start

int umin,vmin,umax,vmax;
int 	ax,ay, (point A)
	bx,by, (point B)
	mx,my; (midpoint)	

//check for trivial accept
//for point A
check for point A
if((ax >= umin && ax <= umax )) && ((ay >= vmin && ay <= vmax))
	return true // point A is within center region(0000);
else return false;

check for point B
if((bx >= umin && bx <= umax )) && ((by >= vmin && by <= vmax))
	return true // point B is within center region(0000);
else return false;

if both return true 
	then trivial accept draw line from point A to point B

else if both return false 
	then trivial reject

else if (A=true || B=false)
{
do 
	//calculate midpoint
	mx = (bx - ax)/2;
	my = (by - ay)/2;
	
	//check if new point (mx,my) is within region
	if ((mx >= umin && mx <= umax) && (my >= vmin && my <= vmax))  
		return true; // midpoint is within region
		draw line from point A to midpoint
	else 
		//midpoint now considered as point B
		mx=bx;
		my=by;
		//calculate new midpoint
		mx=(bx - ax)/2;
		my=(by - ay)/2;
		
		if ((mx >= umin && mx <= umax) && (my >= vmin && my <= vmax))  
		return true; // midpoint is within region
		draw line from point A to midpoint
		
while (A=true || B=false)
}

else if (A=false || B=true)
{
do 
	//calculate midpoint
	mx = (bx - ax)/2;
	my = (by - ay)/2;
	
	//check if new point (mx,my) is within region
	if ((mx >= umin && mx <= umax) && (my >= vmin && my <= vmax))  
		return true; // midpoint is within region
		draw line from point B to midpoint
	else 
		//midpoint now considered as point B
		mx=ax;
		my=ay;
		//calculate new midpoint
		mx=(bx - ax)/2;
		my=(by - ay)/2;
		
		if ((mx >= umin && mx <= umax) && (my >= vmin && my <= vmax))  
		return true; // midpoint is within region
		draw line from point B to midpoint
		
while (A=false || B=true)
}