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Diffstat (limited to 'mesalib/src/glu/sgi/libnurbs/internals/hull.cc')
| -rw-r--r-- | mesalib/src/glu/sgi/libnurbs/internals/hull.cc | 165 |
1 files changed, 165 insertions, 0 deletions
diff --git a/mesalib/src/glu/sgi/libnurbs/internals/hull.cc b/mesalib/src/glu/sgi/libnurbs/internals/hull.cc new file mode 100644 index 000000000..389ba66fb --- /dev/null +++ b/mesalib/src/glu/sgi/libnurbs/internals/hull.cc @@ -0,0 +1,165 @@ +/* +** 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. +*/ + +/* + * hull.c++ + * + */ + +#include "glimports.h" +#include "myassert.h" +#include "mystdio.h" +#include "hull.h" +#include "gridvertex.h" +#include "gridtrimvertex.h" +#include "gridline.h" +#include "trimline.h" +#include "uarray.h" +#include "trimregion.h" + +Hull::Hull( void ) +{} + +Hull::~Hull( void ) +{} + +/*---------------------------------------------------------------------- + * Hull:init - this routine does the initialization needed before any + * calls to nextupper or nextlower can be made. + *---------------------------------------------------------------------- + */ +void +Hull::init( void ) +{ + TrimVertex *lfirst = left.first(); + TrimVertex *llast = left.last(); + if( lfirst->param[0] <= llast->param[0] ) { + fakeleft.init( left.first() ); + upper.left = &fakeleft; + lower.left = &left; + } else { + fakeleft.init( left.last() ); + lower.left = &fakeleft; + upper.left = &left; + } + upper.left->last(); + lower.left->first(); + + if( top.ustart <= top.uend ) { + upper.line = ⊤ + upper.index = top.ustart; + } else + upper.line = 0; + + if( bot.ustart <= bot.uend ) { + lower.line = ⊥ + lower.index = bot.ustart; + } else + lower.line = 0; + + TrimVertex *rfirst = right.first(); + TrimVertex *rlast = right.last(); + if( rfirst->param[0] <= rlast->param[0] ) { + fakeright.init( right.last() ); + lower.right = &fakeright; + upper.right = &right; + } else { + fakeright.init( right.first() ); + upper.right = &fakeright; + lower.right = &right; + } + upper.right->first(); + lower.right->last(); +} + +/*---------------------------------------------------------------------- + * nextupper - find next vertex on upper hull of trim region. + * - if vertex is on trim curve, set vtop point to + * that vertex. if vertex is on grid, set vtop to + * point to temporary area and stuff coordinants into + * temporary vertex. Also, place grid coords in temporary + * grid vertex. + *---------------------------------------------------------------------- + */ +GridTrimVertex * +Hull::nextupper( GridTrimVertex *gv ) +{ + if( upper.left ) { + gv->set( upper.left->prev() ); + if( gv->isTrimVert() ) return gv; + upper.left = 0; + } + + if( upper.line ) { + assert( upper.index <= upper.line->uend ); + gv->set( uarray.uarray[upper.index], upper.line->vval ); + gv->set( upper.index, upper.line->vindex ); + if( upper.index++ == upper.line->uend ) upper.line = 0; + return gv; + } + + if( upper.right ) { + gv->set( upper.right->next() ); + if( gv->isTrimVert() ) return gv; + upper.right = 0; + } + + return 0; +} + +GridTrimVertex * +Hull::nextlower( register GridTrimVertex *gv ) +{ + if( lower.left ) { + gv->set( lower.left->next() ); + if( gv->isTrimVert() ) return gv; + lower.left = 0; + } + + if( lower.line ) { + gv->set( uarray.uarray[lower.index], lower.line->vval ); + gv->set( lower.index, lower.line->vindex ); + if( lower.index++ == lower.line->uend ) lower.line = 0; + return gv; + } + + if( lower.right ) { + gv->set( lower.right->prev() ); + if( gv->isTrimVert() ) return gv; + lower.right = 0; + } + + return 0; +} + |