1 |
/* RCSid $Id$ */ |
2 |
/* |
3 |
* Header for compact triangle mesh geometry |
4 |
* |
5 |
* Include after standard.h, object.h and octree.h |
6 |
*/ |
7 |
|
8 |
#include "copyright.h" |
9 |
|
10 |
#include "lookup.h" |
11 |
|
12 |
#ifndef uint4 |
13 |
#define uint4 unsigned int4 |
14 |
#endif |
15 |
#ifndef BYTE |
16 |
#define BYTE unsigned char |
17 |
#endif |
18 |
|
19 |
/* |
20 |
* Vertex space is minimized without compromising accuracy by using a |
21 |
* 4-byte unsigned int to indicate position in the enclosing octree cube. |
22 |
* The same trick is used for any local (u,v) coordinates, whose limits |
23 |
* are recorded separately in the parent MESH structure. The uvlimit's |
24 |
* in the MESH structure are set such that (0,0) is out of range, so |
25 |
* we use this to indicate an unspecified local coordinate. |
26 |
* A vertex normal, if specified, is stored in a single 4-byte |
27 |
* integer using the codec in dircode.c. The encodedir() function |
28 |
* never generates 0, so we can use this for unspecified normals. |
29 |
* |
30 |
* Vertex ID's are encoded using the bottom 8 bits of a 4-byte integer |
31 |
* to index a vertex in a patch indicated by the 22 bits above (8-29). |
32 |
* For triangle ID's, the top 22 bits (10-31) indicate the patch, and |
33 |
* the bit 9 (0x200) indicates whether the triangle joins patches. |
34 |
* If not, then the bottom 9 bits index into the local PTri array. |
35 |
* If it's a joiner, then the 8th bit indicates whether the triangle joins |
36 |
* two patches, in which case the bottom 8 bits index the PJoin2 array. |
37 |
* Otherwise, the bottom 8 bits index the PJoin1 array. |
38 |
* |
39 |
* These shenanigans minimize vertex reference memory requirements |
40 |
* in compiled mesh structures, where the octree leaves contain sets |
41 |
* of triangle ID's rather than the more usual objects. It seems like |
42 |
* a lot of effort, but it can reduce mesh storage by a factor of 3 |
43 |
* or more. This is important, as the whole point is to model very |
44 |
* complicated geometry with this structure, and memory is the main |
45 |
* limitation. |
46 |
*/ |
47 |
|
48 |
/* A triangle mesh patch */ |
49 |
typedef struct { |
50 |
uint4 (*xyz)[3]; /* up to 256 patch vertices */ |
51 |
int4 *norm; /* vertex normals */ |
52 |
uint4 (*uv)[2]; /* vertex local coordinates */ |
53 |
struct PTri { |
54 |
BYTE v1, v2, v3; /* local vertices */ |
55 |
} *tri; /* local triangles */ |
56 |
short solemat; /* sole material */ |
57 |
int2 *trimat; /* or local material indices */ |
58 |
struct PJoin1 { |
59 |
int4 v1j; /* non-local vertex */ |
60 |
int2 mat; /* material index */ |
61 |
BYTE v2, v3; /* local vertices */ |
62 |
} *j1tri; /* joiner triangles */ |
63 |
struct PJoin2 { |
64 |
int4 v1j, v2j; /* non-local vertices */ |
65 |
int2 mat; /* material index */ |
66 |
BYTE v3; /* local vertex */ |
67 |
} *j2tri; /* double joiner triangles */ |
68 |
short nverts; /* vertex count */ |
69 |
short ntris; /* triangle count */ |
70 |
short nj1tris; /* joiner triangle count */ |
71 |
short nj2tris; /* double joiner triangle count */ |
72 |
} MESHPATCH; |
73 |
|
74 |
/* A loaded mesh */ |
75 |
typedef struct mesh { |
76 |
char *name; /* mesh file name */ |
77 |
int nref; /* reference count */ |
78 |
int ldflags; /* what we've loaded */ |
79 |
CUBE mcube; /* bounds and octree */ |
80 |
FLOAT uvlim[2][2]; /* local coordinate extrema */ |
81 |
OBJECT mat0; /* base material index */ |
82 |
OBJECT nmats; /* number of materials */ |
83 |
MESHPATCH *patch; /* mesh patch list */ |
84 |
int npatches; /* number of mesh patches */ |
85 |
OBJREC *pseudo; /* mesh pseudo objects */ |
86 |
LUTAB lut; /* vertex lookup table */ |
87 |
struct mesh *next; /* next mesh in list */ |
88 |
} MESH; |
89 |
|
90 |
/* A mesh instance */ |
91 |
typedef struct { |
92 |
FULLXF x; /* forward and backward transforms */ |
93 |
MESH *msh; /* mesh object reference */ |
94 |
} MESHINST; |
95 |
|
96 |
/* vertex flags */ |
97 |
#define MT_V 01 |
98 |
#define MT_N 02 |
99 |
#define MT_UV 04 |
100 |
#define MT_ALL 07 |
101 |
|
102 |
/* A mesh vertex */ |
103 |
typedef struct { |
104 |
int fl; /* setting flags */ |
105 |
FVECT v; /* vertex location */ |
106 |
FVECT n; /* vertex normal */ |
107 |
FLOAT uv[2]; /* local coordinates */ |
108 |
} MESHVERT; |
109 |
|
110 |
/* mesh format identifier */ |
111 |
#define MESHFMT "Radiance_tmesh" |
112 |
/* magic number for mesh files */ |
113 |
#define MESHMAGIC ( 1 *MAXOBJSIZ+311) /* increment first value */ |
114 |
|
115 |
#ifdef NOPROTO |
116 |
|
117 |
extern MESH *getmesh(); |
118 |
extern MESHINST *getmeshinst(); |
119 |
extern int getmeshtrivid(); |
120 |
extern int getmeshvert(); |
121 |
extern int getmeshtri(); |
122 |
extern OBJREC *getmeshpseudo(); |
123 |
extern int4 addmeshvert(); |
124 |
extern OBJECT addmeshtri(); |
125 |
extern char *checkmesh(); |
126 |
extern void printmeshstats(); |
127 |
extern void freemesh(); |
128 |
extern void freemeshinst(); |
129 |
extern void readmesh(); |
130 |
extern void writemesh(); |
131 |
|
132 |
#else |
133 |
|
134 |
extern MESH *getmesh(char *mname, int flags); |
135 |
extern MESHINST *getmeshinst(OBJREC *o, int flags); |
136 |
extern int getmeshtrivid(int4 tvid[3], OBJECT *mo, |
137 |
MESH *mp, OBJECT ti); |
138 |
extern int getmeshvert(MESHVERT *vp, MESH *mp, int4 vid, int what); |
139 |
extern int getmeshtri(MESHVERT tv[3], OBJECT *mo, |
140 |
MESH *mp, OBJECT ti, int what); |
141 |
extern OBJREC *getmeshpseudo(MESH *mp, OBJECT mo); |
142 |
extern int4 addmeshvert(MESH *mp, MESHVERT *vp); |
143 |
extern OBJECT addmeshtri(MESH *mp, MESHVERT tv[3], OBJECT mo); |
144 |
extern char *checkmesh(MESH *mp); |
145 |
extern void printmeshstats(MESH *ms, FILE *fp); |
146 |
extern void freemesh(MESH *ms); |
147 |
extern void freemeshinst(OBJREC *o); |
148 |
extern void readmesh(MESH *mp, char *path, int flags); |
149 |
extern void writemesh(MESH *mp, FILE *fp); |
150 |
|
151 |
#endif /* NOPROTO */ |