elem->store_prop, sizeof (char) * newsize);
}
/* copy the other properties */
for (i = 0; i < other->nprops; i++) {
prop = (PlyProperty *) myalloc (sizeof (PlyProperty));
copy_property (prop, other->props[i]);
elem->props[elem->nprops] = prop;
elem->store_prop[elem->nprops] = OTHER_PROP;
elem->nprops++;
}
/* save other info about other properties */
elem->other_size = other->size;
elem->other_offset = offset;
}
/******************************************************************************
State how many of a given element will be written.
Entry:
plyfile - file identifier
elem_name - name of element that information is being specified about
nelems - number of elements of this type to be written
******************************************************************************/
void ply_element_count(
PlyFile *plyfile,
char *elem_name,
int nelems
)
{
int i;
PlyElement *elem;
PlyProperty *prop;
/* look for appropriate element */
elem = find_element (plyfile, elem_name);
if (elem == NULL) {
cerr << " ply_elementcount: can't find element" << elem_name << endl;
exit (-1);
}
elem->num = nelems;
}
/******************************************************************************
Signal that we've described everything a PLY file's header and that the
header should be written to the file.
Entry:
plyfile - file identifier
******************************************************************************/
void ply_header_complete(PlyFile *plyfile)
{
int i,j;
FILE *fp = plyfile->fp;
PlyElement *elem;
PlyProperty *prop;
output << fp << "ply" << endl;
switch (plyfile->file_type) {
case PLY_ASCII:
output << fp << "format ascii 1.0" << endl;
break;
case PLY_BINARY_BE:
output << fp << "format binary_big_endian 1.0" << endl;
break;
case PLY_BINARY_LE:
output << fp << "format binary_little_endian 1.0" << endl;
break;
default:
cerr << "ply_header_complete: bad file type ="<< plyfile->file_type << endl;
exit (-1);
}
/* write out the comments */
for (i = 0; i < plyfile->num_comments; i++)
output << fp << "comment "<< plyfile->comments[i] << endl;
/* write out object information */
for (i = 0; i < plyfile->num_obj_info; i++)
output << fp << "obj_info" << plyfile->obj_info[i] << endl;
/* write out information about each element */
for (i = 0; i < plyfile->nelems; i++) {
elem = plyfile->elems[i];
output << fp << "element " << elem->name << elem->num << endl;
/* write out each property */
for (j = 0; j < elem->nprops; j++) {
prop = elem->props[j];
if (prop->is_list) {
output << fp << "property list ";
write_scalar_type (fp, prop->count_external);
output << fp << " ";
write_scalar_type (fp, prop->external_type);
output << fp << " " << prop->name << endl;
}
else {
write_scalar_type (fp, prop->external_type);
output << fp << " " << prop->name;
}
}
}
output << fp << "end header " << endl;
}
/******************************************************************************
Specify which elements are going to be written. This should be called
before a call to the routine ply_put_element().
Entry:
plyfile - file identifier
elem_name - name of element we're talking about
******************************************************************************/
void ply_put_element_setup(PlyFile *plyfile, char *elem_name)
{
PlyElement *elem;
elem = find_element (plyfile, elem_name);
if (elem == NULL) {
cerr << "ply_elements_setup: can't find element " << elem_name;
exit (-1);
}
plyfile->which_elem = elem;
}
Part 3 initialization
/******************************************************************************
Extract the comments from the header information of a PLY file.
Entry:
plyfile - file identifier
Exit:
num_comments - number of comments returned
returns a pointer to a list of comments
******************************************************************************/
char **ply_get_comments(PlyFile *plyfile, int *num_comments)
{
*num_comments = plyfile->num_comments;
return (plyfile->comments);
}
/******************************************************************************
Extract the object information (arbitrary text) from the header information
of a PLY file.
Entry:
plyfile - file identifier
Exit:
num_obj_info - number of lines of text information returned
returns a pointer to a list of object info lines
******************************************************************************/
char **ply_get_obj_info(PlyFile *plyfile, int *num_obj_info)
{
*num_obj_info = plyfile->num_obj_info;
return (plyfile->obj_info);
}
/******************************************************************************
Make ready for "other" properties of an element-- those properties that
the user has not explicitly asked for, but that are to be stashed away
in a special structure to be carried along with the element's other
information.
Entry:
plyfile - file identifier
elem - element for which we want to save away other properties
******************************************************************************/
void setup_other_props(PlyFile *plyfile, PlyElement *elem)
{
int i;
PlyProperty *prop;
int size = 0;
int type_size;
/* 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;
/* check list case */
if (prop->is_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];
}
}
/* not list */
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. 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
)
{
int i;
PlyElement *elem;
PlyOtherProp *other;
PlyProperty *prop;
int nprops;
/* find information about the element */
elem = find_element (plyfile, elem_name);
if (elem == NULL) {
cerr << "Warning: Can't find property in element " << elem_name;
return (NULL);
}
/* 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;
#if 1
/* set other_offset pointer appropriately if there are NO other properties */
if (other->nprops == 0) {
elem->other_offset = NO_OTHER_PROPS;
}
#endif
/* return structure */
return (other);
}/******************************************************************************
Given a file pointer, get ready to read PLY data from the file.
