Pip Seek

Hans Scharler
/
Pip Seek
on 13 Nov 2026
3
13
7
0
9991
game.m
function g=game()
    % PIP SEEK. Lost radioactive sources, a Geiger counter, and a dark map
    % that your path reveals. Sources decay, so speed pays.
    % Positions are complex numbers: x + iy on the map, column + i row on
    % the screen.
    g.init=@init; g.update=@update; g.render=@render;
end
function s=init(ax)
    ax.YDir='reverse'; ax.Color='k';
    % P1 phosphor: black glass, green light that burns toward white.
    t=(0:255)'/255; colormap(ax,[.01+.75*t.^2.4 .035+.965*t.^.8 .02+.55*t.^2]);
    s.im=image(ax,[1 799],[.5 599.5],zeros(600,400,'uint8'),'CDataMapping','direct','HitTest','off','PickableParts','none');
    % 5x7 font: seven rows per glyph, each row a 5-bit number stored as char(48+n).
    d=['0000000>AAOAAANAANAAN>A@@@A>NAAAAANO@@N@@OO@@N@@@>A@GAA?AAAOAAA>44444>ABDHDBA@@@@@@OAKEEAAAAAIECAA'...
        '>AAAAA>NAAN@@@NAANDBA?@@>11NO444444AAAAAA>AAAAA:4AAAEEE:AA:4444>ACEIA>4<4444>>A1248OO2421A>26:BO22O@N11A>'...
        '68@NAA>O124888>AA>AA>>AA?12<00000<<HI248C3000O000<BD8EB=842124801248@0']-48;
    s.F=permute(reshape(mod(floor(d'./2.^[4:-1:0 5]),2),7,[],6),[1 3 2]); s.ci=ones(1,256); s.ci(' ABCDEFGHIKLMNOPRSTUVWY0123456789.%-&>/'+0)=1:39;
    % The tube: 300 rows of 400 phosphor dots, rounded corners, darker edges.
    u=(-199.5:199.5)/201; v=(-149.5:149.5)'/151; s.vg=sqrt(max(0,min(1,9-9*u.^24-9*v.^24))).*(1-.25*(u.^2+v.^2));
    k=exp(-(-6:6).^2/8); s.k=k/sum(k); s.ring=exp(.05i*pi*(0:40)');
    % The panel: frame, a ratemeter dial over the decades 1 to 1000 counts
    % per second, and a strip chart.
    Z=zeros(300,400); Z([4 20 256 297],5:396)=.3; Z(4:297,[5 396])=.3; Z(294-11*(0:3),100:4:279)=.2; Z(294,100:279)=.3;
    Z=pt(Z,48+294i-34*exp(1i*pi*(0:.01:1)),.5); Z=pt(Z,48+294i-(28:33)'*exp(1i*pi*(0:3)/3),.8);
    s.Z=tx(s,Z,'1            1K',288,8,1,.5,0);
    % The survey map: 97 by 57 m at 4 dots per meter.
    s.G=((0:387)+1i*(0:227)')/4; s.best=0; s.sc=0; s=title(s);
    % The reveal brush: 6 m around you, soft at the edge.
    [u,v]=meshgrid(-24:24); s.dk=u(:)+1i*v(:); s.dw=max(0,1-s.dk.*conj(s.dk)/576);
end
function i=id(q)
    i=min(max(round(imag(q(:)))+300*round(real(q(:)))-300,1),12e4);
end
function X=pt(X,q,v)
    i=id(q); X(i)=max(X(i),v);
end
function B=tx(s,B,t,r,c,k,v,a)
    % Write lines of text into layer B: top row r, column c (a = 0 left,
    % 1 center, 2 right), k dots per font pixel, brightness v.
    t=cellstr(t);
    for n=1:numel(t)
        T=v*kron(reshape(s.F(:,:,s.ci(upper(t{n})+0)),7,[]),ones(k)); [h,w]=size(T);
        R=r+11*n-11+(0:h-1); C=round(c-a*w/2)+(0:w-1); B(R,C)=max(B(R,C),T);
    end
end
function s=title(s)
    % The title is a radiation field shaped like the name of the game. A
    % streak of 500 bacteria is released across the middle, and each one
    % runs and tumbles up the field, as E. coli does toward food. Their
    % clicks draw the letters.
    [s.mode,s.age,s.P,s.r,s.H,s.kc,s.tau]=deal(0,0,zeros(300,400),0,zeros(1,180),0,1.2);
    L=tx(s,zeros(300,400),{'PIP','','','','','','SEEK'},36,204,8,1,1);
    b=exp(-(-60:60).^2/800); b=conv2(b,b,L,'same'); f=conv2(s.k,s.k,L,'same');
    s.TL=f/max(f(:)); s.TF=.6*s.TL+.4*b/max(b(:)); s.A=40+130i+320*rand(500,1)+4i*randn(500,1); s.ah=7*rand(500,1); s.af=0;
end
function s=site(s,k)
    % Site k: more sources, weaker sources, more background and ruins,
    % shorter half-lives, and clicks that fade faster.
