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/* Copyright (c) 1998 Silicon Graphics, Inc. */ |
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|
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#ifndef lint |
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static char SCCSid[] = "$SunId$ SGI"; |
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#endif |
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|
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/* |
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* sm_stree.c |
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*/ |
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#include "standard.h" |
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#include "object.h" |
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|
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#include "sm_geom.h" |
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#include "sm_stree.h" |
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|
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|
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/* Define 4 vertices on the sphere to create a tetrahedralization on |
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the sphere: triangles are as follows: |
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(0,1,2),(0,2,3), (0,3,1), (1,3,2) |
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*/ |
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|
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FVECT stDefault_base[4] = { {SQRT3_INV, SQRT3_INV, SQRT3_INV}, |
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{-SQRT3_INV, -SQRT3_INV, SQRT3_INV}, |
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{-SQRT3_INV, SQRT3_INV, -SQRT3_INV}, |
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{SQRT3_INV, -SQRT3_INV, -SQRT3_INV}}; |
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int stTri_verts[4][3] = { {2,1,0}, |
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{3,2,0}, |
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{1,3,0}, |
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{2,3,1}}; |
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|
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stNth_base_verts(st,i,v1,v2,v3) |
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STREE *st; |
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int i; |
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FVECT v1,v2,v3; |
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{ |
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VCOPY(v1,ST_NTH_BASE(st,stTri_verts[i][0])); |
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VCOPY(v2,ST_NTH_BASE(st,stTri_verts[i][1])); |
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VCOPY(v3,ST_NTH_BASE(st,stTri_verts[i][2])); |
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} |
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|
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/* Frees the 4 quadtrees rooted at st */ |
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stClear(st) |
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STREE *st; |
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{ |
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int i; |
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|
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/* stree always has 4 children corresponding to the base tris |
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*/ |
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for (i = 0; i < 4; i++) |
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qtFree(ST_NTH_ROOT(st, i)); |
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|
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QT_CLEAR_CHILDREN(ST_ROOT(st)); |
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|
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} |
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|
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|
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STREE |
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*stInit(st,center,base) |
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STREE *st; |
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FVECT center,base[4]; |
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{ |
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|
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if(base) |
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ST_SET_BASE(st,base); |
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else |
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ST_SET_BASE(st,stDefault_base); |
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|
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ST_SET_CENTER(st,center); |
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stClear(st); |
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|
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return(st); |
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} |
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|
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|
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/* "base" defines 4 vertices on the sphere to create a tetrahedralization on |
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the sphere: triangles are as follows:(0,1,2),(0,2,3), (0,3,1), (1,3,2) |
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if base is null: does default. |
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|
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*/ |
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STREE |
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*stAlloc(st) |
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STREE *st; |
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{ |
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int i; |
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|
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if(!st) |
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st = (STREE *)malloc(sizeof(STREE)); |
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|
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ST_ROOT(st) = qtAlloc(); |
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|
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QT_CLEAR_CHILDREN(ST_ROOT(st)); |
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|
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return(st); |
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} |
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|
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|
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/* Find location of sample point in the DAG and return lowest level |
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containing triangle. "type" indicates whether the point was found |
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to be in interior to the triangle: GT_FACE, on one of its |
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edges GT_EDGE or coinciding with one of its vertices GT_VERTEX. |
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"which" specifies which vertex (0,1,2) or edge (0=v0v1, 1 = v1v2, 2 = v21) |
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*/ |
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int |
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stPoint_locate(st,npt,type,which) |
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STREE *st; |
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FVECT npt; |
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char *type,*which; |
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{ |
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int i,d,j,id; |
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QUADTREE *rootptr,*qtptr; |
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FVECT v1,v2,v3; |
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OBJECT os[MAXSET+1],*optr; |
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char w; |
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FVECT p0,p1,p2; |
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|
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/* Test each of the root triangles against point id */ |
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for(i=0; i < 4; i++) |
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{ |
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rootptr = ST_NTH_ROOT_PTR(st,i); |
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stNth_base_verts(st,i,v1,v2,v3); |
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/* Return tri that p falls in */ |
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qtptr = qtRoot_point_locate(rootptr,v1,v2,v3,npt,NULL,NULL,NULL); |
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if(!qtptr) |
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continue; |
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/* Get the set */ |
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qtgetset(os,*qtptr); |
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for (j = QT_SET_CNT(os),optr = QT_SET_PTR(os); j > 0; j--) |
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{ |
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/* Find the first triangle that pt falls */ |
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id = QT_SET_NEXT_ELEM(optr); |
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qtTri_verts_from_id(id,p0,p1,p2); |
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d = test_single_point_against_spherical_tri(p0,p1,p2,npt,&w); |
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if(d) |
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{ |
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if(type) |
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*type = d; |
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if(which) |
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*which = w; |
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return(id); |
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} |
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} |
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} |
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if(which) |
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*which = 0; |
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if(type) |
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*type = 0; |
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return(EMPTY); |
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} |
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|
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QUADTREE |
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*stPoint_locate_cell(st,p,t0,t1,t2) |
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STREE *st; |
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FVECT p; |
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FVECT t0,t1,t2; |
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{ |
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int i,d; |
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QUADTREE *rootptr,*qtptr; |
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FVECT v0,v1,v2; |
