cnc-ddraw is a DirectDraw wrapper and emulation layer designed to ensure legacy 2D graphics software runs on modern operating systems. It functions as a compatibility layer that intercepts legacy API calls and redirects them to a modern rendering backend to prevent crashes and black screens.
The project provides a 2D graphics upscaler that uses shaders to increase the resolution of low-fidelity visuals for high-definition screens. It also includes a frame rate controller to synchronize frame timing and limit output speed, which prevents stuttering and performance drops.
The tool manages display modes by allowing users to toggle between windowed and fullscreen views while preserving the original window size and position. It further stabilizes legacy graphics through vertical refresh synchronization.