SilentPatch is a runtime patching system for Grand Theft Auto III, Vice City, and San Andreas that applies bug fixes, stability improvements, and enhancements via DLL injection. The architecture centers around a DirectDraw wrapper (DDraw.dll) that hooks into game processes and loads game-specific patches. Each game has a dedicated module (SilentPatchIII/VC/SA) containing version-specific fixes implemented through pattern scanning and memory hooking. Shared components handle cross-cutting concerns like input, rendering, and configuration. The system reads INI files to toggle features and uses a plugin-like architecture for extensibility (e.g., Special Vehicle Features). It does not alter game files on disk, instead modifying memory addresses at runtime to fix issues like widescreen support, crash bugs, and compatibility problems with other mods.
OptiScaler is a graphics enhancement tool that intercepts upscaler calls from games and redirects them to user-selected backends, enabling upscaler replacement (e.g., DLSS to FSR/XeSS) and frame generation. It functions as a DLL that hooks into DirectX 11/12 and Vulkan APIs to inject custom rendering behavior. The architecture is modular with clear separation between hooking systems, upscaler implementations, frame generation, low-latency technologies, and configuration management. Key entry points include dllmain.h (DLL entry point), hooking modules in hooks/, feature providers in upscalers/, and frame generation implementations in framegen/. The system relies heavily on external SDKs (NVIDIA NGX, AMD FidelityFX, Intel XeSS) and uses Detours for API interception. While well-structured with good abstraction patterns, the codebase shows signs of maintenance complexity due to supporting multiple APIs and upscaler versions, creating combinatorial complexity in testing and compatibility.