On Emscripten, SDL_Delay is implemented as a busy loop. In addition,
everything happens on a single thread. This effectively means that
you have to let Emscripten manage the main loop, since if you do it
yourself the browser will just be frozen.
The recently released SDL 2.0.14 adds a native function for opening URIs
from the host system, superseding the OS-specific implementations of
FILESYSTEM_openDirectory.
This works on macOS, Wayland, and a few more esoteric platforms. X11
doesn't have a concept of DPI-awareness. Note that with this flag
SDL_GetWindowSize() isn't guaranteed to return the actual window size.
This prevents issues when calling std::abs with a float on some older
compilers. While it would normally be promoted to an int, std::abs is
special due to being overloaded despite being a C function. This can
cause errors due to the compiler being unable to find a float overload.
SDL_abs doesn't have this problem, since it's a normal C function.