c.width=c.height=600;m=Math;d=[[-1,0],[0,-1],[1,0],[0,1]];i=j=2;s=o=x=0;k="#000";function g(b,e,f,w,y){a.fillStyle=y;a.fillRect(20*b,20*e,20*w,20*f)}function l(b,e){e.a?l(e,e.a):(b.a=0,g(e.x,e.y,1,1,k))}function n(b,e){return!b?0:e.x==b.x&&e.y==b.y?1:n(b.a,e)}function q(){g(p.x,p.y,1,1,k);x=++x%4;a.font=15+x+"pt Calibri";a.fillStyle="#f00";a.fillText("\u2665",20*p.x,20*(p.y+1))}function r(){p={x:m.floor(30*m.random()),y:m.floor(30*m.random())};n(s,p)||n(o,p)?r():q()} function t(b,e){var f={x:(b.x+d[e][0]+30)%30,y:(b.y+d[e][1]+30)%30,a:b};return n(s,f)||n(o,f)?0:f}function u(b,e,f){if(b=b?t(b,e):0)b.x==p.x&&b.y==p.y?r():l(b,b.a),g(b.x,b.y,1,1,f);return b}function v(){if(s=u(s,i,"#00f")){var b=99,e;for(val=j+3;val<j+6;++val){var f=t(o,val%4),f=f?m.abs(f.x-p.x)+m.abs(f.y-p.y):99;b>=f&&(b=f,e=val)}j=e%4}o=u(o,j,"#0f0");if(!s||!o)i=j=2,s={x:5,y:9,a:0},o={x:5,y:21,a:0},g(0,0,30,30,k),r();q();h=0;setTimeout(v,100)} document.addEventListener("keydown",function(b){b=b.keyCode-37;(b-i)%2&&d[b]&&!h&&(h=1,i=b)},!1);v();
/*
* Classic snake game. Collect hearts before your opponent do. Use
* arrow keys to control your snake.
*/
c.width = c.height = 600;
m = Math;
//offset between moves
d = [[-1,0],//left
[0, -1],//up
[1,0],//right
[0,1]];//down
i = j = 2; // i is current offset index, j isopponent snake offset index
s = o = x = 0; // s is varaible that holds our snake o is reference to opponent snake, x used for heart animation
// colors that was used in game
k = '#000';
//draws a black rectangle to given location
function fillRect(x,y,height,width,color){
a.fillStyle = color;
a.fillRect(x*20,y*20,width*20,height*20);
}
//construct a new node for linked list
function cons(x,y,next){
return {
x:x,
y:y,
n:next};
}
//remove last node from snake and erease it from screen
function removeLast(current, last){
if(!last.n){
current.n = 0;
fillRect(last.x,last.y,1,1,k);
}else
removeLast(last,last.n);
}
// check if given node memver of given list
// comparison is done by location only
function hasItem(list,node){
return !list?0:node.x == list.x && node.y == list.y?1:hasItem(list.n,node);
}
function drawHeart(){
fillRect(p.x,p.y,1,1,k);
x = ++x%4;
a.font = 15 + x + "pt Calibri";
a.fillStyle = '#f00';
a.fillText('♥', p.x*20, (p.y+1)*20);
}
//create a random point on screen for snake to collect
function createPoint(){
p ={x : m.floor(m.random()*30),
y : m.floor(m.random()*30)};
//if point is on snake create another one else draw it on screen
hasItem(s,p)||hasItem(o,p)?createPoint():drawHeart();
}
function getHead(snake,offset){
var res = cons(((snake.x + d[offset][0])+30)%30, // mod 30 makes sure that if we get out of the screen get it snake back from index 0
(((snake.y + d[offset][1])+30)%30),
snake);
return (hasItem(s,res) || hasItem(o,res))?0:res;
}
function movesnake(snake,offset,color){
// if we are starting the game do just set starting values
// pass main logic
//add a new node to snake
snake = snake?getHead(snake,offset):0;
if(snake){
//if we eat point create another point and not remove last node
(snake.x == p.x) && (snake.y == p.y)?createPoint():removeLast(snake,snake.n);
//draw newly created node
fillRect(snake.x,snake.y,1,1,color);
}
return snake;
}
//main loop
function loop(){
s = movesnake(s,i,'#00f');
// move opponent
if(s){
var minimum = 99,
min_index;
for(val=j+3;val<j+6;++val){
var head=getHead(o,val%4),
distance=head?m.abs(head.x-p.x)+m.abs(head.y-p.y):99;
if(minimum>=distance){
minimum=distance;
min_index=val;
}
}//for
j = min_index%4;
// j = [((j-1)+4)%4, j ,(j+1)%4].map(function(x){
// var head = getHead(o,x);
// return [x,
// hasItem(head.n,head) || hasItem(s,head)?99:m.abs(head.x-p.x)+m.abs(head.y-p.y)];}).sort(function(a,b){return a[1]-b[1];
// })[0][0];
}
o = movesnake(o,j,'#0f0');
//move old
//set default values for game
if(!s || !o){
i = j= 2;
s= cons(5,9,0);
o = cons(5,21,0);
fillRect(0,0,30,30,k);
createPoint();
}
drawHeart();
h=0;//this variable makes sure that we are doing only one move on every turn //set system unchanged
setTimeout(loop,100);
}
(function(){
document.addEventListener('keydown', function(e){
//37 = left arrow
//38 = up arrow
//39 = right arrow
//40 = down arrow
var val = e.keyCode - 37;
if(((val - i) % 2)&& //new value is not same of opposite direction
d[val] &&
!h){//there was no move at current loop
h=1;// set system changed
i = val;
}
}, false);
loop();
}());
