SH-3931 WIP Interesting: Add graphs to visualize scene load metrics

changed Units macros and argument order to make it more clear
optimized units for integer types
fixed merging of periodicrecordings...should eliminate duplicate entries in sceneloadmonitor history

1 files changed, 162 insertions, 141 deletions

diff --git a/indra/newview/llfasttimerview.cpp b/indra/newview/llfasttimerview.cpp
index 40526d3357..8e061ec87c 100755
--- a/indra/newview/llfasttimerview.cpp
+++ b/indra/newview/llfasttimerview.cpp
@@ -101,21 +101,15 @@ LLFastTimerView::LLFastTimerView(const LLSD& key)
 	mScrollIndex(0),
 	mHoverID(NULL),
 	mHoverBarIndex(-1),
-	mPrintStats(-1),
-	mRecording(&get_frame_recording()),
-	mPauseHistory(false)
+	mStatsIndex(-1),
+	mPauseHistory(false),
+	mRecording(512)
 {
-	mTimerBars = new std::vector<TimerBar>[MAX_VISIBLE_HISTORY + 1];
+	mTimerBarRows.resize(MAX_VISIBLE_HISTORY);
 }
 
 LLFastTimerView::~LLFastTimerView()
 {
-	if (mRecording != &get_frame_recording())
-	{
-		delete mRecording;
-	}
-	mRecording = NULL;
-	delete [] mTimerBars;
 }
 
 void LLFastTimerView::onPause()
@@ -130,16 +124,11 @@ void LLFastTimerView::setPauseState(bool pause_state)
 	// reset scroll to bottom when unpausing
 	if (!pause_state)
 	{
-		if (mRecording != &get_frame_recording())
-		{
-			delete mRecording;
-		}
-		mRecording = &get_frame_recording();
+		
 		getChild<LLButton>("pause_btn")->setLabel(getString("pause"));
 	}
 	else
 	{
-		mRecording = new PeriodicRecording(get_frame_recording());
 		mScrollIndex = 0;
 
 		getChild<LLButton>("pause_btn")->setLabel(getString("run"));
@@ -175,7 +164,7 @@ BOOL LLFastTimerView::handleRightMouseDown(S32 x, S32 y, MASK mask)
 	{
 		S32 bar_idx = MAX_VISIBLE_HISTORY - ((y - mBarRect.mBottom) * (MAX_VISIBLE_HISTORY + 2) / mBarRect.getHeight());
 		bar_idx = llclamp(bar_idx, 0, MAX_VISIBLE_HISTORY);
-		mPrintStats = mScrollIndex + bar_idx;
+		mStatsIndex = mScrollIndex + bar_idx;
 		return TRUE;
 	}
 	return LLFloater::handleRightMouseDown(x, y, mask);
@@ -262,8 +251,8 @@ BOOL LLFastTimerView::handleHover(S32 x, S32 y, MASK mask)
 	if (hasMouseCapture())
 	{
 		F32 lerp = llclamp(1.f - (F32) (x - mGraphRect.mLeft) / (F32) mGraphRect.getWidth(), 0.f, 1.f);
-		mScrollIndex = llround( lerp * (F32)(mRecording->getNumPeriods() - MAX_VISIBLE_HISTORY));
-		mScrollIndex = llclamp(	mScrollIndex, 0, (S32)mRecording->getNumPeriods());
+		mScrollIndex = llround( lerp * (F32)(mRecording.getNumRecordedPeriods() - MAX_VISIBLE_HISTORY));
+		mScrollIndex = llclamp(	mScrollIndex, 0, (S32)mRecording.getNumRecordedPeriods());
 		return TRUE;
 	}
 	mHoverTimer = NULL;
@@ -272,7 +261,7 @@ BOOL LLFastTimerView::handleHover(S32 x, S32 y, MASK mask)
 	if(mPauseHistory && mBarRect.pointInRect(x, y))
 	{
 		mHoverBarIndex = llmin((mBarRect.mTop - y) / (mBarRect.getHeight() / (MAX_VISIBLE_HISTORY + 2)) - 1,
-								(S32)mRecording->getNumPeriods() - 1,
+								(S32)mRecording.getNumRecordedPeriods() - 1,
 								MAX_VISIBLE_HISTORY);
 		if (mHoverBarIndex == 0)
 		{
@@ -289,7 +278,8 @@ BOOL LLFastTimerView::handleHover(S32 x, S32 y, MASK mask)
 			++it, ++i)
 		{
 			// is mouse over bar for this timer?
-			if (mTimerBars[mHoverBarIndex][i].mVisibleRect.pointInRect(x, y))
+			TimerBarRow& row = mHoverBarIndex == 0 ? mAverageTimerRow : mTimerBarRows[mHoverBarIndex - 1];
+			if (row.mBars[i].mVisibleRect.pointInRect(x, y - row.mBottom))
 			{
 				mHoverID = (*it);
 				if (mHoverTimer != *it)
@@ -301,7 +291,8 @@ BOOL LLFastTimerView::handleHover(S32 x, S32 y, MASK mask)
 					mHoverTimer = (*it);
 				}
 
