Create latex fonts and equations in xfig

(TEXT FLAGS) (From http://xfig.org/userman/frm_attributes.html)
Set the Hidden, Rigid, and Special flags of TEXT objects. These flags are used for special situations, and they are all OFF by default.

Clicking this button with mouse button 2 or mouse button 3 will switch which flag's state should be displayed on the button.
Clicking this button with mouse button 1 will popup this panel:

If the Hidden flag is set ON, the string `<<>>' is displayed on the canvas instead of the text itself. The text will output as usual when Printing or Exporting. This is useful to avoid text with long sequences of LaTeX commands which makes the display hard to read.

If the Rigid flag is ON, the size of the font of the TEXT object will not be changed when a COMPOUND object which includes the TEXT object is scaled.

If the Special flag is ON, special characters (such as `\', for example) in text will not be specially processed but passed to the output `as is' when Exporting. This may be used to put LaTeX commands in text. The use of LaTeX commands is especially helpful to put complex mathematical formulas in the figure, for example. If the Special flag is OFF, the text will be processed before output.