I have a problem calculating the fps of my game.

I have a checktime method checking how many times the update() method is called within a second.
Is this the right way to have the fps?

This checktime method is just after the update() method and has an incrementer and when 1001ms are passed the method will return the number of fps.

If my isometric engine is drawing only the grid of the game (made with polygons) the fps are over 100 but I fill my map with grass tiles the fps slow down to 17-18.
Is that possible?

Please note that the grasstiles are loaded only one time as an ImageIcon and the preloaded with a MediaTracker.

I guessed that I had an error writing the fps code a because isn't possible that a small filled grid can go down to 17fps on a P4 2.8Ghz 512mb..

I am searching an algorythm to create lakes on an array map[][].
The algorythm should select a random place a create a lake (with a random size) but with a regular shape (not with tiles around everywhere).

Does anywone know some guide, tutorial or can explain me how to do it?

This is my first post on this forum, so, Hi Everybody!

I am here to "promote" my project, Tourist Camping Tycoon (tct).
TCT is a camping management simulation game created in an isometric view.
The game work with jIsoEngine, an isometric engine that I made in this project too.

Right now the game can't do much but the engine already does something (you can see screenshots on the wepage).

This project is in very early stages and, please note, that is programmed by me alone in the freetime so the development could be a little slow..

Please check out and tell me what you think about..

The url to this project is:
http://tct.sourceforge.net