src/glu/sgi/libnurbs/internals/trimregion.cc

   1 /*
   2 ** License Applicability. Except to the extent portions of this file are
   3 ** made subject to an alternative license as permitted in the SGI Free
   4 ** Software License B, Version 1.1 (the "License"), the contents of this
   5 ** file are subject only to the provisions of the License. You may not use
   6 ** this file except in compliance with the License. You may obtain a copy
   7 ** of the License at Silicon Graphics, Inc., attn: Legal Services, 1600
   8 ** Amphitheatre Parkway, Mountain View, CA 94043-1351, or at:
   9 **
  10 ** http://oss.sgi.com/projects/FreeB
  11 **
  12 ** Note that, as provided in the License, the Software is distributed on an
  13 ** "AS IS" basis, with ALL EXPRESS AND IMPLIED WARRANTIES AND CONDITIONS
  14 ** DISCLAIMED, INCLUDING, WITHOUT LIMITATION, ANY IMPLIED WARRANTIES AND
  15 ** CONDITIONS OF MERCHANTABILITY, SATISFACTORY QUALITY, FITNESS FOR A
  16 ** PARTICULAR PURPOSE, AND NON-INFRINGEMENT.
  17 **
  18 ** Original Code. The Original Code is: OpenGL Sample Implementation,
  19 ** Version 1.2.1, released January 26, 2000, developed by Silicon Graphics,
  20 ** Inc. The Original Code is Copyright (c) 1991-2000 Silicon Graphics, Inc.
  21 ** Copyright in any portions created by third parties is as indicated
  22 ** elsewhere herein. All Rights Reserved.
  23 **
  24 ** Additional Notice Provisions: The application programming interfaces
  25 ** established by SGI in conjunction with the Original Code are The
  26 ** OpenGL(R) Graphics System: A Specification (Version 1.2.1), released
  27 ** April 1, 1999; The OpenGL(R) Graphics System Utility Library (Version
  28 ** 1.3), released November 4, 1998; and OpenGL(R) Graphics with the X
  29 ** Window System(R) (Version 1.3), released October 19, 1998. This software
  30 ** was created using the OpenGL(R) version 1.2.1 Sample Implementation
  31 ** published by SGI, but has not been independently verified as being
  32 ** compliant with the OpenGL(R) version 1.2.1 Specification.
  33 */
  34
  35 /*
  36  * trimregion.c++
  37  *
  38  */
  39
  40 #include "glimports.h"
  41 #include "myassert.h"
  42 #include "mystdio.h"
  43 #include "trimregion.h"
  44 #include "backend.h"
  45
  46 TrimRegion::TrimRegion( void )
  47 {
  48 }
  49
  50 void
  51 TrimRegion::setDu( REAL du )
  52 {
  53     oneOverDu = 1.0/du;
  54 }
  55
  56 void
  57 TrimRegion::init( long npts, Arc_ptr extrema )
  58 {
  59     left.init( npts, extrema, extrema->pwlArc->npts - 1 );
  60     left.getNextPt();
  61
  62     right.init( npts, extrema, 0 );
  63     right.getPrevPt();
  64 }
  65
  66 void
  67 TrimRegion::getPts( Arc_ptr extrema )
  68 {
  69     left.getNextPts( extrema );
  70     right.getPrevPts( extrema );
  71 }
  72
  73 void
  74 TrimRegion::getPts( Backend &backend )
  75 {
  76     left.getNextPts( bot.vval, backend );
  77     right.getPrevPts( bot.vval, backend );
  78 }
  79
  80 void
  81 TrimRegion::getGridExtent( void )
  82 {
  83     getGridExtent( left.last(), right.last() );
  84 }
  85
  86 void
  87 TrimRegion::getGridExtent( TrimVertex *l, TrimVertex *r )
  88 {
  89     bot.ustart = (long) ((l->param[0] - uarray.uarray[0])*oneOverDu);
  90     if( l->param[0] >= uarray.uarray[bot.ustart] ) bot.ustart++;
  91 //  if( l->param[0] > uarray.uarray[bot.ustart] ) bot.ustart++;
  92     assert( l->param[0] <= uarray.uarray[bot.ustart] );
  93     assert( l->param[0] >= uarray.uarray[bot.ustart-1] );
  94
  95     bot.uend = (long) ((r->param[0] - uarray.uarray[0])*oneOverDu);
  96     if( uarray.uarray[bot.uend] >= r->param[0] ) bot.uend--;
  97 //  if( uarray.uarray[bot.uend] > r->param[0] ) bot.uend--;
  98     assert( r->param[0] >= uarray.uarray[bot.uend] );
  99     assert( r->param[0] <= uarray.uarray[bot.uend+1] );
 100 }
 101
 102 int
 103 TrimRegion::canTile( void )
 104 {
 105     TrimVertex *lf = left.first();
 106     TrimVertex *ll = left.last();
 107     TrimVertex *l = ( ll->param[0] > lf->param[0] ) ? ll : lf;
 108
 109     TrimVertex *rf = right.first();
 110     TrimVertex *rl = right.last();
 111     TrimVertex *r = ( rl->param[0] < rf->param[0] ) ? rl : rf;
 112     return (l->param[0] <= r->param[0]) ? 1 : 0;
 113 }
 114