Modernize Classic PC Game Performance

I’m reviving an older PC game whose entire game-loop was tied directly to CPU cycles. On today’s multi-gigahertz processors that means characters sprint at light-speed, menus animate erratically, and animations desync. I need the timing logic decoupled from raw clock speed and replaced with a frame-rate independent solution so the experience feels identical on any modern Windows machine.

The current source compiles, but the cycle-based code makes it unplayable on contemporary hardware. Your task is to profile the bottlenecks, implement a reliable timer or fixed-timestep approach, and smooth out any knock-on issues that appear once the core loop is refactored (physics accuracy, input buffering, sound sync, etc.). I’m focused purely on performance optimisation; graphical overhauls or new content can stay untouched.

Deliverables
• Updated source with cycle-independent timing logic
• Compiled build that runs consistently on Windows 10/11 at common refresh rates (60 Hz, 120 Hz, 144 Hz)
• Brief technical write-up explaining changes, so I can maintain the project going forward

If you routinely tame legacy C/C++ or DirectX/OpenGL code and have a good eye for deterministic timing, you’ll find the project refreshingly straightforward. Let me know how you would approach isolating the timing dependencies and provide an estimated turnaround.