Creepenator

I clicked a button on my keyboard while I was trying to undo something I can drawn. Suddenly, the options for the pen tool in the top of my screen go away. Some of these settings are hardness, brush width and antialiasing. I looked around for a while and couldn't find a way to turn it back on. The screenshot is of what it used to look like (took of the brush tool) and now it is completely blank.