V_KnifeMetric.cpp

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    1 /*=========================================================================
    2  
    3   Module:    $RCSfile: V_KnifeMetric.cpp,v $
    4  
    5   Copyright (c) 2006 Sandia Corporation.
    6   All rights reserved.
    7   See Copyright.txt or http://www.kitware.com/Copyright.htm for details.
    8  
    9      This software is distributed WITHOUT ANY WARRANTY; without even
   10      the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
   11      PURPOSE.  See the above copyright notice for more information.
   12  
   13 =========================================================================*/
   14  
   15 /*
   16  *
   17  * KnifeMetrics.cpp contains quality calculations for knives
   18  *
   19  * This file is part of VERDICT
   20  *
   21  */
   22  
   23 #define VERDICT_EXPORTS
   24  
   25 #include "moab/verdict.h"
   26 #include "VerdictVector.hpp"
   27 #include <memory.h>
   28  
   29 /*  a knife element
   30  
   31           3
   32          _/\_
   33        _/  | \_
   34    0 _/        \_ 2
   35     |\_    | ___/|
   36     |  \  __/    |
   37     |  1\/ |     |
   38     |    \       |
   39     |_____\|_____|
   40    4       5      6
   41  
   42  
   43     (edge 3,5  is is a hidden line if you will)
   44  
   45     if this is hard to visualize, consider a hex
   46     with nodes 5 and 7 becoming the same node
   47  
   48  
   49 */
   50  
   51 /*!
   52   calculates the volume of a knife element
   53  
   54   this is done by dividing the knife into 4 tets
   55   and summing the volumes of each.
   56 */
   57  
   58 C_FUNC_DEF double v_knife_volume( int num_nodes, double coordinates[][3] )
   59 {
   60     double volume = 0;
   61     VerdictVector side1, side2, side3;
   62  
   63     if( num_nodes == 7 )
   64     {
   65  
   66         // divide the knife into 4 tets and calculate the volume
   67  
   68         side1.set( coordinates[1][0] - coordinates[0][0], coordinates[1][1] - coordinates[0][1],
   69                    coordinates[1][2] - coordinates[0][2] );
   70         side2.set( coordinates[3][0] - coordinates[0][0], coordinates[3][1] - coordinates[0][1],
   71                    coordinates[3][2] - coordinates[0][2] );
   72         side3.set( coordinates[4][0] - coordinates[0][0], coordinates[4][1] - coordinates[0][1],
   73                    coordinates[4][2] - coordinates[0][2] );
   74  
   75         volume = side3 % ( side1 * side2 ) / 6;
   76  
   77         side1.set( coordinates[5][0] - coordinates[1][0], coordinates[5][1] - coordinates[1][1],
   78                    coordinates[5][2] - coordinates[1][2] );
   79         side2.set( coordinates[3][0] - coordinates[1][0], coordinates[3][1] - coordinates[1][1],
   80                    coordinates[3][2] - coordinates[1][2] );
   81         side3.set( coordinates[4][0] - coordinates[1][0], coordinates[4][1] - coordinates[1][1],
   82                    coordinates[4][2] - coordinates[1][2] );
   83  
   84         volume += side3 % ( side1 * side2 ) / 6;
   85  
   86         side1.set( coordinates[2][0] - coordinates[1][0], coordinates[2][1] - coordinates[1][1],
   87                    coordinates[2][2] - coordinates[1][2] );
   88         side2.set( coordinates[3][0] - coordinates[1][0], coordinates[3][1] - coordinates[1][1],
   89                    coordinates[3][2] - coordinates[1][2] );
   90         side3.set( coordinates[6][0] - coordinates[1][0], coordinates[6][1] - coordinates[1][1],
   91                    coordinates[6][2] - coordinates[1][2] );
   92  
   93         volume += side3 % ( side1 * side2 ) / 6;
   94  
   95         side1.set( coordinates[3][0] - coordinates[1][0], coordinates[3][1] - coordinates[1][1],
   96                    coordinates[3][2] - coordinates[1][2] );
   97         side2.set( coordinates[5][0] - coordinates[1][0], coordinates[5][1] - coordinates[1][1],
   98                    coordinates[5][2] - coordinates[1][2] );
   99         side3.set( coordinates[6][0] - coordinates[1][0], coordinates[6][1] - coordinates[1][1],
  100                    coordinates[6][2] - coordinates[1][2] );
  101  
  102         volume += side3 % ( side1 * side2 ) / 6;
  103     }
  104  
  105     return (double)volume;
  106 }
  107  
  108 /*!
  109  
  110   calculate the quality metrics of a knife element.
  111  
  112   There is only one, but we put this here to be consistent with
  113   functions for other element types.  Who knows if we'll add
  114   more metrics.
  115 */
  116  
  117 C_FUNC_DEF void v_knife_quality( int num_nodes,
  118                                  double coordinates[][3],
  119                                  unsigned int metrics_request_flag,
  120                                  KnifeMetricVals* metric_vals )
  121 {
  122     memset( metric_vals, 0, sizeof( KnifeMetricVals ) );
  123  
  124     if( metrics_request_flag & V_KNIFE_VOLUME ) metric_vals->volume = v_knife_volume( num_nodes, coordinates );
  125 }