[Follow up] Improve performance when rendering sample waveforms

include/SampleClipView.h

@@ -67,6 +67,7 @@ public slots:
 	SampleClip * m_clip;
 	SampleThumbnail m_sampleThumbnail;
 	QPixmap m_paintPixmap;
+	long m_paintPixmapXPosition;
 	bool splitClip( const TimePos pos ) override;
 } ;
 

include/SampleThumbnail.h

@@ -54,10 +54,8 @@ class LMMS_EXPORT SampleThumbnail
 	{
 		QRect sampleRect; //!< A rectangle that covers the entire range of samples.
 
-		QRect drawRect; //!< Specifies the location in `sampleRect` where the waveform will be drawn. Equals
-						//!< `sampleRect` when null.
-
-		QRect viewportRect; //!< Clips `drawRect`. Equals `drawRect` when null.
+		QRect viewportRect; //!< Specifies the location in `sampleRect` where the waveform will be drawn. Equals
+							//!< `sampleRect` when null.
 
 		float amplification = 1.0f; //!< The amount of amplification to apply to the waveform.
 
@@ -95,8 +93,8 @@ class LMMS_EXPORT SampleThumbnail
 			Peak operator+(const Peak& other) const { return Peak(std::min(min, other.min), std::max(max, other.max)); }
 			Peak operator+(const SampleFrame& frame) const { return *this + Peak{frame}; }
 
-			float min = std::numeric_limits<float>::max();
-			float max = std::numeric_limits<float>::min();
+			float min = std::numeric_limits<float>::infinity();
+			float max = -std::numeric_limits<float>::infinity();
 		};
 
 		Thumbnail() = default;
@@ -105,6 +103,7 @@ class LMMS_EXPORT SampleThumbnail
 
 		Thumbnail zoomOut(float factor) const;
 
+		Peak* data() { return m_peaks.data(); }
 		Peak& operator[](size_t index) { return m_peaks[index]; }
 		const Peak& operator[](size_t index) const { return m_peaks[index]; }
 
@@ -134,7 +133,7 @@ class LMMS_EXPORT SampleThumbnail
 
 	using ThumbnailCache = std::vector<Thumbnail>;
 	std::shared_ptr<ThumbnailCache> m_thumbnailCache = std::make_shared<ThumbnailCache>();
-
+	std::shared_ptr<const SampleBuffer> m_buffer = SampleBuffer::emptyBuffer();
 	inline static std::unordered_map<SampleThumbnailEntry, std::shared_ptr<ThumbnailCache>, Hash> s_sampleThumbnailCacheMap;
 };
 

src/gui/SampleThumbnail.cpp

@@ -70,6 +70,7 @@
 }
 
 SampleThumbnail::SampleThumbnail(const Sample& sample)
+	: m_buffer(sample.buffer())
 {
 	auto entry = SampleThumbnailEntry{sample.sampleFile(), QFileInfo{sample.sampleFile()}.lastModified()};
 	if (!entry.filePath.isEmpty())
@@ -91,11 +92,9 @@
 		s_sampleThumbnailCacheMap[std::move(entry)] = m_thumbnailCache;
 	}
 
-	if (!sample.buffer()) { throw std::runtime_error{"Cannot create a sample thumbnail with no buffer"}; }
-	if (sample.sampleSize() == 0) { return; }
-
-	const auto fullResolutionWidth = sample.sampleSize() * DEFAULT_CHANNELS;
-	m_thumbnailCache->emplace_back(&sample.buffer()->data()->left(), fullResolutionWidth, fullResolutionWidth);
+	const auto flatBuffer = m_buffer->data()->data();
+	const auto flatBufferSize = m_buffer->size() * DEFAULT_CHANNELS;
+	m_thumbnailCache->emplace_back(flatBuffer, flatBufferSize, flatBufferSize / AggregationPerZoomStep);
 
 	while (m_thumbnailCache->back().width() >= AggregationPerZoomStep)
 	{
@@ -104,54 +103,77 @@
 	}
 }
 
 void SampleThumbnail::visualize(VisualizeParameters parameters, QPainter& painter) const
 {
 	const auto& sampleRect = parameters.sampleRect;
-	const auto& drawRect = parameters.drawRect.isNull() ? sampleRect : parameters.drawRect;
-	const auto& viewportRect = parameters.viewportRect.isNull() ? drawRect : parameters.viewportRect;
+	const auto& viewportRect = parameters.viewportRect.isNull() ? sampleRect : parameters.viewportRect;
 
-	const auto renderRect = sampleRect.intersected(drawRect).intersected(viewportRect);
+	const auto renderRect = sampleRect.intersected(viewportRect);
 	if (renderRect.isNull()) { return; }
 
 	const auto sampleRange = parameters.sampleEnd - parameters.sampleStart;
-	if (sampleRange <= 0 || sampleRange > 1) { return; }
+	if (sampleRange <= 0.0f || sampleRange > 1.0f) { return; }
 
