src/common/mesh.h

/* RCSid $Id: mesh.h,v 2.4 2003/05/13 17:58:32 greg Exp $ */
/*
 * Header for compact triangle mesh geometry
 *
 *  Include after standard.h, object.h and octree.h
 */
#ifndef _RAD_MESH_H_
#define _RAD_MESH_H_
#ifdef __cplusplus
extern "C" {
#endif

#include "copyright.h"

#include "lookup.h"

#ifndef uint4
#define uint4   unsigned int4
#endif
#ifndef BYTE
#define BYTE    unsigned char
#endif

/*
 * Vertex space is minimized without compromising accuracy by using a
 * 4-byte unsigned int to indicate position in the enclosing octree cube.
 * The same trick is used for any local (u,v) coordinates, whose limits
 * are recorded separately in the parent MESH structure.  The uvlimit's
 * in the MESH structure are set such that (0,0) is out of range, so
 * we use this to indicate an unspecified local coordinate.
 * A vertex normal, if specified, is stored in a single 4-byte
 * integer using the codec in dircode.c.  The encodedir() function
 * never generates 0, so we can use this for unspecified normals.
 *
 * Vertex ID's are encoded using the bottom 8 bits of a 4-byte integer
 * to index a vertex in a patch indicated by the 22 bits above (8-29).
 * For triangle ID's, the top 22 bits (10-31) indicate the patch, and
 * the bit 9 (0x200) indicates whether the triangle joins patches.
 * If not, then the bottom 9 bits index into the local PTri array.
 * If it's a joiner, then the 8th bit indicates whether the triangle joins
 * two patches, in which case the bottom 8 bits index the PJoin2 array.
 * Otherwise, the bottom 8 bits index the PJoin1 array.
 *
 * These shenanigans minimize vertex reference memory requirements
 * in compiled mesh structures, where the octree leaves contain sets 
 * of triangle ID's rather than the more usual objects.  It seems like
 * a lot of effort, but it can reduce mesh storage by a factor of 3
 * or more.  This is important, as the whole point is to model very
 * complicated geometry with this structure, and memory is the main
 * limitation.
 */

/* A triangle mesh patch */
typedef struct {
        uint4           (*xyz)[3];      /* up to 256 patch vertices */
        int4            *norm;          /* vertex normals */
        uint4           (*uv)[2];       /* vertex local coordinates */
        struct PTri {
                BYTE            v1, v2, v3;     /* local vertices */
        }               *tri;           /* local triangles */
        short           solemat;        /* sole material */
        int2            *trimat;        /* or local material indices */
        struct PJoin1 {
                int4            v1j;            /* non-local vertex */
                int2            mat;            /* material index */
                BYTE            v2, v3;         /* local vertices */
        }               *j1tri;         /* joiner triangles */
        struct PJoin2 {
                int4            v1j, v2j;       /* non-local vertices */
                int2            mat;            /* material index */
                BYTE            v3;             /* local vertex */
        }               *j2tri;         /* double joiner triangles */
        short           nverts;         /* vertex count */
        short           ntris;          /* triangle count */
        short           nj1tris;        /* joiner triangle count */
        short           nj2tris;        /* double joiner triangle count */
} MESHPATCH;

/* A loaded mesh */
typedef struct mesh {
        char            *name;          /* mesh file name */
        int             nref;           /* reference count */
        int             ldflags;        /* what we've loaded */
        CUBE            mcube;          /* bounds and octree */
        FLOAT           uvlim[2][2];    /* local coordinate extrema */
        OBJECT          mat0;           /* base material index */
        OBJECT          nmats;          /* number of materials */
        MESHPATCH       *patch;         /* mesh patch list */
        int             npatches;       /* number of mesh patches */
        OBJREC          *pseudo;        /* mesh pseudo objects */
        LUTAB           lut;            /* vertex lookup table */
        struct mesh     *next;          /* next mesh in list */
} MESH;

/* A mesh instance */
typedef struct {
        FULLXF          x;              /* forward and backward transforms */
        MESH            *msh;           /* mesh object reference */
} MESHINST;

                                /* vertex flags */
#define MT_V            01
#define MT_N            02
#define MT_UV           04
#define MT_ALL          07

