JS1k: The JavaScript code golfing competition

W=c.width=innerWidth;H=c.height=innerHeight;c.style.display='block';N=[K=[0,0,0,0],I=P=[99,A=X=Y=S=0],R=2];Q=W/4;M=Math;J=M.min;B=M.sin;G=M.cos;E=M.random;L=M.sqrt;function D(c,x,y,r,k){a.beginPath(a.fillStyle='rgb('+(k?c:[c*=64,c,c])+')');a.fill(x?a.arc(x,y,r,0,8,0):a.rect(0,0,W,H))}setInterval(function(){D(0,X+S,Y+S,R);R=m=n=2;if(I)for(F=V=I=0;m--;)for(l=2+m;l--;)if(!m||N[l])for(i=p=m?20:200;i--;D(0,x,y,1))D(!m&i<P[l]*2?4:1,x=(m?Q+(l-1?0:3)-l*3:l*W/2)+Q-E(o=m?3:49)*1.4+B(k=i*6.3/p)*o,y=H/2+G(k)*o+m*(l*60-40),2);if(P[0]){if(F){for(;n--;)for(l=2+n;l--;)x=X-Q-(n?Q+(l-1?0:3)-l*3:l*W/2),y=Y-H/2-n*(l*60-40),k=L(x*x+y*y),n&&!N[l]||(m=k*k*(n?8:.4),T-=x/m,k<(n?6:52)?(I=P[0]--,!n&V<3?P[l]++:(R=9,n?N[l]=0:0)):U-=y/m);X=(X+T+W)%W;Y=(Y+U+H)%H;K[3]?(I=P[0]--,R=9):V=L(T*T+U*U)}else X=Q+53*G(A+=K[2]-K[0]),Y=H/2+53*B(A),K[1]?V=J(4,V+.1):(F=V,T=G(A)*V,U=B(A)*V);S=E()*.4,D([J(k=255,i=-J(-J(V*80|0,k),0)*2),J(k,575-i),0],X+S,Y+S,R,1)}},20);(d=document).onkeydown=d.onkeyup=function(e){K[(k=e.keyCode-37)>>2?4:k]=e.type[5]?.02:0}

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

//________________________________________________________________________
//########################################################################
//##                             |##                |%%                |##    
//##         _______             |##        ________|%%________        |##    
//##   /\ ,-'       `-.          |##       #####################       |##
//##  /  /             \         |##     /##                    ##     |##
//## (_ /  ,.------.___,`        |##____|##   ORION  *          |##____|##
//##  \__/      0) \             |##%%%%###   *     *       *   |##%%%%###
//##    ( (       .__`o          |##    |##           *  TRAIL  /##    |##
//##     )       ,--'            |##      ## __________________/##     |##
//##    /       (              M |##       #####################       |##
//##   |         '             E |##                |%%                |##
//##   |         '|            E |##________________|%%________________|##
//##   `      | | |            R |########################################
//##   |       \  |            K |##__by @veubeke and @UlrikeErdmann___|##
//##   |   \_   \ |            A |########################################
//##   |     \   \|\           T |##   Code and converter script at    |##
//##___|      `\  \ \____________|##___http://games.23inch.de/orion____|##
//########################################################################
//
// Optimizations:
// * used only one-character variables
// * avoided using functions where possible
// * used decreasing "for" loops: "for(i=n;i--;)"
// * see code for details...

//________________________________________________________________________
//## Initialization ######################################################

// resize canvas
width = c.width = innerWidth;
height = c.height = innerHeight;

// get rid of the extra 4 pixel below the canvas
c.style.display = 'block';

// init destructable asteroids 
// opt: values are completely unrelated but evaluate to "true"
asteroids = [

// init key states
keys = [0,0,0,0],

// queue setup and init ship
// opt: combined initialization of population and ship variables
// opt: setup only has to be truthy
setup = population = [99,angle=shipX=shipY=shipRand=0],
shipR = 2

];

// opt: remember planet position
qwidth = width/4;

// opt: remember math functions
M = Math;
min = M.min;
sin = M.sin;
cos = M.cos;
rand = M.random;
sqrt = M.sqrt;

//________________________________________________________________________
//## Painting ############################################################

// draws a circle or the background
// opt: different functionality for 1, 4 and 5 parameters
//      1 - background      (hue)
//      4 - grey circle     (hue,x,y,radius)
//      5 - coloured circle (color,x,y,radius,1)
function draw(c,x,y,r,k) {
  // opt: empty parameter list is used for preceding command
  // opt: parameter c reused for derived value
  a.beginPath(a.fillStyle='rgb('+(k?c:[c*=64,c,c])+')');
  // floating point values make sure that x is never 0 after the start
  a.fill(x?a.arc(x,y,r,0,8,0):a.rect(0,0,width,height))
}