-				mToolTipRect = mTimerBars[mHoverBarIndex][i].mVisibleRect;
+				mToolTipRect = row.mBars[i].mVisibleRect;
+				mToolTipRect.translate(0, row.mBottom);
 			}
 
 			if ((*it)->getCollapsed())
@@ -329,11 +320,11 @@ static std::string get_tooltip(TimeBlock& timer, S32 history_index, PeriodicReco
 	if (history_index == 0)
 	{
 		// by default, show average number of call
-		tooltip = llformat("%s (%d ms, %d calls)", timer.getName().c_str(), (S32)LLUnit<LLUnits::Milliseconds, F64>(frame_recording.getPeriodMean(timer)).value(), (S32)frame_recording.getPeriodMean(timer.callCount()));
+		tooltip = llformat("%s (%d ms, %d calls)", timer.getName().c_str(), (S32)LLUnit<F64, LLUnits::Milliseconds>(frame_recording.getPeriodMean(timer)).value(), (S32)frame_recording.getPeriodMean(timer.callCount()));
 	}
 	else
 	{
-		tooltip = llformat("%s (%d ms, %d calls)", timer.getName().c_str(), (S32)LLUnit<LLUnits::Milliseconds, F64>(frame_recording.getPrevRecording(history_index).getSum(timer)).value(), (S32)frame_recording.getPrevRecording(history_index).getSum(timer.callCount()));
+		tooltip = llformat("%s (%d ms, %d calls)", timer.getName().c_str(), (S32)LLUnit<F64, LLUnits::Milliseconds>(frame_recording.getPrevRecording(history_index).getSum(timer)).value(), (S32)frame_recording.getPrevRecording(history_index).getSum(timer.callCount()));
 	}
 	return tooltip;
 }
@@ -348,7 +339,7 @@ BOOL LLFastTimerView::handleToolTip(S32 x, S32 y, MASK mask)
 			LLRect screen_rect;
 			localRectToScreen(mToolTipRect, &screen_rect);
 
-			std::string tooltip = get_tooltip(*mHoverTimer, mHoverBarIndex > 0 ? mScrollIndex + mHoverBarIndex : 0, *mRecording);
+			std::string tooltip = get_tooltip(*mHoverTimer, mHoverBarIndex > 0 ? mScrollIndex + mHoverBarIndex : 0, mRecording);
 
 			LLToolTipMgr::instance().show(LLToolTip::Params()
 				.message(tooltip)
@@ -366,7 +357,7 @@ BOOL LLFastTimerView::handleToolTip(S32 x, S32 y, MASK mask)
 			TimeBlock* idp = getLegendID(y);
 			if (idp)
 			{
-				LLToolTipMgr::instance().show(get_tooltip(*idp, 0, *mRecording));
+				LLToolTipMgr::instance().show(get_tooltip(*idp, 0, mRecording));
 
 				return TRUE;
 			}
@@ -381,7 +372,7 @@ BOOL LLFastTimerView::handleScrollWheel(S32 x, S32 y, S32 clicks)
 	setPauseState(true);
 	mScrollIndex = llclamp(	mScrollIndex + clicks,
 							0,
-							llmin((S32)mRecording->getNumPeriods(), (S32)mRecording->getNumPeriods() - MAX_VISIBLE_HISTORY));
+							llmin((S32)mRecording.getNumRecordedPeriods(), (S32)mRecording.getNumRecordedPeriods() - MAX_VISIBLE_HISTORY));
 	return TRUE;
 }
 
@@ -389,12 +380,19 @@ static TimeBlock FTM_RENDER_TIMER("Timers", true);
 static const S32 MARGIN = 10;
 static const S32 LEGEND_WIDTH = 220;
 
