/* 
   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: ...
*/


#include "light.h"

#include "glincl.h"

using namespace std;

//! Definition of the Lights
int lightsV[] = {GL_LIGHT0, GL_LIGHT1, GL_LIGHT2, GL_LIGHT3, GL_LIGHT4, GL_LIGHT5, GL_LIGHT6, GL_LIGHT7};


/**
   \brief standard constructor for a Light
*/
Light::Light () 
{
  this->setClassName ("Light");

  glEnable (GL_LIGHTING);
  this->setAmbientColor(.3, .3, .3);
  this->lights = new LightValue*[NUMBEROFLIGHTS];
  for (int i = 0; i < NUMBEROFLIGHTS; i++)
    lights[i] = NULL;
  this->currentLight = NULL;
}

/**
   \brief standard deconstructor
   \todo this deconstructor is not jet implemented - do it

*/
Light::~Light () 
{
  glDisable(GL_LIGHTING);
  
  for (int i = 0; i < NUMBEROFLIGHTS; i++)
    this->deleteLight(i);
  delete lights;
  Light::singletonRef = NULL;
}

/**
   \brief singleton-Reference to the Light-class
*/
Light* Light::singletonRef = NULL;

/**
   \returns The Instance of the Lights
*/
Light* Light::getInstance(void)
{
  if (singletonRef)
    return singletonRef;
  else
    return Light::singletonRef = new Light();
}

/**
   \brief initializes a new Light with default values, and enables GL_LIGHTING
*/
void Light::init(int lightNumber)
{
  PRINTF(3)("initializing Light number %d.\n", lightNumber);
  // enable The light
  glEnable(lightsV[lightNumber]);
  this->currentLight = lights[lightNumber] = new LightValue;
  
  // set default values
  this->currentLight->lightNumber = lightNumber;
  this->setPosition(Vector(0.0, 0.0, 0.0));
  this->setDiffuseColor(1.0, 1.0, 1.0);
  this->setSpecularColor(1.0, 1.0, 1.0);
  //  lmodelAmbient[] = {.1, .1, .1, 1.0};
}

/**
   \brief Adds a new Light, by selecting the First free slot.

   if no slot is free error
*/
int Light::addLight(void)
{
  for (int i = 0; i < NUMBEROFLIGHTS; i++)
    if (!this->lights[i])
      return addLight(i); 
  PRINTF(1)("no more light slots availiable. All %d already taken\n", NUMBEROFLIGHTS);
  return -1;
}

/**
   \brief Adds a new Light
   \param lightNumber The number of the light to add.

   if the Number is not free: warn, automatically choose another slot.
*/
int Light::addLight(int lightNumber)
{
  if (this->lights[lightNumber])
    {
      PRINTF(2)("Lightslot %d is allready taken, trying another one\n", lightNumber);
      return this->addLight();
    }
  this->init(lightNumber);
  this->currentLight = this->lights[lightNumber];
  return lightNumber;
}

/**
   \brief select the light to work with
   \param lightNumber the light to work with
*/
void Light::editLightNumber(int lightNumber)
{
  if (!this->currentLight)
    { 
      PRINTF(1)("no Light defined yet\n");
      return;
    }

  this->currentLight = lights[lightNumber];
}

/**
   \brief Delete the current Light
*/
void Light::deleteLight(void)
{
  if (!this->currentLight)
    { 
      PRINTF(1)("no Light defined yet\n");
      return;
    }

  this->deleteLight(this->currentLight->lightNumber);
}

/**
   \brief delete light.
   \param lightnumber the number of the light to delete
*/
void Light::deleteLight(int lightNumber)
{
  if (this->lights[lightNumber])
    {
      PRINTF(3)("deleting Light number %d\n", lightNumber);
      delete this->lights[lightNumber];
      glDisable(lightsV[lightNumber]);
      this->lights[lightNumber] = NULL;
    }
}

// set Attributes
/**
   \brief Sets a Position for the Light.
   \param position The new position of the Light.
   \todo patrick: is it ok to set a Light Position even if it is derived from p_node??
*/
void Light::setPosition(Vector position)
{
  if (!this->currentLight)
    { 
      PRINTF(1)("no Light defined yet\n");
      return;
    }
  this->currentLight->lightPosition[0] = position.x;
  this->currentLight->lightPosition[1] = position.y;
  this->currentLight->lightPosition[2] = position.z;
  this->currentLight->lightPosition[3] = 0.0;

  glLightfv (GL_LIGHT0, GL_POSITION, this->currentLight->lightPosition);
}

void Light::setPosition(GLfloat x, GLfloat y, GLfloat z)
{
  if (!this->currentLight)
    { 
      PRINTF(1)("no Light defined yet\n");
      return;
    }

  this->currentLight->lightPosition[0] = x;
  this->currentLight->lightPosition[1] = y;
  this->currentLight->lightPosition[2] = z;
  this->currentLight->lightPosition[3] = 0.0;

  glLightfv (GL_LIGHT0, GL_POSITION, this->currentLight->lightPosition);
}

/**
   \brief sets an emitting Diffuse color for the Light
   \param r red
   \param g green
   \param b blue
*/
void Light::setDiffuseColor(GLfloat r, GLfloat g, GLfloat b)
{
  if (!this->currentLight)
    { 
      PRINTF(1)("no Light defined yet\n");
      return;
    }

  this->currentLight->diffuseColor[0] = r;
  this->currentLight->diffuseColor[1] = g;
  this->currentLight->diffuseColor[2] = b;
  this->currentLight->diffuseColor[3] = 1.0;

  glLightfv (GL_LIGHT0, GL_DIFFUSE, this->currentLight->diffuseColor);
}


/**
   \brief sets an emitting Ambient color for the Light
   \param r red
   \param g green
   \param b blue
*/
void Light::setSpecularColor(GLfloat r, GLfloat g, GLfloat b)
{
  if (!this->currentLight)
    { 
      PRINTF(1)("no Light defined yet\n");
      return;
    }

  this->currentLight->specularColor[0] = r;
  this->currentLight->specularColor[1] = g;
  this->currentLight->specularColor[2] = b;
  this->currentLight->specularColor[3] = 1.0;

  glLightfv (GL_LIGHT0, GL_SPECULAR, this->currentLight->specularColor);
}

/**
   \brief sets the ambient Color of the Scene
   \param r red
   \param g green
   \param b blue
*/
void Light::setAmbientColor(GLfloat r, GLfloat g, GLfloat b)
{
  this->ambientColor[0] = r;
  this->ambientColor[1] = g;
  this->ambientColor[2] = b;
  this->ambientColor[3] = 1.0;

  glLightfv (GL_LIGHT0, GL_AMBIENT, this->ambientColor);

}

// get Attributes

/**
   \returns the Position of the Light
*/
Vector Light::getPosition(void)
{
  if (!this->currentLight)
    { 
      PRINTF(1)("no Light defined yet\n");
      return Vector(.0, .0, .0);
    }
  else
    return Vector(this->currentLight->lightPosition[0], this->currentLight->lightPosition[1], this->currentLight->lightPosition[2]);
}