    [s.mode,s.age,s.site,s.t,s.tt,s.D0,s.c0,s.kc,s.P]=deal(1,0,k,0,0,s.D,s.sc,0,zeros(300,400)); s.R=s.P; s.Wm=s.P; s.hl=max(20,70*.85^k/.85);
    s.tau=max(1,4.5*.8^k/.8); s.S=2e4+5e4*.8^k/.8; s.B=5+min(3,k/2-.5); n=min(3,ceil(k/2)); s.z=1i*(8+41*rand); s.th=0;
    s.src=[]; s.W=zeros(0,4);
    while numel(s.src)<n
        z=30+4i+[64 49i]*rand(2,1); if all(abs(s.src-z)>18), s.src(end+1,1)=z; end
    end
    % Ruins: you cannot walk through them, and they absorb radiation, so
    % they cast shadows in the field.
    while size(s.W,1)<2+min(4,k)
        z=[8 2]+[80 46].*rand(1,2); z=[z z+3+[8 6].*rand(1,2)]; q=s.src-min(max(real(s.src),z(1)),z(3))-1i*min(max(imag(s.src),z(2)),z(4));
        if all(abs(q)>5), s.W(end+1,:)=z; end
    end
    s.on=true(n,1);
    for j=1:size(s.W,1)
        i=round(4*s.W(j,:))+[7 25 7 25]; r=i(2):min(252,i(4)); c=i(1):min(394,i(3));
        s.Wm(r,c)=.1*(mod(r'+c,5)==0); s.Wm(r([1 end]),c)=.4; s.Wm(r,c([1 end]))=.4;
    end
    s.Wm(25:40:252,7:40:394)=.3;
    % The true field, revealed along your path: six contours per decade
    % of count rate over a faint wash.
    l=log10(rate(s,s.G)); q=floor(6*l); s.V=s.P;
    s.V(25:252,7:394)=.45*(q~=q(:,[2:end end])|q~=q([2:end end],:))+.1*l;
    s.msg={sprintf('SITE %d',k),sprintf('%d SOURCE%s',n,repmat('S',1,n>1)),sprintf('HALF-LIFE %.0f S',s.hl)};
end
function l=rate(s,z)
    % Counts per second: background, inverse-square sources buried 3 m
    % deep, decaying with the site's half-life, and attenuated by the
    % length of ruin on the line of sight (half absorbed every 6 m).
    l=s.B;
    for i=find(s.on)'
        d=z-s.src(i)+1e-9*(1+1i); L=0*real(d(:));
        for j=1:size(s.W,1)
            t=(s.W(j,[1 3])-real(s.src(i)))./real(d(:)); u=(s.W(j,[2 4])-imag(s.src(i)))./imag(d(:));
            L=L+max(0,min(1,min(max(t,[],2),max(u,[],2)))-max(0,max(min(t,[],2),min(u,[],2))));
        end
        l=l+s.S*2^(-s.t/s.hl)*exp(-.12*reshape(L,size(d)).*abs(d))./(abs(d).^2+9);
    end
end
function w=wo(s)
    % What a source is worth now: 100 at the start of the site, halving
    % every half-life.
    w=round(100*2^(-s.t/s.hl));
end
function b=hit(W,q)
    % The fence at the edge of the map, or a ruin.
    x=real(q); y=imag(q); b=x<0||x>96.75||y<0||y>56.75||any(x>W(:,1)&x<W(:,3)&y>W(:,2)&y<W(:,4));
end
function s=update(s,dt,p)
    s.age=s.age+dt; s.P=s.P*exp(-dt/s.tau); s.kc=0; m=s.mode;
    if ~m
        % The culture on the title screen: slower on the letters, more
        % tumbles when the field falls, and clicks where the field is high.
        A=s.A+90*dt*(1-.8*s.TL(id(s.A))).*exp(1i*s.ah); x=real(A); y=imag(A); o=x<8|x>392|y<24|y>168;
        s.ah(o)=s.ah(o)+pi; s.A=min(max(x,8),392)+1i*min(max(y,24),168); i=id(s.A); f=s.TF(i); t=rand(500,1)<dt*(.3+6*(f<s.af));
        s.ah(t)=7*rand(nnz(t),1); c=rand(500,1)<dt*(.1+40*s.TL(i).^2); s.P(i(c))=1; s.af=f; s.kc=nnz(c)/40;
    elseif m==1
        % A tap starts a turn: you stop and spin in place. The next tap
        % ends it, and you walk the way you face. The fence and the ruins
        % stop you, and you slide along them.
        s.t=s.t+dt; z=s.z; s.tt=xor(s.tt,p); s.th=s.th+3.5*dt*s.tt;
        e=6*dt*exp(1i*s.th)*~s.tt; u=z+real(e)*~hit(s.W,z+real(e)); u=u+1i*imag(e)*~hit(s.W,u+1i*imag(e));
        % Geiger clicks: a Poisson count for this frame, each one left as a
        % speck on the map where it happened. Your path reveals the field.
