src/glu/sgi/libnurbs/internals/reader.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  *  reader.c++
  37  *
  38  * $Date: 2001/03/17 00:25:41 $ $Revision: 1.1 $
  39  * $Header: /home/krh/git/sync/mesa-cvs-repo/Mesa/src/glu/sgi/libnurbs/internals/reader.cc,v 1.1 2001/03/17 00:25:41 brianp Exp $
  40  */
  41
  42 #include <stdio.h>
  43 #include "glimports.h"
  44 #include "nurbsconsts.h"
  45 #include "reader.h"
  46 #include "trimvertex.h"
  47 #include "simplemath.h"
  48
  49 //when read a pwlCurve, if two consecutive points are the same, then
  50 //eliminate one of them. This makes the tessellator more robust. The spec
  51 //assumes the application makes sure there are no redundant points.
  52 //but in Inspector, the trim curves seem to have redundant points a lot.
  53 //I guess other similar users may have the same problem.
  54
  55 #define ELIMINATE_REDUNDANT_POINTS
  56
  57 #ifdef  ELIMINATE_REDUNDANT_POINTS
  58 #define equal(x,y) ( abs(x-y) <= 0.00001)
  59 #endif
  60
  61 #ifdef ELIMINATE_REDUNDANT_POINTS
  62 O_pwlcurve::O_pwlcurve( long _type, long count, INREAL *array, long byte_stride, TrimVertex *trimpts )
  63 {
  64     next = 0;
  65     used = 0;
  66     owner = 0;
  67     pts = trimpts;
  68     npts = (int) count;
  69     int i;
  70
  71     /* copy user data into internal trimming data structures */
  72     switch( _type ) {
  73         case N_P2D: {
  74             TrimVertex *v = pts;
  75             TrimVertex *prev = NULL;
  76             int num = 0;
  77             int doit;
  78             for(i=0; i<count; i++) {
  79                 doit = 1;
  80                 if(prev != NULL)
  81                   {
  82                     if(equal(prev->param[0], array[0]) && equal(prev->param[1], array[1]))
  83                       {
  84                         doit = 0;
  85                       }
  86                   }
  87
  88                 if(doit)
  89                   {
  90                     v->param[0] = (REAL) array[0];
  91                     v->param[1] = (REAL) array[1];
  92                     prev = v;
  93                     v++;
  94                     num++;
  95                   }
  96                 array = (INREAL *) (((char *) array) + byte_stride);
  97               }
  98             npts = num;
  99             break;
 100         }
 101         case N_P2DR: {
 102             TrimVertex *v = pts;
 103             for( TrimVertex *lastv = v + count; v != lastv; v++ ) {
 104                 v->param[0] = (REAL) array[0] / (REAL) array[2];
 105                 v->param[1] = (REAL) array[1] / (REAL) array[2];
 106                 array = (INREAL *) (((char *) array) + byte_stride);
 107             }
 108             break;
 109         }
 110     }
 111 }
 112 #else
 113 O_pwlcurve::O_pwlcurve( long _type, long count, INREAL *array, long byte_stride, TrimVertex *trimpts )
 114 {
 115     next = 0;
 116     used = 0;
 117     owner = 0;
 118     pts = trimpts;
 119     npts = (int) count;
 120
 121     /* copy user data into internal trimming data structures */
 122     switch( _type ) {
 123         case N_P2D: {
 124             TrimVertex *v = pts;
 125             for( TrimVertex *lastv = v + count; v != lastv; v++ ) {
 126                 v->param[0] = (REAL) array[0];
 127                 v->param[1] = (REAL) array[1];
 128                 array = (INREAL *) (((char *) array) + byte_stride);
 129             }
 130             break;
 131         }
 132         case N_P2DR: {
 133             TrimVertex *v = pts;
 134             for( TrimVertex *lastv = v + count; v != lastv; v++ ) {
 135                 v->param[0] = (REAL) array[0] / (REAL) array[2];
 136                 v->param[1] = (REAL) array[1] / (REAL) array[2];
 137                 array = (INREAL *) (((char *) array) + byte_stride);
 138             }
 139             break;
 140         }
 141     }
 142 }
 143 #endif
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