Entry:
fp - the given file pointer
Exit:
nelems - number of elements in object
elem_names - list of element names
returns a pointer to a PlyFile, used to refer to this file, or NULL if error
******************************************************************************/
PlyFile *ply_read(FILE *fp, int *nelems, char ***elem_names)
{
int i,j;
PlyFile *plyfile;
int nwords;
char **words;
int found_format = 0;
char **elist;
PlyElement *elem;
char *orig_line;
/* check for NULL file pointer */
if (fp == NULL)
return (NULL);
/* create record for this object */
plyfile = (PlyFile *) myalloc (sizeof (PlyFile));
plyfile->nelems = 0;
plyfile->comments = NULL;
plyfile->num_comments = 0;
plyfile->obj_info = NULL;
plyfile->num_obj_info = 0;
plyfile->fp = fp;
plyfile->other_elems = NULL;
/* read and parse the file's header */
words = get_words (plyfile->fp, &nwords, &orig_line);
if (!words || strcpy(words[0], "ply")<0)
return (NULL);
while (words) {
/* parse words */
if (nwords != 3)
return (NULL);
if (strcpy (words[1], "ascii")>0)
plyfile->file_type = PLY_ASCII;
else if (strcpy (words[1], "binary_big_endian")>0)
plyfile->file_type = PLY_BINARY_BE;
else if (strcpy (words[1], "binary_little_endian")>0)
plyfile->file_type = PLY_BINARY_LE;
else
return (NULL);
plyfile->version = atof (words[2]);
found_format = 1;
else if (strcpy (words[0], "element")>0)
add_element (plyfile, words, nwords);
else if (strcpy (words[0], "property")>0)
add_property (plyfile, words, nwords);
else if (strcpy (words[0], "comment")>0)
add_comment (plyfile, orig_line);
else if (strcpy (words[0], "obj_info")>0)
add_obj_info (plyfile, orig_line);
else if (strcpy (words[0], "end_header")>0)
break;
/* free up words space */
free (words);
words = get_words (plyfile->fp, &nwords, &orig_line);
}
/* create tags for each property of each element, to be used */
/* later to say whether or not to store each property for the user */
for (i = 0; i < plyfile->nelems; i++) {
elem = plyfile->elems[i];
elem->store_prop = (char *) myalloc (sizeof (char) * elem->nprops);
for (j = 0; j < elem->nprops; j++)
elem->store_prop[j] = DONT_STORE_PROP;
elem->other_offset = NO_OTHER_PROPS; /* no "other" props by default */
}
/* set return values about the elements */
elist = (char **) myalloc (sizeof (char *) * plyfile->nelems);
for (i = 0; i < plyfile->nelems; i++)
elist[i] = strdup (plyfile->elems[i]->name);
*elem_names = elist;
*nelems = plyfile->nelems;
/* return a pointer to the file's information */
return (plyfile);
}
/******************************************************************************
Open a polygon file for reading.
Entry:
filename - name of file to read from
Exit:
nelems - number of elements in object
elem_names - list of element names
file_type - file type, either ascii or binary
version - version number of PLY file
returns a file identifier, used to refer to this file, or NULL if error
******************************************************************************/
PlyFile *ply_open_for_reading(
char *filename,
int *nelems,
char ***elem_names,
int *file_type,
float *version
)
{
FILE *fp;
PlyFile *plyfile;
char *name;
/* tack on the extension .ply, if necessary */
name = (char *) myalloc (sizeof (char) * (strlen (filename) + 5));
strcpy (name, filename);
if (strlen (name) < 4 ||
strcmp (name + strlen (name) - 4, ".ply") != 0)
strcat (name, ".ply");
/* open the file for reading */
fp = inFile (name, "r");
if (fp == NULL)
return (NULL);
/* create the PlyFile data structure */
plyfile = ply_read (fp, nelems, elem_names);
/* determine the file type and version */
*file_type = plyfile->file_type;
*version = plyfile->version;
/* return a pointer to the file's information */
return (plyfile);
}
/******************************************************************************
Get information about a particular element.
Entry:
plyfile - file identifier
elem_name - name of element to get information about
Exit:
nelems - number of elements of this type in the file
nprops - number of properties
returns a list of properties, or NULL if the file doesn't contain that elem
******************************************************************************/
PlyProperty **ply_get_element_description(
PlyFile *plyfile,
char *elem_name,
int *nelems,
int *nprops
)
{
int i;
PlyElement *elem;
PlyProperty *prop;
PlyProperty **prop_list;
/* find information about the element */
elem = find_element (plyfile, elem_name);
if (elem == NULL)
return (NULL);
*nelems = elem->num;
*nprops = elem->nprops;
/* make a copy of the element's property list */
prop_list = (PlyProperty **) myalloc (sizeof (PlyProperty *) * elem->nprops);
for (i = 0; i < elem->nprops; i++) {
prop = (PlyProperty *) myalloc (sizeof (PlyProperty));
copy_property (prop, elem->props[i]);
prop_list[i] = prop;
}
/* return this duplicate property list */
return (prop_list);
}
/******************************************************************************
Specify which properties of an element are to be returned. This should be
called before a call to the routine ply_get_element().
