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feat(frame-pacer): overhaul logic and render FPS limits and presets #2699

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chore(frame-pacer): overhaul logic and render fps limits and presets
githubawn May 5, 2026
922e5d5
greptile fixes
githubawn May 11, 2026
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18 changes: 6 additions & 12 deletions Core/GameEngine/Include/Common/FrameRateLimit.h
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Original file line number Diff line number Diff line change
Expand Up @@ -61,18 +61,12 @@ class RenderFpsPreset
class LogicTimeScaleFpsPreset
{
public:
enum CPP_11(: UnsignedInt)
{
#if RTS_DEBUG
MinFpsValue = 5,
#else
MinFpsValue = LOGICFRAMES_PER_SECOND,
#endif
StepFpsValue = 5,
};

static UnsignedInt getNextFpsValue(UnsignedInt value);
static UnsignedInt getPrevFpsValue(UnsignedInt value);
static UnsignedInt changeFpsValue(UnsignedInt value, FpsValueChange change);
static UnsignedInt getNextFpsValue(UnsignedInt value, UnsignedInt snapValue = 0);
static UnsignedInt getPrevFpsValue(UnsignedInt value, UnsignedInt snapValue = 0);
static UnsignedInt changeFpsValue(UnsignedInt value, FpsValueChange change, UnsignedInt snapValue = 0);

private:
static const UnsignedInt s_fpsValues[];
};

64 changes: 51 additions & 13 deletions Core/GameEngine/Source/Common/FrameRateLimit.cpp
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Expand Up @@ -60,9 +60,11 @@ Real FrameRateLimit::wait(UnsignedInt maxFps)


const UnsignedInt RenderFpsPreset::s_fpsValues[] = {
30, 50, 56, 60, 65, 70, 72, 75, 80, 85, 90, 100, 110, 120, 144, 240, 480, UncappedFpsValue };
15, 30, 50, 56, 60, 65, 70, 72, 75, 80, 85, 90, 100, 110, 120, 144, 240, 480, UncappedFpsValue };

static_assert(LOGICFRAMES_PER_SECOND <= 30, "Min FPS values need to be revisited!");
// TheSuperHackers @info s_fpsValues MUST be strictly ascending; the search loops break on first match.
const UnsignedInt LogicTimeScaleFpsPreset::s_fpsValues[] = {
1, 5, 15, 30, 45, 60, 75, 90, 105, 120, 240, 480, 960, RenderFpsPreset::UncappedFpsValue };
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UnsignedInt RenderFpsPreset::getNextFpsValue(UnsignedInt value)
{
Expand Down Expand Up @@ -102,30 +104,66 @@ UnsignedInt RenderFpsPreset::changeFpsValue(UnsignedInt value, FpsValueChange ch
}
}


UnsignedInt LogicTimeScaleFpsPreset::getNextFpsValue(UnsignedInt value)
UnsignedInt LogicTimeScaleFpsPreset::getNextFpsValue(UnsignedInt value, UnsignedInt snapValue)
{
return value + StepFpsValue;
UnsignedInt nextValue = s_fpsValues[ARRAY_SIZE(s_fpsValues) - 1]; // Default to Uncapped
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Defaults


// Check if snapValue (e.g. current render FPS) is the next closest candidate
if (snapValue > value && snapValue < nextValue)
{
nextValue = snapValue;
}

// Check predefined steps
for (size_t i = 0; i < ARRAY_SIZE(s_fpsValues); ++i)
{
if (s_fpsValues[i] > value)
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I could be wrong, but wouldn't

int fpsValue = s_fpsValues[i];

add a slight performance increase, as otherwise the array value needs to be looked up three times?

