function optics_prism
close all 
figure('position',[78 276 792 402]); 
xp=[-0.2,0.2,0];yp=[0.2,0.2,0.5];B=pi/14; 
ZZ=[xp;yp]'*[cos(B),sin(B);-sin(B),cos(B)]; 
fill(ZZ(:,1),ZZ(:,2),[0.2,0.4,0.6]); 
axis([-1,1,0,1]);hold on;set(gca,'color','k'); 
t=0;A=pi/8;set(gcf,'doublebuffer','on'); 
x=[-1,-1];y=[0,0]; 
H=plot(x,y,'w','linewidth',6); 
while t<0.8; 
pause(0.1); 
t=t+0.1; 
x(2)=-1+t*cos(A); 
y(2)=t*sin(A); 
set(H,'xdata',x,'ydata',y); 
end 
x1=[x(2),x(2)];y1=[y(2),y(2)];H1=plot(x1,y1,'r'); 
H2=plot(x1,y1,'color',[1,1,0]);x2=x1;y2=y1; 
H3=plot(x1,y1,'y');x3=x1;y3=y1; 
H4=plot(x1,y1,'g');x4=x1;y4=y1; 
H5=plot(x1,y1,'color',[0,1,1]);x5=x1;y5=y1; 
H6=plot(x1,y1,'b');x6=x1;y6=y1; 
H7=plot(x1,y1,'color',[1,0,1]);x7=x1;y7=y1; 
t=0; 
C=linspace(pi/16,0,7); 
s=linspace(1,1.2,7); 
while t<0.165; 
pause(0.1);