#include ".\particlesystem.h"
#include "includes.h"
#include <GL/glext.h>
#include <glh/glh_extensions.h>

int CompareInc( const void *arg1, const void *arg2 )
{
	Particle* particle1=(Particle*) arg1;
	Particle* particle2=(Particle*) arg2;

	if(*particle1>*particle2)
		return -1;
	else
		return 1;
}

int CompareDec( const void *arg1, const void *arg2 )
{
	Particle* particle1=(Particle*) arg1;
	Particle* particle2=(Particle*) arg2;

	if(*particle1>*particle2)
		return 1;
	else
		return -1;
}


void ParticleSystem::SortParticles(bool increment)
{
	if(increment)
		qsort( m_ParticleArray, (size_t)m_Count, sizeof(Particle), CompareInc );
	else
		qsort( m_ParticleArray, (size_t)m_Count, sizeof(Particle), CompareDec );
}


ParticleSystem::ParticleSystem(void)
{
	VertexBuffer=NULL;
	TexcoordBuffer=NULL;
	ColorBuffer=NULL;

	m_LastParticle=NULL;
	m_ParticleList=new Particle;

	m_ParticleArray=NULL;

	m_Count=0;
	m_Quota=100;
	m_Type=0;

	m_UpVector=Vector(0,1,0);
	m_RightVector=Vector(1,0,0);

	m_refreshed=false;
	m_refreshonce=false;

	m_LittleSystemRadius=1.0;
}

ParticleSystem::~ParticleSystem(void)
{
}

void ParticleSystem::RefreshParticles(unsigned int Dt,unsigned int TimefromSecond)
{
	if(!m_refreshed)
	{
		//Refresh particle ages, kill dead particles; refresh particle positions
		Particle* thisParticle=m_ParticleList->m_NextParticle;
		Particle* parentParticle=m_ParticleList;

		while(thisParticle)
		{
			if(thisParticle->LiveMore(Dt))
			{
				//refresh particle
				thisParticle->Refresh(Dt);
				//thisParticle->m_Distance=(thisParticle->getPosition()-m_CameraPosition).Length();
				m_LastParticle=thisParticle;
				parentParticle=thisParticle;
				thisParticle=thisParticle->m_NextParticle;
			}
			else
			{
				//kill particle
				parentParticle->m_NextParticle=thisParticle->m_NextParticle;
				delete thisParticle;
				thisParticle=parentParticle->m_NextParticle;
				m_LastParticle=parentParticle;
				m_Count--;
			}
			
		}
		
		//Ask emitter to add new particles
		Particle* Addto=m_LastParticle;
		if(Addto==NULL)Addto=m_ParticleList;
		unsigned int AddedCount=m_Emitter.Emit(TimefromSecond,m_Quota-m_Count,Addto,m_CameraPosition);
		m_Count+=AddedCount;

		//fill array ;update bounding radius
		delete[] m_ParticleArray;
		m_ParticleArray=new Particle[m_Count];		
		
		//RefrBRadius_Dist();

			
		
	}
}

void ParticleSystem::RefrBRadius_Dist(bool refresh_rad)
{
	Particle* thisParticle=m_ParticleList->m_NextParticle;
	if(refresh_rad||!m_refreshed)m_BoundingRadius=0;
		double dist;
		for(unsigned int i=0;i<m_Count;i++)
		{
			thisParticle->m_Distance=(thisParticle->getPosition()-m_CameraPosition).Length();
			thisParticle->m_ID=i;
			
			double oldSize;
			if(refresh_rad||!m_refreshed)
			{
				m_refreshed=true;

				oldSize=thisParticle->getSize();
				thisParticle->setSize(oldSize*m_LittleSystemRadius);
				dist=thisParticle->getPosition().Length()+thisParticle->getSize();
				if(dist>m_BoundingRadius)
					m_BoundingRadius=dist;
			}						
			m_ParticleArray[i]=*thisParticle;

			if(refresh_rad||!m_refreshed)thisParticle->setSize(oldSize);
			thisParticle=thisParticle->m_NextParticle;
		}
}

