src/common/objutil.h

/* RCSid $Id: objutil.h,v 2.12 2021/03/03 18:53:08 greg Exp $ */
/*
 *  Declarations for .OBJ file utility
 *
 *  Include after <stdio.h>
 *
 *  Created by Greg Ward on Wed Feb 11 2004.
 */

#ifndef _OBJUTIL_H_
#define _OBJUTIL_H_

#ifdef __cplusplus
extern "C" {
#endif

#ifndef DUP_CHECK_REVERSE
#define DUP_CHECK_REVERSE       1       /* eliminate flipped duplicates */
#endif
#ifndef POPEN_SUPPORT
#define POPEN_SUPPORT           1       /* support "!command" i/o */
#endif
                                        /* face flags */
#define FACE_DEGENERATE         01
#define FACE_DUPLICATE          02
#define FACE_SELECTED           04
#define FACE_CUSTOM(n)          (FACE_SELECTED<<(n))
#define FACE_RESERVED           (1<<15)

struct Face;                            /* forward declaration */

typedef int             VNDX[3];        /* vertex indices (point,map,normal) */

/* Structure to hold vertex indices and link back to face list */
typedef struct {
        int             vid;            /* vertex id */
        int             tid;            /* texture id */
        int             nid;            /* normal id */
        struct Face     *fnext;         /* next in vertex face list */
} VertEnt;

/* Structure to hold face and its vertex references */
typedef struct Face {
        struct Face     *next;          /* next face in main list */
        short           flags;          /* face selected, etc */
        short           nv;             /* number of vertices */
        short           grp;            /* group/object index */
        short           mat;            /* material index */
        /* in cases where the same vertex appears twice, first has link */
        VertEnt         v[3];           /* vertex list (extends struct) */
} Face;

/* Structure to hold vertex */
typedef struct {
        double          p[3];           /* 3-D position */
        Face            *vflist;        /* linked face list (no repeats) */
} Vertex;

/* Structure to hold texture coordinate */
typedef struct {
        float           u, v;           /* 2-D local texture coordinate */
} TexCoord;

/* Array to hold surface normal */
typedef float           Normal[3];

/* Structure to hold a loaded .OBJ file */
typedef struct {
        char            **descr;        /* descriptive comments */
        int             ndescr;         /* number of comments */
        char            **grpname;      /* object/group name list */
        int             ngrps;          /* number of group names */
        int             lastgrp;        /* last group seen */
        char            **matname;      /* material name list */
        int             nmats;          /* number of materials */
        int             lastmat;        /* last material seen */
        Vertex          *vert;          /* vertex array */
        int             nverts;         /* number of vertices */
        TexCoord        *tex;           /* texture coordinate array */
        int             ntex;           /* number of texture coord's */
        Normal          *norm;          /* surface normal array */
        int             nnorms;         /* number of surface normals */
        Face            *flist;         /* linked face list */
        int             nfaces;         /* count of faces */
} Scene;

/* Allocate a new scene holder */
Scene *         newScene(void);

/* Add a .OBJ file to a scene */
Scene *         loadOBJ(Scene *sc, const char *fspec);

/* Duplicate a scene, optionally selecting faces */
Scene *         dupScene(const Scene *sc, int flreq, int flexc);

/* Transform entire scene */
int             xfScene(Scene *sc, int xac, char *xav[]);
int             xfmScene(Scene *sc, const char *xfm);

/* Add a descriptive comment */
void            addComment(Scene *sc, const char *comment);

/* Find index for comment containing the given string (starting from n) */
int             findComment(Scene *sc, const char *match, int n);

/* Clear comments */
void            clearComments(Scene *sc);

/* Write a .OBJ file, return # faces written or -1 on error */
int             toOBJ(Scene *sc, FILE *fp);
int             writeOBJ(Scene *sc, const char *fspec);

/* Convert indicated faces to Radiance, return # written or -1 on error */
int             toRadiance(Scene *sc, FILE *fp, int flreq, int flexc);
int             writeRadiance(Scene *sc, const char *fspec,
                                int flreq, int flexc);

