Saucer Quest!

Ned Gulley
/
Saucer Quest!
on 13 Nov 2026
3
40
7
3
9980
game.m
function g = game()
%game Saucer Quest: it is 1954 and you are harvesting earthlings.
%
%   Your saucer slides back and forth at cruise altitude. Tap to drop to
%   harvest altitude, stop, and switch on the tractor beam. Tap again to
%   switch it off and zip back up. Farmers are worth 50, cows 100. Beam up
%   a soldier and it is over. Soldiers near the beam run up and shoot.
%   Jets cross between the two altitudes: hit one on the way up or down
%   and you crash.
%
%   Sprite art is stored as encoded strings drawn by D(). Edit the
%   readable specs in tools/buildArt.m and run it to regenerate them.
%   Graphics handles live in capitalized fields of the state.

g.init = @initS;
g.update = @upd;
g.render = @ren;
end

function s = initS(ax)
% World 800x600, y down. Cruise y 110, harvest y 390, ground y 522.
s.L = [250 190 310];                 % jet lanes, in the order levels add them
s.ty = repelem(1:3, [5 4 3]);        % slot types: 1 farmer, 2 cow, 3 soldier
s.r = [1:5 1:4 1:3];                 % rank within type (a level uses the first few)
s.b = 28 - 14*(s.ty == 2);           % walking speeds
s.hi = 0; s.sc = 0; s.t = 0;         % st: 0 level card, 1 play, 2 boom, 3 over
s = lvl(s, 1);
G = 522;
ax.YDir = 'reverse';
P = @(h, x, y, c, varargin) patch(h, x, y, 'w', 'FaceColor', c, 'EdgeColor', 'none', varargin{:});
L = @(h, x, y, c, w) line(h, x(:), y(:), 'Color', c, 'LineWidth', w);
T = @(p, x, y, z, c, varargin) text(p, x, y, '', 'FontSize', z, 'Color', c, ...
    'FontName', 'Impact', 'HorizontalAlignment', 'center', varargin{:});

% Dusk sky, stars, moon, clouds
c = [.06 .1 .27; .96 .56 .5];
P(ax, [0 800 800 0], [0 0 G G], 'interp', 'FaceVertexCData', c([1 1 2 2], :));
scatter(ax, 800*rand(1, 45), 270*rand(1, 45).^1.4, 40*rand(1, 45), 'y', 'p', 'filled');
D(ax, 'PeĀíåÞØÒÎÌÌÎÒØÞåííèãßÜÚÙÙÚÜßãèíēĔēĐċąþöïéäáàááãåéíò÷ýĂćċďđē', 400, 20); %art:moon
for k = [150 560]
    D(ax, 'ebÌúĈÞÖebÌĘþâÜebÌĶĆÞ×ebÌŐčØÒebÌàĎØÒebÌĘĐĎÒeaÌúĄÞÖeaÌĘúâÜeaÌĶĂÞ×eaÌŐĉØÒeaÌàĊØÒeaÌĘČĎÒ', k - 80, k/20 - 18); %art:cloud
end

% Hills, farm, field
x = 0:20:800;
P(ax, [x 800 0], [488 + 14*sin(x/90) + 8*sin(x/37 + 1) 530 530], '#24414F');
D(ax, 'P\ÐĜĲĲĜÜÜĮĮE]ÌħÜÓÐP^Ð×ĕĕ×õõĮĮP_ÒÑÝöďěõãØãõP`ÐðüüðææððpJÐéăăéČČĮĮp^ÐëāāëĎĎĮĮ3JÒëā¡ëāĎĮ¡ĮĎ', 600, 420); %art:farm
P(ax, [0 800 800 0], [G G 600 600], '#5C8A3A');