-static std::map<TimeBlock*, LLColor4> sTimerColors;
+static std::vector<LLColor4> sTimerColors;
 
 void LLFastTimerView::draw()
 {
 	LLFastTimer t(FTM_RENDER_TIMER);
 	
+	if (!mPauseHistory)
+	{
+		mRecording.appendRecording(LLTrace::get_frame_recording().getLastRecording());
+		mTimerBarRows.pop_back();
+		mTimerBarRows.push_front(TimerBarRow());
+	}
+
 	generateUniqueColors();
 
 	// Draw the window background
@@ -417,11 +415,20 @@ void LLFastTimerView::draw()
 	printLineStats();
 	LLView::draw();
 		
-	mAllTimeMax = llmax(mAllTimeMax, mRecording->getLastRecording().getSum(FTM_FRAME));
+	mAllTimeMax = llmax(mAllTimeMax, mRecording.getLastRecording().getSum(FTM_FRAME));
 	mHoverID = NULL;
 	mHoverBarIndex = -1;
 }
 
+void LLFastTimerView::onOpen(const LLSD& key)
+{
+	if (mRecording.getNumRecordedPeriods() == 0)
+	{
+		mRecording.appendPeriodicRecording(LLTrace::get_frame_recording());
+	}
+}
+
+
 void saveChart(const std::string& label, const char* suffix, LLImageRaw* scratch)
 {
 	//read result back into raw image
@@ -828,7 +835,7 @@ void LLFastTimerView::doAnalysisDefault(std::string baseline, std::string target
 	LLSD current = analyzePerformanceLogDefault(target_is);
 	target_is.close();
 
-	//output comparision
+	//output comparison
 	std::ofstream os(output.c_str());
 
 	LLSD::Real session_time = current["SessionTime"].asReal();
@@ -936,7 +943,7 @@ void	LLFastTimerView::onClickCloseBtn()
 void LLFastTimerView::printLineStats()
 {
 	// Output stats for clicked bar to log
-	if (mPrintStats >= 0)
+	if (mStatsIndex >= 0)
 	{
 		std::string legend_stat;
 		bool first = true;
@@ -974,16 +981,16 @@ void LLFastTimerView::printLineStats()
 			}
 			first = false;
 
-			LLUnit<LLUnits::Seconds, F32> ticks;
-			if (mPrintStats > 0)
+			LLUnit<F32, LLUnits::Seconds> ticks;
+			if (mStatsIndex == 0)
 			{
-				ticks = mRecording->getPrevRecording(mPrintStats).getSum(*idp);
+				ticks = mRecording.getPeriodMean(*idp);
 			}
 			else
 			{
-				ticks = mRecording->getPeriodMean(*idp);
+				ticks = mRecording.getPrevRecording(mStatsIndex).getSum(*idp);
 			}
-			LLUnit<LLUnits::Milliseconds, F32> ms = ticks;
+			LLUnit<F32, LLUnits::Milliseconds> ms = ticks;
 
 			timer_stat += llformat("%.1f",ms.value());
 
@@ -993,7 +1000,7 @@ void LLFastTimerView::printLineStats()
 			}
 		}
 		llinfos << timer_stat << llendl;
-		mPrintStats = -1;
+		mStatsIndex = -1;
 	}
 }
 
@@ -1009,7 +1016,7 @@ void LLFastTimerView::drawLineGraph()
 	LLLocalClipRect clip(mGraphRect);
 
 	//normalize based on last frame's maximum
-	static LLUnit<LLUnits::Seconds, F32> max_time = 0.000001;
+	static LLUnit<F32, LLUnits::Seconds> max_time = 0.000001;
 	static U32 max_calls = 0;
 	static F32 alpha_interp = 0.f;
 
@@ -1020,7 +1027,7 @@ void LLFastTimerView::drawLineGraph()
 	else if (mDisplayHz)
 		axis_label = llformat("%d Hz", (int)(1.f / max_time.value()));
 	else
-		axis_label = llformat("%4.2f ms", LLUnit<LLUnits::Milliseconds, F32>(max_time).value());
+		axis_label = llformat("%4.2f ms", LLUnit<F32, LLUnits::Milliseconds>(max_time).value());
 
 	x = mGraphRect.mRight - LLFontGL::getFontMonospace()->getWidth(axis_label)-5;
 	y = mGraphRect.mTop - LLFontGL::getFontMonospace()->getLineHeight();
@@ -1030,10 +1037,10 @@ void LLFastTimerView::drawLineGraph()
 