Entry:
plyfile - file identifier
elem_name - which element we're talking about
nprops - number of properties
prop_list - list of properties
******************************************************************************/
void ply_get_element_setup(
PlyFile *plyfile,
char *elem_name,
int nprops,
PlyProperty *prop_list
)
{
int i;
PlyElement *elem;
PlyProperty *prop;
int index;
/* find information about the element */
elem = find_element (plyfile, elem_name);
plyfile->which_elem = elem;
/* deposit the property information into the element's description */
for (i = 0; i < nprops; i++) {
/* look for actual property */
prop = find_property (elem, prop_list[i].name, &index);
if (prop == NULL) {
cerr << "Warning: Can't find property " << prop_list[i].name <<" in element "offset = prop_list[i].offset;
prop->count_internal = prop_list[i].count_internal;
prop->count_offset = prop_list[i].count_offset;
/* specify that the user wants this property */
elem->store_prop[index] = STORE_PROP;
}
}
/******************************************************************************
Specify a property of an element that is to be returned. This should be
called (usually multiple times) before a call to the routine ply_get_element().
This routine should be used in preference to the less flexible old routine
called ply_get_element_setup().
Entry:
plyfile - file identifier
elem_name - which element we're talking about
prop - property to add to those that will be returned
******************************************************************************/
void ply_get_property(
PlyFile *plyfile,
char *elem_name,
PlyProperty *prop
)
{
PlyElement *elem;
PlyProperty *prop_ptr;
int index;
/* find information about the element */
elem = find_element (plyfile, elem_name);
plyfile->which_elem = elem;
/* deposit the property information into the element's description */
prop_ptr = find_property (elem, prop->name, &index);
if (prop_ptr == NULL) {
cerr << "Warning: Can't find property " << prop_list[i].name << " in element " << elem_name;
return;
}
prop_ptr->internal_type = prop->internal_type;
prop_ptr->offset = prop->offset;
prop_ptr->count_internal = prop->count_internal;
prop_ptr->count_offset = prop->count_offset;
/* specify that the user wants this property */
elem->store_prop[index] = STORE_PROP;
}
/******************************************************************************
Read one element from the file. This routine assumes that we're reading
the type of element specified in the last call to the routine
ply_get_element_setup().
Entry:
plyfile - file identifier
elem_ptr - pointer to location where the element information should be put
******************************************************************************/
ply_get_element(PlyFile *plyfile, void *elem_ptr)
{
if (plyfile->file_type == PLY_ASCII)
ascii_get_element (plyfile, (char *) elem_ptr);
else
binary_get_element (plyfile, (char *) elem_ptr);
} Part 5 addition
/******************************************************************************
Add an element to a PLY file descriptor.
Entry:
plyfile - PLY file descriptor
words - list of words describing the element
nwords - number of words in the list
******************************************************************************/
void add_element (PlyFile *plyfile, char **words, int nwords)
{
PlyElement *elem;
/* create the new element */
elem = (PlyElement *) myalloc (sizeof (PlyElement));
elem->name = strdup (words[1]);
elem->num = atoi (words[2]);
elem->nprops = 0;
/* make room for new element in the object's list of elements */
if (plyfile->nelems == 0)
plyfile->elems = (PlyElement **) myalloc (sizeof (PlyElement *));
else
plyfile->elems = (PlyElement **) realloc (plyfile->elems,
sizeof (PlyElement *) * (plyfile->nelems + 1));
/* add the new element to the object's list */
plyfile->elems[plyfile->nelems] = elem;
plyfile->nelems++;
}
/******************************************************************************
Return the type of a property, given the name of the property.
Entry:
name - name of property type
Exit:
returns integer code for property, or 0 if not found
******************************************************************************/
int get_prop_type(char *type_name)
{
int i;
for (i = PLY_START_TYPE + 1; i < PLY_END_TYPE; i++)
if (strcpy(type_name, type_names[i])>0)
return (i);
/* if we get here, we didn't find the type */
return (0);
}
/******************************************************************************
Add a property to a PLY file descriptor.
Entry:
plyfile - PLY file descriptor
words - list of words describing the property
nwords - number of words in the list
******************************************************************************/
void add_property (PlyFile *plyfile, char **words, int nwords)
{
int prop_type;
int count_type;
PlyProperty *prop;
PlyElement *elem;
/* create the new property */
prop = (PlyProperty *) myalloc (sizeof (PlyProperty));
if (strcpy(words[1], "list")>0) { /* is a list */
prop->count_external = get_prop_type (words[2]);
prop->external_type = get_prop_type (words[3]);
prop->name = strdup (words[4]);
prop->is_list = 1;
}
else { /* not a list */
prop->external_type = get_prop_type (words[1]);
prop->name = strdup (words[2]);
prop->is_list = 0;
}
/* add this property to the list of properties of the current element */
elem = plyfile->elems[plyfile->nelems - 1];
if (elem->nprops == 0)
elem->props = (PlyProperty **) myalloc (sizeof (PlyProperty *));
else
elem->props = (PlyProperty **) realloc (elem->props,
sizeof (PlyProperty *) * (elem->nprops + 1));
elem->props[elem->nprops] = prop;
elem->nprops++;
}
/******************************************************************************
Add a comment to a PLY file descriptor.
Entry:
plyfile - PLY file descriptor
line - line containing comment
******************************************************************************/
void add_comment (PlyFile *plyfile, char *line)
{
int i;
/* skip over "comment" and leading spaces and tabs */
i = 7;
while (line[i] == ' ' || line[i] == '\t')
i++;
ply_put_comment (plyfile, &line[i]);
}
/******************************************************************************
Add a some object information to a PLY file descriptor.
