racknae's Yoshi's Island ASM thread - Summer 2022

Welcome to my C3 thread! My initial plan was to show off a Yoshi's Island hack I've been working on for a couple of months, but unfortunately that's not currently far along enough to showcase. So instead, here's a bunch of small, miscellanious patches I've created for Yoshi's Island!

Yoshi's Island Custom Autoscroll

Patches Page | Download
Yoshi's Island features some very cool and complex autoscrolling sections! Unfortunately, the hard-coded nature of these sequences means that ROM hackers have been stuck using the game's existing set of autoscrollers. Despite these preset autoscroll sequences being relatively simple to edit, the process was fairly tedious and time-consuming, hence very few existing YI hacks feature customized autoscrollers.

This is a comprehensive hex editing patch which allows users to easily create custom autoscrollers that fit their levels, instead of the other way around. I've also included a patch to re-enable an unused autoscroll sequence, and a readme file full of useful information on how YI's autoscrollers are set up.

Yoshi's Island Life Saver

Patches Page | Download
Did you know that the SNES version of Yoshi's Island has a (mostly) fully implemented feature which saves and loads your life count between play sessions? However, due to what appears to be a developer oversight, this feature goes totally unused in the final game; instead, the life counter is overwritten to always be 3 whenever the player loads a save.

This patch re-enables this feature and fixes a bug with its implementation. No more save stating in between levels to preserve your life total! You can also change the amount of lives Yoshi will start with upon loading a new save file, or continuing after a game over. And best of all: this patch does not require free space!

Version 1.1 Font Port

Download
This is a port of the updated font from version 1.1 of Yoshi's Island to version 1.0. The download contains 2 .bin files.
rev1font.bin replaces the standard font. To install it, simply apply the following ASM code to your ROM:

Code

org $09BD2F
  incbin rev1font.bin

rev1font_expanded.bin is meant to be used with the SMW2 Font Expansion patch by Mattrizzle.

Fast Transformation Animation

Download
This patch speeds up the transformation animation so it doesn't take as long. Originally made for Golden Yoshi's Island by somebody else, but I think other people will find it useful, so I've decided to release it.

The edits to shorten the transformation sound effect don't quite work properly, so if you're knowledgeable about ASM and happen to know how to fix it, let me know.

Map Path Editor

Download
This is another hex editing patch which lets you edit the location of the Yoshis on the map screen, as well the paths they take after a level has been completed. This one is incomplete and pretty janky, but feel free to mess around with it!

Currently there is no good tilemap editor for the map screens in Yoshi's Island, so the usefulness of this patch is pretty limited.

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Well, that's about all from me. Hope you enjoy!

Any YI stuff like this is always welcome, even though I don't hack YI now. (I did 5 years back, but gradually lost interest afterwards.) Nice job!

My Mode 0 guide.

My Discord server. It has a lot of archived ASM stuff, so check that out!

Hey, thanks for making these patches! I was putting together a YI hack and a big hex edit patch a while back, though I haven't had much time or motivation for ROM hacking recently. It's good to see signs of life in YI hacking, and seeing even a little activity makes me want to try to hopefully regain that motivation back.

On the subject of the Life Saver patch, does the life counter still roll back to 0 if the player gets an extra life at 999 lives?

Fast transformations are awesome too. It's almost as fast as Yoshi's Island DS transformations. Is there a way to make the transformation animation even faster? There's a tiny pause as soon as the bubble is collected. Still, the patch is definitely good enough as it is. Thanks for putting it up for download.

This is a bit off-topic, but on the subject of Golden Yoshi's Island, I noticed that the title screen for that hack uses more GFX tiles than what is normally possible in YI's title screen. I think it's loading an extra 2bpp GFX file. Is there a patch available for that too?

Always cool to see any activity in YI hacking! I still hope that some day the scene will grow larger and we'll have more people working on projects for it.

I really gotta get into the YI hacking scene there is so much potential in it! Well done on these. I really dig the quality of life quick transformation and life saver.

It's certainly cool to see useful patches for Yoshi's Island. Particularly the overworld path editor and autoscroll editor will proove to be useful.

Hey all! Thanks for the positive response! A couple of small updates: I've submitted both the Custom Autoscroll editor and the Life Saver patch to the YI Patches section, and both Life Saver and the 1.1 Font Port are now available as IPS patches on ROMHacking.net.

Originally posted by UTF

On the subject of the Life Saver patch, does the life counter still roll back to 0 if the player gets an extra life at 999 lives?

Not sure what you mean here. If the game detects that you have more than 999 lives, it immediately sets the life counter back to 999; no rollover occurs on any version of the game that I'm aware of.

If you mean the life underflow glitch, that's still possible to perform with Life Saver installed.

Originally posted by UTF

Is there a way to make the transformation animation even faster? There's a tiny pause as soon as the bubble is collected.

It might be possible, but I'd have to look into it more. From a quick glance at the disassembly, it seems like when the morph bubble gets collected, the game enters the same game state as when Yoshi hits a message block in order to stop him from moving. The timer on that is set so that the message block animation can play fully, so I'm not totally sure if it's possible to remove this delay without also affecting the behaviour of message blocks. (Of course, it's possible that I'm just misinterpreting the code here)

Originally posted by UTF

This is a bit off-topic, but on the subject of Golden Yoshi's Island, I noticed that the title screen for that hack uses more GFX tiles than what is normally possible in YI's title screen. I think it's loading an extra 2bpp GFX file. Is there a patch available for that too?

Mattrizzle is the wizard behind GYI's title screen. He wrote some extremely complicated ASM for it, so I think your best bet is to reach out to him.

Originally posted by racknae

Did you know that the SNES version of Yoshi's Island has a (mostly) fully implemented feature which saves and loads your life count between play sessions? However, due to what appears to be a developer oversight, this feature goes totally unused in the final game; instead, the life counter is overwritten to always be 3 whenever the player loads a save.

That's so unfortunate, lol. I definitely missed such a thing whenever I hit a big win in the bonus games or when attempted the more challenging levels. It's nice to know that it was actually considered at some point and even nicer to see it now being realized!

Fast Transformation is a welcome nice little addition! Vehicle transformations are a trademark YI thing and I always felt like their bits of slowness hampered the experience by a tad, especially when the game is encouraging you to explore around with them (most notably as helicopter), which often requires multiple attempts. So yeah, it's nice to see some ironing out on this aspect!

Map Path Editor also sounds exciting for the possibilites that it may open up for YI map designing!

Like others said, it's always nice to see YI hacking getting some love!

As someone who always welcomes more ressources and ways to hack more games I welcome this thread and its stuff $#tb{^V^}$ .

While I did some YI hacking, I didn't do anything big or finished anything in that regard, maybe one day I shall return to try my hand at it and make something... be sure I will probably come back here for these when the time is right $#tb{^V^}$ .