{
if (s_fpsValues[i] < nextValue)
{
nextValue = s_fpsValues[i];
}
break;
}
}

return nextValue;
}

UnsignedInt LogicTimeScaleFpsPreset::getPrevFpsValue(UnsignedInt value)
UnsignedInt LogicTimeScaleFpsPreset::getPrevFpsValue(UnsignedInt value, UnsignedInt snapValue)
{
if (value - StepFpsValue < MinFpsValue)
UnsignedInt prevValue = s_fpsValues[0]; // Floor/seed for the search loop

// Check if snapValue (e.g. current render FPS) is the previous closest candidate.
// Note: if snapValue == value, neither branch below fires and the snap point is
// intentionally skipped — the caller must step to a different preset.
if (snapValue < value && snapValue > prevValue)
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swapping conditions

if (snapValue > prevValue && snapValue < value)

has better readability

{
return MinFpsValue;
prevValue = snapValue;
}
else

// Check predefined steps
for (int i = (int)ARRAY_SIZE(s_fpsValues) - 1; i >= 0; --i)
{
return value - StepFpsValue;
if (s_fpsValues[i] < value)
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I could be wrong, but wouldn't

int fpsValue = s_fpsValues[i];

add a slight performance increase, as otherwise the array value needs to be looked up three times?

{
if (s_fpsValues[i] > prevValue)
{
prevValue = s_fpsValues[i];
}
break;
}
}

return prevValue;
}

UnsignedInt LogicTimeScaleFpsPreset::changeFpsValue(UnsignedInt value, FpsValueChange change)
UnsignedInt LogicTimeScaleFpsPreset::changeFpsValue(UnsignedInt value, FpsValueChange change, UnsignedInt snapValue)
{
switch (change)
{
default:
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The default falls through to case FpsValueChange_Increase which is quite the curious (and maybe unexpected behaviour. I think it warrants a comment.

Better (if possible): change should only have value FpsValueChange_Increase or FpsValueChange_Decrease, so default should never be called. Maybe put it at the end and add an assert instead.

case FpsValueChange_Increase: return getNextFpsValue(value);
case FpsValueChange_Decrease: return getPrevFpsValue(value);
case FpsValueChange_Increase: return getNextFpsValue(value, snapValue);
case FpsValueChange_Decrease: return getPrevFpsValue(value, snapValue);
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Shouldn't default and case indented here?

}
}
31 changes: 11 additions & 20 deletions Generals/Code/GameEngine/Source/GameClient/MessageStream/CommandXlat.cpp
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Expand Up @@ -211,37 +211,28 @@ bool changeLogicTimeScale(FpsValueChange change)
return false;

const UnsignedInt maxRenderFps = TheFramePacer->getFramesPerSecondLimit();
UnsignedInt maxRenderRemainder = LogicTimeScaleFpsPreset::StepFpsValue;
maxRenderRemainder -= maxRenderFps % LogicTimeScaleFpsPreset::StepFpsValue;
maxRenderRemainder %= LogicTimeScaleFpsPreset::StepFpsValue;

UnsignedInt logicTimeScaleFps = TheFramePacer->getLogicTimeScaleFps();
// Set the value to the max render fps value plus a bit when time scale is
// disabled. This ensures that the time scale does not re-enable with a
// 'surprise' value.

if (!TheFramePacer->isLogicTimeScaleEnabled())
{
logicTimeScaleFps = maxRenderFps + maxRenderRemainder;
logicTimeScaleFps = maxRenderFps;
}
// Ceil the value at the max render fps value plus a bit so that the next fps
// value decrease would undercut the max render fps at the correct step value.
// Example: render fps 72 -> logic value ceiled to 75 -> decreased to 70.
logicTimeScaleFps = min(logicTimeScaleFps, maxRenderFps + maxRenderRemainder);
logicTimeScaleFps = LogicTimeScaleFpsPreset::changeFpsValue(logicTimeScaleFps, change);

// Set value before potentially disabling it.
if (TheFramePacer->isLogicTimeScaleEnabled())
logicTimeScaleFps = LogicTimeScaleFpsPreset::changeFpsValue(logicTimeScaleFps, change, maxRenderFps);

// Ensure logic FPS never exceeds render FPS
if (logicTimeScaleFps > maxRenderFps && logicTimeScaleFps != RenderFpsPreset::UncappedFpsValue)
{
TheFramePacer->setLogicTimeScaleFps(logicTimeScaleFps);
logicTimeScaleFps = maxRenderFps;
}

TheFramePacer->enableLogicTimeScale(logicTimeScaleFps < maxRenderFps);

