r5sdk/r5dev/engine/framelimit.cpp
Kawe Mazidjatari 07dade5d5d Implement high precision frame limiter
Limits frames at a much higher level of precision than 'fps_max' and 'fps_max_gfx', probably ideal to reduce input latency even more. Also changed the logic of the NVIDIA Reflex frame limiter, to which it would use the desktop's refresh rate if set to '-1'. The new render thread frame limiter has a similar behavior. Using desktop refresh rates on the render thread or NVIDIA Reflex frame limiter requires 'fps_max' to be set to 0 (unlimited), as it would otherwise result in a major performance drop due to a contest if fps_max_(gfx/rt) is set to a similar number as fps_max.
2023-09-11 22:20:24 +02:00

148 lines
4.3 KiB
C++

//===========================================================================//
//
// Purpose: High-precision render-thread based frame rate limiter
//
//===========================================================================//
#include <dwmapi.h>
#include "tier0/platform_internal.h"
#include "windows/id3dx.h"
#include "sys_mainwind.h"
#include "framelimit.h"
//-----------------------------------------------------------------------------
// Purpose: constructor
//-----------------------------------------------------------------------------
CFrameLimit::CFrameLimit(void)
{
m_MilliSeconds = 0.0;
m_FramesPerSecond = 0.0;
//effective_ms = 0.0;
//m_Last.QuadPart = 0;
m_Next.QuadPart = 0;
m_Time.QuadPart = 0;
m_Frames = 0;
m_bRestart = false;
}
//-----------------------------------------------------------------------------
// Purpose: initializer
// Input : targetFps -
//-----------------------------------------------------------------------------
void CFrameLimit::Reset(double targetFps)
{
m_MilliSeconds = 1000.0 / targetFps;
m_FramesPerSecond = targetFps;
QueryPerformanceCounter(&m_Start);
m_Next.QuadPart = 0ULL;
m_Time.QuadPart = 0ULL;
//m_Last.QuadPart = m_Start.QuadPart - (LONGLONG)((m_MilliSeconds / 1000.0) * g_pPerformanceFrequency->QuadPart);
m_Next.QuadPart = m_Start.QuadPart + (LONGLONG)((m_MilliSeconds / 1000.0) * g_pPerformanceFrequency->QuadPart);
m_Frames = 0;
}
//-----------------------------------------------------------------------------
// Purpose: halts the thread until the next vertical blank occurs
// Output : true on success, false otherwise
//-----------------------------------------------------------------------------
bool CFrameLimit::WaitForVBlank(void)
{
IDXGIOutput* dxgiOutput;
IDXGISwapChain* swapChain = D3D11SwapChain();
if (swapChain != nullptr &&
SUCCEEDED(swapChain->GetContainingOutput(&dxgiOutput)))
{
DwmFlush();
dxgiOutput->WaitForVBlank();
return true;
}
return false;
}
//-----------------------------------------------------------------------------
// Purpose: runs the frame limiter logic
//-----------------------------------------------------------------------------
void CFrameLimit::Run(void)
{
float targetFps = fps_max_rt->GetFloat();
if (targetFps == 0.0f)
return;
const float globalFps = fps_max->GetFloat();
// Make sure the global fps limiter is 'unlimited'
// before we let the rt frame limiter cap it to
// the desktop's refresh rate; not adhering to
// this will result in a major performance drop.
if (globalFps == 0.0f && targetFps == -1)
{
float desktopRefreshRate = (float)g_pGame->GetDesktopRefreshRate();
//if (dekstopRefreshRate == 59.0f || dekstopRefreshRate == 60.0f)
//{
// desktopRefreshRate = 59.939999f;
//}
targetFps = desktopRefreshRate;
}
if (m_FramesPerSecond != targetFps)
Reset(targetFps);
if (targetFps == 0)
return;
m_Frames++;
QueryPerformanceCounter(&m_Time);
// Actual frametime before we forced a delay
//m_EffectiveMilliSeconds = 1000.0 * ((double)(m_Time.QuadPart - m_Last.QuadPart) / (double)g_pPerformanceFrequency->QuadPart);
if ((double)(m_Time.QuadPart - m_Next.QuadPart) / (double)g_pPerformanceFrequency->QuadPart / (m_MilliSeconds / 1000.0) > (fps_max_rt_tolerance->GetFloat() * m_FramesPerSecond))
{
DevMsg(eDLL_T::ENGINE, "%s: Frame time too long (expected: %3.01fx); restarting...\n",
__FUNCTION__, (double)(m_Time.QuadPart - m_Next.QuadPart) / (double)freq.QuadPart / (m_MilliSeconds / 1000.0) / m_FramesPerSecond );
m_bRestart = true;
}
if (m_bRestart)
{
m_Frames = 0;
m_Start.QuadPart = m_Time.QuadPart + (LONGLONG)((m_MilliSeconds / 1000.0) * (double)g_pPerformanceFrequency->QuadPart);
m_bRestart = false;
//Reset (targetFps);
//return;
}
ID3D11Device* pDevice = D3D11Device();
m_Next.QuadPart = (LONGLONG)((m_Start.QuadPart + (double)m_Frames * (m_MilliSeconds / 1000.0) * (double)g_pPerformanceFrequency->QuadPart));
if (m_Next.QuadPart > 0ULL)
{
while (m_Time.QuadPart < m_Next.QuadPart)
{
if ((double)(m_Next.QuadPart - m_Time.QuadPart) > (0.016666666667 * (double)g_pPerformanceFrequency->QuadPart))
{
WaitForVBlank();
}
QueryPerformanceCounter(&m_Time);
}
if (pDevice != nullptr)
D3D11Device()->Release();
}
//m_Last.QuadPart = m_Time.QuadPart;
}
CFrameLimit g_FrameLimiter;