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xezonxezon
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bugfix(fps): Fix inaccurate frame rate cap
1 parent fc71ca4 commit 8ef9d91

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6 files changed

+104
-37
lines changed

6 files changed

+104
-37
lines changed

‎Core/GameEngine/CMakeLists.txt

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@@ -39,6 +39,7 @@ set(GAMEENGINE_SRC
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# Include/Common/Errors.h
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Include/Common/file.h
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Include/Common/FileSystem.h
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Include/Common/FrameRateLimit.h
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# Include/Common/FunctionLexicon.h
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Include/Common/GameAudio.h
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# Include/Common/GameCommon.h
@@ -569,6 +570,7 @@ set(GAMEENGINE_SRC
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# Source/Common/DamageFX.cpp
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# Source/Common/Dict.cpp
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# Source/Common/DiscreteCircle.cpp
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Source/Common/FrameRateLimit.cpp
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# Source/Common/GameEngine.cpp
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# Source/Common/GameLOD.cpp
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# Source/Common/GameMain.cpp

‎Core/GameEngine/Include/Common/FrameRateLimit.h

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/*
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** Command & Conquer Generals Zero Hour(tm)
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** Copyright 2025 TheSuperHackers
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**
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** This program is free software: you can redistribute it and/or modify
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** it under the terms of the GNU General Public License as published by
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** the Free Software Foundation, either version 3 of the License, or
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** (at your option) any later version.
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**
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** This program is distributed in the hope that it will be useful,
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** but WITHOUT ANY WARRANTY; without even the implied warranty of
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** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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** GNU General Public License for more details.
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**
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** You should have received a copy of the GNU General Public License
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** along with this program. If not, see <http://www.gnu.org/licenses/>.
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*/
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#pragma once
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class FrameRateLimit
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{
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public:
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FrameRateLimit();
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Real wait(UnsignedInt maxFps);
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private:
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LARGE_INTEGER m_freq;
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LARGE_INTEGER m_start;
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};

‎Core/GameEngine/Source/Common/FrameRateLimit.cpp

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@@ -0,0 +1,54 @@
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/*
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** Command & Conquer Generals Zero Hour(tm)
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** Copyright 2025 TheSuperHackers
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**
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** This program is free software: you can redistribute it and/or modify
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** it under the terms of the GNU General Public License as published by
7+
** the Free Software Foundation, either version 3 of the License, or
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** (at your option) any later version.
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**
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** This program is distributed in the hope that it will be useful,
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** but WITHOUT ANY WARRANTY; without even the implied warranty of
12+
** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13+
** GNU General Public License for more details.
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**
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** You should have received a copy of the GNU General Public License
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** along with this program. If not, see <http://www.gnu.org/licenses/>.
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*/
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#include "PreRTS.h"
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#include "Common/FrameRateLimit.h"
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FrameRateLimit::FrameRateLimit()
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{
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QueryPerformanceFrequency(&m_freq);
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QueryPerformanceCounter(&m_start);
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}
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Real FrameRateLimit::wait(UnsignedInt maxFps)
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{
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LARGE_INTEGER tick;
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QueryPerformanceCounter(&tick);
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double elapsedSeconds = static_cast<double>(tick.QuadPart - m_start.QuadPart) / m_freq.QuadPart;
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const double targetSeconds = 1.0 / maxFps;
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const double sleepSeconds = targetSeconds - elapsedSeconds - 0.002; // leave ~2ms for spin wait
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if (sleepSeconds > 0.0)
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{
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// Non busy wait with Munkee sleep
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DWORD dwMilliseconds = static_cast<DWORD>(sleepSeconds * 1000);
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Sleep(dwMilliseconds);
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}
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// Busy wait for remaining time
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do
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{
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QueryPerformanceCounter(&tick);
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elapsedSeconds = static_cast<double>(tick.QuadPart - m_start.QuadPart) / m_freq.QuadPart;
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}
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while (elapsedSeconds < targetSeconds);
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m_start = tick;
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return (Real)elapsedSeconds;
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}