% Earthlings
A = {'PBÐÂÇÇÂööĄĄPBÐÉÎÎÉööĄĄpCÐÁÇÇÁāāĄĄpCÐÉÏÏÉāāĄĄPDÐÀÐÐÀèè÷÷pBÐÂÎÎÂìì÷÷4EÌÓÓĂÒ3FÞÏÏ¡ÓÓ¡××¡Ï×ÒÊ¡ÒÊ¡ÒÊ¡ÒÒ6DÌÍÓëñEGÌÈãÎÎEHÌÈÞÓÊPHÐÃÍÍÃ××ÞÞpIÐÃÍÍÃÜÜÞÞ', ... %art:farmer
    'PJÐ¸¼¼¸øøĄĄpKÐ¸¼¼¸āāĄĄPJÐ¿ÃÃ¿øøĄĄpKÐ¿ÃÃ¿āāĄĄPJÐÍÑÑÍøøĄĄpKÐÍÑÑÍāāĄĄPJÐÓ××ÓøøĄĄpKÐÓ××ÓāāĄĄ3KÎ³®ìöûEJÌÅðÛÓeKÌÀíÎÌeKÌÍôÍÌeKÌ¸ôËËeLÌÇûÌË4MÒØÕ¡ÝàâÜ¡âÜEJÌÛçÏÏeKÌÔäËÊELÌáêÍÌeKÌÛåÉÊ', ... %art:cow
    'PNÐÃÇÇÃööĄĄPNÐÉÍÍÉööĄĄpKÐÂÈÈÂāāĄĄpKÐÉÏÏÉāāĄĄPOÐÂÎÎÂèè÷÷pPÐÂÎÎÂóóõõEGÌÈäÍÎPNÚÁÂÃÅÈËÍÎÏâàÞÜÜÜÞàâ6OÌÊÑìè6QÌÇÖïâ3KÌÒÞæÛpRÜéåéäáàÚàßãÒ×ÜÚßÙØÖÐÔ'}; %art:soldier
for i = 12:-1:1
    s.E(i) = X(ax, A{s.ty(i)}, 0, -60);
end

% Tractor beam (moved to the saucer's x in render)
B = hgtransform(ax);
a = 0:.2:6.3;
P(B, [-22 22 50 -50], [400 400 G G], '#B8FF8A', 'FaceAlpha', .3);
P(B, 58*cos(a), G + 7*sin(a), '#D8FF9A', 'FaceAlpha', .45);
s.Br = L(B, NaN, NaN, '#E8FFC8', 1.5);
s.B = B;

% Jets with contrails, one per lane
for j = 3:-1:1
    s.J(j) = X(ax, 'pJÐžÒÒžÅÂÎËpSÎƀŲƀÅÈËPTÐƒƆžƂÂ²²ÃpUÐƉƅƁƄ»µµ»EVÌǄÁÑÍPTÚǜǖǈƐƀƀƐǈǖÈÃÁÁÄËÎÎÌeKÌǜÈÊÌPWÐƸƪƘƢÊÊÖÖPWÐƊƀźƂÉÉÏÏ', -230, 0); %art:jet
    s.J(j).Children(end).FaceAlpha = .2;
end

% Saucer, with a little green pilot under the dome
S = hgtransform(ax);
h = D(S, 'EXÌĄöÐÑeKÌĀõËÌeKÌĈõËÌ3XÌĄĄíçeYÌĄæÊÊPcâìíïóøþĄĊĐĕęěĜÿùóîêèçèêîóùÿeJÌùóÌÎEZÌĄĊêÐedÌĄĎØÌE[ÌĄĄĀÓeUÌĄąúÌEVÌÚąËËERÌèąËËEVÌöąËËERÌĄąËËEVÌĒąËËERÌĠąËËEVÌĮąËË', -60, -60); %art:saucer
h(6).FaceAlpha = .45;
h(7).FaceAlpha = .6;
s.Hu = h(10);
s.S = S;

