void CPEngine::draw(){	glPushMatrix();	glTranslatef(0,0,-50);	tex.bind();	CParticle *a = h;	glEnable(GL_BLEND);						glBlendFunc(GL_SRC_ALPHA,GL_ONE);				particles = 0;	glDisable(GL_DEPTH_TEST);	while(a != NULL)	{		particles++;		glColor4f(1,1,1,a->life/life);		glBegin(GL_TRIANGLE_STRIP);			glTexCoord2d(0,1); glVertex3f(a->l.x,a->l.y+1,a->l.z);			glTexCoord2d(1,1); glVertex3f(a->l.x+1,a->l.y+1,a->l.z);			glTexCoord2d(0,0); glVertex3f(a->l.x,a->l.y,a->l.z);			glTexCoord2d(1,0); glVertex3f(a->l.x+1,a->l.y,a->l.z);		glEnd();		a=a->next;	}	glPopMatrix();	glDisable(GL_BLEND);							// Enable Blending	glEnable(GL_DEPTH_TEST);}  

  	if(flag == UPDATE || flag == UPDATE_AND_CREATE)	{		CParticle *a=h;		while(a != NULL)		{			a->l.x += a->v.x * deltaT;			a->l.y += a->v.y * deltaT;			a->l.z += a->v.z * deltaT;			a->life -= a->drate * deltaT;			a = a->next;		}		a = h;		CParticle *temp;		while(a != NULL)		{				if(a->life < -life)			{/*				b->next = a->next;				b=a->next;				delete a;*/				if(a == h) 				{					temp=h;					h=h->next;					delete temp;					particles--;					a=h;				}				else 				{					temp=Prev(a);					temp->next=a->next;					delete a;					a= temp;					particles--;				}			}			else				a = a->next;		}	}	if(flag == CREATE || flag == UPDATE_AND_CREATE)	{		if(!stoped)		{			CParticle *a = h;			if(a == NULL && c>= 1 && max >= 1)			{				c--;				a = new CParticle;				a->next = NULL;				a->c = cdef;				a->l = emitloc;				float random_pitch = float(rand()/float(32767/180));				float random_yaw = float(rand()/float(32767/180));				a->v.x = (cosf(random_pitch)) * vel.x;				a->v.y = (sinf(random_pitch)*cosf(random_yaw))* vel.y;				a->v.z = (sinf(random_pitch)*sinf(random_yaw))* vel.z;				a->life = life;				a->drate = randfloat(0,1);				h = a;				particles++;			}			if(a!=NULL)			{				while(a->next != NULL)					a = a->next;				for(int x = 0; x<(c);x++)				{					if(particles < max)					{						particles++;						a->next = new CParticle;						a = a->next;						a->next = NULL;						a->c = cdef;						a->l = emitloc;						a->life = life;						float random_pitch = float(rand()/float(32767/180));						float random_yaw = float(rand()/float(32767/180));						a->v.x = (cosf(random_pitch)) * vel.x;						a->v.y = (sinf(random_pitch)*cosf(random_yaw))* vel.y;						a->v.z = (sinf(random_pitch)*sinf(random_yaw))* vel.z;						a->drate = randfloat(0,1);					}					else						break;				}			}		}	}  

  class CParticle{public:	CVec3d l,v; //LOCATION,OLD LOCATION, VELOCITY	CVec3d c; // Color	CVec3d r;	float life;	float drate; //death rate	CParticle *next; //NEXT PARTICLE};class CPEngine{private:		CParticle *h; //Head particle	bool attractemit;	bool attractparticles;	bool stoped;	CVec3d emitloc; //Emitter location	CVec3d emitspread; // Spread of the emission	CVec3d vel;	CVec3d cdef; //Default color (start)	CVec3d cdest; //Destination color	CVec3d grav;	CTexture tex;	float life;