/*
   orxonox - the future of 3D-vertical-scrollers

   Copyright (C) 2004 orx

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 2, or (at your option)
   any later version.

### File Specific:
   main-programmer: Patrick Boenzli
   co-programmer: ...
*/

#define DEBUG_SPECIAL_MODULE DEBUG_MODULE_COLLISION

#include "cd_engine.h"
#include "obb_tree.h"
#include "debug.h"

#include "model.h"
#include "world_entity.h"
#include "terrain.h"
// #include "player.h"

#include "spatial_separation.h"
#include "quadtree.h"
#include "quadtree_node.h"

#include "bsp_manager.h"

using namespace std;


/**
 *  standard constructor
 */
CDEngine::CDEngine ()
{
  this->setClassID(CL_CD_ENGINE, "CDEngine");
}


/**
 *  the singleton reference to this class
 */
CDEngine* CDEngine::singletonRef = NULL;


/**
 *  standard deconstructor
 */
CDEngine::~CDEngine ()
{
  CDEngine::singletonRef = NULL;
}


/**
 *  this is the collision checking function

    there are some speed improvements that can be done here. a rewrite of the list a would be appropriate to
    be able to enhance iteration speed.
 */
//void CDEngine::checkCollisions()
//{
//  this->checkCollisionObjects();
  //this->checkCollisionGround();
//}

/**
 *  this checks the collisions with the objects
 */
//void CDEngine::checkCollisionObjects()
//{
//   BVTree* tree;
//   tIterator<WorldEntity>* iterator1 = entityList->getIterator();
//   tIterator<WorldEntity>* iterator2 = entityList->getIterator();
//   WorldEntity* entity1 = iterator1->firstElement();
//   WorldEntity* entity2 = iterator2->iteratorElement(iterator1);
//   PRINTF(3)("checking for collisions\n");
//   while( entity1 != NULL)
//   {
//     if( likely(entity1 != this->terrain))
//     {
//       entity2 = iterator2->nextElement();
//
//       while( entity2 != NULL)
//       {
//         if( likely(entity2 != this->terrain))
//         {
//           PRINTF(4)("checking object %s against %s\n", entity1->getName(), entity2->getName());
//           tree = entity1->getOBBTree();
//           if( likely(tree != NULL) && entity2->getOBBTree() != NULL) tree->collideWith(entity1, entity2);
//         }
//         entity2 = iterator2->nextElement();
//       }
//     }
//     entity1 = iterator1->nextElement();
//     entity2 = iterator2->iteratorElement(iterator1);
//     entity2 = iterator2->nextElement();
//   }
//   delete iterator1;
//   delete iterator2;
//}

void CDEngine::checkCollisions(std::list<WorldEntity*>& list1, std::list<WorldEntity*>& list2)
{
  BVTree* tree;
  std::list<WorldEntity*>::iterator entity1, entity2, pre1, pre2;
  PRINTF(3)("checking for collisions\n");

  pre1 = list1.begin();
  while (pre1 != list1.end())
  {
    entity1 = pre1++;
    if( likely((*entity1) != this->terrain))
    {
      pre2 = list2.begin();
      while (pre2 != list2.end())
      {
        entity2 = pre2++;
        if( likely((*entity2) != this->terrain))
        {
          PRINTF(4)("checking object %s against %s\n", (*entity1)->getName(), (*entity2)->getName());
          tree = (*entity1)->getOBBTree();
          if( likely(tree != NULL) && (*entity2)->getOBBTree() != NULL) tree->collideWith(*entity1, *entity2);
        }
      }
    }
  }
}


/**
 *  this checks the collisions with the ground
 */
void CDEngine::checkCollisionGround(std::list<WorldEntity*>& list1)
{
  if( likely( this->terrain != NULL))
  {
    Quadtree* q = dynamic_cast<Terrain*>(this->terrain)->ssp->getQuadtree();
//    QuadtreeNode* n = q->getQuadtreeFromPosition(this->player->getAbsCoor());
  }
  
  if( likely( this->bspManager != NULL))
  {
    std::list<WorldEntity*>::iterator iterator;
    PRINTF(3)("checking for collisions\n");

    iterator = list1.begin();
    while (iterator != list1.end())
    {
      bspManager->checkCollision(*iterator);
      iterator++;
    }
  }
}


/**
 *  this draws the bounding volume tree
 * @param depth until which depth to draw the tree
 * @param drawMode mod which states how to draw it
 */
void CDEngine::drawBV(int depth, int drawMode) const
{
  /* this would operate on  worldList bases, for testing purposes, we only use one OBBTree */
  //this->rootTree->drawBV(depth, drawMode);
  /// FIXME
/*  tIterator<WorldEntity>* iterator = entityList->getIterator();
  WorldEntity* entity = iterator->firstElement();
  while( entity != NULL)
  {
    entity->drawBVTree(depth, drawMode);
    entity = iterator->nextElement();
  }
  delete iterator;*/
}


/**
 * some debug output on the class
 */
void CDEngine::debug()
{
  PRINT(0)("\n=============================| CDEngine::debug() |===\n");
  PRINT(0)("=  CDEngine: Spawning Tree Start\n");
  //this->rootTree->debug();
  PRINT(0)("=  CDEngine: Spawning Tree: Finished\n");
  PRINT(0)("=======================================================\n");

}


/**
 * this spawns a tree for debug purposes only
 */
void CDEngine::debugSpawnTree(int depth, sVec3D* vertices, int numVertices)
{
  if ( this->rootTree == NULL)
    this->rootTree = new OBBTree();
  this->rootTree->spawnBVTree(depth, vertices, numVertices);
}


void CDEngine::drawBV(const std::list<WorldEntity*>& drawList ) const
{
  std::list<WorldEntity*>::const_iterator entity;
  for (entity = drawList.begin(); entity != drawList.end(); entity++)
    if ((*entity)->isVisible())
      (*entity)->drawBVTree(3, 226);
}

/**
 * this draws the debug spawn tree
 */
void CDEngine::debugDraw(int depth, int drawMode)
{
  if(this-> rootTree != NULL)
    this->rootTree->drawBV(depth, drawMode);
}