We are about to switch to a new forum software. Until then we have removed the registration on this forum.
After many days, I have just finished the app I've been working on. It is based on the drawing animation tool included in Deluxe Paint software for Amiga computers, and inspired by hamoid's tutorial about it. However, I had to reimplement the whole idea in order to optimize it. Instead of using PGraphics for every frame, every stroke (time while the screen is pressed) is an instance of a class that saves pressed positions in the actual frame out of the number of frames set, and then it's added to an ArrayList of strokes, so that you can undo the last one. Thanks to everyone here in the forum that helped me indirectly, I hope it can also help somebody else. 8-X