A stupid question ...

[couet]

Hello, I would like to use CDT in the ROOT framework. I am just starting and I am trying to make a small prototype inspired by what I see in the CDT example. ROOt has a C++ interpreter which makes prototyping very easy. The code is the following:

#include "CDT.h"

struct Point2D
{
    double x;
    double y;
};


void CDT_Example() {

   auto g = new TGraph();
   g->SetMarkerColor(kRed);

   // Vector to be passed to CDT
   int np = 10;
   std::vector<Point2D> points(np);

   double x, y, P = 6.;
   TRandom *r = new TRandom();
   for (Int_t N=0; N<np; N++) {
      x = 2*P*(r->Rndm(N))-P;
      y = 2*P*(r->Rndm(N))-P;
      g->AddPoint(x,y);

      // Fill the vector points to be passed to CDT
      points[N].x = x;
      points[N].y = y;

   }

   g->Draw("A*");

   // CDT code
   CDT::Triangulation<double> cdt;

   cdt.insertVertices(
       points.begin(),
       points.end(),
       [](const Point2D& p){ return p.x; },
       [](const Point2D& p){ return p.y; }
   );

   auto t = cdt.triangles;

}

It works fine but I could not find the way to retrieve the triangles after the line auto t = cdt.triangles;.
Many thanks in advance for any help.

[artem-ogre]

After that line t contains std::vector<Triangle>
Each triangle holds indices of it's vertices and neighbor triangles:

/// Triangulation triangle (counter-clockwise winding)
/*
 *      v3
 *      /\
 *   n3/  \n2
 *    /____\
 *  v1  n1  v2
 */
struct CDT_EXPORT Triangle
{
    VerticesArr3 vertices;   ///< triangle's three vertices
    NeighborsArr3 neighbors; ///< triangle's three neighbors

Note: call cdt.eraseSuperTriangle() otherwise vertices and triangles will contain super-triangle (internally created triangle that contains all input vertices)

Does this answer your question?

[couet]

I did the following and it worked. I can see the result:

   auto t = cdt.triangles;

   cdt.eraseSuperTriangle();

   for (int iT = 0; iT < cdt.triangles.size(); iT++) {
      const auto& tri = cdt.triangles[iT];
      const auto& v1  = cdt.vertices[tri.vertices[0]];
      const auto& v2  = cdt.vertices[tri.vertices[1]];
      const auto& v3  = cdt.vertices[tri.vertices[2]];
      auto l1 = new TLine( v1.x, v1.y, v2.x, v2.y); l1->Draw();
      auto l2 = new TLine( v2.x, v2.y, v3.x, v3.y); l2->Draw();
      auto l3 = new TLine( v3.x, v3.y, v1.x, v1.y); l3->Draw();
   }