Canvas Mandelbrot scratch code

mandelbrot.js

var CANVAS_CTX = canvas.getContext('2d');
var DRAW_PIXEL_ID = CANVAS_CTX.createImageData(1,1); 
var DRAW_PIXEL_DATA  = DRAW_PIXEL_ID.data;

function drawPixel(ctx, x, y, r, g, b, a) {
  DRAW_PIXEL_DATA[0]   = r;
  DRAW_PIXEL_DATA[1]   = g;
  DRAW_PIXEL_DATA[2]   = b;
  DRAW_PIXEL_DATA[3]   = a;
  ctx.putImageData( DRAW_PIXEL_ID, x, y );     
}

function drawRow(ctx, y) {
  _(range(0, ctx.width))
    .each(function(x) {
      drawPixel(ctx, x, y, 0 ,0 ,0, 0);
    })
    .value();
}

function renderRows(ctx, y) {
  if ((y || 0) < ctx.height) {
    drawRow(ctx, y);
    setTimeout(0, renderRows(ctx, (y || 0) + 1));
  }
}

renderRows(ctx);

// would like calls like this
draw(red(pixel(10,10)));