% Bullets, score popup, explosion, HUD, messages
s.Bl = scatter(ax, NaN, NaN, 16, [1 .9 .4], 'filled');
s.Pp = T(ax, 0, 0, 16, '#FFE066');
s.Ex = X(ax, 'PSøŊĭłĥĬĖĎĆð÷ÚïÒïÚ÷ðĆĎĖĬĥłĭĎĖĬĥłĭŊĭłĥĬĖĎĆð÷ÚïÒïÚ÷ðĆpRøĳġĮĜġēĎĉüĀîûéûîĀûĉĎēġĜĮġĎēġĜĮġĳġĮĜġēĎĉüĀîûéûîĀûĉ', -70, -70); %art:boom
T(s.Ex, 0, -70, 24, '#E4572E', 'Rotation', 8, 'String', 'KA-BLOOEY!');
s.Hd = T(ax, 400, 20, 18, '#FFD23F');
s.Pn = P(ax, [150 650 650 150], [250 250 380 380], '#101A45', 'FaceAlpha', .75);
s.Tt = T(ax, 400, 190, 62, '#FFD23F');
s.Ms = T(ax, 400, 315, 15, 'w');
end

function s = lvl(s, n)
% Set up level n (level 1 also resets the score) and show its card.
% Saucer mode m: 1 cruise, 2 down, 3 beam, 4 up, 5 gone.
% Soldier alert a: 0 no, 1 running to a firing spot, 2 shooting.
% Each digit group: farmers, cows, soldiers, jet lanes for levels 1-6.
% Past level 6 the jets just get faster.
c = '210121023202321243235433' - 48;
c = c(4*min(n, 6) - (3:-1:0));
s.lv = n; s.sc = s.sc*(n > 1);
s.sx = 400; s.sy = 110; s.vx = 170; s.m = 1; s.hp = 3; s.st = 0;
[s.hit, s.ct, s.pt, s.pv] = deal(0);
s.tl = 'SAUCER QUEST';
s.msg = {sprintf('LEVEL %d:  %d FARMERS  %d COWS  %d SOLDIERS  %d JETS', n, c), '', ...
    'Tap to beam down, tap again to zip up.', 'FARMER 50     COW 100     SOLDIER = DOOM', '', 'TAP TO BEGIN'};
s.x = 60*randperm(12) + 20*rand(1, 12) - 10;
[s.h, s.a, s.ft, s.mz] = deal(zeros(1, 12));
s.f = sign(rand(1, 12) - .5);
s.v = s.b;
s.on = s.r <= c(s.ty);
% Lane velocities. A used lane's jet starts just past its exit, so the
% first update sends it around; an unused lane's starts so far back that
% it never arrives.
s.ls = [1 -1 1].*(170 + 20*n + 80*rand(1, 3));
s.jx = 400 + sign(s.ls).*(700 - 1e7*((1:3) > c(4)));
[s.bz, s.bv] = deal([]);             % bullets: complex position, velocity
end

function s = upd(s, dt, p)
s.t = s.t + dt;
s.ct = s.ct - dt;
s.st = s.st + (s.st == 2 && s.ct < 0);
if p && s.st == 3 && s.ct < -.8, s = lvl(s, 1); end
if p && s.st == 0 && s.ct < -.5, s.st = 1; p = 0; end
p = p && s.st == 1;

% Saucer: slide at cruise, drop, beam, zip back up
s.sx = s.sx + (s.m == 1)*s.vx*dt;
if abs(s.sx - 400) > 340, s.vx = -s.vx; s.sx = 400 + sign(s.sx - 400)*340; end
s.sy = min(s.sy + (s.m == 2)*700*dt, 390);
s.sy = max(s.sy - (s.m == 4)*850*dt, 110);
s.m = s.m - 3*(s.m == 4 && s.sy == 110);
if s.m == 2 && s.sy == 390
    % Beam on: soldiers in earshot run to a firing spot outside the beam
    s.m = 3;
    k = s.on & s.ty == 3 & s.h == 0 & abs(s.x - s.sx) < 340;
    s.a(k) = 1;
end
if p && any(s.m == [1 3]), s.m = s.m + 1; end