-	const auto targetThumbnailWidth = static_cast<int>(static_cast<double>(sampleRect.width()) / sampleRange);
+	const auto targetThumbnailWidth = static_cast<int>(sampleRect.width() / sampleRange);
 	const auto finerThumbnail = std::find_if(m_thumbnailCache->rbegin(), m_thumbnailCache->rend(),
 		[&](const auto& thumbnail) { return thumbnail.width() >= targetThumbnailWidth; });
 
-	if (finerThumbnail == m_thumbnailCache->rend())
-	{
-		qDebug() << "Could not find closest finer thumbnail for a target width of" << targetThumbnailWidth;
-		return;
-	}
+	const auto useOriginalBuffer = finerThumbnail == m_thumbnailCache->rend();
+	const auto drawOriginalBuffer = static_cast<size_t>(targetThumbnailWidth) == m_buffer->size();
 
 	painter.save();
 	painter.setRenderHint(QPainter::Antialiasing, true);
 
-	const auto thumbnailBeginForward = std::max<int>(renderRect.x() - sampleRect.x(), static_cast<int>(parameters.sampleStart * targetThumbnailWidth));
-	const auto thumbnailEndForward = std::max<int>(renderRect.x() + renderRect.width() - sampleRect.x(), static_cast<int>(parameters.sampleEnd * targetThumbnailWidth));
+	const auto thumbnailBeginForward = std::max<int>(renderRect.x() - sampleRect.x(), parameters.sampleStart * targetThumbnailWidth);
+	const auto thumbnailEndForward = std::max<int>(renderRect.x() + renderRect.width() - sampleRect.x(), parameters.sampleEnd * targetThumbnailWidth);
 	const auto thumbnailBegin = parameters.reversed ? targetThumbnailWidth - thumbnailBeginForward - 1 : thumbnailBeginForward;
 	const auto thumbnailEnd = parameters.reversed ? targetThumbnailWidth - thumbnailEndForward : thumbnailEndForward;
 	const auto advanceThumbnailBy = parameters.reversed ? -1 : 1;
 
-	const auto finerThumbnailScaleFactor = static_cast<double>(finerThumbnail->width()) / targetThumbnailWidth;
-	const auto yScale = drawRect.height() / 2 * parameters.amplification;
+	const auto finerThumbnailWidth = useOriginalBuffer ? m_buffer->size() : finerThumbnail->width();
+	const auto finerThumbnailScaleFactor = static_cast<double>(finerThumbnailWidth) / targetThumbnailWidth;
+	const auto yScale = renderRect.height() / 2 * parameters.amplification;
 
 	for (auto x = renderRect.x(), i = thumbnailBegin; x < renderRect.x() + renderRect.width() && i != thumbnailEnd;
-		 ++x, i += advanceThumbnailBy)
+		++x, i += advanceThumbnailBy)
 	{
-		const auto beginAggregationAt = &(*finerThumbnail)[static_cast<int>(std::floor(i * finerThumbnailScaleFactor))];
-		const auto endAggregationAt = &(*finerThumbnail)[static_cast<int>(std::ceil((i + 1) * finerThumbnailScaleFactor))];
-		const auto peak = std::accumulate(beginAggregationAt, endAggregationAt, Thumbnail::Peak{});
-
-		const auto yMin = drawRect.center().y() - peak.min * yScale;
-		const auto yMax = drawRect.center().y() - peak.max * yScale;
-
-		painter.drawLine(x, yMin, x, yMax);
+		if (useOriginalBuffer && drawOriginalBuffer)
+		{
+			const auto value = m_buffer->data()->data()[i];
+			painter.drawPoint(x, renderRect.center().y() - value * yScale);
+			continue;
+		}
+		else
+		{
+			const auto beginIndex = static_cast<size_t>(std::floor(i * finerThumbnailScaleFactor));
+			const auto endIndex = static_cast<size_t>(std::ceil((i + 1) * finerThumbnailScaleFactor));
+
+			auto minPeak = 0.f;
+			auto maxPeak = 0.f;
+
+			if (useOriginalBuffer)
+			{
+				const auto flatBuffer = m_buffer->data()->data();
+				const auto [min, max] = std::minmax_element(flatBuffer + beginIndex, flatBuffer + endIndex);
+				minPeak = *min;
+				maxPeak = *max;
+			}
+			else
+			{
+				const auto beginAggregationAt = finerThumbnail->data() + beginIndex;
+				const auto endAggregationAt = finerThumbnail->data() + endIndex;
+				const auto peak = std::accumulate(beginAggregationAt, endAggregationAt, Thumbnail::Peak{});
+				minPeak = peak.min;
+				maxPeak = peak.max;
+			}
+
+			const auto yMin = renderRect.center().y() - minPeak * yScale;
+			const auto yMax = renderRect.center().y() - maxPeak * yScale;
+			painter.drawLine(x, yMin, x, yMax);
+		}
 	}
 
 	painter.restore();
 }
 
 } // namespace lmms

src/gui/clips/ClipView.cpp

@@ -306,6 +306,8 @@ void ClipView::remove()
 	// as actually deleting the Clip with the deleteLater function. That being said, it shouldn't
 	// be possible to make a Clip without a Track (i.e., Clip::getTrack is never nullptr).
 	m_clip->deleteLater();
+
+	m_trackView->update();
 }
 
