Botlte Rocket Lab

Toshiaki Takeuchi
/
Botlte Rocket Lab
on 12 Nov 2026
4
12
5
0
8728
game.m
function g = game()
g.init = @initState; g.update = @updateState; g.render = @renderFrame;
end

function s = initState(ax)
s.ax=ax;s.ground=520;s.water=.2;s.pressure=30;s.stage=1;s.idle=0;
s.alt=0;s.v=0;s.maxAlt=0;s.fuel=0;s.air0=0;s.jet=0;s.t=0;s.result='';
ax.YDir='reverse';ax.Color=[.35 .78 .98];ax.XLim=[0 800];ax.YLim=[0 600];
o={'HitTest','off','PickableParts','none'};
s.g.sky=rectangle(ax,'Position',[0 -1000 800 3000],'FaceColor',[.35 .78 .98],'EdgeColor','none',o{:});
s.g.ground=rectangle(ax,'Position',[0 s.ground 800 2000],'FaceColor',[.18 .52 .20],'EdgeColor','none',o{:});
s.g.pad=rectangle(ax,'Position',[335 505 130 15],'FaceColor',[.22 .22 .25],'EdgeColor','none',o{:});
s.g.rocket=rectangle(ax,'Position',[394 485 12 25],'Curvature',[.45 .25],'FaceColor',[.96 .96 .92],'EdgeColor',[.15 .15 .18],'LineWidth',1.5,o{:});
s.g.neck=rectangle(ax,'Position',[396 510 8 7],'FaceColor',[.96 .96 .92],'EdgeColor',[.15 .15 .18],'LineWidth',1.5,o{:});
s.g.cap=rectangle(ax,'Position',[395 517 10 3],'FaceColor',[.12 .18 .28],'EdgeColor','none',o{:});
s.g.water=rectangle(ax,'Position',[395 497 10 13],'FaceColor',[.04 .38 .95],'EdgeColor','none',o{:});
s.g.flame=patch(ax,[396 404 400],[520 520 550],[.1 .6 1],'EdgeColor','none','Visible','off',o{:});
s.g.trail=line(ax,400,520,'Color',[.1 .6 1],'LineWidth',2,'Visible','off',o{:});
s.g.dial=rectangle(ax,'Position',[280 185 240 240],'Curvature',[1 1],'FaceColor',[.96 .96 .92],'EdgeColor',[.1 .2 .3],'LineWidth',3,o{:});
s.g.needle=line(ax,[400 400],[305 225],'Color',[.9 .12 .1],'LineWidth',4,o{:});
s.g.hub=rectangle(ax,'Position',[392 297 16 16],'Curvature',[1 1],'FaceColor',[.12 .12 .15],'EdgeColor','none',o{:});
s.g.psi=text(ax,400,365,'','HorizontalAlignment','center','FontSize',25,'FontWeight','bold','Color',[.1 .2 .3],o{:});
s.g.title=text(ax,400,70,'BOTTLE ROCKET LAB','HorizontalAlignment','center','FontSize',24,'FontWeight','bold','Color','w',o{:});
s.g.info=text(ax,400,115,'','HorizontalAlignment','center','FontSize',16,'Color','w',o{:});
s.g.readout=text(ax,25,40,'','FontSize',15,'FontWeight','bold','Color',[.05 .15 .28],o{:});
s.g.alt=text(ax,775,40,'','HorizontalAlignment','right','FontSize',15,'FontWeight','bold','Color',[.05 .15 .28],o{:});
end

function s = updateState(s,dt,pressed)
if s.stage==1
    s.idle=s.idle+dt;s.water=.2+.4*mod(floor(2*s.idle),5);
    if pressed,s.idle=0;s.stage=2;end
    return
end
if s.stage==2
    s.idle=s.idle+dt;s.pressure=30+15*mod(floor(2*s.idle),5);
    if pressed,s.stage=3;end
    return
end
if s.stage==3
    if pressed,s=launch(s);end
    return
end
if s.stage==5
    if pressed,s=resetRound(s);end
    return
end
s.t=s.t+dt;
s.jet=max(0,s.jet-.05*dt);
if s.fuel>0
    va=.002-s.fuel/1000;
    p=(101325+s.pressure*6894.76)*(s.air0/va)^1.4-101325;p=max(p,0);
    a=pi*.011^2;mdot=min(.8*a*sqrt(2*1000*p),s.fuel/dt);
    thrust=mdot*sqrt(2*p/1000);s.fuel=max(0,s.fuel-mdot*dt);
else
    thrust=0;
end
m=.12+s.fuel;drag=.5*1.225*.45*.006*s.v*abs(s.v);
s.v=s.v+(thrust-drag-m*9.81)/m*dt;s.alt=max(0,s.alt+s.v*dt);
s.maxAlt=max(s.maxAlt,s.alt);
if s.alt==0&&s.t>.4&&s.v<=0
    s.stage=5;s.result=sprintf('TOUCHDOWN!  Peak altitude: %.1f m\nTap to build another rocket',s.maxAlt);
end
end

