cocos2d for iPhone

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1. 

   artakus
   Member

   I have a map with tilesize = 32 * 32 and I have a sprite. My map got tree, rock, water etc (object that my sprite cannot move to).

   I want to click my sprite and there will a green box appear (like a new layer) mark the map to show where the sprite (object) able to move. When clicked on the green box, my sprite will move into. The problem here how do i mark the green box to the map and determine only the tile without object (like tree, rock and water) cannot be moved in to? Do I need A* algorithm ?

   Posted 2 years ago #
2. 

   shivaz
   Member

   Check out this post: http://www.cocos2d-iphone.org/forum/topic/890
   or this post: http://www.cocos2d-iphone.org/forum/topic/267

   Lars might be willing to paste up some code from what I gave him - I think my posts were a little dodge. Basic idea is that you have a dictionary with different actions in it - and use a random integer to pick an option. In your case, you don't need it to pick an option - just present options, and if you have a spotManager - you can use that to decide if a spot is busy or not.

   Justin

   Posted 2 years ago #
3. 

   artakus
   Member

   hmm that is what we call as tree decision? is it? So, basically I don't need A* algorithm to achieve that? I went through your post and I found your post with example of code and reading your post make me happy eventhough im not able to understand your code for this moment as you said your code hasn't complete yet.

   Posted 2 years ago #
4. 

   shivaz
   Member

   yes, it is a simple decision tree. If you cut the code back to the most basic point - it is really simple.

   You have an array of arrays. Or in my case a dictionary of arrays.

   Justin

   Posted 2 years ago #
5. 

   Korki696
   Member

   Hey,
   sorry im a little bit late to this post but since Justin said its ok if I post the code. here it is:
   files.me.com/larsk/a5teqt

   And thanks again Justin for helping me with that.
   -Lars

   Posted 2 years ago #
6. 

   shivaz
   Member

   No worries Lars, thanks for posting the code - I didn't want to do it incase I gave away any of your stuff. How are you going with it? I have changed my usage of it a lot - moving a fair amount of the smarts into my custom sprite. So I can now do stuff like:

   [mySprite selectAndMoveAISprite]; - which selects an idle sprite from an NSMutableArray - adds it to an active array - and then gives it a path to follow.

   Justin

   Posted 2 years ago #
7. 

   arian487
   Member

   Kind of late and I'm not even sure what you're asking but here goes.

   I assume you have a character on a map and you want to click him and then all the possible tiles will be highlighted? I'm not even sure if this is the best way but I'd treat each tile as a node and each tile will be connected through an edge. So we'd have a graph and each node that character is NOT able to travel on, I'd simply treat as a node with no connecting edges and give it a sprite (rock for example).

   So now, when you click on your character, you run a shortest path algorithm. I'd use Dijkstras, so after the algorithm is run you'd have an array of visited nodes and if it CAN be visited, it WILL be visited so therefore whichever nodes have been visited, these are the possible places your character can go and you simply highlight them.

   I've written dijkstra's in n^2 so it shouldn't be too hard. This is also good because it becomes REALLY easy to change tiles to unvisitable tiles, and even get fancy with having your character travel in a certain path. Like make some paths more expensive then others and your character will automatically take the best path :)

   Again, I'm not sure if this is what you want. Or if this is even the best way. Let me know if you need help for the algorithm, or if you did it a different way, I'll be curious to see how.

   Posted 2 years ago #
8. 

   artakus
   Member

   im really sorry for the late reply. Thanks for your reply

   @ Justin:

   you said the algorithm name is Decision Tree? where can I find example of it. I did research on google and found nothing about the algorithm.

   @Lars:

   Thanks for posting the code. I compiled and run and it looks great! Anyway is the code related to decision tree? because I didn't find the decision tree part in your code?

   @arian487:

   Thanks for your explanation and yes what I wanna do is, when I click on a character then there will be highlighted tile where I can move my character into the highlighted tile. is there any example about the algorithm? and here is the example of game did that:

   

   

   

   Look at the green box above. How do I do that

   Posted 2 years ago #
9. 

   shivaz
   Member

   Its just the basic idea that at each point you make a branching decision. Wikipedia has some info. Probably more an idea and less of an algorithm.

   It works like this though.

   I am at point 1. I have three options - go to point 2, go to point 3 or go to point 4.
   I pick point 3 - if 3 is busy, I choose point 2, if 2 is busy I choose point 4 - if point 4 is busy, I sleep and try again.

   I am now at point 3. I have ... options ... etc ...

   You can use it to show those options to the user - and allow them to choose - or in the case of the demo I did for Lars, you can get the AI to move itself into an available position.

   Look at the file that has all the actions in it (can't remember what I called it!) - its a NSDictionary or NSArrays - should be able to work it out.

   Justin

   Posted 2 years ago #
10. 

    artakus
    Member

    hmm thanks justin. i understand the idea you given but i dont want my sprite to automatically move. first click on it, there will be a green box appear limitedly in one area like above picture (which i dont know how it appears and what algorithm make it appears). Then second click on the green box, the character will move in the clicked green box. I wonder how to do that.

    Posted 2 years ago #
11. 

    shivaz
    Member

    The way I would do it, would be similar to what is in that file from Lars.

    Build up a slot manager - that you can query about a grid spot. It then returns movement options - checking to see if the destination square is busy or not. Then when the user clicks and moves - update the business of the previous and present square.

    Not really too hard to convert the code to do that. Now once the map gets bigger, you might need to work with something else. The code might scale - but you might start wanting to populate it with info from xml or something.

    Sorry, if that doesn't help.

    Justin

    Posted 2 years ago #

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