%%%%%%%%%%%%%%%%%%%% SURFACE PARAMETREE %%%%%%%%%%%%%%%%%

n=40;
p=40;
u=linspace(-1/2,1/2,n);
v=linspace(0,2*pi,p);
for i=1:n
    for j=1:p
        X(i,j)=(1-u(i)*sin(v(j)/2))*cos(v(j));
        Y(i,j)=(1-u(i)*sin(v(j)/2))*sin(v(j));
        Z(i,j)=u(i)*cos(v(j)/2);
    end
end
surf(X,Y,Z)
axis equal
shading interp
light('position',[-2,2,2])
lighting phong
pause

%%%%% autre méthode :

clear all
clf
ezsurf('(1-u*sin(v/2))*cos(v)','(1-u*sin(v/2))*sin(v)',...
    'u*cos(v/2)',[-1/2,1/2],[0,2*pi])


%%%%%%%%%%%%%%%%%%%%% JEU DE PING %%%%%%%%%%%%%%%%%%%%%%%%

clear all
n=input('nombre de lignes ? ');
p=input('nombre de colonnes ? ');
M=ones(n+2,p+2);
% le jeu sera représenté par la sous-matrice M(2:n+1,2:p+1)
affiche(M);
while sum(sum(M(2:n+1,2:p+1)))~=0   % il y a encore des noirs
    M=joue(M);
    affiche(M)
end
disp('gagné !')

function affiche(M)
clf
[n,p]=size(M);
for j=2:p-1
    for i=2:n-1
        rectangle('position',[j,i,0.9,0.9],'curvature',[1,1],...
            'facecolor',[M(i,j),M(i,j),M(i,j)])
    end
end
axis equal
axis off

function M=joue(M)
[x,y]=ginput(1);
j=floor(x);
i=floor(y);
temp=M(i,j);
M(i-1:i+1,j-1:j+1)=1-M(i-1:i+1,j-1:j+1);
M(i,j)=temp;