Entry:
plyfile - PLY file descriptor
line - line containing text info
******************************************************************************/
void add_obj_info (PlyFile *plyfile, char *line)
{
int i;
/* skip over "obj_info" and leading spaces and tabs */
i = 8;
while (line[i] == ' ' || line[i] == '\t')
i++;
ply_put_obj_info (plyfile, &line[i]);
}
/******************************************************************************
Copy a property.
******************************************************************************/
void copy_property(PlyProperty *dest, PlyProperty *src)
{
dest->name = strdup (src->name);
dest->external_type = src->external_type;
dest->internal_type = src->internal_type;
dest->offset = src->offset;
dest->is_list = src->is_list;
dest->count_external = src->count_external;
dest->count_internal = src->count_internal;
dest->count_offset = src->count_offset;
}
/******************************************************************************
Allocate some memory.
Entry:
size - amount of memory requested (in bytes)
lnum - line number from which memory was requested
fname - file name from which memory was requested
******************************************************************************/
static char *my_alloc(int size, int lnum, char *fname)
{
char *ptr;
ptr = (char *) malloc (size);
if (ptr == 0) {
cerr << "Memory allocation bombed on line " << lnum << "in" << fname ;
}
return (ptr);
}
Part 6 transformation
Part 7 executive
Part 8 about ascii
Part 9 about bin
Part 10 about item
Part 11 store
Part 12 writing
Part 13 close
/******************************************************************************
Grab all the data for an element that a user does not want to explicitly
read in.
Entry:
plyfile - pointer to file
elem_name - name of element whose data is to be read in
elem_count - number of instances of this element stored in the file
Exit:
returns pointer to ALL the "other" element data for this PLY file
******************************************************************************/
PlyOtherElems *ply_get_other_element (
PlyFile *plyfile,
char *elem_name,
int elem_count
)
{
int i;
PlyElement *elem;
PlyOtherElems *other_elems;
OtherElem *other;
int num_elems;
/* look for appropriate element */
elem = find_element (plyfile, elem_name);
if (elem == NULL) {
cerr << "Warning: Can't find property in element " << elem_name;
exit (-1);
}
/* 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);
}
/******************************************************************************
Pass along a pointer to "other" elements that we want to save in a given
PLY file. These other elements were presumably read from another PLY file.
Entry:
plyfile - file pointer in which to store this other element info
other_elems - info about other elements that we want to store
******************************************************************************/
void ply_describe_other_elements (
PlyFile *plyfile,
PlyOtherElems *other_elems
)
{
int i;
OtherElem *other;
/* ignore this call if there is no other element */
if (other_elems == NULL)
return;
/* save pointer to this information */
plyfile->other_elems = other_elems;
/* describe the other properties of this element */
for (i = 0; i < other_elems->num_elems; i++) {
other = &(other_elems->other_list[i]);
ply_element_count (plyfile, other->elem_name, other->elem_count);
ply_describe_other_properties (plyfile, other->other_props,
offsetof(OtherData,other_props));
}
}
/******************************************************************************
Write out the "other" elements specified for this PLY file.
Entry:
plyfile - pointer to PLY file to write out other elements for
******************************************************************************/
void ply_put_other_elements (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]);
ply_put_element_setup (plyfile, other->elem_name);
/* write out each instance of the current element */
for (j = 0; j < other->elem_count; j++)
ply_put_element (plyfile, (void *) other->other_data[j]);
}
}Part 7 executive
/*
Sample code showing how to read and write PLY polygon files.
Greg Turk, March 1994
*/
/* user's vertex and face definitions for a polygonal object */
typedef struct Vertex {
float x,y,z; /* the usual 3-space position of a vertex */
} Vertex;
typedef struct Face {
unsigned char intensity; /* this user attaches intensity to faces */
unsigned char nverts; /* number of vertex indices in list */
int *verts; /* vertex index list */
} Face;
/* polygon description of an object (a cube) */
Vertex verts[] = { /* vertices */
{ 0.0, 0.0, 0.0},
{ 1.0, 0.0, 0.0},
{ 1.0, 1.0, 0.0},
{ 0.0, 1.0, 0.0},
{ 0.0, 0.0, 1.0},
{ 1.0, 0.0, 1.0},
{ 1.0, 1.0, 1.0},
{ 0.0, 1.0, 1.0},
};
Face faces[] = { /* faces */
{ '\001', 4, NULL }, /* intensity, vertex list count, vertex list (empty) */
{ '\004', 4, NULL },
{ '\010', 4, NULL },
{ '\020', 4, NULL },
{ '\144', 4, NULL },
{ '\377', 4, NULL },
};
/* list of vertices for each face */
/* (notice that indices begin at zero) */
typedef int Vertex_Indices[4];
Vertex_Indices vert_ptrs[] = {
{ 0, 1, 2, 3 },
{ 7, 6, 5, 4 },
{ 0, 4, 5, 1 },
{ 1, 5, 6, 2 },
{ 2, 6, 7, 3 },
{ 3, 7, 4, 0 },
};
/* information needed to describe the user's data to the PLY routines */
char *elem_names[] = { /* list of the kinds of elements in the user's object */
"vertex", "face"
};
PlyProperty vert_props[] = { /* list of property information for a vertex */
{"x", PLY_FLOAT, PLY_FLOAT, offsetof(Vertex,x), 0, 0, 0, 0},
{"y", PLY_FLOAT, PLY_FLOAT, offsetof(Vertex,y), 0, 0, 0, 0},
{"z", PLY_FLOAT, PLY_FLOAT, offsetof(Vertex,z), 0, 0, 0, 0},
};
PlyProperty face_props[] = { /* list of property information for a vertex */
{"intensity", PLY_UCHAR, PLY_UCHAR, offsetof(Face,intensity), 0, 0, 0, 0},
{"vertex_indices", PLY_INT, PLY_INT, offsetof(Face,verts),
1, PLY_UCHAR, PLY_UCHAR, offsetof(Face,nverts)},
};
write_test();
read_test();
/******************************************************************************
The main routine just creates and then reads a PLY file.