        % Dose comes from the clicks and from the time spent in the zone.
        s.z=u; l=rate(s,u); n=sum(cumsum(-log(rand(1,80)))<l*dt); w=rand(n,1);
        i=id(7+25i+4*(z+w*(u-z))+randn(n,2)*[1;1i]); s.P(i+[0 1 -1 300 -300])=(w+[2 1 1 1 1])/2;
        s.kc=n; s.D=s.D+(.06+5e-4*l)*dt; s.R=pt(s.R,7+25i+4*u+s.dk,s.dw); f=s.on&abs(s.src-u)<3;
        % A recovered source scores what is left of it.
        if any(f), s.on(f)=0; s.sc=s.sc+nnz(f)*wo(s); s.P=pt(s.P,7+25i+4*u+s.ring*(6:4:18),1); end
        if ~any(s.on)
            s.mode=2; s.age=0; s.best=max(s.best,s.sc);
        elseif s.D>=100
            s.D=100; s.mode=3; s.age=0;
        end
    end
    if p&&(s.age>.8&&m>1||s.age>.6&&~m)
        if m==2, s=site(s,s.site+1); else, s.D=0; s.sc=0; s=site(s,1); end
    end
    % The ratemeter: counts through an RC filter with a 0.6 s time
    % constant, and a strip chart of its last 180 frames.
    s.r=s.r+(s.kc/dt-s.r)*(1-exp(-dt/.6)); s.H=[s.H(2:end) s.r];
end
function render(~,s)
    X=s.Z; m=s.mode; a=s.age; b=mod(a,1)<.6;
    if m
        % The map: grid, ruins, the field where you have walked, recovered
        % sources, and once the site ends, the rest swept in from the top.
        R=s.R; R(1:(m>1)*min(252,round(300*a)),:)=1; X=X+s.Wm+s.V.*R;
        X=pt(X,7+25i+4*reshape(s.src(~s.on|m>1&(b|m<3)),1,[])+10*s.ring,.9); X(9:15,285:361)=.15; X(9:15,285:285+round(.76*s.D))=.9*(s.D<80||b);
        X=tx(s,X,sprintf('%-41sDOSE',sprintf('PIP SEEK   SITE %d   FOUND %d/%d',s.site,sum(~s.on),numel(s.on))),9,10,1,.7,0);
        X=tx(s,X,sprintf('%.0f%%',s.D),9,394,1,.7,2); h={sprintf('SCORE %d',s.sc),sprintf('WORTH %d',wo(s))};
    else
        % Title: boot line, the description typed out, then the prompt.
        T=char('LOST SOURCES. ONE GEIGER COUNTER. NO MAP.','','YOU WALK STRAIGHT. TAP TO TURN. TAP AGAIN TO WALK.','YOUR PATH REVEALS THE FIELD. FOLLOW IT UPHILL.','','SOURCES DECAY. BE FAST. WATCH YOUR DOSE.');
        T((0:5)'*size(T,2)+(1:size(T,2))>70*(a-2.5))=' ';
        X=tx(s,X,[{'RT-1 SURVEY UNIT'};repmat({''},14,1);cellstr(T)],9,40,1,.7,0);
        X=tx(s,X,'> TAP TO DEPLOY',236,200,2,b*(a>7.5),1); h={'',sprintf('BEST %d',s.best)};
    end
    X=max(X,s.P);
    if m
        % You: a bright dot in a ring, and a heading line that spins while
        % you turn.
        q=7+25i+4*s.z; X=pt(X,[q+4*s.ring;q+(5:10)'*exp(1i*s.th);q+[0;1;-1;1i;-1i]],1);
        if m>1&&a>.8||m==1&&a<2.5&&b
            % The site banner, and the result when the site ends.
            X(96:176,60:340)=.1*X(96:176,60:340); X([96 176],60:340)=.6; X(96:176,[60 340])=.6;
            t={s.msg,{sprintf('SITE %d CLEAR',s.site),sprintf('%d POINTS   %.0f S   DOSE %.0f%%',s.sc-s.c0,s.t,s.D-s.D0),sprintf('> TAP FOR SITE %d',s.site+1)},...
                {'DOSE LIMIT',sprintf('SCORE %d   BEST %d',s.sc,s.best),'> TAP TO REDEPLOY'}}; t=t{m};
            X=tx(s,X,t(1),110,200,2,1,1); X=tx(s,X,t(2:3),138,200,1,.8,1);
        end
    end
    % Ratemeter needle, click lamp, strip chart, readout.
    X=pt(X,[48+294i-(0:30)*exp(1i*pi/3*min(3,log10(max(1,s.r)))) (100:279)+294i-11i*min(3,log10(max(1,s.H)))],1);
    X(262:265,88:91)=s.kc>0; X=tx(s,X,{h{1},sprintf('CPS %.0f',s.r),h{2}},264,292,1,.6,0);
    % Glow, the tube's shape, the power-on line, scanlines.
    Y=(X+.9*conv2(s.k,s.k,X,'same')).*s.vg; e=abs((1:300)'-150.5);
    if ~m&&a<.5, Y=Y.*(e<1+600*a^2)+2*max(0,.3-a)*(e<2); end
    s.im.CData=uint8(255*min(1,kron(Y,[1;.45])));
end
Play Game
Preview

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