// Set value after potentially enabling it.
if (TheFramePacer->isLogicTimeScaleEnabled())
const bool enableTimescale = (logicTimeScaleFps < maxRenderFps);
// TheSuperHackers @info Preserve the last real FPS in m_logicTimeScaleFPS so re-enabling timescale resumes from a sane value.
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Add empty line between const bool declaration and comment for better readability

if (enableTimescale)
{
TheFramePacer->setLogicTimeScaleFps(logicTimeScaleFps);
}
TheFramePacer->enableLogicTimeScale(enableTimescale);
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Add empty line between closing bracket and TheFramePacer->enableLogicTimeScale for better readability.

Optionally: remove whiteline below TheFramePacer->enableLogicTimeScale


logicTimeScaleFps = TheFramePacer->getLogicTimeScaleFps();
const UnsignedInt actualLogicTimeScaleFps = TheFramePacer->getActualLogicTimeScaleFps();
Expand Down
31 changes: 11 additions & 20 deletions GeneralsMD/Code/GameEngine/Source/GameClient/MessageStream/CommandXlat.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -210,37 +210,28 @@ bool changeLogicTimeScale(FpsValueChange change)
return false;

const UnsignedInt maxRenderFps = TheFramePacer->getFramesPerSecondLimit();
UnsignedInt maxRenderRemainder = LogicTimeScaleFpsPreset::StepFpsValue;
maxRenderRemainder -= maxRenderFps % LogicTimeScaleFpsPreset::StepFpsValue;
maxRenderRemainder %= LogicTimeScaleFpsPreset::StepFpsValue;

UnsignedInt logicTimeScaleFps = TheFramePacer->getLogicTimeScaleFps();
// Set the value to the max render fps value plus a bit when time scale is
// disabled. This ensures that the time scale does not re-enable with a
// 'surprise' value.

if (!TheFramePacer->isLogicTimeScaleEnabled())
{
logicTimeScaleFps = maxRenderFps + maxRenderRemainder;
logicTimeScaleFps = maxRenderFps;
}
// Ceil the value at the max render fps value plus a bit so that the next fps
// value decrease would undercut the max render fps at the correct step value.
// Example: render fps 72 -> logic value ceiled to 75 -> decreased to 70.
logicTimeScaleFps = min(logicTimeScaleFps, maxRenderFps + maxRenderRemainder);
logicTimeScaleFps = LogicTimeScaleFpsPreset::changeFpsValue(logicTimeScaleFps, change);

// Set value before potentially disabling it.
if (TheFramePacer->isLogicTimeScaleEnabled())
logicTimeScaleFps = LogicTimeScaleFpsPreset::changeFpsValue(logicTimeScaleFps, change, maxRenderFps);

// Ensure logic FPS never exceeds render FPS
if (logicTimeScaleFps > maxRenderFps && logicTimeScaleFps != RenderFpsPreset::UncappedFpsValue)
{
TheFramePacer->setLogicTimeScaleFps(logicTimeScaleFps);
logicTimeScaleFps = maxRenderFps;
}

TheFramePacer->enableLogicTimeScale(logicTimeScaleFps < maxRenderFps);

// Set value after potentially enabling it.
if (TheFramePacer->isLogicTimeScaleEnabled())
const bool enableTimescale = (logicTimeScaleFps < maxRenderFps);
// TheSuperHackers @info Preserve the last real FPS in m_logicTimeScaleFPS so re-enabling timescale resumes from a sane value.
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Add empty line between const bool declaration and comment for better readability

if (enableTimescale)
{
TheFramePacer->setLogicTimeScaleFps(logicTimeScaleFps);
}
TheFramePacer->enableLogicTimeScale(enableTimescale);
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Add empty line between closing bracket and TheFramePacer->enableLogicTimeScale for better readability.

Optionally: remove whiteline below TheFramePacer->enableLogicTimeScale


logicTimeScaleFps = TheFramePacer->getLogicTimeScaleFps();
const UnsignedInt actualLogicTimeScaleFps = TheFramePacer->getActualLogicTimeScaleFps();
Expand Down
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