#include "SphereDrawArray.h"

#include <math.h>

using namespace std;

namespace X3DTK {
namespace GL {

SphereDrawArray::refList SphereDrawArray::_refList = SphereDrawArray::refList();

SphereDrawArray *SphereDrawArray::getInstanceOfSection(unsigned int section)
{
  for (refList::iterator it = _refList.begin(); it != _refList.end(); ++it)
  {
    if ((*it).first == section)
    {
      ++(*it).second.count;
      return (*it).second.ref;
    }  
  }
  
  SphereDrawArray *c = new SphereDrawArray(section);
  data d;
  d.count = 1;
  d.ref = c;
  _refList.push_back(pair<unsigned int, data>(section, d));
  return c;
}

void SphereDrawArray::removeInstance()
{
  for (refList::iterator it = _refList.begin(); it != _refList.end(); ++it)
  {
    if ((*it).first == _section)
    {
      if ((*it).second.count > 0)
      {
        --(*it).second.count;
        if ((*it).second.count == 0)
        {
          delete (*it).second.ref;
          _refList.erase(it);
        }  
      }    
      return;  
    }  
  }
}

SphereDrawArray::SphereDrawArray(unsigned int section)
{
  _section = section;
  unsigned int sub_phi = section;
  unsigned int sub_theta = section;
  
  //filling the vertex array
  _sphereVertexArray = vector<N3F_V3F>(sub_theta*(sub_phi - 1) + 2);  
  
  _sphereVertexArray[0].normal = SFVec3f(0.0f, 1.0f, 0.0f);
  _sphereVertexArray[0].vertex = SFVec3f(0.0f, 1.0f, 0.0f);
  for (unsigned int i = 1; i < sub_phi; ++i)
  {
    for (unsigned int j = 0; j < sub_theta; ++j)
    {
      float phi = (float)PI*(float)i/sub_phi;
      float theta = 2.0f*(float)PI*(float)j/sub_theta;
      SFVec3f vec(sinf(theta)*sinf(phi), cosf(phi), cosf(theta)*sinf(phi));
      _sphereVertexArray[(i - 1)*sub_theta + j + 1].normal = vec;
      _sphereVertexArray[(i - 1)*sub_theta + j + 1].vertex = vec;      
    }
  }
  _sphereVertexArray[sub_theta*(sub_phi - 1) + 1].normal = SFVec3f(0.0f, -1.0f, 0.0f);
  _sphereVertexArray[sub_theta*(sub_phi - 1) + 1].vertex = SFVec3f(0.0f, -1.0f, 0.0f);

  //filling the index array
  _sphereIndexArray = vector<unsigned int>();
  for (unsigned int j = 0; j < sub_theta - 1; ++j)
  {
    _sphereIndexArray.push_back(0);
    _sphereIndexArray.push_back(j + 2);
    _sphereIndexArray.push_back(j + 1);
  }
  _sphereIndexArray.push_back(0);
  _sphereIndexArray.push_back(1);
  _sphereIndexArray.push_back(sub_theta);
  
  for (unsigned int k = 0; k < sub_phi - 2; ++k)
  {
    for (unsigned int j = 0; j < sub_theta - 1; ++j)
    {
      _sphereIndexArray.push_back(1 + (k*sub_theta + j));
      _sphereIndexArray.push_back(1 + ((k + 1)*sub_theta + j + 1));
      _sphereIndexArray.push_back(1 + ((k + 1)*sub_theta + j));
            
      _sphereIndexArray.push_back(1 + ((k + 1)*sub_theta + j + 1));
      _sphereIndexArray.push_back(1 + (k*sub_theta + j));
      _sphereIndexArray.push_back(1 + (k*sub_theta + j + 1));
    }
    _sphereIndexArray.push_back(1 + ((k + 1)*sub_theta + sub_theta - 1));
    _sphereIndexArray.push_back(1 + (k*sub_theta + sub_theta - 1));
    _sphereIndexArray.push_back(1 + ((k + 1)*sub_theta));
      
    _sphereIndexArray.push_back(1 + ((k + 1)*sub_theta));
    _sphereIndexArray.push_back(1 + (k*sub_theta + sub_theta - 1));
    _sphereIndexArray.push_back(1 + (k*sub_theta));
  }
  
  for (unsigned int l = 0; l < sub_theta - 1; ++l)
  {
    _sphereIndexArray.push_back(1 + ((sub_phi - 2)*sub_theta + l));
    _sphereIndexArray.push_back(1 + ((sub_phi - 2)*sub_theta + l + 1));
    _sphereIndexArray.push_back(sub_theta*(sub_phi - 1) + 1);    
  }
  _sphereIndexArray.push_back(1 + ((sub_phi - 2)*sub_theta + sub_theta - 1));
  _sphereIndexArray.push_back(1 + ((sub_phi - 2)*sub_theta));
  _sphereIndexArray.push_back(sub_theta*(sub_phi - 1) + 1);
}

unsigned int SphereDrawArray::getSphereSize() const
{
  return _sphereIndexArray.size();
}

const void *SphereDrawArray::getSphereVertexArrayAddress() const
{
  return &_sphereVertexArray.front();
}
    
const unsigned int *SphereDrawArray::getSphereIndexArrayAddress() const
{
  return &_sphereIndexArray.front();
}

}
}