Drawing a checker board pattern quickly with AS3

Today I needed to dynamically generate a checker board pattern in ActionScript 3. I couldn’t find any examples on how to do it so I made my own. Below is a snippet of code I wrote to draw it and its super fast! I used bitwise operators in the loops to speed it up and it can draw a 2000x2000px area in 10 milliseconds.

// Box colour 1
var even:uint = 0xCCCCCC;

// Box colour 2
var odd:uint = 0x999999;

// Box size
var size:int = 10;

// number of boxes horizontally
var nH:int = stage.stageWidth / size;

// number of boxes vertically
var nV:int = stage.stageHeight / size;

// vars to be used in the loops
var clr:uint;
var i:uint;
var j:uint;

// loop vertical
for (i = 0; i < nV; ++i) { 
  // Flip values of Even and Odd colours using Bitwise operations
  even ^= odd;
  odd ^= even;
  even ^= odd;

  // loop horizontal 
  for (j = 0; j < nH; ++j) { 
    //bitwise modulus 
    //check if column is odd or even, then set colour 
    clr = j & 1 ? even : odd; 

    // draw box with previously set colour 
    graphics.beginFill(clr, 1); 
    graphics.drawRect(Number(j * size), Number(i * size), size, size); 
    graphics.endFill(); 
  }
}