 	//highlight visible range
 	{
-		S32 first_frame = mRecording->getNumPeriods() - mScrollIndex;
+		S32 first_frame = mRecording.getNumRecordedPeriods() - mScrollIndex;
 		S32 last_frame = first_frame - MAX_VISIBLE_HISTORY;
 
-		F32 frame_delta = ((F32) (mGraphRect.getWidth()))/(mRecording->getNumPeriods()-1);
+		F32 frame_delta = ((F32) (mGraphRect.getWidth()))/(mRecording.getNumRecordedPeriods()-1);
 
 		F32 right = (F32) mGraphRect.mLeft + frame_delta*first_frame;
 		F32 left = (F32) mGraphRect.mLeft + frame_delta*last_frame;
@@ -1055,7 +1062,7 @@ void LLFastTimerView::drawLineGraph()
 		}
 	}
 
-	LLUnit<LLUnits::Seconds, F32> cur_max = 0;
+	LLUnit<F32, LLUnits::Seconds> cur_max = 0;
 	U32 cur_max_calls = 0;
 	for(timer_tree_iterator_t it = begin_timer_tree(FTM_FRAME);
 		it != end_timer_tree();
@@ -1070,7 +1077,7 @@ void LLFastTimerView::drawLineGraph()
 			glLineWidth(3);
 		}
 
-		const F32 * col = sTimerColors[idp].mV;// ft_display_table[idx].color->mV;
+		const F32 * col = sTimerColors[idp->getIndex()].mV;// ft_display_table[idx].color->mV;
 
 		F32 alpha = 1.f;
 
@@ -1085,12 +1092,13 @@ void LLFastTimerView::drawLineGraph()
 
 		gGL.color4f(col[0], col[1], col[2], alpha);				
 		gGL.begin(LLRender::TRIANGLE_STRIP);
-		for (U32 j = mRecording->getNumPeriods();
+		for (U32 j = mRecording.getNumRecordedPeriods();
 			j > 0;
 			j--)
 		{
-			LLUnit<LLUnits::Seconds, F32> time = llmax(mRecording->getPrevRecording(j).getSum(*idp), LLUnit<LLUnits::Seconds, F64>(0.000001));
-			U32 calls = mRecording->getPrevRecording(j).getSum(idp->callCount());
+			LLTrace::Recording& recording = mRecording.getPrevRecording(j);
+			LLUnit<F32, LLUnits::Seconds> time = llmax(recording.getSum(*idp), LLUnit<F64, LLUnits::Seconds>(0.000001));
+			U32 calls = recording.getSum(idp->callCount());
 
 			if (alpha == 1.f)
 			{ 
@@ -1098,7 +1106,7 @@ void LLFastTimerView::drawLineGraph()
 				cur_max = llmax(cur_max, time);
 				cur_max_calls = llmax(cur_max_calls, calls);
 			}
-			F32 x = mGraphRect.mRight - j * (F32)(mGraphRect.getWidth())/(mRecording->getNumPeriods()-1);
+			F32 x = mGraphRect.mRight - j * (F32)(mGraphRect.getWidth())/(mRecording.getNumRecordedPeriods()-1);
 			F32 y = mDisplayHz 
 				? mGraphRect.mBottom + (1.f / time.value()) * ((F32) mGraphRect.getHeight() / (1.f / max_time.value()))
 				: mGraphRect.mBottom + time / max_time * (F32)mGraphRect.getHeight();
@@ -1124,7 +1132,7 @@ void LLFastTimerView::drawLineGraph()
 	max_time = lerp(max_time.value(), cur_max.value(), LLSmoothInterpolation::getInterpolant(0.1f));
 	if (max_time - cur_max <= 1 ||  cur_max - max_time  <= 1)
 	{
-		max_time = llmax(LLUnit<LLUnits::Microseconds, F32>(1), LLUnit<LLUnits::Microseconds, F32>(cur_max));
+		max_time = llmax(LLUnit<F32, LLUnits::Microseconds>(1), LLUnit<F32, LLUnits::Microseconds>(cur_max));
 	}
 
 	max_calls = llround(lerp((F32)max_calls, (F32) cur_max_calls, LLSmoothInterpolation::getInterpolant(0.1f)));
@@ -1183,20 +1191,20 @@ void LLFastTimerView::drawLegend( S32 y )
 				scale_offset = llfloor(sinf(mHighlightTimer.getElapsedTimeF32() * 6.f) * 2.f);
 			}
 			bar_rect.stretch(scale_offset);
-			gl_rect_2d(bar_rect, sTimerColors[idp]);
+			gl_rect_2d(bar_rect, sTimerColors[idp->getIndex()]);
 