/* Compute face area (and normal) */
double          faceArea(const Scene *sc, const Face *f, Normal nrm);

/* Eliminate duplicate vertices, return # joined */
int             coalesceVertices(Scene *sc, double eps);

/* Identify duplicate faces */
int             findDuplicateFaces(Scene *sc);

/* Delete indicated faces, return # deleted */
int             deleteFaces(Scene *sc, int flreq, int flexc);

/* Clear face selection */
void            clearSelection(Scene *sc, int set);

/* Invert face selection */
void            invertSelection(Scene *sc);

/* Count number of faces selected */
int             numberSelected(Scene *sc);

/* Select faces by object name (modifies current) */
void            selectGroup(Scene *sc, const char *gname, int invert);

/* Select faces by material name (modifies current) */
void            selectMaterial(Scene *sc, const char *mname, int invert);

/* Execute callback on indicated faces */
int             foreachFace(Scene *sc, int (*cb)(Scene *, Face *, void *),
                                        int flreq, int flexc, void *c_data);

/* Remove texture coordinates from the indicated faces */
int             removeTexture(Scene *sc, int flreq, int flexc);

/* Remove surface normals from the indicated faces */
int             removeNormals(Scene *sc, int flreq, int flexc);

/* Change group for the indicated faces */
int             changeGroup(Scene *sc, const char *gname,
                                        int flreq, int flexc);

/* Change material for the indicated faces */
int             changeMaterial(Scene *sc, const char *mname,
                                        int flreq, int flexc);

/* Add a vertex to our scene, returning index */
int             addVertex(Scene *sc, double x, double y, double z);

/* Add a texture coordinate to our scene, returning index */
int             addTexture(Scene *sc, double u, double v);

/* Add a surface normal to our scene, returning index */
int             addNormal(Scene *sc, double xn, double yn, double zn);

/* Set current group (sc->lastgrp) to given ID */
void            setGroup(Scene *sc, const char *nm);

/* Set current material (sc->lastmat) to given ID */
void            setMaterial(Scene *sc, const char *nm);

/* Add a new face to our scene, using current group and material */
Face *          addFace(Scene *sc, VNDX vid[], int nv);

/* Convert all faces with > 3 vertices to triangles */
int             triangulateScene(Scene *sc);

/* Delete unreferenced vertices, normals, texture coords */
void            deleteUnreferenced(Scene *sc);

/* Free a scene */
void            freeScene(Scene *sc);

/* Find an existing name in a list of names */
int             findName(const char *nm, const char **nmlist, int n);

/* Verbose mode global */
extern int      verbose;

extern char     *emalloc(unsigned int n);
extern char     *ecalloc(unsigned int ne, unsigned int n);
extern char     *erealloc(char *cp, unsigned int n);
extern void     efree(char *cp);

#define getGroupID(sc,nm)       findName(nm, (const char **)(sc)->grpname, (sc)->ngrps)
#define getMaterialID(sc,nm)    findName(nm, (const char **)(sc)->matname, (sc)->nmats)

#define CHUNKSIZ        128     /* object allocation chunk size */

#define chunk_alloc(typ, arr, nold) \
                ((nold)%CHUNKSIZ ? (arr) : \
                (typ *)erealloc((char *)(arr), sizeof(typ)*((nold)+CHUNKSIZ)))

