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Windows: Simplify QueryPerformanceCounter usage

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(cherry picked from commit 5ba38fb208)
This commit is contained in:
Bartłomiej T. Listwon 2022-01-04 22:38:44 +01:00 committed by Rémi Verschelde
parent 57cceb47d1
commit e1429dd80f
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GPG key ID: C3336907360768E1
1 changed files with 6 additions and 11 deletions
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17
platform/windows/os_windows.cpp
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@ -174,12 +174,8 @@ void OS_Windows::initialize_core() {
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)
@ -2460,8 +2456,10 @@ 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
@ -2481,9 +2479,6 @@ 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;
}