/* 
   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_PARTICLE

#include "particle_system.h"

#include "particle_emitter.h"
#include "particle_engine.h"
#include "compiler.h"
#include "material.h"

using namespace std;

/**
   \brief standard constructor
   \param count the Count of particles in the System
   \param type The Type of the ParticleSystem

   \todo this constructor is not jet implemented - do it
*/
ParticleSystem::ParticleSystem (unsigned int maxCount, PARTICLE_TYPE type)
{
   this->setClassName ("ParticleSystem");

   this->maxCount = maxCount;
   this->count = 0;
   this->particleType = type;
   this->particles = NULL;
   this->setConserve(.8);
   this->setLifeSpan(.1);
   this->setInheritSpeed(0);
   this->glID = NULL;
   this->setRadius(1.0, 1.0, 0.0);
   this->setType(PARTICLE_SPRITE, 1);
   ParticleEngine::getInstance()->addSystem(this);
}


/**
   \brief standard deconstructor

*/
ParticleSystem::~ParticleSystem() 
{
  // delete what has to be deleted here
   ParticleEngine::getInstance()->removeSystem(this);
}


void ParticleSystem::setType(PARTICLE_TYPE particleType, int count)
{
  this->particleType = particleType;
  this->dialectCount = count;
  if (glID != NULL)
    delete glID;

  glID = new GLuint[count];
  for (int i = 0; i< count; i++)
    glID[i] = 0;

  glID[0] = glGenLists(count);
  
  material = new Material("transperencyMap");
  material->setDiffuseMap("pictures/radialTransparency.jpg");
  
  glNewList(glID[0], GL_COMPILE);
  glBegin(GL_TRIANGLE_STRIP);
  glTexCoord2f(1, 1);
  glVertex3f(0.0, 1.0, 1.0);
  glTexCoord2f(1, 0);
  glVertex3f(0.0, 1.0, 0.0);
  glTexCoord2f(0, 1);
  glVertex3f(0.0, 0.0, 1.0);
  glTexCoord2f(0, 0);
  glVertex3f(0.0, 0.0, 0.0);
  glEnd();
  glEndList();

  

}

// setting properties
void ParticleSystem::setMaterial(Material* material)
{
  this->material = material;
}



/**
   \brief how much of the speed from the ParticleEmitter should flow onto the ParticleSystem
   \param value a Value between zero and one

   
   if you want to change the value of this variable during emission time (to make it more dynamic)
   you may want to use the animation class
*/
void ParticleSystem::setInheritSpeed(float value)
{
  if (unlikely(value > 1.0))
    this->inheritSpeed = 1;
  else if (unlikely(value < 0.0))
    this->inheritSpeed = 0;
  else
    this->inheritSpeed = value;
}


void ParticleSystem::setLifeSpan(float lifeSpan, float randomLifeSpan)
{
  this->lifeSpan = lifeSpan;
  this->randomLifeSpan = randomLifeSpan;
}

void ParticleSystem::setRadius(float startRadius, float endRadius, float randomStartRadius, float randomEndRadius)
{
  this->startRadius = startRadius;
  this->endRadius = endRadius;
  this->randomStartRadius = randomStartRadius;
  this->randomEndRadius = randomEndRadius;
}

void ParticleSystem::setConserve(float conserve)
{
  if (conserve > 1.0)
    this->conserve = 1.0;
  else if (conserve < 0.0)
    this->conserve = 0.0;
  else
    this->conserve = conserve;
}



void ParticleSystem::tick(float dt)
{
  Particle* tickPart = particles;  // the particle to Tick
  Particle* prevPart = NULL;       // 
  while (likely(tickPart != NULL))
    {
      
      tickPart->position = tickPart->position + tickPart->velocity;
      tickPart->radius += tickPart->radiusIt * dt;

      // many more to come



      if (this->conserve < 1.0)
	tickPart->velocity = tickPart->velocity * this->conserve;
      // find out if we have to delete tickPart
      if ((tickPart->timeToLive -= dt) <= 0)
	{
	  // remove the particle from the list
	  if (likely(prevPart != NULL))
	    {
	      prevPart->next = tickPart->next;
	      delete tickPart;
	      tickPart = prevPart->next;
	    }
	  else
	    {
	      prevPart = NULL;
	      this->particles = tickPart->next;
	      delete tickPart;
	      tickPart = this->particles;
	    }
	  --this->count;
	}
      else
	{      
	  prevPart = tickPart;
	  tickPart = tickPart->next;
	}
    }
}

void ParticleSystem::draw(void)
{
  //  material->select();


  glMatrixMode(GL_MODELVIEW);
  
  Particle* drawPart = particles;
  if (likely(drawPart != NULL))
    {
      glBegin(GL_POINTS);
      while (likely(drawPart != NULL))
	{
	  // draw in DOT mode
	  glPushMatrix();
	  glTranslatef(drawPart->position.x, drawPart->position.y, drawPart->position.z);
	  glScalef(drawPart->radius, drawPart->radius, drawPart->radius);
	  glCallList(*this->glID);
	  
	  //	  	  glVertex3f(drawPart->position.x, drawPart->position.y, drawPart->position.z);
	  drawPart = drawPart->next;
	  glPopMatrix();
	}
      glEnd();
    }
}


void ParticleSystem::addParticle(Vector position, Vector velocity, unsigned int data)
{
  if (this->count <= this->maxCount)
    {
      // if it is the first Particle
      if (unlikely(particles == NULL))
	{
	  this->particles = new Particle;
	  this->particles->next = NULL;
	}
      // filling the List from the beginning
      else
	{
	  Particle* tmpPart = new Particle;
	  tmpPart->next = this->particles;
	  this->particles = tmpPart;
	}
      
      particles->timeToLive = this->lifeSpan + (float)(random()/RAND_MAX)* this->randomLifeSpan;
      particles->position = position;
      particles->velocity = velocity;
      //  particle->rotation = ; //! \todo rotation is once again something to be done.
      particles->mass = this->initialMass + (random()/RAND_MAX -.5)* this->randomInitialMass;
      particles->radius = this->startRadius + (random()/RAND_MAX-.5)*this->randomStartRadius;
      
      particles->radiusIt = (this->endRadius + (random()/RAND_MAX-.5)*this->randomEndRadius - particles->radius) / particles->timeToLive;

      ++this->count;
    }
  else
    PRINTF(4)("maximum count of particles reached not adding any more\n");
}