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Diffstat (limited to 'third_party/glu/libtess/mesh.c')
| -rw-r--r-- | third_party/glu/libtess/mesh.c | 796 |
1 files changed, 796 insertions, 0 deletions
diff --git a/third_party/glu/libtess/mesh.c b/third_party/glu/libtess/mesh.c new file mode 100644 index 0000000..7305fab --- /dev/null +++ b/third_party/glu/libtess/mesh.c @@ -0,0 +1,796 @@ +/* +** License Applicability. Except to the extent portions of this file are +** made subject to an alternative license as permitted in the SGI Free +** Software License B, Version 1.1 (the "License"), the contents of this +** file are subject only to the provisions of the License. You may not use +** this file except in compliance with the License. You may obtain a copy +** of the License at Silicon Graphics, Inc., attn: Legal Services, 1600 +** Amphitheatre Parkway, Mountain View, CA 94043-1351, or at: +** +** http://oss.sgi.com/projects/FreeB +** +** Note that, as provided in the License, the Software is distributed on an +** "AS IS" basis, with ALL EXPRESS AND IMPLIED WARRANTIES AND CONDITIONS +** DISCLAIMED, INCLUDING, WITHOUT LIMITATION, ANY IMPLIED WARRANTIES AND +** CONDITIONS OF MERCHANTABILITY, SATISFACTORY QUALITY, FITNESS FOR A +** PARTICULAR PURPOSE, AND NON-INFRINGEMENT. +** +** Original Code. The Original Code is: OpenGL Sample Implementation, +** Version 1.2.1, released January 26, 2000, developed by Silicon Graphics, +** Inc. The Original Code is Copyright (c) 1991-2000 Silicon Graphics, Inc. +** Copyright in any portions created by third parties is as indicated +** elsewhere herein. All Rights Reserved. +** +** Additional Notice Provisions: The application programming interfaces +** established by SGI in conjunction with the Original Code are The +** OpenGL(R) Graphics System: A Specification (Version 1.2.1), released +** April 1, 1999; The OpenGL(R) Graphics System Utility Library (Version +** 1.3), released November 4, 1998; and OpenGL(R) Graphics with the X +** Window System(R) (Version 1.3), released October 19, 1998. This software +** was created using the OpenGL(R) version 1.2.1 Sample Implementation +** published by SGI, but has not been independently verified as being +** compliant with the OpenGL(R) version 1.2.1 Specification. +** +*/ +/* +** Author: Eric Veach, July 1994. +** +** $Date$ $Revision$ +** $Header: //depot/main/gfx/lib/glu/libtess/mesh.c#6 $ +*/ + +#include "gluos.h" +#include <stddef.h> +#include <assert.h> +#include "mesh.h" +#include "memalloc.h" + +#define TRUE 1 +#define FALSE 0 + +static GLUvertex *allocVertex() +{ + return (GLUvertex *)memAlloc( sizeof( GLUvertex )); +} + +static GLUface *allocFace() +{ + return (GLUface *)memAlloc( sizeof( GLUface )); +} + +/************************ Utility Routines ************************/ + +/* Allocate and free half-edges in pairs for efficiency. + * The *only* place that should use this fact is allocation/free. + */ +typedef struct { GLUhalfEdge e, eSym; } EdgePair; + +/* MakeEdge creates a new pair of half-edges which form their own loop. + * No vertex or face structures are allocated, but these must be assigned + * before the current edge operation is completed. + */ +static GLUhalfEdge *MakeEdge( GLUhalfEdge *eNext ) +{ + GLUhalfEdge *e; + GLUhalfEdge *eSym; + GLUhalfEdge *ePrev; + EdgePair *pair = (EdgePair *)memAlloc( sizeof( EdgePair )); + if (pair == NULL) return NULL; + + e = &pair->e; + eSym = &pair->eSym; + + /* Make sure eNext points to the first edge of the edge pair */ + if( eNext->Sym < eNext ) { eNext = eNext->Sym; } + + /* Insert in circular doubly-linked list before eNext. + * Note that the prev pointer is stored in Sym->next. + */ + ePrev = eNext->Sym->next; + eSym->next = ePrev; + ePrev->Sym->next = e; + e->next = eNext; + eNext->Sym->next = eSym; + + e->Sym = eSym; + e->Onext = e; + e->Lnext = eSym; + e->Org = NULL; + e->Lface = NULL; + e->winding = 0; + e->activeRegion = NULL; + + eSym->Sym = e; + eSym->Onext = eSym; + eSym->Lnext = e; + eSym->Org = NULL; + eSym->Lface = NULL; + eSym->winding = 0; + eSym->activeRegion = NULL; + + return e; +} + +/* Splice( a, b ) is best described by the Guibas/Stolfi paper or the + * CS348a notes (see mesh.h). Basically it modifies the mesh so that + * a->Onext and b->Onext are exchanged. This can have various effects + * depending on whether a and b belong to different face or vertex rings. + * For more explanation see __gl_meshSplice() below. + */ +static void Splice( GLUhalfEdge *a, GLUhalfEdge *b ) +{ + GLUhalfEdge *aOnext = a->Onext; + GLUhalfEdge *bOnext = b->Onext; + + aOnext->Sym->Lnext = b; + bOnext->Sym->Lnext = a; + a->Onext = bOnext; + b->Onext = aOnext; +} + +/* MakeVertex( newVertex, eOrig, vNext ) attaches a new vertex and makes it the + * origin of all edges in the vertex loop to which eOrig belongs. "vNext" gives + * a place to insert the new vertex in the global vertex list. We insert + * the new vertex *before* vNext so that algorithms which walk the vertex + * list will not see the newly created vertices. + */ +static void MakeVertex( GLUvertex *newVertex, + GLUhalfEdge *eOrig, GLUvertex *vNext ) +{ + GLUhalfEdge *e; + GLUvertex *vPrev; + GLUvertex *vNew = newVertex; + + assert(vNew != NULL); + + /* insert in circular doubly-linked list before vNext */ + vPrev = vNext->prev; + vNew->prev = vPrev; + vPrev->next = vNew; + vNew->next = vNext; + vNext->prev = vNew; + + vNew->anEdge = eOrig; + vNew->data = NULL; + /* leave coords, s, t undefined */ + + /* fix other edges on this vertex loop */ + e = eOrig; + do { + e->Org = vNew; + e = e->Onext; + } while( e != eOrig ); +} + +/* MakeFace( newFace, eOrig, fNext ) attaches a new face and makes it the left + * face of all edges in the face loop to which eOrig belongs. "fNext" gives + * a place to insert the new face in the global face list. We insert + * the new face *before* fNext so that algorithms which walk the face + * list will not see the newly created faces. + */ +static void MakeFace( GLUface *newFace, GLUhalfEdge *eOrig, GLUface *fNext ) +{ + GLUhalfEdge *e; + GLUface *fPrev; + GLUface *fNew = newFace; + + assert(fNew != NULL); + + /* insert in circular doubly-linked list before fNext */ + fPrev = fNext->prev; + fNew->prev = fPrev; + fPrev->next = fNew; + fNew->next = fNext; + fNext->prev = fNew; + + fNew->anEdge = eOrig; + fNew->data = NULL; + fNew->trail = NULL; + fNew->marked = FALSE; + + /* The new face is marked "inside" if the old one was. This is a + * convenience for the common case where a face has been split in two. + */ + fNew->inside = fNext->inside; + + /* fix other edges on this face loop */ + e = eOrig; + do { + e->Lface = fNew; + e = e->Lnext; + } while( e != eOrig ); +} + +/* KillEdge( eDel ) destroys an edge (the half-edges eDel and eDel->Sym), + * and removes from the global edge list. + */ +static void KillEdge( GLUhalfEdge *eDel ) +{ + GLUhalfEdge *ePrev, *eNext; + + /* Half-edges are allocated in pairs, see EdgePair above */ + if( eDel->Sym < eDel ) { eDel = eDel->Sym; } + + /* delete from circular doubly-linked list */ + eNext = eDel->next; + ePrev = eDel->Sym->next; + eNext->Sym->next = ePrev; + ePrev->Sym->next = eNext; + + memFree( eDel ); +} + + +/* KillVertex( vDel ) destroys a vertex and removes it from the global + * vertex list. It updates the vertex loop to point to a given new vertex. + */ +static void KillVertex( GLUvertex *vDel, GLUvertex *newOrg ) +{ + GLUhalfEdge *e, *eStart = vDel->anEdge; + GLUvertex *vPrev, *vNext; + + /* change the origin of all affected edges */ + e = eStart; + do { + e->Org = newOrg; + e = e->Onext; + } while( e != eStart ); + + /* delete from circular doubly-linked list */ + vPrev = vDel->prev; + vNext = vDel->next; + vNext->prev = vPrev; + vPrev->next = vNext; + + memFree( vDel ); +} + +/* KillFace( fDel ) destroys a face and removes it from the global face + * list. It updates the face loop to point to a given new face. + */ +static void KillFace( GLUface *fDel, GLUface *newLface ) +{ + GLUhalfEdge *e, *eStart = fDel->anEdge; + GLUface *fPrev, *fNext; + + /* change the left face of all affected edges */ + e = eStart; + do { + e->Lface = newLface; + e = e->Lnext; + } while( e != eStart ); + + /* delete from circular doubly-linked list */ + fPrev = fDel->prev; + fNext = fDel->next; + fNext->prev = fPrev; + fPrev->next = fNext; + + memFree( fDel ); +} + + +/****************** Basic Edge Operations **********************/ + +/* __gl_meshMakeEdge creates one edge, two vertices, and a loop (face). + * The loop consists of the two new half-edges. + */ +GLUhalfEdge *__gl_meshMakeEdge( GLUmesh *mesh ) +{ + GLUvertex *newVertex1= allocVertex(); + GLUvertex *newVertex2= allocVertex(); + GLUface *newFace= allocFace(); + GLUhalfEdge *e; + + /* if any one is null then all get freed */ + if (newVertex1 == NULL || newVertex2 == NULL || newFace == NULL) { + if (newVertex1 != NULL) memFree(newVertex1); + if (newVertex2 != NULL) memFree(newVertex2); + if (newFace != NULL) memFree(newFace); + return NULL; + } + + e = MakeEdge( &mesh->eHead ); + if (e == NULL) return NULL; + + MakeVertex( newVertex1, e, &mesh->vHead ); + MakeVertex( newVertex2, e->Sym, &mesh->vHead ); + MakeFace( newFace, e, &mesh->fHead ); + return e; +} + + +/* __gl_meshSplice( eOrg, eDst ) is the basic operation for changing the + * mesh connectivity and topology. It changes the mesh so that + * eOrg->Onext <- OLD( eDst->Onext ) + * eDst->Onext <- OLD( eOrg->Onext ) + * where OLD(...) means the value before the meshSplice operation. + * + * This can have two effects on the vertex structure: + * - if eOrg->Org != eDst->Org, the two vertices are merged together + * - if eOrg->Org == eDst->Org, the origin is split into two vertices + * In both cases, eDst->Org is changed and eOrg->Org is untouched. + * + * Similarly (and independently) for the