tools/loading_tip_patcher/README.md

loading_tip_patcher

Patches the cycle interval of EU4's loading-tip textbox and (when RE finishes) the loading-screen image cycle. Built because the Clausewitz engine hardcodes the interval in eu4.exe and exposes no define or GUI knob for it.

Status

Skeleton only — not yet functional for end users. The patch sites in eu4.exe have been narrowed down via static RE (see RE_notes.md), but the cycle function itself and the Ironman-bypass functions are still being traced in Ghidra. Once Ghidra analysis finishes, the placeholder VMA/file-offset constants in src/main.cpp are filled in and the patcher becomes usable.

What works today

• config.example.json shows the config schema (no defaults by design; the patcher errors out if tip_interval_seconds is missing or <=0).
• src/main.cpp is a complete Win32 console app skeleton: PID lookup, SHA-256, VirtualProtectEx / WriteProcessMemory plumbing, minimal JSON reader. Currently applies the single patch site at VMA 0x141DC1768 (the 8.0 double in the timer-constants table — prime suspect for the tip-cycle interval).

What is missing (Phase 2 RE work)

• The actual cycle function in eu4.exe that owns tip_interval and the (possibly separate) image_interval (one vs two timers is still undecided).
• The Ironman integrity-check functions (3 sites): hash compute, server upload, load-time verify.
• --revert, --status, --rescan (placeholders in main.cpp).
• state.json write (currently a TODO).
• Path resolution for eu4.exe (currently hardcoded to the Steam install path; needs QueryFullProcessImageNameW).

Build

Requires MinGW-w64 GCC 15.2.0 (ships with msys2). The patcher is a standalone .exe with no MSVC runtime dependency.

cd tools/loading_tip_patcher
make

Output: bin/loading_tip_patcher.exe.

Run

# 1. Edit config.json next to the .exe:
#    cp config.example.json config.json
#    (then set tip_interval_seconds)

# 2. Launch EU4 and start a campaign so eu4.exe is running.

# 3. Apply the patch:
./bin/loading_tip_patcher.exe --apply

Risks (please read)

This tool rewrites bytes in a running Paradox game executable.

• Ironman / achievements: Paradox's cloud-save integrity check hashes the exe. With a patched exe, ironman saves may fail to load on the next session, and the cloud server may refuse to grant achievements. The "Ironman + achievements" feature the user requested is separate RE work in Phase 2 — see RE_notes.md for the planned patches.
• Game updates: Every Paradox patch changes the binary, which moves the timer-constants-table offset. The patcher is designed to refuse to run on an unknown SHA-256; run --rescan to refresh.
• Anti-cheat: Paradox's server-side anti-cheat is out of scope. The patcher only touches eu4.exe; if Paradox bans the account, that is a user-accepted risk.
• Antivirus false positives: a tiny standalone .exe that calls OpenProcess / WriteProcessMemory on a known game process is exactly the signature AV vendors flag. You may need to add an exception.

Files in this directory

File	Purpose
src/main.cpp	The patcher source (~290 LoC, plain Win32)
Makefile	MinGW-w64 GCC build
config.example.json	Sample config (no defaults; user must set interval)
state.json	Per-version patch record — auto-generated, do not edit
RE_notes.md	Static RE findings + breadcrumbs for the cycle function
README.md	This file