/* A mesh vertex */
typedef struct {
        int             fl;             /* setting flags */
        FVECT           v;              /* vertex location */
        FVECT           n;              /* vertex normal */
        FLOAT           uv[2];          /* local coordinates */
} MESHVERT;

                                /* mesh format identifier */
#define MESHFMT         "Radiance_tmesh"
                                /* magic number for mesh files */
#define MESHMAGIC       ( 1 *MAXOBJSIZ+311)     /* increment first value */


extern MESH     *getmesh(char *mname, int flags);
extern MESHINST *getmeshinst(OBJREC *o, int flags);
extern int      getmeshtrivid(int4 tvid[3], OBJECT *mo,
                                MESH *mp, OBJECT ti);
extern int      getmeshvert(MESHVERT *vp, MESH *mp, int4 vid, int what);
extern int      getmeshtri(MESHVERT tv[3], OBJECT *mo,
                                MESH *mp, OBJECT ti, int what);
extern OBJREC   *getmeshpseudo(MESH *mp, OBJECT mo);
extern int4     addmeshvert(MESH *mp, MESHVERT *vp);
extern OBJECT   addmeshtri(MESH *mp, MESHVERT tv[3], OBJECT mo);
extern char     *checkmesh(MESH *mp);
extern void     printmeshstats(MESH *ms, FILE *fp);
extern void     freemesh(MESH *ms);
extern void     freemeshinst(OBJREC *o);
extern void     readmesh(MESH *mp, char *path, int flags);
extern void     writemesh(MESH *mp, FILE *fp);


