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Merge pull request #56497 from Pineapple/qpc-tweaks

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Windows: Simplify QueryPerformanceCounter usage
This commit is contained in:
Rémi Verschelde 2022-01-08 23:40:01 +01:00 committed by GitHub
commit 277a159c48
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GPG key ID: 4AEE18F83AFDEB23
1 changed files with 6 additions and 11 deletions
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17
platform/windows/os_windows.cpp
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@ -184,12 +184,8 @@ void OS_Windows::initialize() {
NetSocketPosix::make_default();
// We need to know how often the clock is updated
if (!QueryPerformanceFrequency((LARGE_INTEGER *)&ticks_per_second))
ticks_per_second = 1000;
// If timeAtGameStart is 0 then we get the time since
// the start of the computer when we call GetGameTime()
ticks_start = 0;
ticks_start = get_ticks_usec();
QueryPerformanceFrequency((LARGE_INTEGER *)&ticks_per_second);
QueryPerformanceCounter((LARGE_INTEGER *)&ticks_start);
// set minimum resolution for periodic timers, otherwise Sleep(n) may wait at least as
// long as the windows scheduler resolution (~16-30ms) even for calls like Sleep(1)
@ -369,8 +365,10 @@ uint64_t OS_Windows::get_ticks_usec() const {
uint64_t ticks;
// This is the number of clock ticks since start
if (!QueryPerformanceCounter((LARGE_INTEGER *)&ticks))
ticks = (UINT64)timeGetTime();
QueryPerformanceCounter((LARGE_INTEGER *)&ticks);
// Subtract the ticks at game start to get
// the ticks since the game started
ticks -= ticks_start;
// Divide by frequency to get the time in seconds
// original calculation shown below is subject to overflow
@ -390,9 +388,6 @@ uint64_t OS_Windows::get_ticks_usec() const {
// seconds
time += seconds * 1000000L;
// Subtract the time at game start to get
// the time since the game started
time -= ticks_start;
return time;
}