Look at these 2 lines of code:

It DOES NOT MATTER if direction is 0 or 1,
the resulting values in area and yy will be the same !

if(direction==0) area+=(yy+1);yy++;
if(direction==1)area+=yy;

This is why case statements are preferred.

Is this what you really want ?

if(direction==0) area+=(yy+1);
yy++;
if(direction==1)area+=yy;