//________________________________________________________________________
//## Main Loop ###########################################################

setInterval(function() {
  // remove ship at previous position
  // opt: also creates the black background in the beginning
  draw(0,shipX+shipRand,shipY+shipRand,shipR);

  // reset ship size
  // opt: loop variables and ship radius are set together
  shipR = m = n = 2;

  // setup - reset ship, draw planets and asteroids
  if(setup)
    // opt: empty loop header is used to reset ship variables
    for(flying=speed=setup=0;m--;)
      // draw 2 planets and 3 asteroids
      for(l=2+m;l--;)
        // if asteroid is still there
        if(!m||asteroids[l])
          // compose all objects of small rings to create a black board
          // look and add small random shifts to increase the effect
          for(i=p=m?20:200;i--;draw(0,x,y,1))
            // opt: "&" replaces "&&" if both operands are truth values
            draw(!m&i<population[l]*2?4:1,
              // opt: "l==1?3:0" -> "l-1?0:3"
              x = (m?qwidth+(l-1?0:3)-l*3:l*width/2)+qwidth
                  // opt: "Math.PI*2" -> "6.3"
                  -rand(o=m?3:49)*1.4+sin(k=i*6.3/p)*o,
              y = height/2+cos(k)*o+m*(l*60-40),2);

  // opt: used condition instead of "clearInterval" to stop game
  if(population[0]) {
    // update flying ship
    if(flying) {
      for(;n--;)
        // update ship speed with gravitation of all objects
        for(l=2+n;l--;)
          x = shipX-qwidth-(n?qwidth+(l-1?0:3)-l*3:l*width/2),
          y = shipY-height/2-n*(l*60-40),
          k = sqrt(x*x+y*y),
          n&&!asteroids[l] || (m = k*k*(n?8:.4),shipSX -= x/m,
            // reset if ship had a collision
            // opt: change ship radius to create a simple explosion
            // opt: "n&&(asteroids[l]=0)" -> "n?asteroids[l]=0:0"
            k<(n?6:52)
              ? (setup = population[0]--,
                 !n&speed<3?population[l]++:(shipR=9,n?asteroids[l]=0:0))
              : shipSY -= y/m);
      shipX = (shipX+shipSX+width)%width;
      shipY = (shipY+shipSY+height)%height;
      // reset if aborted
      keys[3] ? (setup = population[0]--,shipR=9)
              : speed = sqrt(shipSX*shipSX+shipSY*shipSY)
    }
    // update launch position
    else
      shipX = qwidth+53*cos(angle+=keys[2]-keys[0]),
      shipY = height/2+53*sin(angle),
      // increase speed as long as "up" is pressed
      keys[1] ? speed = min(4,speed+.1)
              // launch if "up" has been pressed
              : (flying = speed,
                 shipSX = cos(angle)*speed,
                 shipSY = sin(angle)*speed);
    shipRand = rand()*.4,
    // opt: "Math.max(x,y)" -> "-Math.min(-x,-y)"
    draw([min(k=255,i=-min(-min(speed*80|0,k),0)*2),min(k,575-i),0],
      shipX+shipRand,shipY+shipRand,shipR,1)
  }
},20);

//________________________________________________________________________
//## Event Handler #######################################################

(d=document).onkeydown = d.onkeyup = function(e) {
  // opt: "key < 0 || key > 4" -> "key >> 2"
  // opt: "key[4]" is used as a catch-all to avoid using "if"
  // opt: "e.type == 'keydown'" -> e.type[5]
  // opt: key states are actually needed values instead of true/false
  keys[(k=e.keyCode-37)>>2?4:k] = e.type[5]?.02:0
}

//________________________________________________________________________
//########################################################################
//##           / /  /    /        / /  /     /    /  /  / /  /     /   |##
//## demo     / /  /    /        / /  /     /    /  /  / /  /     /    |##
//## for     / /__/    /________/ /  /_____/    /__/  / /__/     /     |##
//##        /  |%%|    |%%%%%%%%|/   |%%%%%|    |%%| / /%%/     /      |##
//##       /   |%%|   /|%%|/____/   /   |%%|   /|%%|/_/%%/     /       |##
//##      /    |%%|  / |%%%%%%%%|  /    |%%|  / |%%%%%%%%\    /        |##
//##     /_____|%%| /  /_____|%%| /     |%%| /  |%%| / \%%\  /         |##
//##     |%%%%%%%%|/   |%%%%%%%%|/      |%%|/   |%%|/   \%%\/ .com     |##
//##___________________________________________________________________|##
//########################################################################