‎GeneralsMD/Code/GameEngine/Source/Common/GameEngine.cpp

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@@ -44,6 +44,7 @@
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#include "Common/ThingFactory.h"
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#include "Common/file.h"
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#include "Common/FileSystem.h"
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#include "Common/FrameRateLimit.h"
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#include "Common/ArchiveFileSystem.h"
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#include "Common/LocalFileSystem.h"
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#include "Common/CDManager.h"
@@ -842,8 +843,8 @@ extern HWND ApplicationHWnd;
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*/
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void GameEngine::execute( void )
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{
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FrameRateLimit* frameRateLimit = new FrameRateLimit();
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846-
DWORD prevTime = timeGetTime();
847848
#if defined(RTS_DEBUG)
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DWORD startTime = timeGetTime() / 1000;
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#endif
@@ -917,35 +918,28 @@ void GameEngine::execute( void )
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if (TheTacticalView->getTimeMultiplier()<=1 && !TheScriptEngine->isTimeFast())
918919
{
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920-
// I'm disabling this in internal because many people need alt-tab capability. If you happen to be
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// I'm disabling this in debug because many people need alt-tab capability. If you happen to be
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// doing performance tuning, please just change this on your local system. -MDC
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#if defined(RTS_DEBUG)
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::Sleep(1); // give everyone else a tiny time slice.
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#endif
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#if defined(_ALLOW_DEBUG_CHEATS_IN_RELEASE)
928-
if ( ! TheGlobalData->m_TiVOFastMode )
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#else //always allow this cheatkey if we're in a replaygame.
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if ( ! (TheGlobalData->m_TiVOFastMode && TheGameLogic->isInReplayGame()))
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if ( ! TheGlobalData->m_TiVOFastMode )
930+
#else //always allow this cheat key if we're in a replay game.
931+
if ( ! (TheGlobalData->m_TiVOFastMode && TheGameLogic->isInReplayGame()))
931932
#endif
932-
{
933-
// limit the framerate
934-
DWORD now = timeGetTime();
935-
DWORD limit = (1000.0f/m_maxFPS)-1;
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while (TheGlobalData->m_useFpsLimit && (now - prevTime) < limit)
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{
938-
::Sleep(0);
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now = timeGetTime();
940-
}
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//Int slept = now - prevTime;
942-
//DEBUG_LOG(("delayed %d",slept));
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944-
prevTime = now;
945-
946-
}
947-
948-
}
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{
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// TheSuperHackers @bugfix xezon 05/08/2025 Re-implements the frame rate limiter
935+
// with higher resolution counters to cap the frame rate more accurately to the desired limit.
936+
if (TheGlobalData->m_useFpsLimit)
937+
{
938+
frameRateLimit->wait(m_maxFPS);
939+
}
940+
}
941+
942+
}
949943
}
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951945
} // perfgather for execute_loop
@@ -961,6 +955,7 @@ void GameEngine::execute( void )
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962956
}
963957

958+
delete frameRateLimit;
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}
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/** -----------------------------------------------------------------------------------------------

‎GeneralsMD/Code/GameEngineDevice/Source/W3DDevice/GameClient/W3DDisplay.cpp

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@@ -1855,19 +1855,6 @@ void W3DDisplay::draw( void )
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do {
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1858-
{
1859-
if(TheGlobalData->m_loadScreenRender != TRUE)
1860-
{
1861-
1862-
// limit the framerate
1863-
while(TheGlobalData->m_useFpsLimit && (now - prevTime) < minTime-1)
1864-
{
1865-
now = timeGetTime();
1866-
}
1867-
prevTime = now;
1868-
}
1869-
}
1870-
18711858
// update all views of the world - recomputes data which will affect drawing
18721859
if (DX8Wrapper::_Get_D3D_Device8() && (DX8Wrapper::_Get_D3D_Device8()->TestCooperativeLevel()) == D3D_OK)
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{ //Checking if we have the device before updating views because the heightmap crashes otherwise while

‎GeneralsMD/Code/Tools/GUIEdit/Source/GUIEdit.cpp

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@@ -77,8 +77,6 @@
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#include "W3DDevice/Common/W3DFunctionLexicon.h"
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#include "W3DDevice/GameClient/W3DGameWindowManager.h"
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#include "W3DDevice/GameClient/W3DDisplay.h"
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#include "W3DDevice/GameClient/W3DGameWindowManager.h"
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#include "W3DDevice/GameClient/W3DGameFont.h"
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#include "W3DDevice/GameClient/W3DDisplayStringManager.h"
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#include "GameClient/Keyboard.h"

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