Files
SingularityViewer/indra/llcommon/llframetimer.cpp
Aleric Inglewood dfa10281ea LLFrameTimer review and resulting changes.
This makes the class API a bit more sane, although
only a bit, because I had to leave it working with
possibly new code merged in from LL: the API can't
really change. I also removed some unused code.

While reviewing how LLFrameTimer worked however,
I did find a few instances where things where broken:

* sFrameDeltaTime wasn't correctly updated (more
  than once per frame and therefore erratic). This
  only influenced scrolling speed, but still.
* While dragging an inventory item, the scroll
  arrows of a tab container didn't work
  (LLTabContainer::handleDragAndDrop).
* Map zoom interpolation was broken (it interpolated
  between A and B, but used the already updated
  interpolation for A the next frame...
  (added mCurZoomValInterpolationStart).
2011-08-18 19:30:43 +02:00

166 lines
4.9 KiB
C++

/**
* @file llframetimer.cpp
*
* $LicenseInfo:firstyear=2002&license=viewergpl$
*
* Copyright (c) 2002-2009, Linden Research, Inc.
* Copyright (c) 2011, Aleric Inglewood.
*
* Second Life Viewer Source Code
* The source code in this file ("Source Code") is provided by Linden Lab
* to you under the terms of the GNU General Public License, version 2.0
* ("GPL"), unless you have obtained a separate licensing agreement
* ("Other License"), formally executed by you and Linden Lab. Terms of
* the GPL can be found in doc/GPL-license.txt in this distribution, or
* online at http://secondlifegrid.net/programs/open_source/licensing/gplv2
*
* There are special exceptions to the terms and conditions of the GPL as
* it is applied to this Source Code. View the full text of the exception
* in the file doc/FLOSS-exception.txt in this software distribution, or
* online at
* http://secondlifegrid.net/programs/open_source/licensing/flossexception
*
* By copying, modifying or distributing this software, you acknowledge
* that you have read and understood your obligations described above,
* and agree to abide by those obligations.
*
* ALL LINDEN LAB SOURCE CODE IS PROVIDED "AS IS." LINDEN LAB MAKES NO
* WARRANTIES, EXPRESS, IMPLIED OR OTHERWISE, REGARDING ITS ACCURACY,
* COMPLETENESS OR PERFORMANCE.
* $/LicenseInfo$
*/
#include "linden_common.h"
#include "u64.h"
#include "llframetimer.h"
// Local constants.
static F64 const USEC_PER_SECOND = 1000000.0;
static F64 const USEC_TO_SEC_F64 = 0.000001;
// Static members
U64 const LLFrameTimer::sStartTotalTime = totalTime(); // Application start in microseconds since epoch.
U64 LLFrameTimer::sTotalTime = LLFrameTimer::sStartTotalTime; // Current time in microseconds since epoch, updated at least once per frame.
F64 LLFrameTimer::sTotalSeconds = // Current time in seconds since epoch, updated together with LLFrameTimer::sTotalTime.
U64_to_F64(LLFrameTimer::sTotalTime) * USEC_TO_SEC_F64;
F64 LLFrameTimer::sFrameTime = 0.0; // Current time in seconds since application start, updated together with LLFrameTimer::sTotalTime.
// Updated exactly once per frame:
S32 LLFrameTimer::sFrameCount = 0; // Current frame number (number of frames since application start).
U64 LLFrameTimer::sPrevTotalTime = LLFrameTimer::sStartTotalTime; // Previous (frame) time in microseconds since epoch, updated once per frame.
U64 LLFrameTimer::sFrameDeltaTime = 0; // Microseconds between last two calls to LLFrameTimer::updateFrameTimeAndCount.
// static
void LLFrameTimer::updateFrameTime()
{
sTotalTime = totalTime();
sTotalSeconds = U64_to_F64(sTotalTime) * USEC_TO_SEC_F64;
sFrameTime = U64_to_F64(sTotalTime - sStartTotalTime) * USEC_TO_SEC_F64;
}
// static
void LLFrameTimer::updateFrameTimeAndCount()
{
updateFrameTime();
sFrameDeltaTime = sTotalTime - sPrevTotalTime;
sPrevTotalTime = sTotalTime;
++sFrameCount;
}
void LLFrameTimer::reset(F32 expiration)
{
llassert(!mPaused);
mStartTime = sFrameTime;
mExpiry = sFrameTime + expiration;
}
void LLFrameTimer::start(F32 expiration)
{
reset(expiration);
mRunning = true; // Start, if not already started.
}
void LLFrameTimer::stop()
{
llassert(!mPaused);
mRunning = false;
}
// Don't combine pause/unpause with start/stop
// Useage:
// LLFrameTime foo; // starts automatically
// foo.unpause(); // noop but safe
// foo.pause(); // pauses timer
// foo.unpause() // unpauses
// F32 elapsed = foo.getElapsedTimeF32() // does not include time between pause() and unpause()
// Note: elapsed would also be valid with no unpause() call (= time run until pause() called)
void LLFrameTimer::pause()
{
if (!mPaused)
{
mStartTime = sFrameTime - mStartTime; // Abuse mStartTime to store the elapsed time so far.
}
mPaused = true;
}
void LLFrameTimer::unpause()
{
if (mPaused)
{
mStartTime = sFrameTime - mStartTime; // Set mStartTime consistent with the elapsed time so far.
}
mPaused = false;
}
void LLFrameTimer::setTimerExpirySec(F32 expiration)
{
llassert(!mPaused);
mExpiry = mStartTime + expiration;
}
void LLFrameTimer::setExpiryAt(F64 seconds_since_epoch)
{
llassert(!mPaused);
mStartTime = sFrameTime;
mExpiry = seconds_since_epoch - (USEC_TO_SEC_F64 * sStartTotalTime);
}
F64 LLFrameTimer::expiresAt() const
{
F64 expires_at = U64_to_F64(sStartTotalTime) * USEC_TO_SEC_F64;
expires_at += mExpiry;
return expires_at;
}
bool LLFrameTimer::checkExpirationAndReset(F32 expiration)
{
if (hasExpired())
{
reset(expiration);
return true;
}
return false;
}
// static
F32 LLFrameTimer::getFrameDeltaTimeF32()
{
return (F32)(U64_to_F64(sFrameDeltaTime) * USEC_TO_SEC_F64);
}
// static
// Return seconds since the current frame started
F32 LLFrameTimer::getCurrentFrameTime()
{
U64 frame_time = totalTime() - sTotalTime;
return (F32)(U64_to_F64(frame_time) * USEC_TO_SEC_F64);
}
// Glue code to avoid full class .h file #includes
F32 getCurrentFrameTime()
{
return (F32)(LLFrameTimer::getCurrentFrameTime());
}