I think you didn't follow Cedric's comment -- unless you just draw a line, strike-thru text is considered a font change.

Either way, you'll need to break up the text yourself (regardless of its source) to identify the struck-thru text, figure out where it belongs via textWidth(), and then either write the special text with a struck-thru face, or use the textWidth()-derived info to draw a line using line(). Here's just one example snippet, one way to do it:

for this amazing line:

1. int leadingWidth = textWidth("for this ");
2. int struckWidth= textWidth("amazing");
3. text("for this amazing line:",x,y);
4. noFill();
5. stroke(0);
6. line((x+leadingWidth) ,(y-5),(x+leadingWidth +struckWidth),(y-5));
   

kb, http://www.riftgame.com/