Files
choco-chip8/CountdownTimerSDL.cpp

19 lines
581 B
C++

#include "CountdownTimerSDL.hpp"
CountdownTimerSDL::CountdownTimerSDL(unsigned frequency):
mDesiredFrequency{frequency},
mSDLFrequency{SDL_GetPerformanceFrequency()},
mStartTime{0},
mStartValue{0} {}
void CountdownTimerSDL::set(unsigned value) {
mStartTime = SDL_GetPerformanceCounter();
mStartValue = value;
}
unsigned CountdownTimerSDL::get() const {
Uint64 elapsedTime = SDL_GetPerformanceCounter() - mStartTime;
Uint64 elapsedTicks = (elapsedTime * mDesiredFrequency) / mSDLFrequency;
return elapsedTicks >= mStartValue ? 0 : mStartValue - elapsedTicks;
}