You might want to check out [url=http://www.phy.ntnu.edu.tw/ntnujava/index.php?topic=1434.0]Ray tracing (polygon: range from 3-32 faces)[/url]

You will find total internal reflection if you re-arrange the sgape of the prism.
(e.g. check out attachement).


There is another similar applet,too!
[url=http://www.phy.ntnu.edu.tw/ntnujava/index.php?topic=414.0] Prsim optics (slow motion of light entering a prism)[/url]

Let me know in more detail if both the above two simulations do not work for your need!