void ParticleSystem::RefreshBuffer(bool billboard)
{
	/*
	if(VertexBuffer!=NULL)delete VertexBuffer;
	if(TexcoordBuffer!=NULL)delete TexcoordBuffer;
	if(ColorBuffer!=NULL)delete ColorBuffer;
*/
	if(billboard)
	{
		double x,y,z;
		Vector LeftDown=m_UpVector*-1-m_RightVector;
		Vector RightDown=m_UpVector*-1+m_RightVector;
		Vector RightUp=m_UpVector+m_RightVector;
		Vector LeftUp=m_UpVector-m_RightVector;

		VertexBuffer=new float[12*m_Count];
		ColorBuffer=new float[16*m_Count];
		TexcoordBuffer=new float[16*m_Count];

		for(unsigned int i=0;i<m_Count;i++)
		{
			m_ParticleArray[i].getPosition(x,y,z);
			
			float bbsize=2*m_ParticleArray[i].getSize();
			float t=m_ParticleArray[i].getSize()/m_BoundingRadius;
			
			TexcoordBuffer[i*16]=0;TexcoordBuffer[i*16+1]=0;
			TexcoordBuffer[i*16+2]=bbsize;TexcoordBuffer[i*16+3]=t;
			TexcoordBuffer[i*16+4]=1;TexcoordBuffer[i*16+5]=0;
			TexcoordBuffer[i*16+6]=bbsize;TexcoordBuffer[i*16+7]=t;
			TexcoordBuffer[i*16+8]=1;TexcoordBuffer[i*16+9]=1;
			TexcoordBuffer[i*16+10]=bbsize;TexcoordBuffer[i*16+11]=t;
			TexcoordBuffer[i*16+12]=0;TexcoordBuffer[i*16+13]=1;
			TexcoordBuffer[i*16+14]=bbsize;TexcoordBuffer[i*16+15]=t;

			
			ColorBuffer[i*16]=m_ParticleArray[i].m_Color.x;ColorBuffer[i*16+1]=m_ParticleArray[i].m_Color.y;
			ColorBuffer[i*16+2]=m_ParticleArray[i].m_Color.z;ColorBuffer[i*16+3]=m_ParticleArray[i].m_Color.w;
			
			ColorBuffer[i*16+4]=m_ParticleArray[i].m_Color.x;ColorBuffer[i*16+5]=m_ParticleArray[i].m_Color.y;
			ColorBuffer[i*16+6]=m_ParticleArray[i].m_Color.z;ColorBuffer[i*16+7]=m_ParticleArray[i].m_Color.w;
			
			ColorBuffer[i*16+8]=m_ParticleArray[i].m_Color.x;ColorBuffer[i*16+9]=m_ParticleArray[i].m_Color.y;
			ColorBuffer[i*16+10]=m_ParticleArray[i].m_Color.z;ColorBuffer[i*16+11]=m_ParticleArray[i].m_Color.w;
			
			ColorBuffer[i*16+12]=m_ParticleArray[i].m_Color.x;ColorBuffer[i*16+13]=m_ParticleArray[i].m_Color.y;
			ColorBuffer[i*16+14]=m_ParticleArray[i].m_Color.z;ColorBuffer[i*16+15]=m_ParticleArray[i].m_Color.w;

			VertexBuffer[i*12]=x+LeftDown.x*m_ParticleArray[i].getSize();
			VertexBuffer[i*12+1]=y+LeftDown.y*m_ParticleArray[i].getSize();
			VertexBuffer[i*12+2]=z+LeftDown.z*m_ParticleArray[i].getSize();
			VertexBuffer[i*12+3]=x+RightDown.x*m_ParticleArray[i].getSize();
			VertexBuffer[i*12+4]=y+RightDown.y*m_ParticleArray[i].getSize();
			VertexBuffer[i*12+5]=z+RightDown.z*m_ParticleArray[i].getSize();
			VertexBuffer[i*12+6]=x+RightUp.x*m_ParticleArray[i].getSize();
			VertexBuffer[i*12+7]=y+RightUp.y*m_ParticleArray[i].getSize();
			VertexBuffer[i*12+8]=z+RightUp.z*m_ParticleArray[i].getSize();
			VertexBuffer[i*12+9]=x+LeftUp.x*m_ParticleArray[i].getSize();
			VertexBuffer[i*12+10]=y+LeftUp.y*m_ParticleArray[i].getSize();
			VertexBuffer[i*12+11]=z+LeftUp.z*m_ParticleArray[i].getSize();		
			
