code: function (x, y, r, g, b, a) {
  		x = Math.ceil(x);
  		y = Math.ceil(y);
  		var offset = (x + y * this.width) * 4;
  			
  		this.data[offset + 0] = Math.floor(r);
  		this.data[offset + 1] = Math.floor(g);
  		this.data[offset + 2] = Math.floor(b);
  		this.data[offset + 3] = (arguments.length == 5) ? Math.floor(a) : 255;
  	}
docs: setPixel(int x, int y, int r, int g, int b, int a)
  
  Set pixel.
  @param x - x-coordinate of the point.
  @param y - y-coordinate of the point.
  @param r, g, b, a - Values of red, green, blue components and alpha channel, between 0 and 255 (inclusive).