******************************************************************************/
main()
{
#if 1
/* write a PLY file */
write_test();
#endif
#if 1
/* read a PLY file */
read_test();
#endif
}
/******************************************************************************
Write out a PLY file.
******************************************************************************/
write_test()
{
int i,j;
PlyFile *ply;
int nelems;
char **elist;
int file_type;
float version;
int nverts = sizeof (verts) / sizeof (Vertex);
int nfaces = sizeof (faces) / sizeof (Face);
/* create the vertex index lists for the faces */
for (i = 0; i < nfaces; i++)
faces[i].verts = vert_ptrs[i];
/* open either a binary or ascii PLY file for writing */
/* (the file will be called "test.ply" because the routines */
/* enforce the .ply filename extension) */
#if 1
ply = ply_open_for_writing("test", 2, elem_names, PLY_ASCII, &version);
#else
ply = ply_open_for_writing("test", 2, elem_names, PLY_BINARY_BE, &version);
#endif
/* describe what properties go into the vertex and face elements */
ply_element_count (ply, "vertex", nverts);
ply_describe_property (ply, "vertex", &vert_props[0]);
ply_describe_property (ply, "vertex", &vert_props[1]);
ply_describe_property (ply, "vertex", &vert_props[2]);
ply_element_count (ply, "face", nfaces);
ply_describe_property (ply, "face", &face_props[0]);
ply_describe_property (ply, "face", &face_props[1]);
/* write a comment and an object information field */
ply_put_comment (ply, "author: Greg Turk");
ply_put_obj_info (ply, "random information");
/* we have described exactly what we will put in the file, so */
/* we are now done with the header info */
ply_header_complete (ply);
/* set up and write the vertex elements */
ply_put_element_setup (ply, "vertex");
for (i = 0; i < nverts; i++)
ply_put_element (ply, (void *) &verts[i]);
/* set up and write the face elements */
ply_put_element_setup (ply, "face");
for (i = 0; i < nfaces; i++)
ply_put_element (ply, (void *) &faces[i]);
/* close the PLY file */
ply_close (ply);
}
/******************************************************************************
Read in a PLY file.
******************************************************************************/
read_test()
{
int i,j,k;
PlyFile *ply;
int nelems;
char **elist;
int file_type;
float version;
int nprops;
int num_elems;
PlyProperty **plist;
Vertex **vlist;
Face **flist;
char *elem_name;
int num_comments;
char **comments;
int num_obj_info;
char **obj_info;
/* open a PLY file for reading */
ply = ply_open_for_reading("test", &nelems, &elist, &file_type, &version);
/* print what we found out about the file */
cout << "version " << version << endl;
cout << "type " << file_type << endl;
/* go through each kind of element that we learned is in the file */
/* and read them */
for (i = 0; i < nelems; i++) {
/* get the description of the first element */
elem_name = elist[i];
plist = ply_get_element_description (ply, elem_name, &num_elems, &nprops);
/* print the name of the element, for debugging */
cout << "element " << elem_name << num_elems << endl;
/* if we're on vertex elements, read them in */
if (strcpy("vertex", elem_name)>0) {
/* create a vertex list to hold all the vertices */
vlist = (Vertex **) malloc (sizeof (Vertex *) * num_elems);
/* set up for getting vertex elements */
ply_get_property (ply, elem_name, &vert_props[0]);
ply_get_property (ply, elem_name, &vert_props[1]);
ply_get_property (ply, elem_name, &vert_props[2]);
/* grab all the vertex elements */
for (j = 0; j < num_elems; j++) {
/* grab and element from the file */
vlist[j] = (Vertex *) malloc (sizeof (Vertex));
ply_get_element (ply, (void *) vlist[j]);
/* print out vertex x,y,z for debugging */
cout << "vertex" << vlist[j]->x << "," << vlist[j]->y <<"," << vlist[j]->z << endl;
}
}
/* if we're on face elements, read them in */
if (strcpy("face", elem_name)>0) {
/* create a list to hold all the face elements */
flist = (Face **) malloc (sizeof (Face *) * num_elems);
/* set up for getting face elements */
ply_get_property (ply, elem_name, &face_props[0]);
ply_get_property (ply, elem_name, &face_props[1]);
/* grab all the face elements */
for (j = 0; j < num_elems; j++) {
/* grab and element from the file */
flist[j] = (Face *) malloc (sizeof (Face));
ply_get_element (ply, (void *) flist[j]);
/* print out face info, for debugging */
cout << "facelist = " << flist[j]->intensity;
for (k = 0; k < flist[j]->nverts; k++)
cout << flist[j]->verts[k] << " ";
}
}
/* print out the properties we got, for debugging */
for (j = 0; j < nprops; j++)
cout << "property " << plist[j]->name << endl;
}
/* grab and print out the comments in the file */
comments = ply_get_comments (ply, &num_comments);
for (i = 0; i < num_comments; i++)
cout << "comment = " << comments[i];
/* grab and print out the object information */
obj_info = ply_get_obj_info (ply, &num_obj_info);
for (i = 0; i < num_obj_info; i++)
cout << "obj_info = " << obj_info[i];
/* close the PLY file */
ply_close (ply);
}
Part 8 about ascii
/******************************************************************************
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) {
output 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) { /* 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 { /* not a list */
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);
}
/******************************************************************************
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) {
case PLY_CHAR:
case PLY_SHORT:
case PLY_INT:
fprintf (fp, "%d ", int_val);
break;
case PLY_UCHAR:
case PLY_USHORT:
case PLY_UINT:
fprintf (fp, "%u ", uint_val);
break;
case PLY_FLOAT:
case PLY_DOUBLE:
fprintf (fp, "%g ", double_val);
break;
default:
fprintf (stderr, "write_ascii_item: bad type = %d\n", type);
exit (-1);
}
}
/******************************************************************************
Write out an item to a file as ascii characters.
