d=document;c.height=c.width=e=480;q=240;f=a.fillStyle;i=Math.PI*2;v=380;g=w=172;j=95;s=r=l=m=0;n=30;o=n/2;p=1;b=a.createLinearGradient(0,0,0,e);b.addColorStop(0,'#0EF');b.addColorStop(.5,'#f8f');b.addColorStop(.5,'#5e0');b.addColorStop(1,'#fff');a.strokeStyle='#00F';d.onclick=function(e){if(!m){l=10;m=-15;}};setInterval(function(){if(p){if(++s%50==0){++n;o=n/2;}j=(++j+l)%(e+40);r=(r>e+n)?r=(-n*2):++r;r=(r+=2)%(e+n);w+=m;r+=(l*2);l>0?--l:0;if(g-w>0)m+=1;else{l=m=0;w=g;}}a.fillStyle=b;a.fillRect(0,0,e,e);a.beginPath();a.fillStyle='#FDA';a.fillRect(j-20,220,10,20);a.fillStyle='#0F0';a.arc(j-15,200,20,0,i,0);a.fill();a.beginPath();a.lineWidth=n;a.moveTo(r,q);a.lineTo(r,q+20);a.stroke();a.fillStyle='#FEF';a.fillRect(v+20,w,60,50);a.fillStyle='#E90';a.fillRect(v,w+30,80,25);a.fillStyle=f;a.beginPath();a.lineWidth=4;wt=w+50;a.arc(v+15,wt,18,0,90,0);a.moveTo(v+83,w+50);a.arc(v+65,wt,18,0,90,0);a.stroke();a.lineWidth=1;a.strokeText(s+' feet',20,20);if(w==g&&r+o>=(v+15)&&(r-o)<450)p=0;},20);
// https://github.com/PaulECoyote/js1k/blob/master/3.oregon/original/oregon.trail.js
// Oregon Trail 1k Competition entry
//
// Night is falling, how many feet can you travel
// down the trail? Click to turbo boost across the rivers.
//
// By @PaulECoyote
// Shim gives us this:
// var b = document.body;
// var c = document.getElementsByTagName('canvas')[0];
// var a = c.getContext('2d');
d=document;
c.height=c.width=cx=480;
// river y
ry=240;
// default fill style
f = a.fillStyle;
pi2 = Math.PI*2;
// wagon x,y ground y
wx = 380;
gy=wy = 172;
// tree x
tx=95;
// score, river x, force x&y
s=rx=fx=fy=0;
// river width, river width divided by 2
rw=30;
rd=rw/2;
// playing
p=1;
b=a.createLinearGradient(0,0,0,cx);
b.addColorStop(0,'#0EF');
b.addColorStop(0.5,'#f8f');
b.addColorStop(0.5,'#5e0');
b.addColorStop(1,'#fff');
a.strokeStyle = '#00F';
d.onclick = function(e){
if(!fy){
fx=10;
fy=-15;
}
};
setInterval(function () {
if(p){
++s;
if(s%500==0){++rw;rd=rw/2;}
tx=(++tx + fx)% (cx+40);
rx=(rx>cx+rw)?rx=(-rw*2):++rx;
rx= (rx+=2)% (cx+rw);
wy+=fy;
rx+=(fx*2);
fx>0?--fx:0;
if(gy-wy>0) fy+=1; else {fx=fy=0; wy=gy;}
}
a.fillStyle = b;
a.fillRect(0, 0, cx, cx);
// Tree
a.beginPath();
a.fillStyle = '#FDA';
a.fillRect(tx-20, 220, 10, 20);
a.fillStyle = '#0F0';
a.arc(tx-15, 200, 20, 0, pi2, false);
a.fill();
// River
a.beginPath();
a.lineWidth = rw;
a.moveTo(rx,ry);
a.lineTo(rx,ry+20);
a.stroke();
// Wagaon
a.fillStyle = '#FEF';
a.fillRect(wx + 20, wy, 60, 50);
a.fillStyle = '#E90';
a.fillRect(wx, wy + 30, 80, 25);
a.fillStyle = f;
// Wheels
a.beginPath();
a.lineWidth = 4;
wt=wy+50;
a.arc(wx + 15, wt, 18, 0, 90, 0);
a.moveTo(wx + 83, wy + 50);
a.arc(wx + 65, wt, 18, 0, 90, 0);
a.stroke();
// Score
a.lineWidth = 1;
a.strokeText(s+' feet',20,20);
if (wy==gy && rx+rd>=(wx+15) && (rx-rd)<450)p=0;
}, 20);
