Provided by: libsdl3-doc_3.2.20+ds-2_all 

NAME
SDL_SECONDS_TO_NS - Convert seconds to nanoseconds.
SYNOPSIS
#include <SDL3/SDL_timer.h>
#define SDL_SECONDS_TO_NS(S) (((Uint64)(S)) * SDL_NS_PER_SECOND)
DESCRIPTION
This only converts whole numbers, not fractional seconds.
MACRO PARAMETERS
S the number of seconds to convert.
RETURN VALUE
Returns S, expressed in nanoseconds.
THREAD SAFETY
It is safe to call this macro from any thread.
AVAILABILITY
This macro is available since SDL 3.2.0.
Simple Directmedia Layer SDL 3.2.20 SDL_SECONDS_TO_NS(3)