Lords Of Tech

C++20 Resumable functions: Goodbye state machines, no one will mourn you

C++20 allows writing functions that suspend and can continue at the next line. This has an amazing application at avoiding writing annoying and error-prone state machines. This article showcases how coroutines can clean up a function that would usually need an ugly state machine.

Error codes are far slower than exceptions

TL;DR On modern 64-bit PC architectures, C++ exceptions only add unreachable code with destructor calls into functions and their effect on performance is below 1%, but such low values are difficult to measure. Handling rare errors with return values requires additional branching that slows down the program in realistic scenarios by about 5% and are also less convenient. If an exception is actually thrown, stack unwinding costs about 2 ┬Ás per stack frame.

Optimising a scene for VR in Unreal Engine

Since I bought Oculus Quest, I felt that it lacked a proper Doom-like action shooter. I created a scene in the editor based on what I envisioned, but it was absolutely impossible to run on Oculus Quest. This article describes various tricks I have used to bring it to Quest without too much sacrifice.