MATChess

on 8 Nov 2026
2
18
9
1
9391
game.m
function gg=game()
KN=[1 2;2 1;-1 2;-2 1;1 -2;2 -1;-1 -2;-2 -1];DI=[1 0;-1 0;0 1;0 -1;1 1;1 -1;-1 1;-1 -1];
PV=[100;320;330;500;900;2e4];GC=char([32 9823 9822 9821 9820 9819 9818]);
RR=repmat((1:8)',1,8);CC=RR';CT=min(RR,9-RR)+min(CC,9-CC);
BC=[.55 .37 .25;.94 .85 .68];BC=BC(mod(RR(:)+CC(:),2)+1,:);
[BD,SEL,LAST,J,LM,lv,tm,t1,te,Hp,Hq,Hs,Hu,Hb,A,Zs]=deal(0);
gg.init=@ini;gg.update=@step;gg.render=@draw;
function S=ini(ax)
A=ax;ax.Color=[0.1 0.35 0.15];ax.XLim=[0 800];ax.YLim=[0 600];
tx={'Color','w','FontWeight','bold','HorizontalAlignment','center','VerticalAlignment','middle'};
X=136+66*(CC(:)-.5);Y=50+66*(RR(:)-.5);e=repmat({' '},64,1);
Hs=patch(ax,'Faces',reshape(1:256,64,4),'Vertices',[X-33 Y-33;X+33 Y-33;X+33 Y+33;X-33 Y+33],'FaceVertexCData',BC,'FaceColor','flat','EdgeColor','none');
Hq=text(ax,X,Y-2,e,'FontSize',44,'FontName','DejaVu Sans',tx{:},'Color','k');Hq=Hq(:);
Hp=text(ax,X,Y-2,e,'FontSize',39,'FontName','DejaVu Sans',tx{:});Hp=Hp(:);
Hb=text(ax,[70 70 70],[470 420 370],{' EASY ','NORMAL',' TOUGH'},'FontSize',10,tx{:},'BackgroundColor',[.2 .45 .8],'EdgeColor','w','Margin',5);
Hu=text(ax,400,588,'','FontSize',14,tx{:});
text(ax,400,22,{'MATLAB (white) starts. You are dark. Click your piece (green = legal moves), then click a green square.','Buttons at left: choose level and restart. After the game ends, click to play again.'},'FontSize',8,tx{:});
set(ax.Children,'HitTest','off','PickableParts','none');
lv=2;newg;S=0;
end
function newg
BD=zeros(8);BD(1,:)=-[4 2 3 5 6 3 2 4];BD(2,:)=-1;BD(7,:)=1;BD(8,:)=[4 2 3 5 6 3 2 4];
SEL=[];LAST=[];LM=zeros(0,4);t1=0;J=1;Zs='MATLAB is thinking...';
end
function S=step(S,dt,p)
tm=tm+dt;
if J==1
t1=t1+dt;
if t1>.5,mach;end
elseif p
C=A.CurrentPoint(1,1:2);k=find(abs(C(1)-70)<55&abs(C(2)-[470 420 370])<18,1);
if k,lv=k;newg;elseif J==3,if tm-te>.5,newg;end,else,clk(C);end
end
end
function clk(C)
c=ceil((C(1)-136)/66);r=ceil((C(2)-50)/66);
if c<1||c>8||r<1||r>8,SEL=[];return;end
if BD(r,c)<0,SEL=[r c];return;end
if ~isempty(SEL)
k=find(LM(:,1)==SEL(1)&LM(:,2)==SEL(2)&LM(:,3)==r&LM(:,4)==c,1);
if k,BD=mk(BD,LM(k,:));LAST=LM(k,:);J=1;t1=0;Zs='MATLAB is thinking...';end
end
SEL=[];
end
function mach
M=legal(BD,1);
if isempty(M)
[r,c]=find(BD==6);
if att(BD,r,c,-1),Zs='CHECKMATE - you win! Click to restart.';else,Zs='STALEMATE - draw. Click to restart.';end
J=3;te=tm;return
end
v=pick(BD,M,1,lv);BD=mk(BD,v);LAST=v;LM=legal(BD,-1);
[r,c]=find(BD==-6);ck=att(BD,r,c,1);J=2;Zs='Your move.';
