Inventory System Port to Godot 4 C# Complete!

Greetings to all and a Happy Thanksgiving to those of us in America.  As my wonderful wife is hard at work preparing for Thanksgiving tomorrow, I am finishing what has been a very huge re-write of my game's inventory system from Godot 3 and GDScript to Godot 4 and C#.  It took longer than I expected, but then I did chase many rabbits which resulted in many great new features.

I want to talk a little bit about what the process was like and compare the two implementations.  Permit me to dive right in.

Godot 3: (March 2023)

Godot 3 Alpha

The Godot 3 version stored static inventory item definitions in Resource files.  This worked well and made updating the properties of each inventory item easy to do directly from the Godot user interface.  All instanced data was stored in Godot dictionaries.  The system was comprised of a Singleton for much of the inventory system logic, three UI nodes for the slots (small, medium, large) and a UI node for the base inventory window (shown below).  The inventory window dynamically builds itself based on the configuration of the properties stored in the Resource file for the respective container object.  The system had two types of objects, being containers and items.  Liquids were considered items.  It offered basic drag and drop, stack splitting and animated opening and closing.  Finally, it supported weight values shown in standard and metric systems.

I enjoyed learning about the Resource system in Godot and I only have one critique about it.  Sometimes my data structures were complex and when my resource contained an array, it was very difficult to add something to the array without having to re-key the data into the array in order to pick up a change.  GD Script was also fun to learn and I was able to quickly put together a basic system.

Godot 4: (November 2023)

Godot 4 Alpha

The Godot 4 version of the inventory system was essentially a complete re-write from GDScript to C#.  I switched from Godot Resources to JSON files and from Godot dictionaries to C# dictionaries.  I also switched from using Godot Signals to using C# Event Handlers.  Hum... what else...  I structured my Visual Studio solution to be close to a Clean Architecture style where I have my scripts broken down into an Application folder for the UI scripts, a Domain folder for my inventory classes, and an infrastructure folder for injections like my JSON implementation., etc.  It's not completely Clean Architecture simply because everything is on one DLL.  But it helps me organize my code.

There are so many new features as I found myself chasing rabbits. Even so, it was a rewarding experience to put this system together (again).  Let me share some feature highlights with you.

Inventory Window Base Scene

• Inventory container window scenes build dynamically from JSON definitions where each container can have up to three slot sizes in any combination of slot counts and slot columns.
• Container windows can be dragged anywhere in the game and locked in a set position.
• Containers that have child containers can be opened via double-click or clicking the bottom right icon to open/close all child containers at once.
• Weights can be configured to show in standard or metric measures.
  
• Static JSON-based inventory definition files for image locations and data for items, containers, and liquids.  The goal is to allow players to be able to introduce their own items into the game or tweak any item to customize the game experience.
• Instance game data will also be saved as JSON files.
  
• Sound effects for valid and invalid actions, including liquids pouring from one container to another with the sound effect selected based on how much liquid is actually being moved around.
• Extensive drag and drop scenarios (item to slot, item to container, item to item, container to container, etc.
• Shift-drag-and-drop to split stacks in half.
• Ctrl-drag-and-drop to bring up a quantity dialog for specific amounts.
• Auto-merge and auto-fill when dragging items onto slots and containers while respecting volume constraints.
• Containers have max volume constraints and separate liquid unit measurements for those containers that can hold liquid.
• Dragging an item from a slot will double the size of the item visually
• Custom tooltips which display summary information for containers, items, and liquids.

These are some of the features currently coded for the inventory system.  Some features I want to add in the future include selecting multiple slots at one time for drag-and-drop between containers, the ability to sort items inside containers based on name, type, etc., and the ability to pick up all items and deposit them into the player's inventory from a loot drop.

What's next on my list?  I am now going to move on to finishing my flora system along with all remaining features of the Godot 3 version that have not yet been ported over.  I hope you have enjoyed reading about my game.  Feel free to comment or suggest here in my blog, or on Twitter.

Until next time,

I'm Bound2bCoding