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PEGASUS: Rewrite TimeBase to be a bit more accurate with timing

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This commit is contained in:
Matthew Hoops 2011-09-17 21:16:52 -04:00
parent e90287f7f1
commit 1390db1df1
2 changed files with 55 additions and 42 deletions
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92
engines/pegasus/timers.cpp
View File

@ -56,6 +56,16 @@ TimeBase::TimeBase(const TimeScale preferredScale) {
_callBackList = 0;
_paused = false;
_flags = 0;
_lastMillis = 0;
_time = 0;
_rate = 0;
_startTime = 0;
_startScale = 1;
_stopTime = 0xffffffff;
_stopScale = 1;
_master = 0;
_pausedRate = 0;
((PegasusEngine *)g_engine)->addTimeBase(this);
}
@ -70,39 +80,18 @@ TimeBase::~TimeBase() {
}
void TimeBase::setTime(const TimeValue time, const TimeScale scale) {
// So, we're saying the *current* time from g_system->getMillis() is
// what time/scale is. Which means we need to subtract time/scale from
// the offset so that g_system->getMillis() - _currentOffset is
// equal to time/scale.
_timeOffset = g_system->getMillis() - time * 1000 / ((scale == 0) ? _preferredScale : scale);
// TODO: Also adjust the slaves' offsets (once we're actually using the
// masters for calculating time)
_time = Common::Rational(time, (scale == 0) ? _preferredScale : scale);
}
TimeValue TimeBase::getTime(const TimeScale scale) {
if (_paused)
return _pausedTime;
Common::Rational normalTime = Common::Rational((g_system->getMillis() - _timeOffset) * ((scale == 0) ? _preferredScale : scale), 1000);
// Adjust it according to our rate
return (normalTime * getEffectiveRate()).toInt();
return _time.getNumerator() * ((scale == 0) ? _preferredScale : scale) / _time.getDenominator();
}
void TimeBase::setRate(const Common::Rational rate) {
if (rate == 0) {
_paused = false;
_timeOffset = 0;
} else if (_timeOffset != 0) {
// Convert the time from the old rate to the new rate
_timeOffset = g_system->getMillis() - (rate * (g_system->getMillis() - _timeOffset) / _rate).toInt();
} else {
// TODO: Check this
setTime(_startTime, _startScale);
}
_rate = rate;
if (_rate == 0)
_paused = false;
}
Common::Rational TimeBase::getEffectiveRate() const {
@ -125,7 +114,6 @@ void TimeBase::pause() {
if (isRunning() && !_paused) {
_pausedRate = getRate();
stop();
_pausedTime = getTime();
_paused = true;
}
}
@ -150,9 +138,9 @@ bool TimeBase::isRunning() {
return true;
if (rate > 0)
return getTime() < getStop();
return getTime() != getStop();
return getTime() > getStart();
return getTime() != getStart();
}
void TimeBase::setStart(const TimeValue startTime, const TimeScale scale) {
@ -208,31 +196,55 @@ void TimeBase::setMasterTimeBase(TimeBase *tb) {
}
void TimeBase::checkCallBacks() {
uint32 time = getTime();
uint32 startTime = getStart();
uint32 stopTime = getStop();
// Nothing to do if we're paused or not running
if (_paused || !isRunning())
return;
Common::Rational startTime = Common::Rational(_startTime, _startScale);
Common::Rational stopTime = Common::Rational(_stopTime, _stopScale);
// First step: update the times
if (_lastMillis == 0) {
_lastMillis = g_system->getMillis();
} else {
uint32 curTime = g_system->getMillis();
if (_lastMillis == curTime) // No change
return;
_time += Common::Rational(curTime - _lastMillis, 1000) * getEffectiveRate();
_lastMillis = curTime;
// Clip time to the boundaries
if (_time >= stopTime)
_time = stopTime;
else if (_time <= startTime)
_time = startTime;
}
// TODO: Update the slaves?
// Check if we've triggered any callbacks
for (TimeBaseCallBack *runner = _callBackList; runner != 0; runner = runner->_nextCallBack) {
if (runner->_type == kCallBackAtTime && runner->_trigger == kTriggerTimeFwd) {
if (time >= (runner->_param2 * _preferredScale / runner->_param3) && getRate() > 0)
if (_time >= (runner->_param2 * _preferredScale / runner->_param3) && getRate() > 0)
runner->callBack();
} else if (runner->_type == kCallBackAtExtremes) {
if (runner->_trigger == kTriggerAtStop) {
if (time >= stopTime)
if (_time == stopTime)
runner->callBack();
} else if (runner->_trigger == kTriggerAtStart) {
if (time <= startTime)
if (_time == startTime)
runner->callBack();
}
}
}
// Loop if necessary
if (getFlags() & kLoopTimeBase) {
// Loop
if (time >= startTime)
setTime(stopTime);
else if (time <= stopTime)
setTime(startTime);
if (_time == startTime)
_time = stopTime;
else if (_time == stopTime)
_time = startTime;
}
}

5
engines/pegasus/timers.h
View File

@ -115,9 +115,10 @@ protected:
bool _paused;
uint32 _startTime, _startScale;
uint32 _stopTime, _stopScale;
int32 _timeOffset;
uint32 _flags;
TimeValue _pausedTime;
Common::Rational _time;
uint32 _lastMillis;
private:
Common::Rational getEffectiveRate() const;