JS1k: The JavaScript code golfing competition

M=Math.min;function K(x,y,r,u,v){r?a.beginPath()|a.fill(a.arc(x,y,r,u||0,v||7,0)):a.fillStyle='#'+'a000b4bbfff5'.substr(x,3);return K}function P(e){C=k=64;c.height=c.width=E=C*4;K(e?1:6)(0,0,E*2);if(e){for(i in D)i-S&&a[I='putImageData'](D[X[i]],i%4*C,i/4<<6);S+1&&a.fillRect(N+5,O+5,C,C)|a[I](D[T],N,O)}else{for(K(8)(90,590,E*2)(1)(145,y=24,14)(x=150,12,z=10,1,4)(134,y,z)(x,57,i=y);i+9;)K(180+i,71-i*i--/40+Math.sin(A)*y/(33-i),4);for(i=205;--i;i<18&&K(s=C+(i%6-3)*i<<1,t=y+i*z+M(i-4?0:A*A*2,x),4)(0)(s,t,4,6,3))j=i%49*(i%21)/9,K(3)(E/2,l=z-j,j+=i,1.2,2)(8)(E/2,l-j%2,j,1.7,2);for(K(9)(x,21,4,4,7)(x,21,4,8,5);--k;K(8)(j*7%E,j*k%E,k%2+1))j=k*k+A;A+=.3}}P(A=0);for(X=[D=[x=16]];x--;X[x]=x*6%47%16)D[x]=a.getImageData(x%4*C,x/4<<6,63,63);P(R=S=-1);setInterval(c.onmousedown=c.onmousemove=document.onmouseup=function(e){f=e?e.type:P(R);if(f&&R){N=-M(32-M(x=e.clientX,219),0);O=-M(32-M(y=e.clientY,219),0);p=(x|y)>>8;z=x/C|y/C<<2;f[8]!='n'||p?C:T=X[S=z];if(!f[8]&&S+1){p||(X[S]=X[z],X[z]=T);S=-1;R=0;for(i in X)R|=X[i]-i}}},C)

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// X-Mas Cartoon Puzzle for JS1K by @veubeke
// See http://games.23inch.de/puzzle/ for (ugly) converter script

// Version 1.1 changes:
// - minor drag&drop bugs
// - transparent shadow
// + more animations after finish and snow on the tree

// Optimizations used:
// * Content
//   * Interlaced colors in one string
//   * Procedurally generated tree, decoration, falling snow
//   * Grouped painting of same-color parts
//   * Created fake shadow with fillRect instead of using built-in shadow
//   * Built whole scene with circle (segments)
// * Syntax
//   * Used 'a ? b : c' instead of 'if(a) b; else c'
//   * Used 'a && b' and 'a || b' instead of 'if(a) b' and 'if(!a) b'
//   * Used '|' instead of '||' and '|' instead of '+' (for different operator priority)
//   * Used 'a,b,c' or 'a|b|c' instead of '{a;b;c}'
//   * Used 'for(a=b;a--)' instead of 'for(a=0;a<b;a++)' (or '--a' for 'a=1')
//   * Used calls w/o parameter for other statements e.g. a.fill(a.rect(...))
//   * Used || for default arguments
//   * Used 2^n sizes to allow for exsessive shifting
//   * Used bit operations for rounding
//   * Set height to clear canvas
//   * Let often used function return itself to chain calls
//   * Exploited operator hierarchy to avoid ()
//   * ...
//   * Didn't use ~ to check for -1 because opera 10/11 fails after 10th call(bug has been filed)
// * Other
//   * Cached often used function (names)
//   * Used every function for multiple purpoises

// Global variables:
//  a - context, b - body, c - canvas
//  C        - tile size
//  anim     - animation step
//  data     - tile image data
//  map      - index to tile map
//  mousex/y - current mouse position
//  running  - whether the puzzle is still incomplete
//  source   - dragged tile source
//  tile     - dragged tile
mmin = Math.min;

// ark - draw a circle (segment) or set a color
// 1   parameter  - set color
// 3,5 parameters - draw circle (segment)
// 4   parameter  - draw rectangle
//
// Interlaced colors 
// a00           decoration
//  000          cat, border
//    0b4        tree
//       bbf     sky
//         fff   snow
//          ff5  eye 
function ark(x,y,r,u,v) {
  r ? a.beginPath() | a.fill(a.arc(x,y,r,u||0,v||7,0))
    : a.fillStyle = '#'+'a000b4bbfff5'.substr(x,3);
  // Returns itself so calls can be chained
  return ark
}

// paint - paint image or rearrange tiles
function paint(e) {
  C = k = 64;
  // Reset canvas
  c.height = c.width = size = C*4;
  // Paint sky or tile background/borders
  ark(e?1:6)(0,0,size*2);

  // Rearrange tiles
  if(e) {
    // Paste placed tiles
    for(i in data)
      i-source && a[pimd='putImageData'](data[map[i]], i%4*C, i/4<<6);
    // Paste dragged tile if currently dragging
    source+1 && a.fillRect(mousex+5, mousey+5, C,C) | a[pimd](data[tile], mousex, mousey)
  }

  // Paint image / animation
  else {
    //  Snow,              cat: head         ears                        body
    for(ark(8)(90,590,size*2)(1)(145,y=24,14)(x=150,12,z=10,1,4)(134,y,z)(x,57,i=y); i+9;)
      // Tail
      ark(180+i,71-i*i--/40+Math.sin(anim)*y/(33-i),4);

    // Globes
    for(i=205; --i; i<18 && ark(s=C+(i%6-3)*i<<1,t=y+i*z+mmin(i-4?0:anim*anim*2,x),4)(0)(s,t,4,6,3))
      j = i%49*(i%21)/9,
      // Tree                        snow on tree
      ark(3)(size/2,l=z-j,j+=i,1.2,2)(8)(size/2,l-j%2,j,1.7,2);

    // Cat's eye, snowflakes (will fall if painted repeatedly)
    for(ark(9)(x,21,4,4,7)(x,21,4,8,5); --k; ark(8)(j*7%size,j*k%size,k%2+1))
      j = k*k+anim;
    anim += .3
  }
}
// Paint initial image
paint(anim=0);

// Create and 'randomize' tiles
for(map=[data=[x=16]]; x--; map[x]=x*6%47%16)
  data[x] = a.getImageData(x%4*C,x/4<<6,63,63);

// Draw tiles
paint(running=source=-1);

// Add event handlers and start animation loop
setInterval(
  c.onmousedown = c.onmousemove =
  // 'Mouse up' has to be catched at the document level to not lose
  // actions outside of the page.
  document.onmouseup = function(e) {
    // Paint tiles / animation when not in an event handler.
    // Check for e.type is necessary for firefox as it adds a latency parameter
    f = e ? e.type : paint(running);
    if(f && running) {
      // Handle dragging
      mousex = -mmin(32-mmin(x=e.clientX, 219), 0);
      mousey = -mmin(32-mmin(y=e.clientY, 219), 0);

      // Check boundaries
      p = (x|y) >> 8;
 
      // Get tile 
      z = x/C | y/C<<2;
    
      // Handle grabbing
      f[8]!='n' || p ? C : tile = map[source=z];

      // Handle drop
      if(!f[8] && source+1) { // try ~source here in opera and have fun :D
        // Switch tiles
        p || (map[source] = map[z], map[z] = tile);

        // Reset
        source = -1;
    
        // Check if finished.
        running = 0;
        for(i in map)
          running |= map[i]-i
      }
    }
  }
, C)