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Codechange: switch all video drivers to std::chrono for keeping time

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On all OSes we tested the std::chrono::steady_clock is of a high
enough resolution to do millisecond measurements, which is all we
need.

By accident, this fixes a Win32 driver bug, where we would never
hit our targets, as the resolution of the clock was too low to
do accurate millisecond measurements with (it was ~16ms resolution
instead).
This commit is contained in:
Patric Stout
2021-02-17 14:46:19 +01:00
committed by Patric Stout
parent d437445c67
commit 25f6851ca1
7 changed files with 44 additions and 101 deletions
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27
src/video/dedicated_v.cpp
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@@ -195,14 +195,6 @@ static bool InputWaiting()
return select(STDIN + 1, &readfds, nullptr, nullptr, &tv) > 0;
}
static uint32 GetTime()
{
struct timeval tim;
gettimeofday(&tim, nullptr);
return tim.tv_usec / 1000 + tim.tv_sec * 1000;
}
#else
static bool InputWaiting()
@@ -210,11 +202,6 @@ static bool InputWaiting()
return WaitForSingleObject(_hInputReady, 1) == WAIT_OBJECT_0;
}
static uint32 GetTime()
{
return GetTickCount();
}
#endif
static void DedicatedHandleKeyInput()
@@ -248,8 +235,9 @@ static void DedicatedHandleKeyInput()
void VideoDriver_Dedicated::MainLoop()
{
uint32 cur_ticks = GetTime();
uint32 next_tick = cur_ticks + MILLISECONDS_PER_TICK;
auto cur_ticks = std::chrono::steady_clock::now();
auto last_cur_ticks = cur_ticks;
auto next_tick = cur_ticks;
/* Signal handlers */
#if defined(UNIX)
@@ -290,15 +278,14 @@ void VideoDriver_Dedicated::MainLoop()
}
while (!_exit_game) {
uint32 prev_cur_ticks = cur_ticks; // to check for wrapping
InteractiveRandom(); // randomness
if (!_dedicated_forks) DedicatedHandleKeyInput();
cur_ticks = GetTime();
_realtime_tick += cur_ticks - prev_cur_ticks;
if (cur_ticks >= next_tick || cur_ticks < prev_cur_ticks || _ddc_fastforward) {
next_tick = cur_ticks + MILLISECONDS_PER_TICK;
cur_ticks = std::chrono::steady_clock::now();
_realtime_tick += std::chrono::duration_cast<std::chrono::milliseconds>(cur_ticks - last_cur_ticks).count();
if (cur_ticks >= next_tick || _ddc_fastforward) {
next_tick = cur_ticks + std::chrono::milliseconds(MILLISECONDS_PER_TICK);
GameLoop();
UpdateWindows();