GaussQuadratureLin.cpp

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// Gmsh - Copyright (C) 1997-2022 C. Geuzaine, J.-F. Remacle
//
// See the LICENSE.txt file in the Gmsh root directory for license information.
// Please report all issues on https://gitlab.onelab.info/gmsh/gmsh/issues.
 
#include <vector>
#include "GaussIntegration.h"
#include "GaussLegendre1D.h"
 
static std::vector<IntPt *> GQL(40, nullptr);
 
IntPt *getGQLPts(int order)
{
  if(static_cast<int>(GQL.size()) < order + 1)
    GQL.resize(order + 1, nullptr);
  if(!GQL[order]) {
    // number of Gauss Point: (order + 1) / 2 *ROUNDED UP*
    int n = (order + 1) / (double)2 + 0.5;
    double *pt, *wt;
    gmshGaussLegendre1D(n, &pt, &wt);
    IntPt *intpt = new IntPt[n];
    for(int i = 0; i < n; i++) {
      intpt[i].pt[0] = pt[i];
      intpt[i].pt[1] = 0.0;
      intpt[i].pt[2] = 0.0;
      intpt[i].weight = wt[i];
    }
    GQL[order] = intpt;
  }
  return GQL[order];
}
 
int getNGQLPts(int order)
{
  return (order + 1) / (double)2 + 0.5;
}