How can I make Objects fall down the screen in waves?

[Kenenth]

In my app, there are objects that are getting pulled down the screen by an nsTimer that fires every 1/60 of a second and pulls each object (these objects are stored into an array) down the screen. But, to make the game more interesting, I want the objects to fall down the screen in waves. Like an example:

In the first wave, 4 objects fall down the screen. Then there is a pause of 5 seconds. Then, in the second wave, 8 objects fall down the screen, and there is a 5 sec pause, and then in the third wave, 12 objects fall down the screen and there is a 5 second pause ect. There are an unlimited number of waves, the goal of the app is to see how many wave the user can go without dying.


Any ideas? I imagine that its a very complicated task. Here is some info about the structure of the app (if needed):

An NSTimer Fires every second to generate an object at the top of the screen with a random x value. These objects are stored into an NSMutableArray.

Another NSTimer fires every 1/60 of a second and runs through the MutableArray and pulls the troops down 1 pixel every time the NSTimer is fired.

[smithdale87]

It's not complicated at all, and there are definitely multiple solutions. I would choose a very OOP approach and start by defining a "Wave" object.

You just need a way to isolate the properties that define each wave. For instance, the # of objects in the wave could be one property, as well as the length of time to wait before the first object comes down ( this would be the "pause" in between each of the waves that you mention ).

So you could start by defining a few arbitrary waves:

//this wave will have 5 objects, and would wait 3 seconds before starting
Wave* wave1 = [Wave waveWithObjectCount: 5 andInitialPause: 3];

//this wave will have 3 objects and wait 8 seconds before starting
Wave* wave2 = [Wave waveWithObjectCount: 3 and InitialPause:8];

...// and so on

In order to get your "unlimited" effect, you could create, say 10 different waves and then store them all in an NSArray and just loop through them over and over again.

Now, with y our timer, you would just go through and grab each Wave object out of the array and add your troops to the screen and so forth just like you have been doing.