WatermelonDS Status Update

Hi everyone!

I want to share a public status update after reading and responding to the feedback from the last two posts:

What I’ve Been Working On Lately

and

New WatermelonDS Test Build

I want to share what is working, what still needs attention, and what I will be focusing on next. 

First of all, thank you.

The feedback has been extremely useful. The test build is already showing very promising results, especially with Vulkan performance at high internal resolutions.

The good news is that the build is reaching the kind of performance I wanted to test. We already have reports of games running at IR 8x and 60 FPS on supported devices.

But the build is not ready for a public release yet.

There are still some important issues I want to fix first, especially around audio stability and some device-specific driver crashes.

What worked well

The current test build confirmed several important things:

• Vulkan performance is much better at high internal resolutions

• IR 8x is now realistic in some games and devices

• The new UI and visual presentation are being tested by more users

• The improved library, menus, and in-game controls are working as the new base

• The new rendering direction is promising on both Mali and Adreno devices

• External display support is improving, but still needs fixes

This is very encouraging because it means the new path is going in the right direction.

Current blockers

There are a few issues that need to be fixed before I feel comfortable releasing this publicly.

Audio pitch and speed instability

Some users reported that audio can sound slower, deeper, or unstable.

This can happen even at low internal resolution, so it does not look like a GPU performance problem.

This is one of the most important things to fix before a public release.

Audio delay at high internal resolution

Some users also reported audio delay when using very high internal resolutions, especially around IR 5x to IR 8x.

At lower resolutions, such as IR 4x, the audio can stay synchronized.

This looks like a different issue from the pitch problem, probably related to audio buffering when the GPU is under heavier load.

It still needs further testing and investigation. 

Custom driver crashes

Some custom Turnip drivers can crash when launching the emulator.

For now, I recommend using the system driver.

If your device works with Kimchi Qualcomm v840, that can also be used, but the safest recommendation for now is:

Use the system driver if custom drivers crash.

I still need more logs to fully diagnose this.

Other issues being tracked

I am also tracking several other reports:

• Vulkan flicker during scene transitions

• Black screens or visual glitches in some complex scenes

• A small hitch that appears around every two minutes when RetroAchievements is enabled

• External display not being detected if it was already connected before starting the game

• Very slow ROM scanning on very large SD card libraries

• Crash when selecting a game on some devices

• Audio not being captured correctly while streaming on some setups

Some of these already have a likely cause, and others still need logs or videos to confirm.

What I will fix first

My current priority order is:

1. Fix external screen detection when the display is already connected before launching the game

2. Investigate and fix the periodic RetroAchievements hitch

3. Fix the audio pitch and speed instability

4. Investigate custom driver crashes once I receive logcat reports

5. Fix the accumulated audio delay at high internal resolutions

6. Continue fixing Vulkan flicker and transition issues

7. Improve ROM scanning and streaming audio capture behavior

The audio issues are especially important because they directly affect normal gameplay.

FastPath direction

FastPath is becoming the main direction for the Vulkan renderer.

The goal is to simplify the renderer options and focus development on one path instead of keeping confusing old options around.

This does NOT mean the work is finished.

It means that from here, the priority is to keep fixing bugs, improve compatibility, and make the normal Vulkan path and FastPath converge into one stable and fast rendering experience.

What I need from testers

If you are testing the current build, your reports are very helpful.

Useful information includes:

• Device model

• Android version

• GPU if known

• Game tested

• Renderer used

• Internal resolution used

• Whether RetroAchievements was enabled

• Whether shaders were enabled

• Whether an external display was used

• Whether you were using the system driver or a custom driver

• Steps to reproduce the issue

• Screenshots or video if possible

• Logs if available

For driver crashes, a logcat is especially important.

For emulator-side issues, please enable MelonDualLog in:

Settings > System

The log file should be created in your ROM folder.

If you are reporting a problem, the more of this information you can provide, the easier it is for me to reproduce and investigate it. 

About the public release

I do not want to rush the public release.

The performance improvements are very exciting, but I want the next public build to be in a better state, especially for audio and overall stability.

The goal is to use this test period to fix the most important issues first, then prepare a much better public version.

Thank you

Thank you to everyone testing, reporting issues, sending videos, and helping isolate problems.

This feedback is exactly what helps make WatermelonDS better across more Android devices.

The current build is already showing that the new Vulkan direction has a lot of potential.

Now the focus is fixing the remaining problems and making the experience stable enough for everyone.

- Sapphire 💙