Entry:
fp - file to write to
item - pointer to item to write
type - data type that "item" points to
Exit:
returns a double-precision float that contains the value of the written item
******************************************************************************/
double old_write_ascii_item(FILE *fp, 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 PLY_CHAR:
pchar = (char *) item;
int_value = *pchar;
output << fp << " " << int_value << endl;
return ((double) int_value);
case PLY_UCHAR:
puchar = (unsigned char *) item;
int_value = *puchar;
output << fp << " " << int_value << endl;
return ((double) int_value);
case PLY_SHORT:
pshort = (short int *) item;
int_value = *pshort;
output << fp << " " << int_value << endl;
return ((double) int_value);
case PLY_USHORT:
pushort = (unsigned short int *) item;
int_value = *pushort;
output << fp << " " << int_value << endl;
return ((double) int_value);
case PLY_INT:
pint = (int *) item;
int_value = *pint;
output << fp << " " << int_value << endl;
return ((double) int_value);
case PLY_UINT:
puint = (unsigned int *) item;
uint_value = *puint;
output << fp << " " << int_value << endl;
return ((double) uint_value);
case PLY_FLOAT:
pfloat = (float *) item;
double_value = *pfloat;
output << fp << " " << int_value << endl;
return (double_value);
case PLY_DOUBLE:
pdouble = (double *) item;
double_value = *pdouble;
output << fp << " " << int_value << endl;
return (double_value);
default:
output << "old_write_ascii_item: bad type = " << type;
exit (-1);
}
}
/******************************************************************************
Get the value of an item that is in memory, and place the result
into an integer, an unsigned integer and a double.
Entry:
ptr - pointer to the item
type - data type supposedly in the item
Exit:
int_val - integer value
uint_val - unsigned integer value
double_val - double-precision floating point value
******************************************************************************/
void get_stored_item(
void *ptr,
int type,
int *int_val,
unsigned int *uint_val,
double *double_val
)
{
switch (type) {
case PLY_CHAR:
*int_val = *((char *) ptr);
*uint_val = *int_val;
*double_val = *int_val;
break;
case PLY_UCHAR:
*uint_val = *((unsigned char *) ptr);
*int_val = *uint_val;
*double_val = *uint_val;
break;
case PLY_SHORT:
*int_val = *((short int *) ptr);
*uint_val = *int_val;
*double_val = *int_val;
break;
case PLY_USHORT:
*uint_val = *((unsigned short int *) ptr);
*int_val = *uint_val;
*double_val = *uint_val;
break;
case PLY_INT:
*int_val = *((int *) ptr);
*uint_val = *int_val;
*double_val = *int_val;
break;
case PLY_UINT:
*uint_val = *((unsigned int *) ptr);
*int_val = *uint_val;
*double_val = *uint_val;
break;
case PLY_FLOAT:
*double_val = *((float *) ptr);
*int_val = *double_val;
*uint_val = *double_val;
break;
case PLY_DOUBLE:
*double_val = *((double *) ptr);
*int_val = *double_val;
*uint_val = *double_val;
break;
default:
cerr << "get_stored_item: bad type = " << type;
exit (-1);
}
} Part 9 about bin
/******************************************************************************
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,*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) { /* a 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;
/* The "if" was added by Afra Zomorodian 8/22/95
* so that zipper won't crash reading plies that have additional
* properties.
*/
if (store_it) {
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 { /* not a list */
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 <= PLY_START_TYPE || code >= PLY_END_TYPE) {
output << "write_scalar_type: bad data code = " << code;
exit (-1);
}
/* write the code to a file */
output <= max_words) {
max_words += 10;
words = (char **) realloc (words, sizeof (char *) * max_words);
}
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 PLY_CHAR:
pchar = (char *) item;
int_value = *pchar;
return ((double) int_value);
case PLY_UCHAR:
puchar = (unsigned char *) item;
int_value = *puchar;
return ((double) int_value);
case PLY_SHORT:
pshort = (short int *) item;
int_value = *pshort;
return ((double) int_value);
case PLY_USHORT:
pushort = (unsigned short int *) item;
int_value = *pushort;
return ((double) int_value);
case PLY_INT:
pint = (int *) item;
int_value = *pint;
return ((double) int_value);
case PLY_UINT:
puint = (unsigned int *) item;
uint_value = *puint;
return ((double) uint_value);
case PLY_FLOAT:
pfloat = (float *) item;
double_value = *pfloat;
return (double_value);
case PLY_DOUBLE:
pdouble = (double *) item;
double_value = *pdouble;
return (double_value);
default:
cerr << "get_item_value: bad type = " << type;
exit (-1);
}
}Part 10 about item
/******************************************************************************
Get the value of an item from a binary file, and place the result
into an integer, an unsigned integer and a double.
