V_PyramidMetric.cpp

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    1 /*=========================================================================
    2  
    3   Module:    $RCSfile: V_PyramidMetric.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  * PyramidMetrics.cpp contains quality calculations for Pyramids
   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 /*
   30   the pyramid element
   31  
   32        5
   33        ^
   34        |\
   35       /| \\_
   36      |  \   \
   37      |  | \_ \_
   38      /   \/4\  \
   39     |   /|    \ \_
   40     | /  \      \ \
   41     /     |       \
   42   1 \_    |      _/3
   43       \_   \   _/
   44         \_ | _/
   45           \_/
   46           2
   47  
   48     a quadrilateral base and a pointy peak like a pyramid
   49  
   50 */
   51  
   52 /*!
   53   the volume of a pyramid
   54  
   55   the volume is calculated by dividing the pyramid into
   56   2 tets and summing the volumes of the 2 tets.
   57 */
   58  
   59 C_FUNC_DEF double v_pyramid_volume( int num_nodes, double coordinates[][3] )
   60 {
   61  
   62     double volume = 0;
   63     VerdictVector side1, side2, side3;
   64  
   65     if( num_nodes == 5 )
   66     {
   67         // divide the pyramid into 2 tets and calculate each
   68  
   69         side1.set( coordinates[1][0] - coordinates[0][0], coordinates[1][1] - coordinates[0][1],
   70                    coordinates[1][2] - coordinates[0][2] );
   71  
   72         side2.set( coordinates[3][0] - coordinates[0][0], coordinates[3][1] - coordinates[0][1],
   73                    coordinates[3][2] - coordinates[0][2] );
   74  
   75         side3.set( coordinates[4][0] - coordinates[0][0], coordinates[4][1] - coordinates[0][1],
   76                    coordinates[4][2] - coordinates[0][2] );
   77  
   78         // volume of the first tet
   79         volume = ( side3 % ( side1 * side2 ) ) / 6.0;
   80  
   81         side1.set( coordinates[3][0] - coordinates[2][0], coordinates[3][1] - coordinates[2][1],
   82                    coordinates[3][2] - coordinates[2][2] );
   83  
   84         side2.set( coordinates[1][0] - coordinates[2][0], coordinates[1][1] - coordinates[2][1],
   85                    coordinates[1][2] - coordinates[2][2] );
   86  
   87         side3.set( coordinates[4][0] - coordinates[2][0], coordinates[4][1] - coordinates[2][1],
   88                    coordinates[4][2] - coordinates[2][2] );
   89  
   90         // volume of the second tet
   91         volume += ( side3 % ( side1 * side2 ) ) / 6.0;
   92     }
   93     return (double)volume;
   94 }
   95  
   96 C_FUNC_DEF void v_pyramid_quality( int num_nodes,
   97                                    double coordinates[][3],
   98                                    unsigned int metrics_request_flag,
   99                                    PyramidMetricVals* metric_vals )
  100 {
  101     memset( metric_vals, 0, sizeof( PyramidMetricVals ) );
  102  
  103     if( metrics_request_flag & V_PYRAMID_VOLUME ) metric_vals->volume = v_pyramid_volume( num_nodes, coordinates );
  104 }