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Diffstat (limited to 'src/glu/sgi/libnurbs/internals/varray.cc')
| -rw-r--r-- | src/glu/sgi/libnurbs/internals/varray.cc | 146 |
1 files changed, 146 insertions, 0 deletions
diff --git a/src/glu/sgi/libnurbs/internals/varray.cc b/src/glu/sgi/libnurbs/internals/varray.cc new file mode 100644 index 00000000000..9b60f59b72a --- /dev/null +++ b/src/glu/sgi/libnurbs/internals/varray.cc @@ -0,0 +1,146 @@ +/* +** 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. +*/ + +/* + * varray.c++ + * + * $Date: 2002/11/01 23:35:07 $ $Revision: 1.2 $ + * $Header: /cvs/mesa/Mesa/src/glu/sgi/libnurbs/internals/varray.cc,v 1.2 2002/11/01 23:35:07 brianp Exp $ + */ + +#include "glimports.h" +#include "myassert.h" +#include "mystdio.h" +#include "varray.h" +#include "arc.h" +#include "simplemath.h" // glu_abs() + +#define TINY 0.0001 +inline long sgn( REAL x ) +{ + return (x < -TINY) ? -1 : ((x > TINY) ? 1 : 0 ); +} + + +Varray::Varray( void ) +{ + varray = 0; + size = 0; +} + +Varray::~Varray( void ) +{ + if( varray ) delete[] varray; +} + +inline void +Varray::update( Arc_ptr arc, long dir[2], REAL val ) +{ + register long ds = sgn(arc->tail()[0] - arc->prev->tail()[0]); + register long dt = sgn(arc->tail()[1] - arc->prev->tail()[1]); + + if( dir[0] != ds || dir[1] != dt ) { + dir[0] = ds; + dir[1] = dt; + append( val ); + } +} + +void +Varray::grow( long guess ) +{ + if( size < guess ) { + size = guess * 2; + if( varray ) delete[] varray; + varray = new REAL[size]; + assert( varray != 0 ); + } +} + +long +Varray::init( REAL delta, Arc_ptr toparc, Arc_ptr botarc ) +{ + Arc_ptr left = toparc->next; + Arc_ptr right = toparc; + long ldir[2], rdir[2]; + + ldir[0] = sgn( left->tail()[0] - left->prev->tail()[0] ); + ldir[1] = sgn( left->tail()[1] - left->prev->tail()[1] ); + rdir[0] = sgn( right->tail()[0] - right->prev->tail()[0] ); + rdir[1] = sgn( right->tail()[1] - right->prev->tail()[1] ); + + vval[0] = toparc->tail()[1]; + numquads = 0; + + while( 1 ) { + switch( sgn( left->tail()[1] - right->prev->tail()[1] ) ) { + case 1: + left = left->next; + update( left, ldir, left->prev->tail()[1] ); + break; + case -1: + right = right->prev; + update( right, rdir, right->tail()[1] ); + break; + case 0: + if( glu_abs(left->tail()[1] - botarc->tail()[1]) < TINY) goto end; + if( glu_abs(left->tail()[0]-right->prev->tail()[0]) < TINY && + glu_abs(left->tail()[1]-right->prev->tail()[1]) < TINY) goto end; + left = left->next; + break; + } + } + +end: + append( botarc->tail()[1] ); + + grow( ((long) ((vval[0] - vval[numquads])/delta)) + numquads + 2 ); + + long i, index = 0; + for( i=0; i<numquads; i++ ) { + voffset[i] = index; + varray[index++] = vval[i]; + REAL dist = vval[i] - vval[i+1]; + if( dist > delta ) { + long steps = ((long) (dist/delta)) +1; + float deltav = - dist / (REAL) steps; + for( long j=1; j<steps; j++ ) + varray[index++] = vval[i] + j * deltav; + } + } + voffset[i] = index; + varray[index] = vval[i]; + return index; +} + |