Didn't have time to write a blog post last week, so this week you get a double update. For the past two weeks I've been working on the map and saving systems. There's really not much to say about the save functionality, other than the fact that it employs Godot's resource system, which turns out to be very simple to use in that capacity. Basically I just made a resource class that contains all the data I want to keep track of, and then I copy that data from/into the actively running game to save or load. I had to rework a few systems to allow for mid-game loading, but that's about as far as the system goes. I can't really show it in action within the scope of my .gif maker either, so I suppose you'll just have to take my word that it works as intended.

Now as for the map... I decided that the best way for me to implement Metroid's specific style of map was to use tilemaps. Rather than just using a single tilemap and changing each cell based on whether the map tile has been revealed, explored, or still unseen, I went with several tilemaps stacked on top of each other. The "hidden" layer is on top, followed by "revealed", "explored", and "occupied". This makes the map itself a little bit of a pain to set up, since I have to draw several different versions of the same geography, but it does make things much simpler at runtime, allowing me to simply hide individual tiles on each layer as the player discovers more of the map. 

The map itself is currently hidden in game, and will remain that way until I can get the pause menu up and running, but I did also get the mini-map working. I considered just using a second camera pointing at the map proper and projecting it onto the HUD, but I found it difficult to maintain the proper visual with that approach. Instead, I made use of another small tilemap on the HUD.  This tilemap looks at the current state of the full-sized map and simply swaps out the tile sprites to reflect the map state in the player's immediate vicinity. 

A simple timer hooked up to a visibility toggle gets me the effect for the blinking tile on the player's current position. I ran into a little bit of trouble getting the map to play nice with the instant-load system I have hooked up for debug, but it turned out that I was accidentally using C# syntax for one of my for loops instead of GDScript. Turns out it's hard to drop 10 years worth of muscle memory, who would have guessed?

With these two features in a state that I'm satisfied enough with, we're just left with Sound and the Pause menu for implementation. Getting pretty close to the end here now, and my brain is already at work trying to churn up ideas for what comes next.

See you next time.

No update for last week, between the Holiday and a few personal obligations, I didn't really accomplish much worth talking about. Mostly I just did some research into my next project goal; tile sets.

Turns out Godot has plenty of tools to make setting up tile sets particularly simple, and a bunch more tools to give you just about all the control you could need. So, armed with a bunch of new knowledge I started off this week by... realizing that the tile set sprites I found for Super Metroid were incomplete. Honestly, I'm finding more and more that the Super Metroid sprites that I have access to are far from the comprehensive collection that I had first thought they were. The GBA Metroid games on the other hand, have proven to be quite thorough. In this particular case, the sprites that I was missing were these little guys:

These represent tiles that can be destroyed by specific weapons from Samus' arsenal. For some reason, all of the sprite collections I could find for the Super Metroid tiles only had the tiles representing Speed Boost and Power Bomb blocks, and I did quite a bit of digging. Those ones up above are specifically the versions from Zero Mission, and since these are lower resolution than the tiles from the SNES, I've decided to just use the GBA tiles in general moving forward. I would do that same with Samus' own sprites to keep things consistent, but redoing all of the animations, let alone having to clean up and repair the sprite sheets would likely take more than a full work week by itself. If it bothers me enough as I continue through this project I'll consider revisiting the issue later, but for now we'll simply have to live with it.

Now, getting the tile sets working within Godot was actually pretty fast and easy once I found the sheets I wanted to use. I messed around a bit with setting up the auto-tiling tool with a few different terrain types, applied physics shapes to the individual tiles I was using, and then went about replacing the white block platforms of my test scene. Here are the results:

Definitely an improvement visually. As a bonus, I also figured out how to get slope movement working properly.

Usually that's a massive pain, good on Godot for having built-in systems to handle it. In any case, because getting the tiles in went so smoothly, I moved onto the "stretch goal" that I set myself for the week; tile destruction. This is something that I've been thinking over for a decent while, and I think I came up with a pretty decent solution. Tile maps in Godot are considered to be a single object, so no matter what tile a projectile hits, it returns the tile map itself as the object it hit, and the tiles themselves don't have any logic attached to them. That means that I can't attach any sort of "Destroyable" script to tiles that I want to be able to blast away.  Instead, I leveraged the ability to create multiple tile map layers, and I placed tiles on a second layer to signify both that they can be destroyed, and specifically what they can be destroyed by.

When a projectile registers a collision with a tile map, I get the coordinates of the tile it hit and see if a corresponding tile exists on the "destructible" layer.  If it does, I check to see if that tile can be destroyed by the projectile that hit it before removing the tile on both the "destructible" and "terrain" layers. I then spawn a pooled object that plays the tile destruction animation while also storing information about the tile in question, include what type of tile it was originally as well as whether or not it will need to reform after a few seconds (since that's a thing that happens sometimes in Metroid games).  Reformed tiles only show the "destructible" layer version of the tile, since that's how it works in the source material.

There's still some work to be done here, such as how certain weapons can reveal a destructible tile without actually destroying it, but that sort of stuff is probably going to have to wait until I actually get more weapons implemented. First though, I think I'm going to make my next goal getting a basic enemy working, that way we have something besides the ground to shoot at.

See you next time.