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/* RCSid $Id$ */ |
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/* |
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* Header for compact triangle mesh geometry |
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* |
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* Include after standard.h, object.h and octree.h |
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*/ |
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|
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#include "copyright.h" |
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|
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#ifndef uint4 |
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#define uint4 unsigned int4 |
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#endif |
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#ifndef BYTE |
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#define BYTE unsigned char |
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#endif |
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|
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/* |
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* Vertex space is minimized without compromising accuracy by using a |
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* 4-byte unsigned int to indicate position in the enclosing octree cube. |
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* The same trick is used for any local (u,v) coordinates, whose limits |
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* are recorded separately in the parent MESH structure. The uvlimit's |
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* in the MESH structure are set such that (0,0) is out of range, so |
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* we use this to indicate an unspecified local coordinate. |
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* A vertex normal, if specified, is stored in a single 4-byte |
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* integer using the codec in dircode.c. The encodedir() function |
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* never generates 0, so we can use this for unspecified normals. |
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* |
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* Vertex ID's are encoded using the bottom 8 bits of a 4-byte integer |
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* to index a vertex in a patch indicated by the 20 bits above (9-29). |
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* For triangle ID's, the top 10 bits (11-31) indicate the patch, and |
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* the 10th bit indicates whether the triangle joins patches. |
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* If not, then the bottom 9 bits index into the local PTri array. |
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* If it's a joiner, then the 9th bit indicates whether the triangle joins |
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* two patches, in which case the bottom 8 bits index the PJoin2 array. |
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* Otherwise, the bottom 8 bits index the PJoin1 array. |
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* |
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* These shenanigans minimize vertex reference memory requirements |
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* in compiled mesh structures, where the octree leaves contain sets |
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* of triangle ID's rather than the more usual objects. It seems like |
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* a lot of effort, but it can reduce mesh storage by a factor of 3 |
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* or more. This is important, as the whole point is to model very |
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* complicated geometry with this structure, and memory is the main |
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* limitation. (We also optimize intersection tests for triangles.) |
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*/ |
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|
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/* A triangle mesh patch */ |
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typedef struct { |
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uint4 (*xyz)[3]; /* up to 256 patch vertices */ |
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int4 *norm; /* vertex normals */ |
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uint4 (*uv)[2]; /* vertex local coordinates */ |
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struct PTri { |
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BYTE v1, v2, v3; /* local vertices */ |
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} *tri; /* local triangles */ |
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struct PJoin1 { |
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int4 v1j; /* non-local vertex */ |
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BYTE v2, v3; /* local vertices */ |
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} *j1tri; /* joiner triangles */ |
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struct PJoin2 { |
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int4 v1j, v2j; /* non-local vertices */ |
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BYTE v3; /* local vertex */ |
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} *j2tri; /* double joiner triangles */ |
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short nverts; /* vertex count */ |
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short ntris; /* triangle count */ |
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short nj1tris; /* joiner triangle count */ |
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short nj2tris; /* double joiner triangle count */ |
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} MESHPATCH; |
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|
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/* A loaded mesh */ |
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typedef struct mesh { |
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char *name; /* mesh file name */ |
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int nref; /* reference count */ |
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int ldflags; /* what we've loaded */ |
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CUBE mcube; /* bounds and octree */ |
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FLOAT uvlim[2][2]; /* local coordinate extrema */ |
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MESHPATCH *patch; /* mesh patch list */ |
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int npatches; /* number of mesh patches */ |
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char *cdata; /* opaque client data pointer */ |
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struct mesh *next; /* next mesh in list */ |
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} MESH; |
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|
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/* A mesh instance */ |
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typedef struct { |
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FULLXF x; /* forward and backward transforms */ |
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MESH *msh; /* mesh object reference */ |
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} MESHINST; |
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|
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/* vertex flags */ |
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#define MT_V 01 |
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#define MT_N 02 |
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#define MT_UV 04 |
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#define MT_ALL 07 |
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|
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/* A mesh vertex */ |
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typedef struct { |
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int fl; /* setting flags */ |
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FVECT v; /* vertex location */ |
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FVECT n; /* vertex normal */ |
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FLOAT uv[2]; /* local coordinates */ |
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} MESHVERT; |
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|
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/* mesh format identifier */ |
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#define MESHFMT "Radiance_tmesh" |
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/* magic number for mesh files */ |
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#define MESHMAGIC ( 0 *MAXOBJSIZ+311) /* increment first value */ |
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|
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#ifdef NOPROTO |
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|
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extern MESH *getmesh(); |
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extern INSTANCE *getmeshinst(); |
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extern int getmeshtrivid(); |
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extern int getmeshvert(); |
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extern int getmeshtri(); |
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extern int4 addmeshvert(); |
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extern OBJECT addmeshtri(); |
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extern void printmeshstats(); |
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extern void freemesh(); |
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extern void freemeshinst(); |
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extern void readmesh(); |
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extern void writemesh(); |
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|
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#else |
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|
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extern MESH *getmesh(char *mname, int flags); |
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extern MESHINST *getmeshinst(OBJREC *o, int flags); |
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extern int getmeshtrivid(int4 tvid[3], MESH *mp, OBJECT ti); |
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extern int getmeshvert(MESHVERT *vp, MESH *mp, int4 vid, int what); |
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extern int getmeshtri(MESHVERT tv[3], MESH *mp, OBJECT ti, int what); |
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extern int4 addmeshvert(MESH *mp, MESHVERT *vp); |
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extern OBJECT addmeshtri(MESH *mp, MESHVERT tv[3]); |
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extern void printmeshstats(MESH *ms, FILE *fp); |
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extern void freemesh(MESH *ms); |
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extern void freemeshinst(OBJREC *o); |
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extern void readmesh(MESH *mp, char *path, int flags); |
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extern void writemesh(MESH *mp, FILE *fp); |
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|
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#endif /* NOPROTO */ |