face structure, + * - if eOrg->Lface == eDst->Lface, one loop is split into two + * - if eOrg->Lface != eDst->Lface, two distinct loops are joined into one + * In both cases, eDst->Lface is changed and eOrg->Lface is unaffected. + * + * Some special cases: + * If eDst == eOrg, the operation has no effect. + * If eDst == eOrg->Lnext, the new face will have a single edge. + * If eDst == eOrg->Lprev, the old face will have a single edge. + * If eDst == eOrg->Onext, the new vertex will have a single edge. + * If eDst == eOrg->Oprev, the old vertex will have a single edge. + */ +int __gl_meshSplice( GLUhalfEdge *eOrg, GLUhalfEdge *eDst ) +{ + int joiningLoops = FALSE; + int joiningVertices = FALSE; + + if( eOrg == eDst ) return 1; + + if( eDst->Org != eOrg->Org ) { + /* We are merging two disjoint vertices -- destroy eDst->Org */ + joiningVertices = TRUE; + KillVertex( eDst->Org, eOrg->Org ); + } + if( eDst->Lface != eOrg->Lface ) { + /* We are connecting two disjoint loops -- destroy eDst->Lface */ + joiningLoops = TRUE; + KillFace( eDst->Lface, eOrg->Lface ); + } + + /* Change the edge structure */ + Splice( eDst, eOrg ); + + if( ! joiningVertices ) { + GLUvertex *newVertex= allocVertex(); + if (newVertex == NULL) return 0; + + /* We split one vertex into two -- the new vertex is eDst->Org. + * Make sure the old vertex points to a valid half-edge. + */ + MakeVertex( newVertex, eDst, eOrg->Org ); + eOrg->Org->anEdge = eOrg; + } + if( ! joiningLoops ) { + GLUface *newFace= allocFace(); + if (newFace == NULL) return 0; + + /* We split one loop into two -- the new loop is eDst->Lface. + * Make sure the old face points to a valid half-edge. + */ + MakeFace( newFace, eDst, eOrg->Lface ); + eOrg->Lface->anEdge = eOrg; + } + + return 1; +} + + +/* __gl_meshDelete( eDel ) removes the edge eDel. There are several cases: + * if (eDel->Lface != eDel->Rface), we join two loops into one; the loop + * eDel->Lface is deleted. Otherwise, we are splitting one loop into two; + * the newly created loop will contain eDel->Dst. If the deletion of eDel + * would create isolated vertices, those are deleted as well. + * + * This function could be implemented as two calls to __gl_meshSplice + * plus a few calls to memFree, but this would allocate and delete + * unnecessary vertices and faces. + */ +int __gl_meshDelete( GLUhalfEdge *eDel ) +{ + GLUhalfEdge *eDelSym = eDel->Sym; + int joiningLoops = FALSE; + + /* First step: disconnect the origin vertex eDel->Org. We make all + * changes to get a consistent mesh in this "intermediate" state. + */ + if( eDel->Lface != eDel->Rface ) { + /* We are joining two loops into one -- remove the left face */ + joiningLoops = TRUE; + KillFace( eDel->Lface, eDel->Rface ); + } + + if( eDel->Onext == eDel ) { + KillVertex( eDel->Org, NULL ); + } else { + /* Make sure that eDel->Org and eDel->Rface point to valid half-edges */ + eDel->Rface->anEdge = eDel->Oprev; + eDel->Org->anEdge = eDel->Onext; + + Splice( eDel, eDel->Oprev ); + if( ! joiningLoops ) { + GLUface *newFace= allocFace(); + if (newFace == NULL) return 0; + + /* We are splitting one loop into two -- create a new loop for eDel. */ + MakeFace( newFace, eDel, eDel->Lface ); + } + } + + /* Claim: the mesh is now in a consistent state, except that eDel->Org + * may have been deleted. Now we disconnect eDel->Dst. + */ + if( eDelSym->Onext == eDelSym ) { + KillVertex( eDelSym->Org, NULL ); + KillFace( eDelSym->Lface, NULL ); + } else { + /* Make sure that eDel->Dst and eDel->Lface point to valid half-edges */ + eDel->Lface->anEdge = eDelSym->Oprev; + eDelSym->Org->anEdge = eDelSym->Onext; + Splice( eDelSym, eDelSym->Oprev ); + } + + /* Any isolated vertices or faces have already been freed. */ + KillEdge( eDel ); + + return 1; +} + + +/******************** Other Edge Operations **********************/ + +/* All these routines can be implemented with the basic edge + * operations above. They are provided for convenience and efficiency. + */ + + +/* __gl_meshAddEdgeVertex( eOrg ) creates a new edge eNew such that + * eNew == eOrg->Lnext, and eNew->Dst is a newly created vertex. + * eOrg and eNew will have the same left face. + */ +GLUhalfEdge *__gl_meshAddEdgeVertex( GLUhalfEdge *eOrg ) +{ + GLUhalfEdge *eNewSym; + GLUhalfEdge *eNew = MakeEdge( eOrg ); + if (eNew == NULL) return NULL; + + eNewSym = eNew->Sym; + + /* Connect the new edge appropriately */ + Splice( eNew, eOrg->Lnext ); + + /* Set the vertex and face information */ + eNew->Org = eOrg->Dst; + { + GLUvertex *newVertex= allocVertex(); + if (newVertex == NULL) return NULL; + + MakeVertex( newVertex, eNewSym, eNew->Org ); + } + eNew->Lface = eNewSym->Lface = eOrg->Lface; + + return eNew; +} + + +/* __gl_meshSplitEdge( eOrg ) splits eOrg into two edges eOrg and eNew, + * such that eNew == eOrg->Lnext. The new vertex is eOrg->Dst == eNew->Org. + * eOrg and eNew will have the same left face. + */ +GLUhalfEdge *__gl_meshSplitEdge( GLUhalfEdge *eOrg ) +{ + GLUhalfEdge *eNew; + GLUhalfEdge *tempHalfEdge= __gl_meshAddEdgeVertex( eOrg ); + if (tempHalfEdge == NULL) return NULL; + + eNew = tempHalfEdge->Sym; + + /* Disconnect eOrg from eOrg->Dst and connect it to eNew->Org */ + Splice( eOrg->Sym, eOrg->Sym->Oprev ); + Splice( eOrg->Sym, eNew ); + + /* Set the vertex and face information */ + eOrg->Dst = eNew->Org; + eNew->Dst->anEdge = eNew->Sym; /* may have pointed to eOrg->Sym */ + eNew->Rface = eOrg->Rface; + eNew->winding = eOrg->winding; /* copy old winding information */ + eNew->Sym->winding = eOrg->Sym->winding; + + return eNew; +} + + +/* __gl_meshConnect( eOrg, eDst ) creates a new edge from eOrg->Dst + * to eDst->Org, and returns the corresponding half-edge eNew. + * If eOrg->Lface == eDst->Lface, this splits one loop into two, + * and the newly created loop is eNew->Lface. Otherwise, two disjoint + * loops are merged into one, and the loop eDst->Lface is destroyed. + * + * If (eOrg == eDst), the new face will have only two edges. + * If (eOrg->Lnext == eDst), the old face is reduced to a single edge. + * If (eOrg->Lnext->Lnext == eDst), the old face is reduced to two edges. + */ +GLUhalfEdge *__gl_meshConnect( GLUhalfEdge *eOrg, GLUhalfEdge *eDst ) +{ + GLUhalfEdge *eNewSym; + int joiningLoops = FALSE; + GLUhalfEdge *eNew = MakeEdge( eOrg ); + if (eNew == NULL) return NULL; + + eNewSym = eNew->Sym; + + if( eDst->Lface != eOrg->Lface ) { + /* We are connecting two disjoint loops -- destroy eDst->Lface */ + joiningLoops = TRUE; + KillFace( eDst->Lface, eOrg->Lface ); + } + + /* Connect the new edge appropriately */ + Splice( eNew, eOrg->Lnext ); + Splice( eNewSym, eDst ); + + /* Set the vertex and face information */ + eNew->Org = eOrg->Dst; + eNewSym->Org = eDst->Org; + eNew->Lface = eNewSym->Lface = eOrg->Lface; + + /* Make sure the old face points to a valid half-edge */ + eOrg->Lface->anEdge = eNewSym; + + if( ! joiningLoops ) { + GLUface *newFace= allocFace(); + if (newFace == NULL) return NULL; + + /* We split one loop into two -- the new loop is eNew->Lface */ + MakeFace( newFace, eNew, eOrg->Lface ); + } + return eNew; +} + + +/******************** Other Operations **********************/ + +/* __gl_meshZapFace( fZap ) destroys a face and removes it from the + * global face list. All edges of fZap will have a NULL pointer as their + * left face. Any edges which also have a NULL pointer as their right face + * are deleted entirely (along with any isolated vertices this produces). + * An entire mesh can be deleted by zapping its faces, one at a time, + * in any order. Zapped faces cannot be used in further mesh operations! + */ +void __gl_meshZapFace( GLUface *fZap ) +{ + GLUhalfEdge *eStart = fZap->anEdge; + GLUhalfEdge *e, *eNext, *eSym; + GLUface *fPrev, *fNext; + + /* walk around face, deleting edges whose right face is also NULL */ + eNext = eStart->Lnext; + do { + e = eNext; + eNext = e->Lnext; + + e->Lface = NULL; + if( e->Rface == NULL ) { + /* delete the edge -- see __gl_MeshDelete above */ + + if( e->Onext == e ) { + KillVertex( e->Org, NULL ); + } else { + /* Make sure that e->Org points to a valid half-edge */ + e->Org->anEdge = e->Onext; + Splice( e, e->Oprev ); + } + eSym = e->Sym; + if( eSym->Onext == eSym ) { + KillVertex( eSym->Org, NULL ); + } else { + /* Make sure that eSym->Org points to a valid half-edge */ + eSym->Org->anEdge = eSym->Onext; + Splice( eSym, eSym->Oprev ); + } + KillEdge( e ); + } + } while( e != eStart ); + + /* delete from circular doubly-linked list */ + fPrev = fZap->prev; + fNext = fZap->next; + fNext->prev = fPrev; + fPrev->next = fNext; + + memFree( fZap ); +} + + +/* __gl_meshNewMesh() creates a new mesh with no edges, no vertices, + * and no loops (what we usually call a "face"). + */ +GLUmesh *__gl_meshNewMesh( void ) +{ + GLUvertex *v; + GLUface *f; + GLUhalfEdge *e; + GLUhalfEdge *eSym; + GLUmesh *mesh = (GLUmesh *)memAlloc( sizeof( GLUmesh )); + if (mesh == NULL) { + return NULL; + } + + v = &mesh->vHead; + f = &mesh->fHead; + e = &mesh->eHead; + eSym = &mesh->eHeadSym; + + v->next = v->prev = v; + v->anEdge = NULL; + v->data = NULL; + + f->next = f->prev = f; + f->anEdge = NULL; + f->data = NULL; + f->trail = NULL; + f->marked = FALSE; + f->inside = FALSE; + + e->next = e; + e->Sym = eSym; + e->Onext = NULL; + e->Lnext = NULL; + e->Org = NULL; + e->Lface = NULL; + e->winding = 0; + e->activeRegion = NULL; + + eSym->next = eSym; + eSym->Sym = e; + eSym->Onext = NULL; + eSym->Lnext = NULL; + eSym->Org = NULL; + eSym->Lface = NULL; + eSym->winding = 0; + eSym->activeRegion = NULL; + + return mesh; +} + + +/* __gl_meshUnion( mesh1, mesh2 ) forms the union of all structures in + * both meshes, and returns the new mesh (the old meshes are destroyed). + */ +GLUmesh *__gl_meshUnion( GLUmesh *mesh1, GLUmesh *mesh2 ) +{ + GLUface *f1 = &mesh1->fHead; + GLUvertex *v1 = &mesh1->vHead; + GLUhalfEdge *e1 = &mesh1->eHead; + GLUface *f2 = &mesh2->fHead; + GLUvertex *v2 = &mesh2->vHead; + GLUhalfEdge *e2 = &mesh2->eHead; + + /* Add the faces, vertices, and edges of mesh2 to those of mesh1 */ + if( f2->next != f2 ) { + f1->prev->next = f2->next; + f2->next->prev = f1->prev; + f2->prev->next = f1; + f1->prev = f2->prev; + } + + if( v2->next != v2 ) { + v1->prev->next = v2->next; + v2->next->prev = v1->prev; + v2->prev->next = v1; + v1->prev = v2->prev; + } + + if( e2->next != e2 ) { + e1->Sym->next->Sym->next = e2->next; + e2->next->Sym->next = e1->Sym->next; + e2->Sym->next->Sym->next = e1; + e1->Sym->next = e2->Sym->next; + } + + memFree( mesh2 ); + return mesh1; +} + + +#ifdef DELETE_BY_ZAPPING + +/* __gl_meshDeleteMesh( mesh ) will free all storage for any valid mesh. + */ +void __gl_meshDeleteMesh( GLUmesh *mesh ) +{ + GLUface *fHead = &mesh->fHead; + + while( fHead->next != fHead ) { + __gl_meshZapFace( fHead->next ); + } + assert( mesh->vHead.next == &mesh->vHead ); + + memFree( mesh ); +} + +#else + +/* __gl_meshDeleteMesh( mesh ) will free all storage for any valid mesh. + */ +void __gl_meshDeleteMesh( GLUmesh *mesh ) +{ + GLUface *f, *fNext; + GLUvertex *v, *vNext; + GLUhalfEdge *e, *eNext; + + for( f = mesh->fHead.next; f != &mesh->fHead; f = fNext ) { + fNext = f->next; + memFree( f ); + } + + for( v = mesh->vHead.next; v != &mesh->vHead; v = vNext ) { + vNext = v->next; + memFree( v ); + } + + for( e = mesh->eHead.next; e != &mesh->eHead; e = eNext ) { + /* One call frees both e and e->Sym (see EdgePair above) */ + eNext = e->next; + memFree( e ); + } + + memFree( mesh ); +} + +#endif + +#ifndef NDEBUG + +/* __gl_meshCheckMesh( mesh ) checks a mesh for self-consistency. + */ +void __gl_meshCheckMesh( GLUmesh *mesh ) +{ + GLUface *fHead = &mesh->fHead; + GLUvertex *vHead = &mesh->vHead; + GLUhalfEdge *eHead = &mesh->eHead; + GLUface *f, *fPrev; + GLUvertex *v, *vPrev; + GLUhalfEdge *e, *ePrev; + + fPrev = fHead; + for( fPrev = fHead ; (f = fPrev->next) != fHead; fPrev = f) { + assert( f->prev == fPrev ); + e = f->anEdge; + do { + assert( e->Sym != e ); + assert( e->Sym->Sym == e ); + assert( e->Lnext->Onext->Sym == e ); + assert( e->Onext->Sym->Lnext == e ); + assert( e->Lface == f ); + e = e->Lnext; + } while( e != f->anEdge ); + } + assert( f->prev == fPrev && f->anEdge == NULL && f->data == NULL ); + + vPrev = vHead; + for( vPrev = vHead ; (v = vPrev->next) != vHead; vPrev = v) { + assert( v->prev == vPrev ); + e = v->anEdge; + do { + assert( e->Sym != e ); + assert( e->Sym->Sym == e ); + assert( e->Lnext->Onext->Sym == e ); + assert( e->Onext->Sym->Lnext == e ); + assert( e->Org == v ); + e = e->Onext; + } while( e != v->anEdge ); + } + assert( v->prev == vPrev && v->anEdge == NULL && v->data == NULL ); + + ePrev = eHead; + for( ePrev = eHead ; (e = ePrev->next) != eHead; ePrev = e) { + assert( e->Sym->next == ePrev->Sym ); + assert( e->Sym != e ); + assert( e->Sym->Sym == e ); + assert( e->Org != NULL ); + assert( e->Dst != NULL ); + assert( e->Lnext->Onext->Sym == e ); + assert( e->Onext->Sym->Lnext == e ); + } + assert( e->Sym->next == ePrev->Sym + && e->Sym == &mesh->eHeadSym + && e->Sym->Sym == e + && e->Org == NULL && e->Dst == NULL + && e->Lface == NULL && e->Rface == NULL ); +} + +#endif |