#ifdef __cplusplus
}
#endif
#endif /* _RAD_MESH_H_ */

Revision:	2.5
Committed:	Fri Jun 6 16:38:47 2003 UTC (20 years, 10 months ago) by schorsch
Content type:	text/plain
Branch:	MAIN
Changes since 2.4:	+12 -20 lines
Log Message:	* empty log message *
#	User	Rev	Content
1	schorsch	2.5	/* RCSid $Id: mesh.h,v 2.4 2003/05/13 17:58:32 greg Exp $ */
2	greg	2.1	/*
3			* Header for compact triangle mesh geometry
4			*
5			* Include after standard.h, object.h and octree.h
6			*/
7	schorsch	2.5	#ifndef _RAD_MESH_H_
8			#define _RAD_MESH_H_
9			#ifdef __cplusplus
10			extern "C" {
11			#endif
12	greg	2.1
13			#include "copyright.h"
14
15	greg	2.3	#include "lookup.h"
16
17	greg	2.1	#ifndef uint4
18			#define uint4 unsigned int4
19			#endif
20			#ifndef BYTE
21			#define BYTE unsigned char
22			#endif
23
24			/*
25			* Vertex space is minimized without compromising accuracy by using a
26			* 4-byte unsigned int to indicate position in the enclosing octree cube.
27			* The same trick is used for any local (u,v) coordinates, whose limits
28			* are recorded separately in the parent MESH structure. The uvlimit's
29			* in the MESH structure are set such that (0,0) is out of range, so
30			* we use this to indicate an unspecified local coordinate.
31			* A vertex normal, if specified, is stored in a single 4-byte
32			* integer using the codec in dircode.c. The encodedir() function
33			* never generates 0, so we can use this for unspecified normals.
34			*
35			* Vertex ID's are encoded using the bottom 8 bits of a 4-byte integer
36	greg	2.2	* to index a vertex in a patch indicated by the 22 bits above (8-29).
37			* For triangle ID's, the top 22 bits (10-31) indicate the patch, and
38			* the bit 9 (0x200) indicates whether the triangle joins patches.
39	greg	2.1	* If not, then the bottom 9 bits index into the local PTri array.
40	greg	2.2	* If it's a joiner, then the 8th bit indicates whether the triangle joins
41	greg	2.1	* two patches, in which case the bottom 8 bits index the PJoin2 array.
42			* Otherwise, the bottom 8 bits index the PJoin1 array.
43			*
44			* These shenanigans minimize vertex reference memory requirements
45			* in compiled mesh structures, where the octree leaves contain sets
46			* of triangle ID's rather than the more usual objects. It seems like
47			* a lot of effort, but it can reduce mesh storage by a factor of 3
48			* or more. This is important, as the whole point is to model very
49			* complicated geometry with this structure, and memory is the main
50	greg	2.3	* limitation.
51	greg	2.1	*/
52
53			/* A triangle mesh patch */
54			typedef struct {
55			uint4 (xyz)[3]; / up to 256 patch vertices */
56			int4 norm; / vertex normals */
57			uint4 (uv)[2]; / vertex local coordinates */
58			struct PTri {
59			BYTE v1, v2, v3; /* local vertices */
60			} tri; / local triangles */
61	greg	2.3	short solemat; /* sole material */
62			int2 trimat; / or local material indices */
63	greg	2.1	struct PJoin1 {
64			int4 v1j; /* non-local vertex */
65	greg	2.3	int2 mat; /* material index */
66	greg	2.1	BYTE v2, v3; /* local vertices */
67			} j1tri; / joiner triangles */
68			struct PJoin2 {
69			int4 v1j, v2j; /* non-local vertices */
70	greg	2.3	int2 mat; /* material index */
71	greg	2.1	BYTE v3; /* local vertex */
72			} j2tri; / double joiner triangles */
73			short nverts; /* vertex count */
74			short ntris; /* triangle count */
75			short nj1tris; /* joiner triangle count */
76			short nj2tris; /* double joiner triangle count */
77			} MESHPATCH;
78
79			/* A loaded mesh */
80			typedef struct mesh {
81			char name; / mesh file name */
82			int nref; /* reference count */
83			int ldflags; /* what we've loaded */
84			CUBE mcube; /* bounds and octree */
85			FLOAT uvlim[2][2]; /* local coordinate extrema */
86	greg	2.3	OBJECT mat0; /* base material index */
87			OBJECT nmats; /* number of materials */
88	greg	2.1	MESHPATCH patch; / mesh patch list */
89			int npatches; /* number of mesh patches */
90	greg	2.3	OBJREC pseudo; / mesh pseudo objects */
91			LUTAB lut; /* vertex lookup table */
92	greg	2.1	struct mesh next; / next mesh in list */
93			} MESH;
94
95			/* A mesh instance */
96			typedef struct {
97			FULLXF x; /* forward and backward transforms */
98			MESH msh; / mesh object reference */
99			} MESHINST;
100
101			/* vertex flags */
102			#define MT_V 01
103			#define MT_N 02
104			#define MT_UV 04
105			#define MT_ALL 07
106
107			/* A mesh vertex */
108			typedef struct {
109			int fl; /* setting flags */
110			FVECT v; /* vertex location */
111			FVECT n; /* vertex normal */
112			FLOAT uv[2]; /* local coordinates */
113			} MESHVERT;
114
115			/* mesh format identifier */
116			#define MESHFMT "Radiance_tmesh"
117			/* magic number for mesh files */
118	greg	2.3	#define MESHMAGIC ( 1 MAXOBJSIZ+311) / increment first value */
119	greg	2.1
120
121			extern MESH getmesh(char mname, int flags);
122			extern MESHINST getmeshinst(OBJREC o, int flags);
123	greg	2.3	extern int getmeshtrivid(int4 tvid[3], OBJECT *mo,
124			MESH *mp, OBJECT ti);
125	greg	2.1	extern int getmeshvert(MESHVERT vp, MESH mp, int4 vid, int what);
126	greg	2.3	extern int getmeshtri(MESHVERT tv[3], OBJECT *mo,
127			MESH *mp, OBJECT ti, int what);
128			extern OBJREC getmeshpseudo(MESH mp, OBJECT mo);
129	greg	2.1	extern int4 addmeshvert(MESH mp, MESHVERT vp);
130	greg	2.3	extern OBJECT addmeshtri(MESH *mp, MESHVERT tv[3], OBJECT mo);
131			extern char checkmesh(MESH mp);
132	greg	2.1	extern void printmeshstats(MESH ms, FILE fp);
133			extern void freemesh(MESH *ms);
134			extern void freemeshinst(OBJREC *o);
135			extern void readmesh(MESH mp, char path, int flags);
136			extern void writemesh(MESH mp, FILE fp);
137
138	schorsch	2.5
139			#ifdef __cplusplus
140			}
141			#endif
142			#endif /* _RAD_MESH_H_ */
143