DIVA Fine Window

An x64 DLL mod loaded by DIVA Mod Loader that adjusts the FINE timing window in Hatsune Miku: Project DIVA Mega Mix+. It also prevents scores from being submitted to the leaderboard while preserving local score saving and leaderboard viewing.

Supported Version

Developed and tested with the following DivaMegaMix.exe (Version: v1.04):

SHA-256: 6F4DF714C28515C93B3023E7D6DAFA9095DD8835F762D54DB1726FB8BC04504D

The DLL uses a byte-pattern scan instead of hard-coded absolute module addresses. If the pattern no longer matches after a game update, the mod will skip hook installation and report the problem in its log instead of modifying an unknown location.

Building

Requires Visual Studio 2022, the MSVC x64 toolchain, and CMake 3.21 or later:

cmake -S . -B build -A x64
cmake --build build --config Release

The resulting file is:

build\Release\DivaFineWindow.dll

You can also push the project to GitHub. GitHub Actions will produce a ZIP artifact named DivaFineWindow-x64.

Installation

Place the following structure in the game's mods directory:

mods/
└─ DIVA Fine Window/
   ├─ DivaFineWindow.dll
   └─ config.toml

DIVA Mod Loader must already be installed in the game's root directory.

For a manual installation, open the DIVA Mod Loader config.toml next to DivaMegaMix.exe and add "DIVA Fine Window" to its priority list. Keep any existing mod names in the list, for example:

priority = ["...", "DIVA Fine Window"]

Alternatively, you can install the mod using DIVA Mod Manager. If you prefer not to install it as a mod, run the Cheat Engine script in the doc directory instead; it provides the same function.

Configuration

Edit config.toml in the mod directory:

fine_window_ms = 100

Default timing windows:

• COOL: ±30 ms
• FINE: ±70 ms
• SAFE: ±100 ms
• Outer window: ±130 ms

The allowed range is 30–130 ms. At 100 ms, inputs that would normally fall within the 70–100 ms SAFE range are classified as FINE first. To retain part of the SAFE range, use a value such as 80 or 90.

Restart the game after changing the configuration. Score submission to the leaderboard is always blocked while this mod is enabled.

How It Works

When loaded, the DLL scans for this byte pattern:

F3 0F 10 4A 18 0F 2F 89 84 32 01 00

In the supported version, this location corresponds to DivaMegaMix.exe+26D31E:

movss xmm1,[rdx+18]

The DLL allocates a nearby code cave and replaces the entry point with a 5-byte relative jump. The code cave uses the judgment-manager pointer held in RCX at that point to write the positive and negative FINE boundaries to RCX+13274 and RCX+13278. It then executes the original instruction and jumps back to the game.

The mod does not modify the executable on disk and does not require Cheat Engine or an external hooking library.

Logging

The DLL creates the following file in its own directory:

DivaFineWindow.log

On success, the log records the configured window size and the matched RVA. It also reports pattern-scan and memory-protection failures.