-			LLUnit<LLUnits::Milliseconds, F32> ms = 0;
+			LLUnit<F32, LLUnits::Milliseconds> ms = 0;
 			S32 calls = 0;
 			if (mHoverBarIndex > 0 && mHoverID)
 			{
 				S32 hidx = mScrollIndex + mHoverBarIndex;
-				ms = mRecording->getPrevRecording(hidx).getSum(*idp);
-				calls = mRecording->getPrevRecording(hidx).getSum(idp->callCount());
+				ms = mRecording.getPrevRecording(hidx).getSum(*idp);
+				calls = mRecording.getPrevRecording(hidx).getSum(idp->callCount());
 			}
 			else
 			{
-				ms = LLUnit<LLUnits::Seconds, F64>(mRecording->getPeriodMean(*idp));
-				calls = (S32)mRecording->getPeriodMean(idp->callCount());
+				ms = LLUnit<F64, LLUnits::Seconds>(mRecording.getPeriodMean(*idp));
+				calls = (S32)mRecording.getPeriodMean(idp->callCount());
 			}
 
 			std::string timer_label;
@@ -1254,7 +1262,8 @@ void LLFastTimerView::generateUniqueColors()
 {
 	// generate unique colors
 	{
-		sTimerColors[&FTM_FRAME] = LLColor4::grey;
+		sTimerColors.reserve(LLTrace::TimeBlock::getNumIndices());
+		sTimerColors[FTM_FRAME.getIndex()] = LLColor4::grey;
 
 		F32 hue = 0.f;
 
@@ -1274,7 +1283,7 @@ void LLFastTimerView::generateUniqueColors()
 			LLColor4 child_color;
 			child_color.setHSL(hue, saturation, lightness);
 
-			sTimerColors[idp] = child_color;
+			sTimerColors[idp->getIndex()] = child_color;
 		}
 	}
 }
@@ -1315,7 +1324,7 @@ void LLFastTimerView::drawTicks()
 {
 	// Draw MS ticks
 	{
-		LLUnit<LLUnits::Milliseconds, U32> ms = mTotalTimeDisplay;
+		LLUnit<U32, LLUnits::Milliseconds> ms = mTotalTimeDisplay;
 		std::string tick_label;
 		S32 x;
 		S32 barw = mBarRect.getWidth();
@@ -1382,127 +1391,127 @@ void LLFastTimerView::updateTotalTime()
 	switch(mDisplayMode)
 	{
 	case 0:
-		mTotalTimeDisplay = mRecording->getPeriodMean(FTM_FRAME)*2;
+		mTotalTimeDisplay = mRecording.getPeriodMean(FTM_FRAME)*2;
 		break;
 	case 1:
 		mTotalTimeDisplay = mAllTimeMax;
 		break;
 	case 2:
 		// Calculate the max total ticks for the current history
-		mTotalTimeDisplay = mRecording->getPeriodMax(FTM_FRAME);
+		mTotalTimeDisplay = mRecording.getPeriodMax(FTM_FRAME);
 		break;
 	default:
-		mTotalTimeDisplay = LLUnit<LLUnits::Milliseconds, F32>(100);
+		mTotalTimeDisplay = LLUnit<F32, LLUnits::Milliseconds>(100);
 		break;
 	}
 
-	mTotalTimeDisplay = LLUnit<LLUnits::Milliseconds, F32>(llceil(mTotalTimeDisplay.as<LLUnits::Milliseconds>().value() / 20.f) * 20.f);
+	mTotalTimeDisplay = LLUnit<F32, LLUnits::Milliseconds>(llceil(mTotalTimeDisplay.as<LLUnits::Milliseconds>().value() / 20.f) * 20.f);
 }
 
 void LLFastTimerView::drawBars()
 {
-	updateTotalTime();
-	if (mTotalTimeDisplay <= 0.0) return;
-
 	LLLocalClipRect clip(mBarRect);
 