#ifdef __cplusplus
}
#endif

#endif  /* ! _OBJUTIL_H_ */
Revision:	2.13
Committed:	Fri Mar 12 03:59:25 2021 UTC (4 years, 1 month ago) by greg
Content type:	text/plain
Branch:	MAIN
Changes since 2.12:	+9 -5 lines
Log Message:	feat: added routine to triangulate .OBJ scene in memory
#	User	Rev	Content
1	greg	2.13	/* RCSid $Id: objutil.h,v 2.12 2021/03/03 18:53:08 greg Exp $ */
2	greg	2.1	/*
3			* Declarations for .OBJ file utility
4			*
5			* Include after <stdio.h>
6			*
7			* Created by Greg Ward on Wed Feb 11 2004.
8			*/
9
10			#ifndef _OBJUTIL_H_
11			#define _OBJUTIL_H_
12
13	greg	2.13	#ifdef __cplusplus
14			extern "C" {
15			#endif
16
17	greg	2.1	#ifndef DUP_CHECK_REVERSE
18			#define DUP_CHECK_REVERSE 1 /* eliminate flipped duplicates */
19			#endif
20			#ifndef POPEN_SUPPORT
21			#define POPEN_SUPPORT 1 /* support "!command" i/o */
22			#endif
23			/* face flags */
24	greg	2.10	#define FACE_DEGENERATE 01
25			#define FACE_DUPLICATE 02
26			#define FACE_SELECTED 04
27	greg	2.11	#define FACE_CUSTOM(n) (FACE_SELECTED<<(n))
28	greg	2.13	#define FACE_RESERVED (1<<15)
29	greg	2.1
30			struct Face; /* forward declaration */
31
32	greg	2.6	typedef int VNDX[3]; /* vertex indices (point,map,normal) */
33
34			/* Structure to hold vertex indices and link back to face list */
35	greg	2.1	typedef struct {
36			int vid; /* vertex id */
37			int tid; /* texture id */
38			int nid; /* normal id */
39			struct Face fnext; / next in vertex face list */
40			} VertEnt;
41
42			/* Structure to hold face and its vertex references */
43			typedef struct Face {
44			struct Face next; / next face in main list */
45			short flags; /* face selected, etc */
46			short nv; /* number of vertices */
47			short grp; /* group/object index */
48			short mat; /* material index */
49			/* in cases where the same vertex appears twice, first has link */
50			VertEnt v[3]; /* vertex list (extends struct) */
51			} Face;
52
53			/* Structure to hold vertex */
54			typedef struct {
55			double p[3]; /* 3-D position */
56			Face vflist; / linked face list (no repeats) */
57			} Vertex;
58
59			/* Structure to hold texture coordinate */
60			typedef struct {
61			float u, v; /* 2-D local texture coordinate */
62			} TexCoord;
63
64			/* Array to hold surface normal */
65			typedef float Normal[3];
66
67			/* Structure to hold a loaded .OBJ file */
68			typedef struct {
69			char *descr; / descriptive comments */
70			int ndescr; /* number of comments */
71			char *grpname; / object/group name list */
72			int ngrps; /* number of group names */
73			int lastgrp; /* last group seen */
74			char *matname; / material name list */
75			int nmats; /* number of materials */
76			int lastmat; /* last material seen */
77			Vertex vert; / vertex array */
78			int nverts; /* number of vertices */
79			TexCoord tex; / texture coordinate array */
80			int ntex; /* number of texture coord's */
81			Normal norm; / surface normal array */
82			int nnorms; /* number of surface normals */
83			Face flist; / linked face list */
84			int nfaces; /* count of faces */
85			} Scene;
86
87			/* Allocate a new scene holder */
88			Scene * newScene(void);
89
90			/* Add a .OBJ file to a scene */
91			Scene * loadOBJ(Scene sc, const char fspec);
92
93	greg	2.9	/* Duplicate a scene, optionally selecting faces */
94			Scene * dupScene(const Scene *sc, int flreq, int flexc);
95	greg	2.1
96	greg	2.2	/* Transform entire scene */
97	greg	2.3	int xfScene(Scene sc, int xac, char xav[]);
98	greg	2.2	int xfmScene(Scene sc, const char xfm);
99
100	greg	2.1	/* Add a descriptive comment */
101			void addComment(Scene sc, const char comment);
102
103	greg	2.8	/* Find index for comment containing the given string (starting from n) */
104			int findComment(Scene sc, const char match, int n);
105
106	greg	2.1	/* Clear comments */
107			void clearComments(Scene *sc);
108
109			/* Write a .OBJ file, return # faces written or -1 on error */
