/*
   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: Benjamin Grauer
   co-programmer: ...
*/

//#define DEBUG_SPECIAL_MODULE DEBUG_MODULE_

#include "element_2d.h"
#include "render_2d.h"

#include "graphics_engine.h"
#include "p_node.h"
#include "load_param.h"
#include "tinyxml.h"
#include "class_list.h"

using namespace std;


/**
 * standard constructor
 * @todo this constructor is not jet implemented - do it
*/
Element2D::Element2D ()
{
  this->init();
}

/**
 * standard deconstructor
*/
Element2D::~Element2D ()
{
  // delete what has to be deleted here
  Render2D::getInstance()->unregisterElement2D(this);
}


/**
 * initializes a Element2D
 */
void Element2D::init()
{
  this->setClassID(CL_ELEMENT_2D, "Element2D");

  this->setVisibility(true);
  this->setActiveness(true);
  this->setPosition2D(0,0);
  this->setAlignment(E2D_ALIGN_NONE);
  this->layer = E2D_TOP;

  Render2D::getInstance()->registerElement2D(this);
}

/**
 * Loads the Parameters of an Element2D from...
 * @param root The XML-element to load from
 */
void Element2D::loadParams(const TiXmlElement* root)
{
  LoadParam<Element2D>(root, "alignment", this, &Element2D::setAlignment)
      .describe("loads the alignment: (either: center, left, right or screen-center)");

  LoadParam<Element2D>(root, "layer", this, &Element2D::setLayer)
      .describe("loads the layer onto which to project: (either: top, medium, bottom, below-all)");

  LoadParam<Element2D>(root, "bind-node", this, &Element2D::setBindNode)
      .describe("sets a node, this 2D-Element should be shown upon (name of the node)");

  LoadParam<Element2D>(root, "2d-position", this, &Element2D::setPosition2D)
      .describe("the _relative_ position (away from alignment) this 2d-element shows");

  LoadParam<Element2D>(root, "visibility", this, &Element2D::setVisibility)
      .describe("if the Element is visible or not");
}

/**
 * sets the alignment of the 2D-element in form of a String
 * @param alignment the alignment @see loadParams
*/
void Element2D::setAlignment(const char* alignment)
{
  if (!strcmp(alignment, "center"))
    this->setAlignment(E2D_ALIGN_CENTER);
  else if (!strcmp(alignment, "left"))
    this->setAlignment(E2D_ALIGN_LEFT);
  else if (!strcmp(alignment, "right"))
    this->setAlignment(E2D_ALIGN_RIGHT);
  else if (!strcmp(alignment, "screen-center"))
    this->setAlignment(E2D_ALIGN_SCREEN_CENTER);
}


/**
 * moves a Element to another layer
 * @param layer the Layer this is drawn on
 */
void Element2D::setLayer(E2D_LAYER layer)
{
  Render2D::getInstance()->moveToLayer(this, layer);
  this->layer = layer;
}

/**
 * sets the layer onto which this 2D-element is projected to.
 * @param layer the layer @see loadParams
 */
void Element2D::setLayer(const char* layer)
{
  if (!strcmp(layer, "top"))
    this->setLayer(E2D_TOP);
  else if (!strcmp(layer, "medium"))
    this->setLayer(E2D_MEDIUM);
  else if (!strcmp(layer, "bottom"))
    this->setLayer(E2D_BOTTOM);
  else if (!strcmp(layer, "below-all"))
    this->setLayer(E2D_BELOW_ALL);
}


/**
 * sets a node, this 2D-Element should be shown upon
 * @param bindNode the name of the Node (should be existing)
 */
void Element2D::setBindNode(const char* bindNode)
{
  const PNode* tmpBindNode = dynamic_cast<const PNode*>(ClassList::getObject(bindNode, CL_PARENT_NODE));
  if (tmpBindNode != NULL)
    this->bindNode = tmpBindNode;
}

/**
 * this sets the position of the Element on the screen.
 * Use this in the your tick function, if you want the element to be automatically positioned.
 */
void Element2D::positioning()
{
  // setting the Position of this 2D-Element.
  if (this->alignment == E2D_ALIGN_SCREEN_CENTER)
  {
    absPos2D.x = GraphicsEngine::getInstance()->getResolutionX()/2 + this->relPos2D[0];
    absPos2D.y = GraphicsEngine::getInstance()->getResolutionY()/2 + this->relPos2D[1];
    absPos2D.depth = 0;
  }
  else if (this->bindNode)
  {
    GLdouble projectPos[3];
    gluProject(this->bindNode->getAbsCoor().x,
               this->bindNode->getAbsCoor().y,
               this->bindNode->getAbsCoor().z,
               GraphicsEngine::modMat,
               GraphicsEngine::projMat,
               GraphicsEngine::viewPort,
               projectPos,
               projectPos+1,
               projectPos+2);
    absPos2D.x = projectPos[0] + this->relPos2D[0];
    absPos2D.y = GraphicsEngine::getInstance()->getResolutionY() - projectPos[1] + this->relPos2D[1];
    absPos2D.depth = projectPos[2];
  }
  else
  {
    absPos2D.x = this->relPos2D[0];
    absPos2D.y = this->relPos2D[1];
    absPos2D.depth = 0;
  }
}

/**
 * ticks the 2d-Element
 * @param dt the time elapsed since the last tick
 */
void Element2D::tick(float dt)
{
  this->positioning();
}