 

src/gui/clips/SampleClipView.cpp

@@ -45,7 +45,8 @@ namespace lmms::gui
 SampleClipView::SampleClipView( SampleClip * _clip, TrackView * _tv ) :
 	ClipView( _clip, _tv ),
 	m_clip( _clip ),
-	m_paintPixmap()
+	m_paintPixmap(),
+	m_paintPixmapXPosition(0)
 {
 	// update UI and tooltip
 	updateSample();
@@ -210,15 +211,20 @@ void SampleClipView::paintEvent( QPaintEvent * pe )
 
 	if( !needsUpdate() )
 	{
-		painter.drawPixmap( 0, 0, m_paintPixmap );
+		painter.drawPixmap(m_paintPixmapXPosition, 0, m_paintPixmap);
 		return;
 	}
 
 	setNeedsUpdate( false );
 
-	if (m_paintPixmap.isNull() || m_paintPixmap.size() != size())
+	// Use the clip's height to avoid artifacts when rendering while something else is overlaying the clip.
+	const auto viewPortRect = QRect(0, 0, pe->rect().width(), rect().height());
+
+	m_paintPixmapXPosition = pe->rect().x();
+
+	if (m_paintPixmap.isNull() || m_paintPixmap.size() != viewPortRect.size())
 	{
-		m_paintPixmap = QPixmap(size());
+		m_paintPixmap = QPixmap(viewPortRect.size());
 	}
 
 	QPainter p( &m_paintPixmap );
@@ -274,12 +280,14 @@ void SampleClipView::paintEvent( QPaintEvent * pe )
 	float sampleLength = m_clip->sampleLength() * ppb / ticksPerBar;
 
 	const auto& sample = m_clip->m_sample;
+
+	const auto sampleRextX = static_cast<int>(offsetStart) - m_paintPixmapXPosition;
+
 	if (sample.sampleSize() > 0)
 	{
 		const auto param = SampleThumbnail::VisualizeParameters{
-			.sampleRect = QRect(offsetStart, spacing, sampleLength, height() - spacing),
-			.drawRect = QRect(0, spacing, width(), height() - spacing),
-			.viewportRect = pe->rect(),
+			.sampleRect = QRect(sampleRextX, spacing, sampleLength, height() - spacing),
+			.viewportRect = viewPortRect,
 			.amplification = sample.amplification(),
 			.reversed = sample.reversed()
 		};
@@ -295,12 +303,15 @@ void SampleClipView::paintEvent( QPaintEvent * pe )
 
 	// inner border
 	p.setPen( c.lighter( 135 ) );
-	p.drawRect( 1, 1, rect().right() - BORDER_WIDTH,
+	p.drawRect(
+		-m_paintPixmapXPosition + 1,
+		1,
+		rect().right() - BORDER_WIDTH,
 		rect().bottom() - BORDER_WIDTH );
 
 	// outer border
 	p.setPen( c.darker( 200 ) );
-	p.drawRect( 0, 0, rect().right(), rect().bottom() );
+	p.drawRect( -m_paintPixmapXPosition, 0, rect().right(), rect().bottom() );
 
 	// draw the 'muted' pixmap only if the clip was manualy muted
 	if( m_clip->isMuted() )
@@ -332,7 +343,7 @@ void SampleClipView::paintEvent( QPaintEvent * pe )
 
 	p.end();
 
-	painter.drawPixmap( 0, 0, m_paintPixmap );
+	painter.drawPixmap(m_paintPixmapXPosition, 0, m_paintPixmap);
 }
 
 

src/gui/editors/AutomationEditor.cpp

@@ -1219,6 +1219,7 @@ void AutomationEditor::paintEvent(QPaintEvent * pe )
 
 			const auto param = SampleThumbnail::VisualizeParameters{
 				.sampleRect = QRect(startPos, yOffset, sampleWidth, sampleHeight),
+				.viewportRect = pe->rect(),
 				.amplification = sample.amplification(),
 				.sampleStart = static_cast<float>(sample.startFrame()) / sample.sampleSize(),
 				.sampleEnd = static_cast<float>(sample.endFrame()) / sample.sampleSize(),