110			int toOBJ(Scene sc, FILE fp);
111			int writeOBJ(Scene sc, const char fspec);
112
113			/* Convert indicated faces to Radiance, return # written or -1 on error */
114			int toRadiance(Scene sc, FILE fp, int flreq, int flexc);
115			int writeRadiance(Scene sc, const char fspec,
116			int flreq, int flexc);
117
118			/* Compute face area (and normal) */
119			double faceArea(const Scene sc, const Face f, Normal nrm);
120
121			/* Eliminate duplicate vertices, return # joined */
122			int coalesceVertices(Scene *sc, double eps);
123
124			/* Identify duplicate faces */
125			int findDuplicateFaces(Scene *sc);
126
127			/* Delete indicated faces, return # deleted */
128			int deleteFaces(Scene *sc, int flreq, int flexc);
129
130			/* Clear face selection */
131			void clearSelection(Scene *sc, int set);
132
133			/* Invert face selection */
134			void invertSelection(Scene *sc);
135
136			/* Count number of faces selected */
137			int numberSelected(Scene *sc);
138
139			/* Select faces by object name (modifies current) */
140			void selectGroup(Scene sc, const char gname, int invert);
141
142			/* Select faces by material name (modifies current) */
143			void selectMaterial(Scene sc, const char mname, int invert);
144
145			/* Execute callback on indicated faces */
146			int foreachFace(Scene sc, int (cb)(Scene , Face , void *),
147			int flreq, int flexc, void *c_data);
148
149			/* Remove texture coordinates from the indicated faces */
150			int removeTexture(Scene *sc, int flreq, int flexc);
151
152			/* Remove surface normals from the indicated faces */
153			int removeNormals(Scene *sc, int flreq, int flexc);
154
155			/* Change group for the indicated faces */
156			int changeGroup(Scene sc, const char gname,
157			int flreq, int flexc);
158
159			/* Change material for the indicated faces */
160			int changeMaterial(Scene sc, const char mname,
161			int flreq, int flexc);
162
163	greg	2.7	/* Add a vertex to our scene, returning index */
164	greg	2.5	int addVertex(Scene *sc, double x, double y, double z);
165
166	greg	2.7	/* Add a texture coordinate to our scene, returning index */
167	greg	2.5	int addTexture(Scene *sc, double u, double v);
168
169	greg	2.7	/* Add a surface normal to our scene, returning index */
170	greg	2.5	int addNormal(Scene *sc, double xn, double yn, double zn);
171
172	greg	2.7	/* Set current group (sc->lastgrp) to given ID */
173	greg	2.5	void setGroup(Scene sc, const char nm);
174
175	greg	2.7	/* Set current material (sc->lastmat) to given ID */
176	greg	2.5	void setMaterial(Scene sc, const char nm);
177
178	greg	2.7	/* Add a new face to our scene, using current group and material */
179	greg	2.6	Face * addFace(Scene *sc, VNDX vid[], int nv);
180
181	greg	2.13	/* Convert all faces with > 3 vertices to triangles */
182			int triangulateScene(Scene *sc);
183
184	greg	2.9	/* Delete unreferenced vertices, normals, texture coords */
185			void deleteUnreferenced(Scene *sc);
186
187	greg	2.1	/* Free a scene */
188			void freeScene(Scene *sc);
189
190			/* Find an existing name in a list of names */
191			int findName(const char nm, const char *nmlist, int n);
192
193			/* Verbose mode global */
194			extern int verbose;
195
196			extern char *emalloc(unsigned int n);
197			extern char *ecalloc(unsigned int ne, unsigned int n);
198			extern char erealloc(char cp, unsigned int n);
199	greg	2.12	extern void efree(char *cp);
200
201			#define getGroupID(sc,nm) findName(nm, (const char **)(sc)->grpname, (sc)->ngrps)
202			#define getMaterialID(sc,nm) findName(nm, (const char **)(sc)->matname, (sc)->nmats)
203	greg	2.1
204			#define CHUNKSIZ 128 /* object allocation chunk size */
205
206			#define chunk_alloc(typ, arr, nold) \
207			((nold)%CHUNKSIZ ? (arr) : \
208			(typ )erealloc((char )(arr), sizeof(typ)*((nold)+CHUNKSIZ)))
209
210			#ifdef __cplusplus
211			}
212			#endif
213
214			#endif /* ! _OBJUTIL_H_ */