 	S32 bar_height = mBarRect.getHeight() / (MAX_VISIBLE_HISTORY + 2);
-	S32 vpad = llmax(1, bar_height / 4); // spacing between bars
+	const S32 vpad = llmax(1, bar_height / 4); // spacing between bars
 	bar_height -= vpad;
 
+	updateTotalTime();
+	if (mTotalTimeDisplay <= 0.0) return;
+
 	drawTicks();
-	S32 y = mBarRect.mTop - ((S32)LLFontGL::getFontMonospace()->getLineHeight() + 4);
-	drawBorders(y, mBarRect.mLeft, bar_height, vpad);
+	const S32 bars_top = mBarRect.mTop - ((S32)LLFontGL::getFontMonospace()->getLineHeight() + 4);
+	drawBorders(bars_top, mBarRect.mLeft, bar_height, vpad);
 
 	// Draw bars for each history entry
-	// Special: -1 = show running average
+	// Special: 0 = show running average
 	LLPointer<LLUIImage> bar_image = LLUI::getUIImage("Rounded_Square");
+
+	const S32 image_width = bar_image->getTextureWidth();
+	const S32 image_height = bar_image->getTextureHeight();
+
 	gGL.getTexUnit(0)->bind(bar_image->getImage());
-	const S32 histmax = llmin((S32)mRecording->getNumPeriods(), MAX_VISIBLE_HISTORY) + 1;
+	{	
+		const S32 histmax = llmin((S32)mRecording.getNumRecordedPeriods(), MAX_VISIBLE_HISTORY);
 
-	for (S32 bar_index = 0; bar_index < histmax && y > LINE_GRAPH_HEIGHT; bar_index++)
-	{
-		S32 history_index = (bar_index > 0)
-			? bar_index + mScrollIndex
-			: -1;
-		mTimerBars[bar_index].clear();
-		mTimerBars[bar_index].reserve(LLInstanceTracker<LLTrace::TimeBlock>::instanceCount());
-
-		updateTimerBarWidths(&FTM_FRAME, mTimerBars[bar_index], history_index, true);
-		LLRect frame_bar_rect(mBarRect.mLeft, y, mBarRect.mLeft + mTimerBars[bar_index][0].mWidth, y-bar_height);
-		mTimerBars[bar_index][0].mVisibleRect = frame_bar_rect;
-		updateTimerBarFractions(&FTM_FRAME, 0, mTimerBars[bar_index]);
-		drawBar(&FTM_FRAME, frame_bar_rect, mTimerBars[bar_index], 0, bar_image);
-				
-		y -= (bar_height + vpad);
-		if (bar_index == 0)
-			y -= bar_height;
-	}
+		llassert(mTimerBarRows.size() >= histmax);
+
+		// update widths
+		updateTimerBarWidths(&FTM_FRAME, mAverageTimerRow, -1);
+		mAverageTimerRow.mBars[0].mVisibleRect = LLRect(mBarRect.mLeft, 0, mBarRect.mLeft + mAverageTimerRow.mBars[0].mWidth, -bar_height);
+		updateTimerBarFractions(&FTM_FRAME, mAverageTimerRow);
+
+		for (S32 history_index = 0; history_index < histmax; history_index++)
+		{
+			TimerBarRow& row = mTimerBarRows[history_index];
+			if (row.mBars.empty())
+			{
+				row.mBars.reserve(LLInstanceTracker<LLTrace::TimeBlock>::instanceCount());
+				updateTimerBarWidths(&FTM_FRAME, row, history_index);
+				row.mBars[0].mVisibleRect = LLRect(mBarRect.mLeft, 0, mBarRect.mLeft + row.mBars[0].mWidth, -1);
+				updateTimerBarFractions(&FTM_FRAME, row);
+			}
+		}
+
+		// draw bars
+		LLRect frame_bar_rect(	mBarRect.mLeft, 
+								bars_top, 
+								mBarRect.mLeft + mAverageTimerRow.mBars[0].mWidth, 
+								bars_top - bar_height);
+		mAverageTimerRow.mBottom = frame_bar_rect.mBottom;
+		drawBar(&FTM_FRAME, frame_bar_rect, mAverageTimerRow, image_width, image_height, false);
+		frame_bar_rect.translate(0, -(bar_height + vpad + bar_height));
+
+		for(S32 bar_index = mScrollIndex; bar_index < llmin(histmax, mScrollIndex + MAX_VISIBLE_HISTORY); ++bar_index)
+		{
+			TimerBarRow& row = mTimerBarRows[bar_index];
+			row.mBottom = frame_bar_rect.mBottom;
+			drawBar(&FTM_FRAME, frame_bar_rect, row, image_width, image_height, false);
+
+			frame_bar_rect.translate(0, -(bar_height + vpad));
+		}
+
+	}	
 	gGL.getTexUnit(0)->unbind(LLTexUnit::TT_TEXTURE);
 }
 
 static LLFastTimer::DeclareTimer FTM_UPDATE_TIMER_BAR_WIDTHS("Update timer bar widths");
 