function s = launch(s)
if s.pressure>85
    s.stage=5;s.result=sprintf('BOTTLE BURST!  %d PSI exceeds the safe limit.\nTap to try again',s.pressure);
elseif s.water==0||s.water>=2
    s.stage=5;s.result='NO LIFTOFF!  A rocket needs both water and compressed air.\nTap to try again';
else
    s.fuel=s.water;s.air0=.002-s.water/1000;s.jet=1;s.stage=4;
end
end

function renderFrame(~,s)
isBottle=s.stage==1||s.stage==3||s.stage>=4;
isGauge=s.stage==2;
s.g.rocket.Visible=onoff(isBottle);s.g.water.Visible=onoff(isBottle);
s.g.neck.Visible=onoff(isBottle);s.g.cap.Visible=onoff(isBottle);
s.g.pad.Visible=onoff(isBottle);s.g.ground.Visible=onoff(isBottle);
s.g.trail.Visible=onoff(s.stage==4&&s.jet>0);s.g.dial.Visible=onoff(isGauge);
s.g.needle.Visible=onoff(isGauge);s.g.hub.Visible=onoff(isGauge);s.g.psi.Visible=onoff(isGauge);
s.g.title.Visible=onoff(s.stage<=3);s.g.readout.Visible=onoff(s.stage>=3);
s.g.alt.Visible=onoff(s.stage>=4);
if s.stage==1
    setBottleView(s);setRocket(s,s.ground);
    s.g.info.String=sprintf('FILL THE 2 L BOTTLE: %d%% WATER  •  TAP TO LOCK',round(50*s.water));
elseif s.stage==2
    setWide(s);ang=pi*(.25+1.5*(s.pressure-30)/60);
    s.g.needle.XData=[400 400+82*cos(ang)];s.g.needle.YData=[305 305-82*sin(ang)];
    s.g.psi.String=sprintf('%d PSI',s.pressure);
    s.g.info.String='SET AIR PRESSURE  •  TAP TO LOCK';
elseif s.stage==3
    setFocus(s);setRocket(s,s.ground);
    s.g.info.String=sprintf('READY: %d%% WATER, %d PSI  •  TAP TO LAUNCH',round(50*s.water),s.pressure);
elseif s.stage==4
    d=5*s.alt;setFlightCamera(s,d);setRocket(s,s.ground-d);
    s.g.trail.XData=[400 400];s.g.trail.YData=[s.ground s.ground-d];
    y=s.ground-d;s.g.flame.XData=[396 404 400];s.g.flame.YData=[y y y+30];
    s.g.flame.Visible=onoff(s.jet>0);s.g.info.String='FLIGHT IN PROGRESS';
elseif s.stage==5
    setWide(s);setRocket(s,s.ground-s.alt);s.g.flame.Visible='off';s.g.info.String=s.result;
end
s.g.readout.String=sprintf('Water: %d%%     Pressure: %d PSI',round(50*s.water),s.pressure);
s.g.alt.String=sprintf('PEAK\n%.1f m',s.maxAlt);
end

function setRocket(s,base)
s.g.rocket.Position=[394 base-35 12 25];
s.g.neck.Position=[396 base-10 8 7];s.g.cap.Position=[395 base-3 10 3];
amount=s.fuel;
if s.stage<=3,amount=s.water;end
h=25*amount/2;s.g.water.Position=[395 base-10-h 10 h];
end

function setWide(s)
s.ax.XLim=[0 800];s.ax.YLim=[0 600];
s.g.title.Position=[400 70 0];s.g.info.Position=[400 115 0];
s.g.readout.Position=[25 40 0];s.g.alt.Position=[775 40 0];
end

function setBottleView(s)
s.ax.XLim=[303 497];s.ax.YLim=[400 540];
s.g.title.Position=[400 415 0];s.g.info.Position=[400 430 0];
s.g.readout.Position=[25 40 0];s.g.alt.Position=[775 40 0];
end

function setFocus(s)
s.ax.XLim=[255 545];s.ax.YLim=[350 560];
s.g.title.Position=[400 370 0];s.g.info.Position=[400 395 0];
s.g.readout.Position=[400 420 0];
end

function setFlightCamera(s,d)
z=1+3.5*(1-exp(-s.alt/200));r=max(105*z,d/2+70);c=s.ground-d/2;
s.ax.XLim=[400-1.38*r 400+1.38*r];s.ax.YLim=[c-r c+r];
s.g.info.Position=[400 s.ground-60 0];
s.g.readout.Position=[400-75*z c-r+25 0];
s.g.alt.Position=[400+75*z c-r+25 0];
end

function s = resetRound(s)
s.water=.2;s.pressure=30;s.stage=1;s.idle=0;s.alt=0;s.v=0;s.maxAlt=0;
s.fuel=0;s.air0=0;s.jet=0;s.t=0;s.result='';
end

function v = onoff(tf)
if tf,v='on';else,v='off';end
end
Play Game
Preview

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