• At the end of each section, I added a zip file you can download so that you can check how your code compares with mine.  I removed this before, but figured that it's really useful.

Made some major updates.  I apologize if you're in the middle of the site at this time.  I pretty much rewrote the whole code, but I feel the updated code is much better and easier to understand.  If you are in the middle of this, then you'll have to start from the beginning again.  I know that will deter some of you from finishing, but think of it this way.  At least the second time around you should understand everything better right?  If it makes you feel better I've started this from scratch at least a dozen times.  Here are some of the changes that I made:

• I reorganized the spritesheet so that it removes unused images.  
• I removed the hash method in the vector class since I only had that for one thing and that one thing was removed as well.  Don't worry about what that one thing was, it's gone now.  
• As much as it hurts me, I removed the stack file as well.  You don't need to use stacks, but I kept the page there in case you need to use stacks somewhere.  
• I rewrote the node finding algorithm.  Oh man, was it ever confusing before!  What was I thinking?  This new algorithm makes much more sense and is a lot shorter.
• Added some more spritesheets at the end if you want to do some sprite swaps.  It's easy to make your own as well.  
• Added sections and removed sections.  
• Removed the code files you would find at the bottom of each page.  It was just too much work on my end.  If I changed just one ittie bittie thing early on, then I would have to update all of the zip files from that point on with that one tiny change.  You'll just have to go through each section and write the code yourself.  I kept the one at the bottom of this page though since that shows the full code.  It's easier to update that than 3 dozen other ones.