MegaVolts Launcher

C++ game launcher for MegaVolts. A small, skinnable launcher for Windows that draws its own borderless UI with Dear ImGui and DirectX 11, keeps the game up to date with a chunked patcher, and can start the game from the website through a megavolts:// link, like Steam's steam://.

Features

Launcher

• Custom borderless window with rounded corners, transparency and a shadow
• Fully skinnable from launcher.ini (window, logo, buttons, news, progress bars, fonts, colors), missing keys are filled with defaults
• FreeType fonts with configurable size, spacing and outline
• DPI aware with runtime scaling
• Single instance only, using a named mutex
• Play, Update and Exit buttons plus web links (Club, Shop, Support, Discord, News)
• Animated progress bars that follow the real patch progress
• Starts the game without the launcher's elevated token

Patcher (src/patch/)

• Chunked patching, files are split into 4 MiB chunks and only the changed ones download
• JSON manifest with per-chunk SHA-1, read by a small custom parser (MiniJsonParser)
• Manifest is verified with an RSA signature (BCrypt) before anything is applied
• Every chunk is SHA-1 checked before it's kept
• Self update: the launcher can patch itself, restart, and clean up the old copy
• A bare exe can pull its own skin files (LR\) through the same chunk system
• Won't patch while the game or launcher is running, shows per file and total progress plus speed
• Networking over WinHTTP, no extra HTTP library

megavolts:// link

• The launcher registers itself for megavolts:// in the user registry, no admin needed
• The Start button on the website opens megavolts://startgame, then it patches and runs the game

How it's built

• Multithreaded: the patcher runs on its own thread so the UI stays smooth, the progress animation runs on another
• Thread safe state with std::atomic and std::mutex so the UI and patch threads don't clash
• Patching can be cancelled with a flag the worker checks between steps
• Progress is sent back to the UI through callbacks so the two sides stay separate
• RAII wrappers for handles, the mutex and process tokens so nothing leaks on errors
• INI reader handles UTF-8 and UTF-16 byte order marks
• DPI and monitor functions loaded at runtime with fallbacks, runs on Windows 7 to 11
• Written in C++17, just the Windows SDK and a few small vendored libraries

Dependencies

• Dear ImGui for the UI (DirectX 11 and Win32 backends, FreeType renderer)
• FreeType for fonts
• stb_image for loading PNG and GIF