-S32 LLFastTimerView::updateTimerBarWidths(LLTrace::TimeBlock* time_block, std::vector<TimerBar>& bars, S32 history_index, bool visible)
+S32 LLFastTimerView::updateTimerBarWidths(LLTrace::TimeBlock* time_block, TimerBarRow& row, S32 history_index, bool visible)
 {
+	std::vector<TimerBar>& bars = row.mBars;
 	LLFastTimer _(FTM_UPDATE_TIMER_BAR_WIDTHS);
-	F32 self_time_frame_fraction = history_index == -1
-		? (mRecording->getPeriodMean(time_block->selfTime()) / mTotalTimeDisplay) 
-		: (mRecording->getPrevRecording(history_index).getSum(time_block->selfTime()) / mTotalTimeDisplay);
+	const F32 self_time_frame_fraction = history_index == -1
+										? (mRecording.getPeriodMean(time_block->selfTime()) / mTotalTimeDisplay) 
+										: (mRecording.getPrevRecording(history_index).getSum(time_block->selfTime()) / mTotalTimeDisplay);
 
-	S32 self_time_width = llround(self_time_frame_fraction * (F32)mBarRect.getWidth());
+	const S32 self_time_width = llround(self_time_frame_fraction * (F32)mBarRect.getWidth());
 	S32 full_width = self_time_width;
 
-	bool children_visible = visible;
-
 	// reserve a spot for this bar to be rendered before its children
 	// even though we don't know its size yet
-	S32 bar_rect_index = bars.size();
-	if (visible)
-	{
-		bars.push_back(TimerBar());
-	}
+	bars.push_back(TimerBar());
+	TimerBar& timer_bar = bars.back();
 
-	if (time_block->getCollapsed())
-	{
-		children_visible = false;
-	}
+	const bool children_visible = visible && !time_block->getCollapsed();
 	for (TimeBlock::child_iter it = time_block->beginChildren(), end_it = time_block->endChildren(); it != end_it; ++it)
 	{
-		full_width += updateTimerBarWidths(*it, bars, history_index, children_visible);
+		full_width += updateTimerBarWidths(*it, row, history_index, children_visible);
 	}
 
-	if (visible)
-	{
-		TimerBar& timer_bar = bars[bar_rect_index];
-
-		timer_bar.mWidth = full_width;
-		timer_bar.mSelfWidth = self_time_width;
-		timer_bar.mColor = sTimerColors[time_block];
-
-		BOOL is_child_of_hover_item = (time_block == mHoverID);
-		TimeBlock* next_parent = time_block->getParent();
-		while(!is_child_of_hover_item && next_parent)
-		{
-			is_child_of_hover_item = (mHoverID == next_parent);
-			if (next_parent->getParent() == next_parent) break;
-			next_parent = next_parent->getParent();
-		}
-
-		if (mHoverID != NULL 
-			&& time_block != mHoverID 
-			&& !is_child_of_hover_item)
-		{
-			timer_bar.mColor = lerp(timer_bar.mColor, LLColor4::grey, 0.8f);
-		}
-	}
+	timer_bar.mWidth     = full_width;
+	timer_bar.mSelfWidth = self_time_width;
+	timer_bar.mTimeBlock = time_block;
+	timer_bar.mVisible   = visible;
+	
 	return full_width;
 }
 
 static LLFastTimer::DeclareTimer FTM_UPDATE_TIMER_BAR_FRACTIONS("Update timer bar fractions");
 