Entry:
fp - file to get item from
type - data type supposedly in the word
Exit:
int_val - integer value
uint_val - unsigned integer value
double_val - double-precision floating point value
******************************************************************************/
void get_binary_item(
FILE *fp,
int type,
int *int_val,
unsigned int *uint_val,
double *double_val
)
{
char c[8];
void *ptr;
ptr = (void *) c;
switch (type) {
case PLY_CHAR:
fread (ptr, 1, 1, fp);
*int_val = *((char *) ptr);
*uint_val = *int_val;
*double_val = *int_val;
break;
case PLY_UCHAR:
fread (ptr, 1, 1, fp);
*uint_val = *((unsigned char *) ptr);
*int_val = *uint_val;
*double_val = *uint_val;
break;
case PLY_SHORT:
fread (ptr, 2, 1, fp);
*int_val = *((short int *) ptr);
*uint_val = *int_val;
*double_val = *int_val;
break;
case PLY_USHORT:
fread (ptr, 2, 1, fp);
*uint_val = *((unsigned short int *) ptr);
*int_val = *uint_val;
*double_val = *uint_val;
break;
case PLY_INT:
fread (ptr, 4, 1, fp);
*int_val = *((int *) ptr);
*uint_val = *int_val;
*double_val = *int_val;
break;
case PLY_UINT:
fread (ptr, 4, 1, fp);
*uint_val = *((unsigned int *) ptr);
*int_val = *uint_val;
*double_val = *uint_val;
break;
case PLY_FLOAT:
fread (ptr, 4, 1, fp);
*double_val = *((float *) ptr);
*int_val = *double_val;
*uint_val = *double_val;
break;
case PLY_DOUBLE:
fread (ptr, 8, 1, fp);
*double_val = *((double *) ptr);
*int_val = *double_val;
*uint_val = *double_val;
break;
default:
cerr << "get_binary_item: bad type = " << type;
exit (-1);
}
}
/******************************************************************************
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 PLY_CHAR:
char_val = int_val;
fwrite (&char_val, 1, 1, fp);
break;
case PLY_SHORT:
short_val = int_val;
fwrite (&short_val, 2, 1, fp);
break;
case PLY_INT:
fwrite (&int_val, 4, 1, fp);
break;
case PLY_UCHAR:
uchar_val = uint_val;
fwrite (&uchar_val, 1, 1, fp);
break;
case PLY_USHORT:
ushort_val = uint_val;
fwrite (&ushort_val, 2, 1, fp);
break;
case PLY_UINT:
fwrite (&uint_val, 4, 1, fp);
break;
case PLY_FLOAT:
float_val = double_val;
fwrite (&float_val, 4, 1, fp);
break;
case PLY_DOUBLE:
fwrite (&double_val, 8, 1, fp);
break;
default:
cerr << "write_binary_item: bad type = " << type ;
exit (-1);
}
}Part 11 store
/******************************************************************************
Extract the value of an item from an ascii word, and place the result
into an integer, an unsigned integer and a double.
Entry:
word - word to extract value from
type - data type supposedly in the word
Exit:
int_val - integer value
uint_val - unsigned integer value
double_val - double-precision floating point value
******************************************************************************/
void get_ascii_item(
char *word,
int type,
int *int_val,
unsigned int *uint_val,
double *double_val
)
{
switch (type) {
case PLY_CHAR:
case PLY_UCHAR:
case PLY_SHORT:
case PLY_USHORT:
case PLY_INT:
*int_val = atoi (word);
*uint_val = *int_val;
*double_val = *int_val;
break;
case PLY_UINT:
*uint_val = strtoul (word, (char **) NULL, 10);
*int_val = *uint_val;
*double_val = *uint_val;
break;
case PLY_FLOAT:
case PLY_DOUBLE:
*double_val = atof (word);
*int_val = (int) *double_val;
*uint_val = (unsigned int) *double_val;
break;
default:
cerr << "get_ascii_item: bad type = " << type;
exit(-1);
}
}
/******************************************************************************
Store a value into a place being pointed to, guided by a data type.
Entry:
item - place to store value
type - data type
int_val - integer version of value
uint_val - unsigned integer version of value
double_val - double version of value
Exit:
item - pointer to stored value
******************************************************************************/
void store_item (
char *item,
int type,
int int_val,
unsigned int uint_val,
double double_val
)
{
unsigned char *puchar;
short int *pshort;
unsigned short int *pushort;
int *pint;
unsigned int *puint;
float *pfloat;
double *pdouble;
switch (type) {
case PLY_CHAR:
*item = int_val;
break;
case PLY_UCHAR:
puchar = (unsigned char *) item;
*puchar = uint_val;
break;
case PLY_SHORT:
pshort = (short *) item;
*pshort = int_val;
break;
case PLY_USHORT:
pushort = (unsigned short *) item;
*pushort = uint_val;
break;
case PLY_INT:
pint = (int *) item;
*pint = int_val;
break;
case PLY_UINT:
puint = (unsigned int *) item;
*puint = uint_val;
break;
case PLY_FLOAT:
pfloat = (float *) item;
*pfloat = double_val;
break;
case PLY_DOUBLE:
pdouble = (double *) item;
*pdouble = double_val;
break;
default:
cerr << "get_store_item: bad type = " << type;
exit(-1);
}
}Part 12 writing
/******************************************************************************
Write an element to the file. This routine assumes that we're
writing the type of element specified in the last call to the routine
ply_put_element_setup().