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|
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|
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/* Test each of the root triangles against point id */ |
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for(i=0; i < 4; i++) |
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{ |
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rootptr = ST_NTH_ROOT_PTR(st,i); |
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stNth_base_verts(st,i,v0,v1,v2); |
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/* Return tri that p falls in */ |
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qtptr = qtRoot_point_locate(rootptr,v0,v1,v2,p,t0,t1,t2); |
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/* NOTE: For now return only one triangle */ |
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if(qtptr) |
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return(qtptr); |
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} /* Point not found */ |
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return(NULL); |
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} |
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|
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|
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QUADTREE |
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*stAdd_tri_from_pt(st,p,t_id) |
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STREE *st; |
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FVECT p; |
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int t_id; |
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{ |
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int i,d; |
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QUADTREE *rootptr,*qtptr; |
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FVECT v0,v1,v2; |
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|
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|
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/* Test each of the root triangles against point id */ |
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for(i=0; i < 4; i++) |
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{ |
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rootptr = ST_NTH_ROOT_PTR(st,i); |
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stNth_base_verts(st,i,v0,v1,v2); |
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/* Return tri that p falls in */ |
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qtptr = qtRoot_add_tri_from_point(rootptr,v0,v1,v2,p,t_id); |
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/* NOTE: For now return only one triangle */ |
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if(qtptr) |
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return(qtptr); |
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} /* Point not found */ |
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return(NULL); |
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} |
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|
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int |
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stAdd_tri(st,id,v0,v1,v2) |
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STREE *st; |
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int id; |
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FVECT v0,v1,v2; |
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{ |
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|
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int i,found; |
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QUADTREE *rootptr; |
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FVECT t0,t1,t2; |
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|
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found = 0; |
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for(i=0; i < 4; i++) |
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{ |
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rootptr = ST_NTH_ROOT_PTR(st,i); |
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stNth_base_verts(st,i,t0,t1,t2); |
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found |= qtRoot_add_tri(rootptr,id,v0,v1,v2,t0,t1,t2,0); |
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} |
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return(found); |
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} |
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|
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int |
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stApply_to_tri_cells(st,v0,v1,v2,func,arg) |
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STREE *st; |
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FVECT v0,v1,v2; |
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int (*func)(); |
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char *arg; |
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{ |
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int i,found; |
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QUADTREE *rootptr; |
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FVECT t0,t1,t2; |
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|
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found = 0; |
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for(i=0; i < 4; i++) |
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{ |
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rootptr = ST_NTH_ROOT_PTR(st,i); |
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stNth_base_verts(st,i,t0,t1,t2); |
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found |= qtApply_to_tri_cells(rootptr,v0,v1,v2,t0,t1,t2,func,arg); |
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} |
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return(found); |
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} |
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|
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|
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|
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|
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int |
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stRemove_tri(st,id,v0,v1,v2) |
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STREE *st; |
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int id; |
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FVECT v0,v1,v2; |
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{ |
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|
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int i,found; |
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QUADTREE *rootptr; |
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FVECT t0,t1,t2; |
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|
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found = 0; |
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for(i=0; i < 4; i++) |
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{ |
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rootptr = ST_NTH_ROOT_PTR(st,i); |
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stNth_base_verts(st,i,t0,t1,t2); |
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found |= qtRemove_tri(rootptr,id,v0,v1,v2,t0,t1,t2); |
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} |
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return(found); |
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} |
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|
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|
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|
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|
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|
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#if 0 |
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int |
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stAdd_tri_opt(st,id,v0,v1,v2) |
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STREE *st; |
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int id; |
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FVECT v0,v1,v2; |
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{ |
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|
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int i,found; |
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QUADTREE *qtptr; |
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FVECT pt,t0,t1,t2; |
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|
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/* First add all of the leaf cells lying on the triangle perimeter: |
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mark all cells seen on the way |
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*/ |
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/* clear all of the flags */ |
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qtClearAllFlags(); /* clear all quadtree branch flags */ |
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|
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/* Now trace each triangle edge-marking cells visited, and adding tri to |
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the leafs |
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*/ |
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stAdd_tri_from_pt(st,v0,id,t0,t1,t2); |
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/* Find next cell that projection of ray intersects */ |
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VCOPY(pt,v0); |
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/* NOTE: Check if in same cell */ |
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while(traceEdge(pt,v1,t0,t1,t2,pt)) |
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{ |
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stAdd_tri_from_pt(st,pt,id,t0,t1,t2); |
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traceEdge(pt,v1,t0,t1,t2,pt); |
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} |
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while(traceEdge(pt,v2,t0,t1,t2,pt)) |
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{ |
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stAdd_tri_from_pt(st,pt,id,t0,t1,t2); |
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traceEdge(pt,v2,t0,t1,t2,pt); |
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} |
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while(traceEdge(pt,v0,t0,t1,t2,pt)) |
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{ |
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stAdd_tri_from_pt(st,pt,id,t0,t1,t2); |
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traceEdge(pt,v2,t0,t1,t2,pt); |
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} |
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|
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/* NOTE: Optimization: if <= 2 cells added: dont need to fill */ |
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/* Traverse: follow nodes with flag set or one vertex in triangle */ |
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|
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} |
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|
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#endif |
