#include "BasicDrawer.h"

#include <iostream>

using namespace std;

namespace X3DTK {
namespace MESH {

void BasicDrawer::drawFaces(MyMesh *M)
{
  glEnable(GL_LIGHTING);
  
  // Getting the faces.
  const MyMesh::MFFace &faces = M->getFaces();
  // iterating the faces. 
  for (MyMesh::MFFace::const_iterator f = faces.begin(), end = faces.end() ; f != end; ++f)
  {
    glBegin(GL_POLYGON);
    // getting the edges of the face.
    const MySFFace::MFEdge &edges = (*f)->getEdges();
    // iterating the edges to iterate the vertices of the face.
    for (MySFFace::MFEdge::const_iterator e = edges.begin(), end = edges.end() ; e != end; ++e)
    {
      // Getting the vertex.
      MySFVertex *v = (*e)->getFromVertex();
      // setting the normal of the vertex.
      glNormal3fv(v->data().getNormalOfFace(*f));

      // setting the color of the vertex depending on the distance.
      glColor3fv(getColor(v->data().getDistance()));
      
      // Getting the point data.   
      glVertex3fv(v->data().getPoint());
    }
    glEnd();
  }
}

SFColor BasicDrawer::getColor(float level) const
{
  float r, g, b;
  float f, q, V, S, t, v;
  int i;
  
  v = 4.0f*(1.0f - level);
  i = (int)floorf(v);
  f = v - i;
  q = 1.0f - f;
  t = f;
  V = 1.0f;
  S = 0.0f;

  switch(i)
  {
    case 0 : r = V;  g = t;  b = S; break;
    case 1 : r = q;  g = V;  b = S; break;
    case 2 : r = S;  g = V;  b = t;  break;
    case 3 : r = S;  g = q;  b = V;  break;
    case 4 : r = t;  g = S;  b = V;  break;
    default : r = 0.0f;  g = 0.0f;  b = 0.0f;  break;
  }
  
  return SFColor(r, g, b);
}

}
}