I've been messing around making some small elements of an RPG game engine. Just today I've gotten a dialog system that pulls from XML all the NPC messages, user options, and some data that can trigger actions within the game (start quests, give gold, etc). I even made a dialog editor so that it is easy to add new messages to a dialog as well as define as to where a user option will take the dialog in the xml. I.E. Say "I'm done talking" will lead to a conversation ending message while "Who are you" takes you to a message about who the person is.

After I did this I got bored and started work on an inventory system. I've gotten it so that I have a base class Item, a class for managing inventory called Inventory, and a kind of data in-between class called InventorySlot that stores a single Item and an integer stating how many of that item is contained in this particular slot.

My concern is this, I work with MySQL all day at work and this InventorySlot class would make since as table but for a game (in C++) is this good design? Or should I be doing this some other way? I thought about doing a 2D array where [][0] would be the item and [][1] would be the quantity. However this would make the inventory size a constant. Using inventorySlots I can keep them all in a Vector and expand/shrink it as I need to.

Thoughts?

Well just think of your stuff in terms of objects.. it makes since though I would use a struct for the InventorySlot rather than a class - just because you dont really need a public/private interface for the inventory slot..

So.. you have an inventory that needs to be able to contain data and manipulate that data - sounds like a class is in order (like you have already)

and you have an inventory slot which needs to simply contain some data that can be easily accessed from within the inventory class - sounds like a struct is in order

I would do something like...

#define INVENTORY_SLOT_MAX 20

#include <vector>

class Inventory
{
	struct Slot
	{
		Slot(): item(NULL), count(0)  // make sure to initialize your data!
		{};

		Item * item;
		unsigned int count;
	};
public:

	Inventory()
	{
		inventorySlots.resize(INVENTORY_SLOT_MAX);  // in constructor resize the inventorySlots vector to the max inventory slot count
	};
	// Constructors/Destructors and functions to manipulate the inventory


private:

	std::vector<Slot> inventorySlots;  // A vector containing all of your inventory slots

};

please forgive if something is a bit syntactically incorrect i just whipped this up as a quick example of an approach you could take

Yep that's almost exactly how I have it right now. Then for my Inventory class I have an "addItem(Item item)" function. It iterates through the list to see if the item has been added before. If it has then it increments counts by 1 otherwise it'll create a new slot and set count to 1.

It may be better to use a HashTable (std::map) for easy searching. And maybe put an id for each item and use that as key. Just a thought.