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/* Copyright (c) 1998 Silicon Graphics, Inc. */ |
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/* SCCSid "$SunId$ SGI" */ |
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/* |
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* sm_stree.h - header file for spherical quadtree code: |
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* |
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*/ |
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#define STR_INDEX(s) (stRoot_indices[(s)]) |
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#define STR_NTH_INDEX(s,n) (stRoot_indices[(s)][(n)]) |
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#define ST_NUM_ROOT_NODES 8 |
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/* The base is an octahedron: Each face contains a planar quadtree. At |
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the root level, the "top" (positive y) four faces, and bottom four faces |
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are stored together:forming two root quadtree nodes |
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*/ |
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typedef struct _STREE { |
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QUADTREE qt[2]; /* root[0]= top four faces, root[1]=bottom 4 faces*/ |
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FVECT center; /* sphere center */ |
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/* will go **************************************************/ |
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FVECT base[6]; /* 6 vertices on sphere that define base octahedron: |
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in canonical form: origin(0,0,0) points (1,0,0), |
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(0,1,0),(0,0,1),(-1,0,0),(0,-1,0),(0,0,-1) */ |
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FPEQ fplane[8]; /* Face plane equations */ |
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FVECT enorms[8][3]; /* Edge normals: For plane through edge and origin*/ |
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/* gone ****************************************************************/ |
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}STREE; |
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#define ST_BASEI(n) ((n)>>2) /* root index: top or bottom */ |
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#define ST_INDEX(n) ((n) & 0x3) /* which child in root */ |
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#define ST_QT(s,i) ((s)->qt[ST_BASEI(i)]) /* top or bottom root*/ |
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#define ST_QT_PTR(s,i) (&ST_QT(s,i)) /* ptr to top(0)/bottom(1)root*/ |
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#define ST_TOP_QT(s) ((s)->qt[0]) /* top root (y>0)*/ |
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#define ST_BOTTOM_QT(s) ((s)->qt[1]) /* bottom qt (y <= 0)*/ |
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#define ST_TOP_QT_PTR(s) (&ST_TOP_QT(s)) /* ptr to top qt */ |
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#define ST_BOTTOM_QT_PTR(s) (&ST_BOTTOM_QT(s)) /* ptr to bottom qt*/ |
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#define ST_ROOT_QT(s,n) QT_NTH_CHILD(ST_QT(s,n),ST_INDEX(n)) |
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#define ST_CLEAR_QT(st) (ST_TOP_QT(st)=EMPTY,ST_BOTTOM_QT(st)=EMPTY) |
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#define ST_INIT_QT(st) (QT_CLEAR_CHILDREN(ST_TOP_QT(st)), \ |
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QT_CLEAR_CHILDREN(ST_BOTTOM_QT(st))) |
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/* Will go *****************************************************/ |
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#define ST_BASE(s) ((s)->base) |
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#define ST_NTH_BASE(s,n) ((s)->base[(n)]) |
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#define ST_NTH_V(s,n,i) ST_NTH_BASE(s,stBase_verts[(n)][(i)]) |
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#define ST_SET_NTH_BASE(s,n,b) VCOPY(ST_NTH_BASE(s,n),b) |
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#define ST_SET_BASE(s,b) (VCOPY(ST_NTH_BASE(s,0),(b)[0]), \ |
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VCOPY(ST_NTH_BASE(s,1),(b)[1]), \ |
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VCOPY(ST_NTH_BASE(s,2),(b)[2]), \ |
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VCOPY(ST_NTH_BASE(s,3),(b)[3]), \ |
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VCOPY(ST_NTH_BASE(s,4),(b)[4]), \ |
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VCOPY(ST_NTH_BASE(s,5),(b)[5])) |
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#define ST_NTH_PLANE(s,i) ((s)->fplane[(i)]) |
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#define ST_NTH_NORM(s,i) (ST_NTH_PLANE(s,i).n) |
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#define ST_NTH_D(s,i) (ST_NTH_PLANE(s,i).d) |
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#define ST_EDGE_NORM(s,i,n) ((s)->enorms[(i)][(n)]) |
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/* gone *****************************************************/ |
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#define ST_CENTER(s) ((s)->center) |
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#define ST_SET_CENTER(s,b) VCOPY(ST_CENTER(s),b) |
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#define ST_COORD(s,p,r) VSUB(r,p,ST_CENTER(s)) |
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#define ST_CLEAR_FLAGS(s) qtClearAllFlags() |
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/* Point location based on coordinate signs */ |
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#define stLocate_root(p) (((p)[2]>0.0?0:4)|((p)[1]>0.0?0:2)|((p)[0]>0.0?0:1)) |
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#define ST_CLIP_VERTS 16 |
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/* STREE functions |
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void stInit(STREE *st,FVECT center) |
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Initializes an stree structure with origin 'center': |
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Frees existing quadtrees hanging off of the roots |
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STREE *stAlloc(STREE *st) |
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Allocates a stree structure and creates octahedron base |
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void stClear(STREE *st) |
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Frees any existing root children and clears roots |
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QUADTREE stPoint_locate(STREE *st,FVECT p) |
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Returns quadtree leaf node containing point 'p'. |
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int stAdd_tri(STREE *st,int id,FVECT t0,t1,t2) |
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Add triangle 'id' with coordinates 't0,t1,t2' to the stree: returns |
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FALSE on error, TRUE otherwise |
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int stRemove_tri(STREE *st,int id,FVECT t0,t1,t2) |
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Removes triangle 'id' with coordinates 't0,t1,t2' from stree: returns |
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FALSE on error, TRUE otherwise |
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int stTrace_ray(STREE *st,FVECT orig,dir,int (*func)(),int *arg1,*arg2) |
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Trace ray 'orig-dir' through stree and apply 'func(arg1,arg2)' at each |
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node that it intersects |
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int stApply_to_tri(STREE *st,FVECT t0,t1,t2,int (*edge_func)(), |
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(*tri_func)(),int arg1,*arg2) |
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Visit nodes intersected by tri 't0,t1,t2'.Apply 'edge_func(arg1,arg2,arg3)', |
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to those nodes intersected by edges, and interior_func to ALL nodes: |
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ie some Nodes will be visited more than once |
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*/ |
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extern int stBase_verts[8][3]; |
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extern STREE *stAlloc(); |
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extern QUADTREE stPoint_locate(); |
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