%% Test 
%% ****
%%  **
%% is stable
%% Assume a single region and a single line at each level.
%% 1. Find x co-ordinates of the base
%% 2. Find number of blocks on each side
%% 3. Return whether the number of blocks on each side is the same

%% test([[[0,1],'*'],[[1,1],'*'],[[2,1],'*'],[[3,1],'*'],[[0,0],' '],[[1,0],'*'],[[2,0],'*'],[[3,0],' ']],0,3,0,1).

%%test(Map,XMin,XMax1,YMin,YMax) :-
%%	XMax2 is XMax1 + 1,
%%	findbase1(Map,XMin,XMax,0,Base1,Base2),
	
findbase1(Map,XMin,XMax,0,Base1,Base2) :-
	findbase2(Map,XMin,XMax,0,[],Base),
	first(Base,Base1),
	last(Base,Base2).
findbase2(_Pixels,X,X,_Y1,Base,Base).
findbase2([Pixel|Pixels],X1,XMax,Y,Base1,Base2) :-
	Pixel = [Coords, '*'],
	Coords = [X1, Y],
	append(Base1,[X1],Base3),
	X2 is X1 + 1,
	findbase2(Pixels,X2,XMax,Y,Base3,Base2).
findbase2([Pixel|Pixels],X1,XMax,Y,Base1,Base2) :-
        Pixel = [Coords, ' '],
        Coords = [X1, Y],
        X2 is X1 + 1,
        findbase2(Pixels,X2,XMax,Y,Base1,Base2).
findbase2([Pixel|Pixels],X,XMax,Y1,Base1,Base2) :-
        Pixel = [Coords, _Symbol],
        Coords = [X, Y2],
	not(Y1=Y2),
        findbase2(Pixels,X,XMax,Y1,Base1,Base2).
first([Base1|_Tail],Base1).
last([Base2],Base2).
last([_Head|Tail],Base2) :-
	last(Tail,Base2).