if isempty(LM)
J=3;te=tm;Zs='STALEMATE - draw. Click to restart.';
if ck,Zs='CHECKMATE - MATLAB wins! Click to restart.';end
elseif ck,Zs='CHECK! Your move.';end
end
function draw(~,~)
u=BD(:)<0;st=num2cell(GC(abs(BD(:))+1)');C3=BC;Y=[.8 .82 .4];
if ~isempty(LAST),C3(LAST(1)+8*LAST(2)-8,:)=Y;C3(LAST(3)+8*LAST(4)-8,:)=Y;end
for s=[1 -1]
[r,c]=find(BD==6*s);
if att(BD,r,c,-s),C3(r+8*c-8,:)=[.9 .35 .3];end
end
if ~isempty(SEL)&&J==2
k=LM(:,1)==SEL(1)&LM(:,2)==SEL(2);
C3(LM(k,3)+8*LM(k,4)-8,:)=repmat([.55 .85 .5],nnz(k),1);C3(SEL(1)+8*SEL(2)-8,:)=[.3 .75 .3];
end
cb=repmat([.2 .45 .8],3,1);cb(lv,:)=[.9 .6 .1];
Hs.FaceVertexCData=C3;set(Hp,{'String'},st);set(Hq,{'String'},st);
set(Hp,{'Color'},num2cell(u*[.1 .15 .45]+~u*[1 1 1],2));set(Hb,{'BackgroundColor'},num2cell(cb,2));Hu.String=Zs;
end
function v=pick(b,M,s,l)
v=M(1,:);z=-1e5;
for i=1:size(M,1)
b2=mk(b,M(i,:));
if l==3,x=-nm(b2,-s,2,-1e5,-z);else,x=-nm(b2,-s,l-1,-1e5,1e5)+rand*(10+70*(l==1));end
if x>z,z=x;v=M(i,:);end
end
if l==1&&rand<.3,v=M(randi(size(M,1)),:);end
end
function v=nm(b,s,d,a,be)
v=s*ev(b);
if abs(v)>1e4,v=v+sign(v)*d;return;end
M=gen(b,s);
if d==0||isempty(M),return;end
[~,o]=sort(abs(b(sub2ind([8 8],M(:,3),M(:,4)))),'descend');M=M(o,:);v=-1e5;
for i=1:size(M,1)
x=-nm(mk(b,M(i,:)),-s,d-1,-be,-a);
if x>v,v=x;end
if v>a,a=v;end
if a>=be,break;end
end
end
function v=ev(b)
a=abs(b);s=sign(b);k=a>0;j=a>1&a<4;
v=sum(PV(a(k)).*s(k))+3*sum(CT(j).*s(j))+4*(sum(7-RR(b==1))-sum(RR(b==-1)-2));
end
function M=legal(b,s)
M=gen(b,s);k=false(size(M,1),1);
for i=1:size(M,1)
b2=mk(b,M(i,:));[r,c]=find(b2==6*s);k(i)=~att(b2,r,c,-s);
end
M=M(k,:);
end
function b=mk(b,v)
p=b(v(1),v(2));b(v(3),v(4))=p;b(v(1),v(2))=0;
if abs(p)==1&&(v(3)==1||v(3)==8),b(v(3),v(4))=5*p;end
end
function a=att(b,r,c,s)
M=gen(b,s);a=any(M(:,3)==r&M(:,4)==c);
end
function M=gen(b,s)
M=zeros(0,4);[R,C]=find(b*s>0);
for i=1:numel(R)
r=R(i);c=C(i);p=b(r,c)*s;
if p==1
d=-s;r2=r+d;
if r2>0&&r2<9
if b(r2,c)==0
M(end+1,:)=[r c r2 c];
if r==4.5+2.5*s&&b(r+2*d,c)==0,M(end+1,:)=[r c r+2*d c];end
end
for k=[-1 1]
if c+k>0&&c+k<9&&b(r2,c+k)*s<0,M(end+1,:)=[r c r2 c+k];end
end
end
else
O=DI;K1=1:8;L=8;
if p==2,O=KN;L=1;elseif p==6,L=1;elseif p==3,K1=5:8;elseif p==4,K1=1:4;end
for k=K1
r2=r;c2=c;
for n=1:L
r2=r2+O(k,1);c2=c2+O(k,2);
if r2<1||r2>8||c2<1||c2>8||b(r2,c2)*s>0,break;end
M(end+1,:)=[r c r2 c2];
if b(r2,c2)~=0,break;end
end
end
end
end
end
end
Play Game
Preview

Play Game opens this in MATLAB Drive. Click Run this app there to play.