% Jets: one per lane; each re-enters a random while after leaving
s.jx = s.jx + s.ls*dt;
k = sign(s.ls).*(s.jx - 400) > 660;
s.jx(k) = 400 - sign(s.ls(k)).*(560 + 600*rand(1, nnz(k)));
if s.st == 1 && ~mod(s.m, 2) && any(abs(s.jx - s.sx) < 90 & abs(s.L - s.sy) < 28)
    s = boom(s, 'Mid-air collision with an Air Force jet!');
end

% Beam: full lift if wholly inside it, a slow crawl if only partly.
% Anything let go falls back down.
bm = s.m == 3;
w = 9 + 17*(s.ty == 2);              % half widths
o = bm*s.on.*max(0, min(s.x + w, s.sx + 50) - max(s.x - w, s.sx - 50))./w/2;
s.h = max(0, s.h + 75*dt*((o > .99) + (o <= .99).*o/4) - 250*dt*(o == 0));
k = s.h >= 100;
if s.st == 1 && any(k & s.ty == 3), s = boom(s, 'You beamed up a soldier. He brought a grenade.'); end
v = 50*sum(s.ty(k & s.ty < 3));
if v, s.sc = s.sc + v; s.pv = v; s.pt = 1; end
s.on(k) = 0; s.h(k) = 0;
if s.st == 1 && ~any(s.on & s.ty < 3), s = lvl(s, s.lv + 1); s.tl = 'HARVEST COMPLETE!'; end

% Alerted soldiers run into position, then fire at the saucer
s.a = s.a*bm;
g = s.on & s.h == 0;
a = g & s.a > 0;
d = min(max(s.sx + sign(s.x - s.sx).*(125 + 8*(1:12)), 15), 785) - s.x;
s.x = s.x + a.*sign(d).*min(abs(d), 130*dt);
s.f(a) = sign(s.sx - s.x(a));
q = a & abs(d) < 3;
s.ft = s.ft - q*dt;
s.mz = s.mz - dt;
k = find(q & s.ft < 0, 1);
if any(k)
    z = s.x(k) + 16*s.f(k) + 490i;
    s.ft(k) = 1 + .6*rand; s.mz(k) = .08;
    s.bz(end + 1) = z; s.bv(end + 1) = 430*exp(1i*angle(s.sx + 1i*s.sy - z) + .08i*randn);
end

% Everyone else wanders, changing course now and then
k = g & ~s.a;
n = k & rand(1, 12) < dt/3;
s.f(n) = -s.f(n);
s.v(n) = s.b(n)*(rand > .25);
b = abs(s.x - 400) > 380 & s.f.*(s.x - 400) > 0;
s.f(b) = -s.f(b);
s.x = s.x + k.*s.f.*s.v*dt;

% Bullets
s.bz = s.bz + s.bv*dt;
d = s.bz - s.sx - 1i*s.sy;
k = (real(d)/54).^2 + (imag(d)/16).^2 < 1 & s.st == 1;
if any(k), s.hp = s.hp - nnz(k); s.hit = .4; end
k = k | abs(s.bz - 400 - 300i) > 520;
s.bz(k) = []; s.bv(k) = [];
if s.hp < 1 && s.st == 1, s = boom(s, 'Shot down by the Army!'); end
s.hit = s.hit - dt; s.pt = s.pt - 1.2*dt;
end

function s = boom(s, w)
s.st = 2; s.ct = 1.3; s.m = 5;
s.hi = max(s.hi, s.sc);
s.tl = 'GAME OVER';
s.msg = {w, '', sprintf('Final score: %d', s.sc), '', 'Tap to try again'};
end

function ren(~, s)
t = s.t;