		}
	}
	else
	{
		double x,y,z;
		
		if(VertexBuffer==NULL)VertexBuffer=new float[3*m_Count];
		if(ColorBuffer==NULL)ColorBuffer=new float[4*m_Count];
		if(TexcoordBuffer==NULL)TexcoordBuffer=new float[m_Count*2];
		
		for(unsigned int i=0;i<m_Count;i++)
		{
			m_ParticleArray[i].getPosition(x,y,z);
									
			ColorBuffer[i*4]=m_ParticleArray[i].m_Color.y;
			ColorBuffer[4*i+1]=m_ParticleArray[i].m_Color.y;
			ColorBuffer[4*i+2]=m_ParticleArray[i].m_Color.z;
			ColorBuffer[4*i+3]=m_ParticleArray[i].m_Color.w;
						
			VertexBuffer[i*3]=x;
			VertexBuffer[i*3+1]=y;
			VertexBuffer[i*3+2]=z;	

			TexcoordBuffer[2*i]=m_ParticleArray[i].m_ID;
			TexcoordBuffer[2*i+1]=m_ParticleArray[i].getSize();
			
		}

	}
}

void ParticleSystem::RenderAsPoints(bool sprites)
{
	
	glEnableClientState(GL_VERTEX_ARRAY);
	glEnableClientState(GL_TEXTURE_COORD_ARRAY);
	glEnableClientState(GL_COLOR_ARRAY);
			
	glVertexPointer (3, GL_FLOAT, 0, VertexBuffer);
	glColorPointer(4,GL_FLOAT,0,ColorBuffer);
	glTexCoordPointer(2,GL_FLOAT,0,TexcoordBuffer);
	
	if(sprites)
	{
	  glEnable(GL_POINT_SPRITE_ARB);
      glTexEnvi(GL_POINT_SPRITE_ARB, GL_COORD_REPLACE_ARB, GL_TRUE);
      glEnable(GL_VERTEX_PROGRAM_POINT_SIZE_NV);
      
	}

	glDrawArrays(GL_POINTS, 0, m_Count);

	if(sprites)
	{
		glDisable(GL_POINT_SPRITE_ARB);
		glDisable(GL_VERTEX_PROGRAM_POINT_SIZE_NV);
		glTexEnvi(GL_POINT_SPRITE_ARB, GL_COORD_REPLACE_ARB, GL_FALSE);
	}

	glDisableClientState( GL_VERTEX_ARRAY );				// Disable Vertex Arrays
	glDisableClientState( GL_TEXTURE_COORD_ARRAY );	
	glDisableClientState( GL_COLOR_ARRAY );	
	
}

void ParticleSystem::RenderAsBillboard()
{
	
	glEnableClientState(GL_VERTEX_ARRAY);
	glEnableClientState(GL_TEXTURE_COORD_ARRAY);
	glEnableClientState(GL_COLOR_ARRAY);
			
	glVertexPointer (3, GL_FLOAT, 0, VertexBuffer);
	glTexCoordPointer(4,GL_FLOAT,0,TexcoordBuffer);
	glColorPointer(4,GL_FLOAT,0,ColorBuffer);
	
	glDrawArrays(GL_QUADS, 0, m_Count*4);

	glDisableClientState( GL_VERTEX_ARRAY );				// Disable Vertex Arrays
	glDisableClientState( GL_TEXTURE_COORD_ARRAY );	
	glDisableClientState( GL_COLOR_ARRAY );	

	
}