short RandomInRange(short min, short max);

typedef pascal struct plugInParameterNumber {
	double realPart, imPart;
} plugInParameterNumber;

typedef pascal plugInParameterNumber plugInParameterArray[];
typedef pascal plugInParameterArray* plugInParameterPtr;
typedef pascal plugInParameterPtr* plugInParameterHandle;

pascal enum {deg, rad, grad};

float WhereExt(short which, float rx, float rz, float range_x, float range_z, float rangeT_x, float rangeT_z, int intvls, float alpha, float beta, float xo, float zo);
float randomVar(float mean, float rangeT);

void pascal main(plugInParameterHandle params, int mode)
{
 /*============================================================================
    params     Input parameters (fields 1,2,...)
               Result   (field 0)
  ============================================================================
  which	rx	rz	range_x	range_z	rangeT_x rangeT_z intvls	alpha	beta	xo		zo
  1		2	3		4		5		6		7		8		9		10		11		12		*/
	
	GetDateTime((unsigned long*) &qd.randSeed);
	
	float rx, rz, alpha, beta, xo, zo, range_x, range_z, rangeT_x, rangeT_z;
	int intvls;
	short which;
	
	which	= (**params)[1].realPart;
	rx		= (**params)[2].realPart;
	rz		= (**params)[3].realPart;
	range_x	= (**params)[4].realPart;
	range_z	= (**params)[5].realPart;
	rangeT_x= (**params)[6].realPart;
	rangeT_z= (**params)[7].realPart;
	intvls	= (**params)[8].realPart;
	alpha	= (**params)[9].realPart;
	beta	= (**params)[10].realPart;
	xo		= (**params)[11].realPart;	
	zo		= (**params)[12].realPart;
	
	(**params)[0].realPart = WhereExt(which, rx, rz, range_x, range_z, rangeT_x, rangeT_z, intvls, alpha, beta, xo, zo);	
}


float WhereExt(short which, float rx, float rz, float range_x, float range_z, float rangeT_x, float rangeT_z, int intvls, float alpha, float beta, float xo, float zo)
{
	float *x_new = new float[intvls];
	float *z_new = new float[intvls];
	float *x_old = new float[intvls];
	float *z_old = new float[intvls];
	
	short *comb_matrix = new short[intvls];
	
	float tot_x, tot_z, new_av_x, new_av_z;	

	for(short i = 0; i <= intvls - 1; i++)
		comb_matrix[i] = i;

	for(short i = 0; i <= intvls - 1; i++)
	{
		x_old[i] = xo;
		z_old[i] = zo;
	}

	for(short gen = 1; gen <= 500; gen++)
	{
		tot_x = 0;
		tot_z = 0;
		
		for(short n = 1; n <= intvls * 10; n++)
		{
			short dummy;
			short i1 = RandomInRange(0, intvls - 1);
			short i2 = RandomInRange(0, intvls - 1);
			
			dummy = comb_matrix[i1];
			comb_matrix[i1] = comb_matrix[i2];
			comb_matrix[i2] = dummy;
		}
		
		for(short i = 0; i <= intvls - 1; i++)
		{
			short xi = i;
			short zi = comb_matrix[i];
			
			x_new[xi] = randomVar(rx + range_x / intvls * xi, rangeT_x) * x_old[xi] * (1 - x_old[xi] - alpha * z_old[zi]);
			z_new[zi] = randomVar(rz + range_z / intvls * zi, rangeT_z) * z_old[zi] * (1 - z_old[zi] - beta * x_old[xi]);
		
			x_old[xi] = x_new[xi];
			z_old[zi] = z_new[zi];
			
			tot_x += x_new[xi];
			tot_z += z_new[zi];
		}
		
		new_av_x = tot_x / intvls;
		new_av_z = tot_z / intvls;
		
		if(which == 1)	// x
		{
			if(new_av_x <= 0 && new_av_z > 0)
			{
				delete x_new;
				delete z_new;
				delete x_old;
				delete z_old;
				delete comb_matrix;
				return gen;			
			}
		
			if(new_av_z <= 0)
			{
				delete x_new;
				delete z_new;
				delete x_old;
				delete z_old;
				delete comb_matrix;
				return 0;
			}
		}
		
		if(which == 2)	// z
		{		
			if(new_av_z <= 0 && new_av_x > 0)
			{
				delete x_new;
				delete z_new;
				delete x_old;
				delete z_old;	
				delete comb_matrix;			
				return gen;
			}	
			
			if(new_av_x <= 0)
			{
				delete x_new;
				delete z_new;
				delete x_old;
				delete z_old;
				delete comb_matrix;
				return 0;
			}

		}	
		
		if(which == 3)	// both
		{
			if(new_av_x <= 0 && new_av_z <= 0)
			{
				delete x_new;
				delete z_new;
				delete x_old;
				delete z_old;
				delete comb_matrix;				
				return gen;
			}
			
			if(new_av_x <= 0 || new_av_z <= 0)
			{
				delete x_new;
				delete z_new;
				delete x_old;
				delete z_old;
				delete comb_matrix;
				return 0;
			}
		}
	}
	
	delete x_new;
	delete z_new;
	delete x_old;
	delete z_old;
	delete comb_matrix;
	return 0;
}


short RandomInRange(short min, short max)
{
	unsigned short	value;	
	short			range;
	long			temp;

	value = Random();
	range = max - min;
	temp  = ((long)range * value) / 65536;	
	return  (temp + min);
}

float randomVar(float mean, float rangeT) {
	float rand = (rangeT*Random())/65536.0; // uniform: 0-rangeT
	return rand - (rangeT/2) + mean; // uniform: mean(+/-)range/2
}