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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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#include "sm_qtree.h" |
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#define SQRT3_INV 0.5773502692 |
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typedef struct _STREE { |
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QUADTREE root; /* quadtree triangulation of sphere */ |
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FVECT center; /* sphere center */ |
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FVECT base[4]; /* 4 vertices on sphere that define base triangulation |
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of 4 triangles: assume cover sphere and triangles |
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are base verts (0,1,2),(0,2,3),(0,3,1), and (1,3,2) |
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*/ |
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}STREE; |
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#define ST_ROOT(s) ((s)->root) |
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#define ST_NTH_ROOT(s,n) QT_NTH_CHILD(ST_ROOT(s),n) |
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#define ST_NTH_ROOT_PTR(s,n) QT_NTH_CHILD_PTR(ST_ROOT(s),n) |
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#define ST_CLEAR_ROOT(s) QT_CLEAR_CHILDREN(ST_ROOT(s)) |
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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_BASE(s) ((s)->base) |
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#define ST_NTH_BASE(s,n) ((s)->base[(n)]) |
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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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#define ST_COORD(s,p,r) VSUB(r,p,ST_CENTER(s)) |
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/* STREE functions |
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STREE *stInit(STREE *st) |
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Initialize STREE: if st = NULL, allocate a new one, else clear |
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return pointer to initialized structure |
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QUADTREE *stPoint_locate(STREE *st,FVECT pt) |
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Find stree node that projection of pt on sphere falls in |
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stInsert_tri() |
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for every quadtree tri in the base- find node all leaf nodes that |
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tri overlaps and add tri to set. If this causes any of the nodes |
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to be over threshhold- split |
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stDelete_tri() |
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for every quadtree tri in the base- find node all leaf nodes that |
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tri overlaps. If this causes any of the nodes to be under |
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threshold- merge |
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*/ |
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extern int stTri_verts[4][3]; |
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extern FVECT stDefault_base[4]; |
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