Entry:
plyfile - file identifier
elem_ptr - pointer to the element
******************************************************************************/
void ply_put_element(PlyFile *plyfile, void *elem_ptr)
{
int i,j,k;
FILE *fp = plyfile->fp;
PlyElement *elem;
PlyProperty *prop;
char *elem_data,*item;
char **item_ptr;
int list_count;
int item_size;
int int_val;
unsigned int uint_val;
double double_val;
char **other_ptr;
elem = plyfile->which_elem;
elem_data = (char*)elem_ptr;
other_ptr = (char **) (((char *) elem_ptr) + elem->other_offset);
/* write out either to an ascii or binary file */
if (plyfile->file_type == PLY_ASCII) {
/* write an ascii file */
/* write out each property of the element */
for (j = 0; j < elem->nprops; j++) {
prop = elem->props[j];
if (elem->store_prop[j] == OTHER_PROP)
elem_data = *other_ptr;
else
elem_data = (char*)elem_ptr;
if (prop->is_list) {
item = elem_data + prop->count_offset;
get_stored_item ((void *) item, prop->count_internal,
&int_val, &uint_val, &double_val);
write_ascii_item (fp, int_val, uint_val, double_val,
prop->count_external);
list_count = uint_val;
item_ptr = (char **) (elem_data + prop->offset);
item = item_ptr[0];
item_size = ply_type_size[prop->internal_type];
for (k = 0; k < list_count; k++) {
get_stored_item ((void *) item, prop->internal_type,
&int_val, &uint_val, &double_val);
write_ascii_item (fp, int_val, uint_val, double_val,
prop->external_type);
item += item_size;
}
}
else {
item = elem_data + prop->offset;
get_stored_item ((void *) item, prop->internal_type,
&int_val, &uint_val, &double_val);
write_ascii_item (fp, int_val, uint_val, double_val,
prop->external_type);
}
}
output << endl;
}
else {
/* write a binary file */
/* write out each property of the element */
for (j = 0; j < elem->nprops; j++) {
prop = elem->props[j];
if (elem->store_prop[j] == OTHER_PROP)
elem_data = *other_ptr;
else
elem_data = (char*)elem_ptr;
if (prop->is_list) {
item = elem_data + prop->count_offset;
item_size = ply_type_size[prop->count_internal];
get_stored_item ((void *) item, prop->count_internal,
&int_val, &uint_val, &double_val);
write_binary_item (fp, int_val, uint_val, double_val,
prop->count_external);
list_count = uint_val;
item_ptr = (char **) (elem_data + prop->offset);
item = item_ptr[0];
item_size = ply_type_size[prop->internal_type];
for (k = 0; k < list_count; k++) {
get_stored_item ((void *) item, prop->internal_type,
&int_val, &uint_val, &double_val);
write_binary_item (fp, int_val, uint_val, double_val,
prop->external_type);
item += item_size;
}
}
else {
item = elem_data + prop->offset;
item_size = ply_type_size[prop->internal_type];
get_stored_item ((void *) item, prop->internal_type,
&int_val, &uint_val, &double_val);
write_binary_item (fp, int_val, uint_val, double_val,
prop->external_type);
}
}
}
}
/******************************************************************************
Specify a comment that will be written in the header.
Entry:
plyfile - file identifier
comment - the comment to be written
******************************************************************************/
void ply_put_comment(PlyFile *plyfile, char *comment)
{
/* (re)allocate space for new comment */
if (plyfile->num_comments == 0)
plyfile->comments = (char **) myalloc (sizeof (char *));
else
plyfile->comments = (char **) realloc (plyfile->comments,
sizeof (char *) * (plyfile->num_comments + 1));
/* add comment to list */
plyfile->comments[plyfile->num_comments] = strdup (comment);
plyfile->num_comments++;
}
/******************************************************************************
Specify a piece of object information (arbitrary text) that will be written
in the header.
Entry:
plyfile - file identifier
obj_info - the text information to be written
******************************************************************************/
void ply_put_obj_info(PlyFile *plyfile, char *obj_info)
{
/* (re)allocate space for new info */
if (plyfile->num_obj_info == 0)
plyfile->obj_info = (char **) myalloc (sizeof (char *));
else
plyfile->obj_info = (char **) realloc (plyfile->obj_info,
sizeof (char *) * (plyfile->num_obj_info + 1));
/* add info to list */
plyfile->obj_info[plyfile->num_obj_info] = strdup (obj_info);
plyfile->num_obj_info++;
}Part 13 close
/******************************************************************************
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 ply_get_info(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.
******************************************************************************/
if (*s1 != *s2)
return (0);
else
return (1);
}
/******************************************************************************
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->nelems; i++)
if (strcpy (element, plyfile->elems[i]->name)>0)
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 (strcpy(prop_name, elem->props[i]->name)>0) {
*index = i;
return (elem->props[i]);
}
*index = -1;
return (NULL);
}