% Saucer and beam
s.S.Visible = s.m < 5;
s.S.Matrix = makehgtform('translate', [s.sx, s.sy + 2*sin(3*t), 0], ...
    'zrotate', .06*sign(s.vx)*(s.m == 1));
s.Hu.FaceColor = [.84 .87 .9] + (s.hit > 0 && mod(t, .12) < .06)*[.16 -.47 -.5];
s.B.Visible = s.m == 3;
s.B.Matrix = makehgtform('translate', [s.sx 0 0]);
u = mod(.8*t + (0:2)/3, 1);
a = (0:.3:6.6)';
x = [(50 - 28*u).*cos(a); NaN(1, 3)];
y = [522 - 120*u + 4*sin(a); NaN(1, 3)];
set(s.Br, 'XData', x(:), 'YData', y(:));

% Earthlings: bob, shrink in the beam, mirror to face.
% A soldier's last shape is his muzzle flash.
for i = 1:12
    h = s.h(i);
    s.E(i).Visible = s.on(i);
    s.E(i).Children(1).Visible = s.mz(i) > 0 || s.ty(i) < 3;
    M = makehgtform('translate', [s.x(i), 522 - h - (h == 0)*2*abs(sin(12*t + i)), 0], ...
        'scale', 1 - h/180);
    M(:, [1 3]) = M(:, [1 3])*s.f(i);
    s.E(i).Matrix = M;
end

% Jets
for j = 1:3
    M = makehgtform('translate', [s.jx(j) s.L(j) 0]);
    M([1 11]) = sign(s.ls(j));
    s.J(j).Matrix = M;
end

% Bullets, popup, explosion
set(s.Bl, 'XData', real(s.bz), 'YData', imag(s.bz));
s.Pp.Visible = s.pt > 0;
s.Pp.Position = [s.sx, s.sy - 84 + 50*s.pt, 0];
s.Pp.String = "+" + s.pv;
s.Ex.Visible = s.st == 2;
s.Ex.Matrix = makehgtform('translate', [s.sx s.sy 0], 'scale', min(5.3 - 4*s.ct, 1));

% HUD and messages
s.Hd.String = sprintf('LEVEL %d     SCORE %d     HI %d     SHIELDS %s', s.lv, s.sc, max(s.hi, s.sc), repmat('●', 1, s.hp));
set([s.Tt s.Pn s.Ms], 'Visible', s.st == 0 || s.st == 3);
s.Tt.String = s.tl;
s.Ms.String = s.msg;
end

function q = X(p, a, dx, dy)
% New transform under p with encoded art a drawn into it.
q = hgtransform(p);
D(q, a, dx, dy);
end

function h = D(p, a, dx, dy)
% Draw encoded shapes (format in tools/buildArt.m) into parent p.
C = reshape('21335A432D44853CCCEB8EC6B33FFF222EABEDA452563321532FD6F92CCDE557DF9AB7F6F56789DDEBBA887B33722FD6EDFB9D9EF556FEA', 3, [])';
v = double(a) - 200;
v(v == -39) = NaN;
h = gobjects(0);
i = 1;
while i < numel(a)
    k = a(i);
    c = ['#' C(a(i + 1) - 64, :)];
    q = v(i + 3:i + 2 + v(i + 2));
    i = i + 3 + v(i + 2);
    x = q(1:end/2) + dx;
    y = q(end/2 + 1:end) + dy;
    if lower(k) == 'e'
        x = q(1) + dx + q(3)*cos(0:.2:6.3);
        y = q(2) + dy + q(4)*sin(0:.2:6.3);
    end
    if k < 'A'
        h(end + 1) = line(p, x, y, 'Color', c, 'LineWidth', (k - 48)/2); %#ok<AGROW>
    else
        h(end + 1) = patch(p, x, y, 'w', 'FaceColor', c, 'EdgeColor', '#213', 'EdgeAlpha', +(k < 'a')); %#ok<AGROW>
    end
end
end
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