-S32 LLFastTimerView::updateTimerBarFractions(LLTrace::TimeBlock* time_block, S32 timer_bar_index, std::vector<TimerBar>& bars)
+S32 LLFastTimerView::updateTimerBarFractions(LLTrace::TimeBlock* time_block, TimerBarRow& row, S32 timer_bar_index)
 {
+	std::vector<TimerBar>& bars = row.mBars;
 	LLFastTimer _(FTM_UPDATE_TIMER_BAR_FRACTIONS);
 	TimerBar& timer_bar = bars[timer_bar_index];
 	S32 child_time_width = timer_bar.mWidth - timer_bar.mSelfWidth;
@@ -1518,11 +1527,6 @@ S32 LLFastTimerView::updateTimerBarFractions(LLTrace::TimeBlock* time_block, S32
 	}
 	children_rect.mRight = children_rect.mLeft + timer_bar.mWidth - timer_bar.mSelfWidth;
 
-	if (children_rect.getHeight() > MIN_BAR_HEIGHT)
-	{
-		children_rect.mTop -= 1;
-		children_rect.mBottom += 1;
-	}
 	timer_bar.mChildrenRect = children_rect;
 
 	//now loop through children and figure out portion of bar image covered by each bar, now that we know the
@@ -1548,7 +1552,7 @@ S32 LLFastTimerView::updateTimerBarFractions(LLTrace::TimeBlock* time_block, S32
 				children_rect.mLeft + llround(child_timer_bar.mEndFraction * children_rect.getWidth()), 
 				children_rect.mBottom);
 
-			timer_bar_index = updateTimerBarFractions(child_time_block, timer_bar_index, bars);
+			timer_bar_index = updateTimerBarFractions(child_time_block, row, timer_bar_index);
 
 			bar_fraction_start = child_timer_bar.mEndFraction;
 		}
@@ -1556,25 +1560,29 @@ S32 LLFastTimerView::updateTimerBarFractions(LLTrace::TimeBlock* time_block, S32
 	return timer_bar_index;
 }
 
-S32 LLFastTimerView::drawBar(LLTrace::TimeBlock* time_block, LLRect bar_rect, std::vector<TimerBar>& bars, S32 bar_index, LLPointer<LLUIImage>& bar_image)
+S32 LLFastTimerView::drawBar(LLTrace::TimeBlock* time_block, LLRect bar_rect, TimerBarRow& row, S32 image_width, S32 image_height, bool hovered, S32 bar_index)
 {
-	TimerBar& timer_bar = bars[bar_index];
+	TimerBar& timer_bar = row.mBars[bar_index];
+
+	hovered |= mHoverID == time_block;
 
 	// animate scale of bar when hovering over that particular timer
 	if (bar_rect.getWidth() > 0)
 	{
 		LLRect render_rect(bar_rect);
 		S32 scale_offset = 0;
-		if (time_block == mHoverID)
+		if (mHoverID == time_block)
 		{
 			scale_offset = llfloor(sinf(mHighlightTimer.getElapsedTimeF32() * 6.f) * 3.f);
 			render_rect.mTop += scale_offset;
 			render_rect.mBottom -= scale_offset;
 		}
 
-		gGL.color4fv(timer_bar.mColor.mV);
+		LLColor4 color = sTimerColors[time_block->getIndex()];
+		if (!hovered) color = lerp(color, LLColor4::grey, 0.8f);
+		gGL.color4fv(color.mV);
 		gl_segmented_rect_2d_fragment_tex(render_rect,
-			bar_image->getTextureWidth(), bar_image->getTextureHeight(), 
+			image_width, image_height, 
 			16, 
 			timer_bar.mStartFraction, timer_bar.mEndFraction);
 	}
@@ -1584,7 +1592,20 @@ S32 LLFastTimerView::drawBar(LLTrace::TimeBlock* time_block, LLRect bar_rect, st
 		for (TimeBlock::child_iter it = time_block->beginChildren(), end_it = time_block->endChildren(); it != end_it; ++it)
 		{
 			++bar_index;
-			bar_index = drawBar(*it, timer_bar.mChildrenRect, bars, bar_index, bar_image);
+			LLRect children_rect = timer_bar.mChildrenRect;
+			children_rect.translate(0, row.mBottom);
+			if (bar_rect.getHeight() > MIN_BAR_HEIGHT)
+			{
+				// shrink as we go down a level
+				children_rect.mTop = bar_rect.mTop - 1;
+				children_rect.mBottom = bar_rect.mBottom + 1;
+			}
+			else
+			{
+				children_rect.mTop = bar_rect.mTop;
+				children_rect.mBottom = bar_rect.mBottom;
+			}
+			bar_index = drawBar(*it, children_rect, row, image_width, image_height, hovered, bar_index);
 		}
 	}