What does setTextMatrix of contentByte class in iText do?

I am using iText and am very new to it. There have been several situations where I think I could 开发者_如何转开发have figured out the problem with my code if I knew what I was doing - I use examples without knowing the workings behind the code, and even as I look at the source I can't figure out what the programmer was thinking.

What does setTextMatrix of contentByteArray in iText do? And how do I figure out the parameter values I need?

For example:

cb.setTextMatrix(1, 0);

1. The input parameters are x,y coordinates in points, unless CTM scaling was defined.
2. 0,0 would be the bottom left of the template you are referencing.
3. The position is the 'baseline' of the text, rather than the top or the bottom.

Transcribed from this source: https://sourceforge.net/p/itext/mailman/message/12855218/

first parameter sets left margin, second parameter sets bottom margin.