I came across this snippet,  http://processing.org/learning/topics/continuouslines.html, it helps to scribe like MS Paint. However, I was wondering to add the functionality of UNDOing an action (like MS paint again). So, if we scrible two separate lines/circle/random_shape or anything, on pressing the undo-button or space-bar or anything, the last action is erased. 

Any help (with code snippet?), will be very helpful and appreciated. Thanks a lot!!  

So, I came across this tutorial,  http://processing.org/learning/topics/continuouslines.html and now I know how to scrible. I wanted to implement an added functionality, where if we encircle a scrible, the circled section gets colored. Like flood fill. That is, if I scrible around a car's image, on completing the scrible around the car's border, the car turns red colored. Please help with a code snippet if possible. If you think this question should have been asked under "Programming questions", I shall do so. Thanks a lot. 

I have researched about this topic on forums, and know that this issue is faced by many. But the suggestions on forum is overwhelming, and out of my understanding therefore asking it again. Sorry. 

My program talks well with the MySQL locally, but when I moved my "applet" folder to web server (is Java required to be installed?, I think its LAMP/supports CGI scripts only -- if Java is required? how to check if Java is installed in my web server? if not, please ignore this concern), and created MySQL database remotely, its not working. I wrote a PHP script, and created a Data.pde. Hardcoding something, my PHP script is talking well with the MySQL database. And, my Data,pde has the data (there are few variables - int and floats).

I am clueless how to make Data.pde talk with PHP script I have. If the variables' data can be sent from Data.pde to the PHP script, I think that would be done. Please help me with a code snippet if possible. I am on tight time constraints, quick help will be greatly/deeply appreciated. Thanks in advance.